WT/DS381/RW/USA  
WT/DS381/RW 2 
 
26 October  2017 
(17-5783) Page: 1/202 
  Original: English  
 
  UNITED  STATES – MEASURES CONCERNING THE IMPORTATION, 
MARKETING AND SALE O F TUNA AND TUNA PROD UCTS  
RECOURSE TO ARTICLE 21.5 OF THE DSU BY T HE UNITED STATES  
UNITED  STATES – MEASURES CONCERNING THE IMPORTATION, 
MARKETING AND SALE O F TUNA AND TUNA PROD UCTS  
SECOND RECOURSE TO ARTI CLE 21.5 OF THE DSU BY MEXICO  
REPORT S OF THE PANELS  
 
 WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  TABLE OF CONTENTS  
1  INTRODUCTION  ................................ ................................ .......................  14 
1.1  Complaint by the United States  ................................ ................................ ......14 
1.1.1   Establishment and composition of the Panel requested by the United 
States  ................................ ................................ ................................ ......... 14 
1.2  Complaint by Mexico  ................................ ................................ .................... 14 
1.2.1   Request for consultations  ................................ ................................ .............. 14 
1.2.2   Establishment and composition of the Panel requested by Mexico  ....................... 14 
1.3  Panel proceedings  ................................ ................................ ........................ 15 
1.3.1   General  ................................ ................................ ................................ .......15 
1.3.2   Procedures for a partially open  meeting  ................................ .......................... 15 
1.3.3   Additional working procedures on Business Confidential Information (BCI)  .......... 16 
2  FACTUAL ASPECTS ................................ ................................ ....................  17 
2.1  The measure at issue  ................................ ................................ ................... 17 
3  PARTIES' REQUESTS FO R FINDINGS AND RECOM MENDATIONS  ...............  17 
4  ARGUMENTS OF THE PAR TIES  ................................ ................................ .. 18 
5  ARGUMENTS OF THE THI RD PARTIES  ................................ .......................  18 
6  INTERIM REVIEW  ................................ ................................ .....................  18 
6.1  Requests from the United States  ................................ ................................ ....18 
6.2  Requests from Mexico  ................................ ................................ ................... 23 
7  FINDINGS  ................................ ................................ ................................  31 
7.1  Introduction  ................................ ................................ ................................ 31 
7.1.1   Procedural overview  ................................ ................................ ..................... 31 
7.1.2   Format of thes e Reports  ................................ ................................ ................ 31 
7.2  Preliminary Issue: United States' request to lift the confidentiality of its 
statements at the Panels' substantive meetings with the parties and third 
parties  ................................ ................................ ................................ ........ 32 
7.2.1   Procedural background  ................................ ................................ ................. 32 
7.2.2   Merits of the United States' request for a partially open meeting  ........................ 32 
7.3  Preliminary Issue: United States' failure to request consultations  ....................... 37 
7.4  The measure at issue  ................................ ................................ ................... 39 
7.4.1   Elements of the measure at issue  ................................ ................................ ...39 
7.4.2   Description of the measure at issue  ................................ ................................ 41 
7.5  Claim under Article 2.1 of  the TBT Agreement ................................ .................. 46 
7.5.1   Introduction: "technical regulation", "like products", and "detrimental 
impact"  ................................ ................................ ................................ .......46 
7.5.2   "Legitima te regulatory distinction": the applicable legal standard  ....................... 48 
7.6  Burden and standard of proof  ................................ ................................ ........ 62 
7.7  Factual findings  ................................ ................................ ............................ 64 
7.7.1   Introduction  ................................ ................................ ................................ 64 
7.7.1.1   Findings made in previous proceedings  ................................ ........................... 64 
7.7.1.1.1   Previous findings regarding the appropriate methodology to be used  .................. 64 WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.7.1.1.2   Previous factual findings: observable and unobservable harms to dolphins  .......... 66 
7.7.1.2   Preliminary issues about the methodology to assess evidence  ............................ 68 
7.7.1.2.1   The methodology that we should use to conduct the assessment of t he 
different risk profiles of the relevant fisheries  ................................ .................. 68 
7.7.1.2.1.1   General approach  ................................ ................................ ......................... 69 
7.7.1.2.1.2   Use of a standardized benc hmark  ................................ ................................ ...70 
7.7.1.2.1.3   PBR methodology  ................................ ................................ ......................... 71 
7.7.1.2.1.4   Absolute levels of adverse effects  ................................ ................................ ...74 
7.7.1.2.1.5   Per set methodology  ................................ ................................ ..................... 75 
7.7.1.2.1.6   Per set data contained in Exhibit USA -179 Rev. ................................ ................ 79 
Issues regarding the numerical calculations  ................................ ................................ ........... 80 
Issues regarding the reliability of the exhibits supporting the numerical calculations  ................... 82 
7.7.1.2.1.7   Overall conclusion  ................................ ................................ ........................ 84 
7.7.1.2.2   Differences between different kinds of harms posed to dolphins  ......................... 84 
7.7.1.2. 3  Difficulties in assessing the data on the record  ................................ ................. 86 
7.7.2   Findings on the risk profiles of individual fishing methods  ................................ ..87 
7.7.2.1  Setting on dolphins  ................................ ................................ ...................... 87 
7.7.2.1.1   Introduction  ................................ ................................ ................................ 87 
7.7.2.1.2   Findings made in the previous proceedings  ................................ ...................... 87 
7.7.2.1.3   Panels' assessment in the present proceedings  ................................ ................ 90 
7.7.2.2   Purse seine fishing without setting on dolphins  ................................ ..............  100 
7.7.2.2.1   Introduction  ................................ ................................ ..............................  100 
7.7.2.2.2   Findings made in the previous proceedings  ................................ ....................  101 
7.7.2.2.3   Panels' assessment in the present proceedings  ................................ ..............  102 
7.7.2.2.4   Overall conclusion  ................................ ................................ ......................  120 
7.7.2.3   Gillnet fishing  ................................ ................................ ............................  120 
7.7.2.3.1   Introduction  ................................ ................................ ..............................  120 
7.7.2.3.2   Findings made in the previous proceedings  ................................ ....................  126 
7.7.2.3.3   Panels' assessment in the present proceedings  ................................ ..............  130 
7.7.2.4   Longline fishing  ................................ ................................ ..........................  138 
7.7.2.4.1   Introductio n ................................ ................................ ..............................  138 
7.7.2.4.2   Panels' assessment in the present proceedings  ................................ ..............  139 
7.7.2.5   Trawl fishing  ................................ ................................ ..............................  144 
7.7.2.5.1   Introduction  ................................ ................................ ..............................  144 
7.7.2.5.2   Panels' assessment in the present proceedings  ................................ ..............  145 
7.7.2.6   Tuna handlining  ................................ ................................ .........................  147 
7.7.2.6.1   Introduction  ................................ ................................ ..............................  147 
7.7.2.6.2   Panels' assessment in the present proceedings  ................................ ..............  148 
7.7.2.7   Pole and line fishing  ................................ ................................ ...................  151 
7.7.2.7.1   Introduction  ................................ ................................ ..............................  151 
7.7.2.7.2   Panels' a ssessment in the present proceedings  ................................ ..............  151 WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.7.2.8   Overall relative assessment of the method -specific findings  .............................  152 
7.8  Whether t he 2016 Tuna Measure is consistent with Article 2.1 of the TBT 
Agreement  ................................ ................................ ................................  153 
7.8.1   Introduction  ................................ ................................ ..............................  153 
7.8.2   Eligibility criteria  ................................ ................................ ........................  155 
7.8.3   The certification requirements  ................................ ................................ ..... 157 
7.8.4   The tracking and verification requirements  ................................ ....................  172 
7.8.4.1   Introduction  ................................ ................................ ..............................  172 
7.8.4.2   Arguments of the parties in the present proceedings  ................................ ...... 174 
7.8.4.3   Differences between the NOAA and the AIDCP regimes with respect to 
tracking and verification  ................................ ................................ ..............  177 
7.8.4.4   Panels' assessment  ................................ ................................ ....................  180 
7.8.5   The determination provisions  ................................ ................................ ....... 185 
7.8.6   Overall assessment of the consistency of the 2016 Tuna Measure with 
Article 2.1 of the TBT Agreement  ................................ ................................ . 191 
7.9  Whether the 2016 Tuna Measure is consistent with Articles I:1 and III:4, 
and complies with the requirements of Article XX, of the GATT 1994  ................  194 
7.9.1   Findings made in the previous proceedings  ................................ ....................  194 
7.9.2   Assessment of Mexico's claims under Articles I:1, III:4, and the United 
States' defence XX of the GATT 1994 in the present proceedings  .....................  196 
8  CONCLUSIONS AND RECO MMENDATION(S)  ................................ ...........  200  
8.1  Proceedings brought by the United States: Conclusions and 
Recommendations  ................................ ................................ ......................  201 
8.2  Proceedings brought by Mexico: Conclusions and Recommendations  ................  202 
 WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  LIST OF ANNEXES  
ANNEX  A 
WORKING PROCEDURES O F THE PANEL S 
Contents  Page  
Annex  A-1 Working Pr ocedures of the Panel (Article 21.5 – United States)     A-2 
Annex A -2 Working Procedures of the Panel (Article 21.5 – Mexico II)     A-6 
Annex  A-3 Procedures o f the Panels Concerning Business Confidential Information     A-10 
Annex  A-4 Additional Working Procedures of the Panels on Partially Open Hearings     A-11 
ANNEX B  
ARGUMENTS OF THE PAR TIES 
Contents  Page  
Annex  B-1 Executive summary of the arguments of the United States       B-2 
Annex  B-2 Executive summary of the arguments of Mexico  B-13 
ANNEX  C 
ARGUMENTS OF THE THIRD  PARTIES  
Contents  Page  
Annex  C-1 Executive summary of the arguments of Australia  C-2 
Annex  C-2 Executive summary of the arguments of Brazil  C-5 
Annex  C-3 Executive summary of the arguments of Canada  C-8 
Annex C -4 Executive summary o f the arguments of Ecuador  C-12 
Annex C -5 Executive summary of the arguments of the European Union  C-13 
Annex C -6 Executive summary of the arguments of Japan  C-16 
Annex C -7 Executive summary of the arguments of New Zealand  C-19 
Annex C -8 Executive summ ary of the arguments of Norway  C-21 
 
 
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  CASES CITED IN THESE  REPORT S 
Short Title  Full Case Title and Citation  
Brazil – Aircraft (Article 
21.5 – Canada)  Appellate Body Report, Brazil – Export Financing Programme for Aircraft – 
Recourse by Canada to Articl e 21.5 of the DSU , WT/DS46/AB/RW , adopted 4 
August 2000, DSR 2000:VIII, p. 4067  
Canada – Renewable Energy 
/ Canada – Feed-in Tariff 
Program  Panel Reports, Canada – Certain Measures Affecting the Renewable Energy 
Generation Sector / Canada – Measures Relating to the Feed -in Tariff Program , 
WT/DS412/R  and Add.1 / WT/DS426/R  and Add.1, adopted 24 May 2013, as 
modified by Appellate Body Reports WT/DS412/AB/R / WT/DS426/AB/R, DSR 
2013:I, p. 237  
Canada – Dairy (Article 21.5 
– New Zealand and US)  Panel Report, Canada – Measures Affecting the Importation of Milk and the 
Exportation of Dairy Products – Recourse to Article 21.5 of the DSU by New 
Zealand and the United States , WT/DS103/RW , WT/DS113/RW , adopted 18 
December 2001, as reversed by Appellate Body Report WT/DS103/AB/RW, 
WT/DS113/AB/RW, DSR 2001:XIII, p. 6865  
EU – Biodiesel (Argentina)  Appellate Body Report, European  Union – Anti-Dumping Measures on Biodiesel 
from Argentina , WT/DS473/AB/ R and Add.1, adopted 26 October 2016  
EC – Hormones  Appellate Body Report, EC Measures Concerning Meat and Meat Products 
(Hormones) , WT/DS26/AB/R , WT/DS48/AB/R , adopted 13 February 1998, DSR 
1998:I, p. 135  
EC and certain member 
States – Large Civil Aircraft  Appellate Body Report, European Communities and Certain Member States – 
Measures Affecting Trade in Large Civil Aircraft , WT/DS316/AB/R , adopted 1 
June 2011, DSR 2011:I, p. 7  
EC – Seal Products  Panel Reports, European Communities – Measures Prohibiting the Importation 
and Marketing of Seal Products , WT/DS400/R  and Add.1 / WT/DS401/R  and 
Add.1, adopted 18 June  2014, as modified by Appellate Body Reports 
WT/DS400/AB/R  / WT/DS401/AB/R , DSR 2014:II, p. 365  
Japan – Apples  Appellate Body Report, Japan – Measures Affecting the Importation of Apples , 
WT/DS245/AB/R , adopted 10 December 2003, DSR 2003:IX, p. 4391  
Japan – DRAMs (Korea)  Appellate Body Report, Japan – Countervailing Duties on Dynamic Random 
Access Memories from Korea , WT/DS336/AB/R  and Corr.1,  adopted 17 
December 2007, DSR 2007:VII, p. 2703  
Mexico – Corn Syrup 
(Article 21.5 – US) Appellate Body Report, Mexico – Anti-Dumping Investigation of High Fructose 
Corn Syrup (HFCS) from the United States – Recourse to Article 21.5 of the 
DSU by the Unit ed States , WT/DS132/AB/RW , adopted 21 November 2001, 
DSR 2001:XIII, p. 6675 
US – Clove Cigarettes  Appellate Body Report, United States – Measures Affecting the Production and 
Sale of Clove Cigarettes , WT/DS406/AB/R , adopted 24 April 2012, DSR 2012: 
XI, p. 5751  
US – Continued Suspension  Appellate Body Report, United States – Continued Suspension of Obligations in 
the EC – Hormones Dispute , WT/DS320/AB/R , adopted 14 November 2008, 
DSR 2008:X, p. 3507  
US – Continued  Suspension  Panel Report, United States – Continued Suspension of Obligations in the EC – 
Hormones Dispute , WT/DS320/R  and Add.1 to Add.7, adopted 14 November 
2008, as modified by Appellate Body Report WT/DS320/AB/R, DSR 2008:XI, p. 
3891 
US – Continued Zeroing  Panel Report, United States – Continued Existence and Application of Zeroing 
Methodology , WT/DS350/R , adopted 19 February 2009, as modified a s 
Appellate Body Report WT/DS350/AB/R, DSR 2009:III, p. 1481  
US – COOL (Article 21.5 – 
Canada and Mexico)  Panel Reports, United States – Certain Country of Origin Labelling (COOL) 
Requirements – Recourse to Article 21.5 of the DSU by Canada and Mexico , 
WT/DS384/RW  and Add.1 / WT/DS386/RW  and Add.1, adopted 29 May 2015, 
as modified by Appellate Body Reports WT/DS384/AB/RW / WT/DS386/AB/RW  
US – Gasoline Appellate Body Report, United States – Standards for Reformulated and 
Conventional Gasoline , WT/DS2/AB/R , adopted 20 May 1996, DSR 1996:I, p. 3  
US – Shrimp  Appellate Body Report, United States – Import Prohibition of Certain Shrimp 
and Shrimp Products , WT/DS58/AB/R , adopted 6 November 1998, DSR 
1998:VII, p. 2755  
US – Softwood Lumber VI 
(Article 21.5 – Canada),  Appellate Body Report, United St ates – Investigation of the International Trade 
Commission in Softwood Lumber from Canada – Recourse to Article 21.5 of the 
DSU by Canada , WT/DS277/AB/RW , adopted 9 May 2006, and Corr.1, DSR 
2006:XI, p. 4865  
US – Tax Incentives  Panel Report, United States – Conditional Tax Incentives for Large Civil Aircraft , 
WT/DS487/R  and Add.1, circulated to WTO Members 28  November 201 6 
(appealed by the Unite d States 16 December 2016)  
US – Tuna II (Mexico)  Appellate Body Report, United States – Measures Concerning the Importation, 
Marketing and Sale of Tuna and Tuna Products , WT/DS381/AB/R , adopted 13 WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  Short Title  Full Case Title and Citation  
June 2012, DSR 2012:IV, p. 1837  
US – Tuna II (Mexico)  Panel Report, United States – Measures Concerning the Importation, Marke ting 
and Sale of Tuna and Tuna Products , WT/DS381/R , adopted 13 June 2012, as 
modified by Appellate Body Report WT/DS381/AB/R, DSR 2012:IV, p. 2013  
US – Tuna II (Mexico) 
(Article 21.5 – Mexico)  Appellate Body Report, United States – Measures Concerning the Importation, 
Marketing and Sale of Tuna and Tuna Products – Recourse to Article 21.5 of the 
DSU by Mexico , WT/DS381/AB/RW  and Add.1, adopted 3  December 2015  
US – Tuna II (Mexico) 
(Article 21.5 – Mexico)  Panel Report, United States – Measures Concerning the Importation, Marketing 
and Sale of Tuna and Tuna Products – Recourse to Article 21.5 of the DSU by 
Mexico , WT/DS381/RW , Add.1 and Corr.1, adopted 3 December 2015, as 
modified by Appellate Body Report WT/DS381/AB/ RW 
US – Tuna II (Mexico) 
(Article 22.6 – US) Decision by the Arbitrator, United States – Measures Concerning the 
Importation, Marketing and Sale of Tuna and Tuna Products – Recourse to 
Article 22.6 of the DSU by the United States , WT/DS381/ARB , 25 April 2017  
US – Upland Cotton (Article 
21.5 – Brazil)  Panel Report, United Sta tes – Subsidies on Upland Cotton – Recourse to Article 
21.5 of the DSU by Brazil , WT/DS267/RW  and Corr.1, adopted 20 June 2008, 
as modified by Appellate Body Report WT/DS267/AB/RW, DSR 2008:III, p. 997  
US – Wool Shirts and 
Blouses  Appellate Body Report, United States – Measure Affecting Imports of Woven 
Wool Shirts and Blouses  from India , WT/DS33/AB/R , adopted 23 May 1997, and 
Corr.1, DSR 1997:I, p. 323  
 
 WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  EXHI BITS REFERRED TO IN THESE REPORTS  
Exhibit  Title 
USA-01 Dolphin Protection Consumer Information Act (DPCIA), 16 USC Section  1385 (2011)  
USA-02 Dolphin Safe Tuna Labeling Regulations, 50 CFR Section  216, Subpart H (2016)  
USA-03 50 CFR Section 216.24 (2016)  
USA-04  NOAA Fisheries Certificate of Origin (Form 370)  
USA-07 Enhanced Document Requirements and Captain Training Requirements To Support Use of the 
Dolphin Safe Label on Tuna Products, 81 Fed. Reg. 15,444 (Mar ch 23, 2016)  
USA-09 Evgen y V. Romanov, Bycatch in the Tuna Purse Seine Fisheries of the Western Indian Ocean, 
100 Fisheries Bulletin 90 (2002)  
USA-10 NOAA, Dolphin -Safe Captain 's Training Course (Mar ch 23, 2016)  
USA-11 William Jacobson Second Witness Statement (July 21, 2014)  
USA-12 Tim Gerrodette, The Tuna -Dolphin Issue, in Perrin, Wursig and Thewissen (eds.)  
Encyclopedia of Marine Mammals  (2d ed. 2009)  
USA-13 Tables Summarizing Fishery -by-Fishery Evidence on the Record  
USA-14 IATTC, Tuna, Billfishes and Other Pelagic Species  in the Eastern Pacific Ocean in 2014, Doc. 
IATTC -89-04a, IATTC 89th Meeting (June 29 -July 3, 2015)  
USA-15 IATTC, Report on the International Dolphin Conservation Program, Doc. MOP -32-05, 32nd 
Meeting of the Parties (Oct ober 20, 2015)  
USA-16 IATTC, EPO D ataset 2009 -2013 
USA-17 Summary Information on Whale Shark and Cetacean Interactions in the Tropical WCPFC 
Purse Seine Fishery, Paper prepared by SPC -OFP, 8th Regular Session, Koror, Palau 
(November  2011)  
USA-18 WCPFC Scientific Committee, Fifth Regular Session Summary Report (2009)  
USA-19 Monin J. Amande et al., Bycatch of the European Purse Seine Tuna Fishery in the Atlantic 
Ocean for the 2003 -2007 Period, 23 Aquat. Living Resour. 353 (2010)  
USA-20 Monin J. Amande et al., Bycatch and Discards of the E uropean Purse Seine Tuna Fishery in 
the Atlantic Ocean: Estimation and Characteristics for 2008 and 2009, 66 ICCAT Collect. Vol. 
Sci. Papers 2113 (2011)  
USA-21 Monin J. Amande et al., Precision in Bycatch Estimates: The Case of Tuna Purse Seine 
Fisheries in the Indian Ocean, ICES J. Mar. Sci. (2012)  
USA-27 Federated States of Micronesia, Annual Report to the Commission, WCPFC -SC11 -AR/CCM -06, 
(July 27. 2015)  
USA-29 Japan, Annual Report to the Commission, WCPFC -SC11/AR/CCM -10 (July 31, 2015)  
USA-30 Korea,  Annual Report to the Commission, WCPFC -SC11 -AR/CCM -12 (Aug ust 30, 2015)  
USA-31 Chinese Taipei, Annual Report to the Commission, WCPFC -SC11 -AR/CCM -23 (Nov ember  3, 
2015)  
USA-33 Australia, Annual Report to the Commission, WCPFC -SC10 -AR/CMM -01 (July 2014)  
USA-34 Federated States of Micronesia, Annual Report to the Commission, WCPFC -SC10 -AR/CCM -06 
(August 2014)  
USA-35 Japan, Annual Report to the Commission, WCPFC -SC10/AR/CCM -10 (July 2014)  
USA-36 Kirbati, Annual Report to the Commission, WCPFC -SC11/AR/CCM -11 (July 20, 2015)  
USA-38 Philippines, Annual Report to the Commission, WCPFC -SC11/AR/CCM -20 (Sept ember  28, 
2015)  
USA-39 NOAA Fisheries, 2015 Stock Assessment and Fishery Evaluation (SAFE) Report for Atlantic 
Highly Migratory Species (2015)  
USA-40 Herna ndez-Milian, et al., Results of a Short Study of Interactions of Cetaceans and Longline 
Fisheries in Atlantic Waters, 612 Hydrobiologia 254 (2008)  
USA-42 Barbara E. Curry, Stress in Mammals: The Potential Influence of Fishery -Induced Stress on 
Dolphins in  the Eastern Tropical Pacific Ocean, NOAA Technical Memorandum (1999)  
USA-43 Shawn R. Noren, and Elizabeth F. Edwards, Physiological and Behavioral Development in 
Delphinid Calves: Implications for Calf Separation and Mortality Due to Tuna Purse ‑Seine 
Sets, 23 Marine Mammal Science (2007)  
USA-44 Frederick Archer et al., Annual Estimates of the Unobserved Incidental Kill of Pantropical 
Spotted Dolphin (Stenella Attenuata Attenuata) Calves in the Tuna Purse -Seine Fishery of 
the Eastern Tropical Pa cific, 102 Fishery Bulletin 233 (2004)  
USA-45 Katie L. Cramer, Wayne L. Perryman and Tim Gerrodette, Declines in Reproductive Output in 
Two Dolphin Populations Depleted by the Yellowfin Tuna Purse Seine Fishery, 369 Marine 
Ecology Progress Series 273 (200 8) 
USA-46 Albert C. Myrick and Peter C. Perkins, Adrenocortical Color Darkness and Correlates as 
Indicators of Continuous Acute Premortem Stress in Chased and Purse Seine Captured Male 
Dolphins, 2 Pathophysiology 191 (1995)  
USA-47 Stephen B. Reilly et al ., Report of the Scientific Research Program Under the International 
Dolphin Conservation Program Act (2005)  
USA-48 Paul R. Wade et al., Depletion of Spotted and Spinner Dolphins in the Eastern Tropical 
Pacific: Modeling Hypothesis for their Lack of Recov ery, 343 Marine Ecology Progress Series 
1 (2007)  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  USA-50 Agreement for the Conservation of Dolphins (1992)  
USA-52 William Jacobson Witness Statement (May 26, 2014)  
USA-53 Eric L. Gilman and Carl Gustaf Lundin, IUCN Global Marine Programme, Minimizing Byc atch 
of Sensitive Species Groups in Marine Capture Fisheries: Lessons from Tuna Fisheries (2011)  
USA-58 16 USC Section  1362(13)  
USA-60 Martin Hall and Marlon Roman, Bycatch and Non -Tuna Catch in the Tropical Purse Seine 
Fisheries of the World, FAO Fisher ies and  Aquaculture Technical Paper 568  (2013)  
USA-61 William A. Karp, Lisa L. Desfosse, and Samantha G. Brooke (eds.), NMFS, US National 
Bycatch Report, at 391, Table 4.6.C.1 and 394, Table 4.6.D.1 (2011)  
USA-62 National Bycatch Report First Edition Upd ate, Table 8.3  
USA-63 National Bycatch Report First Edition Update, Table 8.4  
USA-66 United Nations General Assembly Res. 46/215, Large -Scale Pelagic Drift -net Fishing and Its 
Impact on the Living Marine Resources of the World 's Oceans and Seas (Dec ember  20, 1991)  
USA-67 NMFS, 2012 Report of The Secretary Of Commerce to the Congress of the United States 
Concerning US Actions Taken On Foreign Large -Scale High Seas Driftnet Fishing (2012)  
USA-68 Megan J. Peterson et al., Killer Whale (Orcinus orca) Depred ation Effects on Catch Rates of 
Six Groundfish Species: Implications for Commercial Longline Fisheries in Alaska, 70 ICES J. 
of Marine Science 1220 (2013)  
USA-90 International Dolphin Conservation Program, System for Tracking and Verifying Tuna, as 
amende d (2015)  
USA-91 AIDCP, Tuna Tracking Form  
USA-101 NMFS, Proposed Rule: List of Fisheries for 2017, 81 Fed. Reg. 54,019 (Aug ust 15, 2016)  
USA-104 Andre E. Punt, Independent Review of the Eastern Pacific Ocean Dolphin Population 
Assessment, IATTC Special Report (2013)  
USA-105 Philippines, Annual Report to the Commission, WCPFC SC12 -AR/CCM -20 (June 2016)  
USA-107 Papua New Guinea, Annual Report to the Commission, WCPFC -SC12/AR/CMM -19 (Aug ust 
2016)  
USA-108 Peter Williams and Peter Terawasi, WCPFC, Overview  of Tuna Fisheries in the Western and 
Central Pacific Ocean, Including Economic Conditions – 2015 (Aug ust 30, 2016)  
USA-109 WCPFC, 7th Annual Report for the Regional Observer Programme (Sept ember  3, 2015)  
USA-110 WCPFC, 8th Annual Report for the Regional  Observer Programme (Sept ember  14, 2016)  
USA-111 Dolphin Mortalities Per Set Due to ETP Dolphin Sets and in Other Fisheries  
USA-113 NMFS, False Killer Whale: Hawaiian Islands Stock Complex (Jan uary 8, 2013)  
USA-114 NMFS, False Killer Whale: Hawaiian Is lands Stock Complex (Dec ember  31, 2015)  
USA-118 Karin A. Forney, SFSC, Estimates of Cetacean Mortality and Injury in Two US Pacific Longline 
Fisheries, 1994 -2002 (2004)  
USA-127 Hsiang -Wen Huang, Bycatch of High Sea Longline Fisheries and Measures Taken b y Taiwan: 
Actions and Challenges, 35 Mar. Pol' y 712 (2011)  
USA-133 Dolphin Bycatch Rate Due to Dolphin Sets in the ETP and Fisheries Where Per Set Data Are 
Unavailable  
USA-140 Elizabeth Edwards, Fishery Effects on Dolphins Targeted by Tuna Purse -Seiners in the 
Eastern Tropical Pacific Ocean, 20 Int 'l J. Comp. Psychology 217 (2007)  
USA-142 Letter from Annika Machensen, WWF, to Sian Morgan on WWF input: Northeastern Tropical 
Purse Seine YFT and SKJ Fishery (Jan uary 16, 2015)  
USA-144 Letter from Daniel Sud daby, WWF, to the Independent Adjudicator, MSC, on Notice of 
Objection for the Northeastern Tropical Pacific Purse Seine Yellowfin and Skipjack Tuna 
Fishery (Oct ober 24, 2016)  
USA-145 Lauriane Escalle et al., Cetaceans and Tuna Purse Seine Fisheries in th e Atlantic and Indian 
Oceans: Interactions but Few Mortalities, 522 Mar. Ecol. Prog. Ser. 255 (2015)  
USA-148 James Joseph, FAO, Managing Fishing Capacity of the World Tuna Fleet, Chapter 4: The Tuna 
Fishing Vessels of the World (2003)  
USA-150 China, Annu al Report to the Commission, WCPFC -SC12 -AR/CMM -03 (Aug ust 2016)  
USA-151 Federated States of Micronesia (FSM), Annual Report to the Commission, WCPFC -SC12 -
AR/CMM -06 (Sept ember  21, 2016)  
USA-152 Japan, Annual Report to the Commission, WCPFC -SC12/AR/CMM -10 (July 5, 2016)  
USA-153 Kirbati, Annual Report to the Commission, WCPFC -SC12 -AR/CMM -11 (Sept ember  23, 2016)  
USA-154 Marshall Islands, Annual Report to the Commission, WCPFC -SC12 -AR/CMM -13 (Aug ust 2016)  
USA-155 Solomon Islands, Annual Report to the Commis sion, WCPFC -SC12 -AR/CMM -22 (Sept ember  
24, 2016)  
USA-156 Chinese Taipei, Annual Report to the Commission (Aug ust 2016)  
USA-157 United States, Annual Report to the Commission, WCPFC -SC12 -AR/CMM -27 (Aug ust 2016)  
USA-160 Al Kingston and Simon Northridge, Ex tension Trial of an Acoustic Deterrent System to 
Minimise Dolphin and Porpoise Bycatch in Gill and Tangle Net Fisheries (2011)  
USA-162 FAO, Tuna Midwater Pair Trawling, http://www.fao.org/fishery/fishtech/1013/en  
USA-163 Alison McCarthy et al., Pilot Obs erver Programme in Irish Pelagic Trawl and Gillnet Fisheries: 
Implementing Council Regulation (EC) No 812/2004 (2011)  
USA-164 John Boyd et al., Report on the Pilot Observer Programme in Irish Pelagic Trawl Fisheries: 
Implementing Council Regulation (EC) N o 812/2004 (2012)  
USA-166 18 US C Section  545 
USA-167 18 US C Section  3571 
USA-169 16 US C Section  3372 WT/DS381/RW/USA • WT/DS381/RW 2 
 
- 10 - 
 
  USA-170 US Department of Commerce, Civil Monetary Penalty Adjustments for Inflation, 81 Fed. Re g. 
36454 (June 7, 2016)  
USA-172 16 USC Section 3374  
USA-173 18 USC Section 1001  
USA-174 16 USC Section 1375  
USA-178 David Macias Lopez et al., Marine Mammal Bycatch in Spanish Mediterranean Large Pelagic 
Longline Fisheries, with a Focus on Risso 's Dolphin (Grampus Griseus), 25 Aquat. Living Res. 
321 (2012)  
USA-179 Rev.  Tables Summarizing Fishery -by-Fishery Evidence on the Record  
USA-184 China, Annual Report to the Commission, WCPFC -SC11/AR/CCM -03 (Aug ust 2015)  
USA-185 Marshall Islands, Annual Report to the Commission, WCPFC -SC11 -AR/CCM -13 (Aug ust 2015)  
USA-186 Solomon Islands, Annual Report to the Commission, WCPFC -SC11 -AR/CCM -22 (Aug ust 
2015)  
USA-187 United States, Annual Report to the Commission, WCPFC -SC11/AR/CCM -20 (July 31, 2015)  
USA-189 Hsiang -Wen Huang and Kwang -Ming Liu, Bycatch and Discards by Taiwanese Large -Scale 
Tuna Longline Fleets in the Indian Ocean, 106 Fish. Res. 261 (2010)  
USA-191 Emmanuel Chassot et al., Statistics of the French Purse Seine Fishing Fleet Targeting 
Tropical Tunas in the Atlantic Ocean (1991 -2013), 71 ICCAT Collect. Vol . Sci. Papers 540 
(2015)  
USA-196 Geoffrey R. McPherson et al., Acoustic Alarms to Reduce Marine Mammal Bycatch from 
Gillnets in Queensland Waters: Optimising the Alarm Type and Spacing, 2 Proc. Acoustics 
363 (2004)  
USA-197 Shane Griffiths et al., Biology , Fisheries and Status of Longtail Tuna (Thuunus tongol), with 
Special Reference to Recreational Fisheries in Australian Waters, Final report of Fisheries 
Research and Development Corporation (2010)  
USA-198 NMFS, California/Oregon Drift Gillnet Observer P rogram Observed Catch  
USA-199 NMFS, California Set Gillnet Observer Program Observed Catch  
USA-200 Martin Hall and Marlon Roman, Bycatch and Non -Tuna Catch in the Tropical Purse Seine 
Fisheries of the World, FAO Fisheries and Aquaculture Technical Paper 569 (2013)  
USA-205 Sian Morgan et al., SCS Global Services, MSC Full -Assessment Report: The Northeastern 
Tropical Pacific Purse Seine Yellowfin and Skipjack Fishery (2016)  
USA-206 Frederick I. Archer et al., Estimation of Relative Exposure of Dolphins to  Fishery Activity, 410 
Marine Ecology Progress Series 245 (2010)  
USA-222 MRAG Americas, Tri Marine (Apr. 26, 2016)  
USA-225 FAO, Tuna Pole and Line Fishing  
USA-226 FAO, Tuna Purse Seining  
USA-227 Tim Lawson, Secretariat of the Pacific Community, Methods  for Analysing Bycatches with 
Observer Data (Aug ust 2001)  
USA-228 Shelley Clarke, Towards an Integrated Shark Conservation and Management Measure for the 
Western and Central Pacific Ocean, WCPFC -SC9-2013/EB -WP-08 (August 2013)  
USA-230 Sandra Clermont et al., IOTC, EU Purse Seine Fishery Interaction with Marine Turtles in the 
Atlantic and Indian Oceans: A 15 Years Analysis, IOTC 2012 WPEB08 35_V2 (Sept ember  
2012)  
USA-236 Value of Philippine Tuna Exports Drops in 2014, The Freeman (Aug ust 12, 2015)  
USA-237 High Seas Pocket Fishing Rules Released, Bus. World (Mar ch 4, 2014)  
USA-238 WCPFC, Conservation and Management Measure 2011 -01 for Temporary Extension of CMM 
2008-01 
MEX-01 Section 1385 (Dolphin Protection Consumer Information Act), as contained in Sub chapter II 
(Conservation and Protection of Marine Mammals) of Chapter 31 (Marine Mammal 
Protection), 16 USC Section  1385(d)  
MEX-02 US Code of Federal Regulations  (CFR) , Title 50, Part 216, Subpart H (Dolphin Safe Tuna 
Labeling), as amended by the 2013 Fin al Rule and the 2016 Interim Final Rule  
MEX-03 Earth Island Institute v. Hogarth , 494 F.3d 757 (9th Cir. 2007); Earth Island Institute v. 
Hogarth , 484 F.3d 1123 (9th Cir. 2007)  
MEX-05 Public Opinion Strategies, National Survey Methodology (Oct ober 16, 20 10) 
MEX-06 IATTC, Fishery Status Report No. 14 (2016)  
MEX-07 Government Accountability Office, National Marine Fisheries Service:  
Improvements are Needed in the Federal Process Used to Protect Marine  
Mammals from Commercial Fishing, GAO 09 -78 (Dec ember  2008) 
MEX-08 AIDCP, Report on the International Dolphin Conservation Program,  
Document MOP -28-05 (Oct ober 18, 2013)  
MEX-13 NOAA Technical Memorandum NMFS, Estimates of 2006 Dolphin Abundance In The Eastern 
Tropical Pacific, With Revised Estimates From 198 6-2003 (April 2008)  
MEX-14 David St. Aubin, et al., Hematological, serum, and plasma chemical constituents in 
pantropical spotted dolphins (Stenella attenuata) following chase, encirclement, and tagging, 
Marine Mammal Science, 29(1) (Jan uary 2013)  
MEX-15 FAO, Tuna Driftnet Fishing  
MEX-16 World Wildlife Fund Pakistan and Australian Marine Mammal Centre, An  
Assessment of Cetacean Mortality in the Tuna Fisheries of Pakistan, IOTC -2014-WPEB10 -
INF25 (28 Oct ober 2014)  
MEX-17 K.S.S.M. Yousuf, et al., Observati ons On Incidental Catch Of Cetaceans In Three Landing WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  Centres Along The Indian Coast, Marine Biodiversity Records, Vol. 2 (2009)  
MEX-18 Natural Resources Defense Council, Net Loss: The Killing of Marine Mammals in Foreign 
Fisheries (Jan uary 2014)  
MEX-19 Convention on Migratory Species, Report of the Second Workshop on The Biology and 
Conservation of Small Cetaceans and Dugongs of South -East Asia, CMS Technical Series 
Publication No. 9 (July 2002)  
MEX-21 Young and Iudicello, Worldwide Bycatch of Cetaceans , US Department of Commerce, NOAA 
Tech. Memo. NMFS -OPR-36 (July 2007)  
MEX-22 Convention on Migratory Species, Report of the Third Southeast Asian Marine Mammal 
Symposium, CMS Technical Series No. 32 (2015)  
MEX-23 Papua New Guinea, Annual Report to the Co mmission, WCPFC -SC11 -AR/CCM -19 (Aug ust 
2015)  
MEX-24 Western and Central Pacific Fisheries Commission (WCPFC), Yearbook 2014 (15 Oct ober 
2015)  
MEX-25 Secretariat of the Pacific Community, Status of Tuna Stocks and Management Challenges in 
the WCPO  
MEX-26 FAO, Industrial Tuna Longlining  
MEX-34 Turtle Restoration Project, Pillaging the Pacific (November 16, 2004)  
MEX-36 R. Baird and A. Gogone, False Killer Whale Dorsal Fin Disfigurements as a Possible Indicator 
of Long -Line Fishery Interactions in Hawaiia n Waters, Pacific Science (October 2005)  
MEX-37 FAO, Trawl Nets  
MEX-38 FAO, Tuna handlining  
MEX-39 Marine Research Center, Ministry of Fisheries and Agriculture, Republic of  
Maldives, Handline Large Yellowfin Tuna Fishery of the Maldives, IOTC - 
2009-WPTT-15 (Oct ober 2009)  
MEX-40 Adam, Jauharee and Miller, Review of Yellowfin Tuna Fisheries in the  
Maldives, IOTC –2015–WPTT17 –17 (8 Oct ober 2015)  
MEX-41 Marine Research Center, Ministry of Fisheries and Agriculture, Republic of  
Maldives, Association of Yell owfin Tuna And Dolphins In Maldivian Waters,  
IOTC 1998 -ECT-22 (1998)  
MEX-42 R.C. Anderson, Cetaceans and Tuna Fisheries in the Western and Central Indian Ocean, 
IPNLF Technical Report 2, International Pole and Line Foundation (2014)  
MEX-47 US Department of Commerce Enhanced Document Requirements and Captain Training 
Requirements to Support Use of the Dolphin Safe Label on Tuna Products; Interim Final Rule, 
81 Fed. Reg. 15444 (March 23, 2016)  
MEX-49 US Department of Commerce, Fish and Fish Product Import Provisions of the Marine Mammal 
Protection Act; Final Rule, 81 Fed. Reg. 54390 (Aug ust 15, 2016)  
MEX-52 Presidential Task Force on Combating Illegal Unreported and Unregulated (IUU) Fishing and 
Seafood Fraud Action Plan for Implementing Recommendations 14 /15; Commerce Trusted 
Trader Program, 81 Fed. Reg. 25646 (April 29, 2016)  
MEX-53 J. Barlow, Inferring trackline detection probabilities, g(0), for cetaceans from apparent 
densities in different survey conditions, Marine Mammal Science (2015)  
MEX-56 NOAA,  Dolphin -Safe Captain's Training Course (March 23, 2016)  
MEX-57 Bumblebee Seafoods, Comments on Enhanced Document Requirements and Captain Training 
Requirements to Support Use of Dolphin Safe Label on Tuna Products (April 15, 2016)  
MEX-58 Tri Marine, Enh anced Document Requirements and Captain Training Requirements to 
Support Use of Dolphin Safe Label on Tuna Products, p. 1 (April 22, 2016)  
MEX-59 AIDCP, Resolution To Adopt The Modified System For Tracking And Verification Of Tuna (20 
June 2001)  
MEX-60 Letter from US Department of Commerce to US tuna importer (March 28, 2016)  
MEX-71 Greenpeace International, Dolphins die in trawler nets  
MEX-72 S. Allen et al., Patterns of Dolphin Bycatch in a North -Western Australian Trawl Fishery, 
PLOS ONE, Vol. 9, Iss ue 4 (April 2014)  
MEX-82 International Seafood Sustainability Foundation, Fishing Methods  
MEX-86 Agenda de trabajo para el curso de observadores a bordo de barcos atuneros de la Comisión 
Interamericana del Atún Tropical , Manta - Ecuador, mayo 23 al 9 de junio de 2016  
MEX-93 Comparison of Track and Verification of Dolphin -Safe Tuna under the AIDCP and the Revised 
Measure  
MEX-95 Table summarizing the data available regarding the relative overall risks of adverse effects 
on dolphins caused by different fis hing methods in different ocean areas  
MEX-99 50 CFR Part 300 (International Fisheries Regulations), table of contents  
MEX-102 US Department of Commerce, Differentiating Serious and Non -Serious Injury of Marine 
Mammals: Report of the Serious Injury Techni cal Workshop 10 -13 September 2007, Seattle, 
Washington (September 2008)  
MEX-103 AIDCP, Report on the International Dolphin Conservation Program, Document  
MOP-34-05 (10 October 2016)  
MEX-104 US National Oceanic and Atmospheric Administration, Impact of Gh ost Fishing via Derelict 
Fishing Gear (March 2015)  
MEX-105 US Department of Commerce, Differentiating Serious and Non -Serious Injury of Marine 
Mammals Taken Incidental to Commercial Fishing Operations: Report of the Serious Injury 
Workshop, 1 -2 April 1997 , Silver Spring, Maryland (January 1998)  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  MEX-106 International Dolphin Conservation Program, Tuna Tracking Form (Form A)  
MEX-111 FAO, Pole and Line  
MEX-112 M. Donahue and E. Edwards, An Annotated Bibliography of Available Literature regarding 
Cetacean I nteractions with Tuna Purse Seine Fisheries Outside of the Eastern Tropical Pacific, 
NOAA Southwest Fisheries Science Center Administrative Report LJ -96-20 (Nov ember  1996)  
MEX-113 
 Kobe II Bycatch Workshop Background Paper  
MEX-116 WCPFC, Status of ROP Da ta Management, WCPFC -TCC11 -2015-IP05_rev1 (10  
September 2015)  
MEX-117 L. Dolar, Incidental Takes of Small Cetaceans in Fisheries in Palawan, Central  
Visayas and Northern Mindanao in the Philippines, in Report of International  
Whaling Commission (Special I ssue 15) (1994)  
MEX-118 NOAA, Marine Mammal Stock Assessment Report, False Killer Whale: Hawaiian  
Islands (December 31, 2015)  
MEX-120 L. Mannocci et al., Assessing the Impact of Bycatch on Dolphin Populations: the  
Case of the Common Dolphin in the Easter n North Atlantic, Plos One 7(2) e32615 (February 
2012)  
MEX-122 NOAA Fisheries, CA Thresher Shark/Swordfish Drift Gillnet Fishery  
MEX-124 National Marine Fisheries Service, Biological Opinion on the US WCPO Purse Seine Fishery 
(November 1, 2006)  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  ABBREVI ATIONS USED IN THESE  REPORT S 
Abbreviation  Description  
2016 Rule  Enhanced Document Requirements and Captain Training Requirements to 
Support Use of the Dolphin Safe Label on Tuna Products, 81 Fed. Reg. 
15,444 (Mar ch 23, 2016)  
2013 Rule  Enhanced Document  Requirements to Support Use of the Dolphin Safe Label 
on Tuna Products, 78 Fed. Reg. 40,997 (July 9, 2013)  
AIDCP  Agreement on the International Dolphin Conservation Program  
BCI  Business confidential information  
BPUE  Bycatch per unit of effort  
CFR  Code of Federal Regulations  
DMLs  Dolphin Mortality Limits  
DPCIA  Dolphin Protection Consumer Information Act  
DSB  Dispute Settlement Body  
DSU  Understanding on Rules and Procedures Governing the Settlement of 
Disputes  
EEZs Exclusive Economic Zo nes 
EII  Earth Island Institute  
EPO  Eastern Pacific Ocean  
ETAO  Eastern Tropical Atlantic Ocean  
ETP  Eastern Tropical Pacific  
FAD  Fish Aggregating Device  
FAO  United Nations Food and Agriculture Organization  
Form 370  NOAA Fisheries Certificate o f Origin  (Form 370)  
GAO Government Accountability Office  
GATT 1994  General Agreement on Tariffs and Trade 1994  
Hogarth ruling  Earth Island Institute et al v William T. Hogarth , 494 F.3d 757 (9th Cir. 
2007)  
ICCAT  International Commission for the Cons ervation of Atlantic Tunas  
IATTC  Inter-American Tropical Tuna Commission  
IO Indian Ocean  
IOTC Indian Ocean Tuna Commission  
IDCP International Dolphin Conservation  Program  
IUU Illegal, Unreported and Unregulated Fishing  
MMPA  Marine Mammal Protection  Act 
NMFS  National Marine Fisheries Service  
NOAA  National Oceanic and Atmospheric Administration  
PBR Potential Biological Removal  
RFMOs  Regional Fishery Management Organizations  
TBT Agreement  Agreement on Technical Barriers to Trade  
TTF Tuna Tr acking Form  
TTVP Tuna Tracking and Verification Program  
USC United States Code  
Vienna Convention  Vienna Convention on the Law of Treaties, Done at Vienna, 23 May 1969, 
1155 UNTS 331; 8 International Legal Materials 679  
WCPFC  Western and Central Pacif ic Fisheries Commission  
WCPO  Western and Central Pacific Ocean  
WIO Western Indian Ocean  
WTO  World Trade Organization  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  1  INTRODUCTION  
1.1  Complaint by the United States  
1.1.1   Establishment and composition of the Panel requested by the United States  
1.1.  On 11 April 2016, the United States requested the establishment of a panel pursuant to 
Article  21.5 of the Understanding on Rules and Procedures Governing the Settlement of Disputes  
(DSU), with standard terms of reference1, with respect to certain measures concerning the 
importation, marketing, and sale of tuna and tuna products, as further described in Section 2.1. At 
its meeting on 9 May 2016, the Dispute Settlement Body (DSB) referred this dispute to the original 
panel, if possible, in accordance with Article  21.5 o f the DSU.2 
1.2.  The Panel's terms of reference are the following:  
To examine, in the light of the relevant provisions of the covered agreements cited by 
the parties to the dispute, the matter referred to the DSB by the United States in 
document WT/DS381/32 and  to make such findings as will assist the DSB in making 
the recommendations or in giving the rulings provided for in those agreements.3 
1.3.  Due to the unavailability of the chairperson of the original panel, the parties agreed on a 
replacement. The Panel was c omposed on 27 May 2016 as follows:  
Chairperson:  Stefán Haukur Jóhannesson  
 
Members:   Mary Elizabeth Chelliah  
   Franz Perrez  
 
1.4.  Australia, Brazil, Canada, China, Ecuador, the European Union, Guatemala, India, Japan, 
Korea, New Zealand, and Norway notified th eir interest in participating in the Panel proceedings as 
third parties.  
1.2  Complaint by Mexico  
1.2.1   Request for consultations  
1.5.  On 13 May 2016, Mexico requested consultations with the United States pursuant to Articles 
4 and 21.5 of the DSU, Article 14 of the Agree ment on Technical Barriers to Trade (TBT 
Agreement ), and Article XXII of the General Agreement on Tariffs and Trade 1994 (GATT 1994 ) 
with respect to certain measures concerning the importation, marketing, and sale of tuna and tuna 
products.4 
1.6.  Consultations were held on 2 June 2016. However, the parties were unable to resolve their 
dispute.  
1.2.2   Establishment and composition of the Panel requested by Mexico  
1.7.  On 9 June 2016, Mexico requested the establishment of a panel pursuant to Articles  6 and 
21.5 of the DSU, Ar ticle 14 of the TBT Agreement, and Article XXIII of the GATT 1994, with 
standard terms of reference.5 At its meeting on 22 June 2016, the DSB referred this dispute to the 
original panel, if possible, in accordance with Article  21.5 of the DSU.6 
1.8.  The Panel's  terms of reference are the following:  
                                                
1 WT/DS381/32.  
2 See WT/DS381/37.  
3 WT/DS381/37.  
4 See WT/DS381/36  and WT/DS381/36 /Corr.1 . 
5 WT/DS381/38.  
6 WT/DS381/39.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  To examine, in the light of the relevant provisions of the covered agreements cited by 
the parties to the dispute, the matter referred to the DSB by Mexico in document 
WT/DS381/38 and to make such findings as will ass ist the DSB in making the 
recommendations or in giving the rulings provided for in those agreements.7 
1.9.  Due to the unavailability of the chairperson of the original panel, the parties agreed on a 
replacement. The Panel was composed on 11 July 2016 as follows : 
Chairperson:  Stefán Haukur Jóhannesson  
 
Members:   Mary Elizabeth Chelliah  
   Franz Perrez  
 
1.10.   Australia, Brazil, Canada, China, Ecuador, the European Union, Guatemala, Japan, Korea, 
New Zealand, and Norway notified their interest in participating in the Pan el proceedings as third 
parties.  
1.3  Panel proceedings  
1.3.1   General  
1.11.   After consulting with the parties, the Panel in the proceedings brought by the United States 
adopted its Working Procedures and timetable on 4 July 2016. After further consultations with the 
partie s, on 29 July 2016 , the Panels in both the proceedings brought by the United States and the 
proceedings brought by Mexico adopted a harmonized timetable for the proceedings. Following 
further consultations with the parties, the Panels modified their harmon ized timetable on 
10 August 2016 to extend the deadline for written submissions from third parties.  
1.12.   On 3 August 2016, the Panel in the proceedings brought by Mexico adopted its Working 
Procedures.8 On the same day, the Panel in the proceedings brought by t he United States modified 
its Working Procedures9 to harmonize them with the Working Procedures adopted by the Panel in 
the proceedings brought by Mexico.  
1.13.   The Panels held a consolidated substantive meeting with the parties on 24 and 25 January 
2017. Becaus e different Members reserved their rights as third parties in the proceedings brought 
by the United States, on the one hand, and Mexico, on the other hand, two third party sessions 
were held on 25 January 2017. On 27 February  2017, the Panels issued the de scriptive part of 
their Reports to the parties. The Panels issued their Interim Reports to the parties on 9 June 2017 , 
and their Final Reports to the parties on 12 July 2017 . 
1.3.2   Procedures for a partially open meeting  
1.14.   On 10 June 2016, a t the organizational meeting of the Panel in the proceedings brought by 
the United States , the United States proposed a change to the working procedures to allow the 
Panel's substantive meeting to be publicly observed or, if Mexico did not agree to this, to allow a 
party to requ est a partially open meeting, whereby that party's statements during the Panel's 
meeting with the parties could be viewed by the public, either simultaneously or through a delayed 
broadcast, whereas statements of a party that wished to maintain the confide ntiality of these 
statements could not be so viewed . 
1.15.   On 4 July 2016, the Panel in the proceedings brought by the United States sought the views 
of the third parties on this procedural issue. Nine third parties provided their views. S ix third 
parties oppose d the United States' request, whereas three did not.  
1.16.   On 14 July 2016, a t the organizational meeting  of the Panel in the proceedings brought by 
Mexico , the United States made the same proposal for a change to the working procedures.  
                                                
7 WT/DS381/39.  
8 See the Panel's Working Procedures ( Article 21.5 – Mexico II ) in Annex A -2. 
9 See the Panel's Working Procedures ( Article 21.5 – United States ) in Annex A -1. WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  1.17.   On 29 July 2016, t hrough  a joint communication with the arbitrator acting under 
Article  22.6 of the DSU in the same  dispute, the Panels informed the parties that they considered 
themselves to have the authority to authorize the United States to lift the confidentialit y of its 
statements at the substantive meeting with the parties. They further indicated that the partial  
public observation of the meeting would be through delayed viewing (delayed closed -circuit 
television broadcasting), to ensure that the confidentiality of Mexico's  statements would not be 
breached. The parties were informed that the reasons supporting this determination would be 
elaborated by the Panels in their Reports.10 
1.18.   On 13 December 2016, pursuant to paragraph 3 of the Panels' Working Procedures, the 
United Stat es requested that the Panels authorize it to lift the confidentiality of its statements 
made during the Panels' meeting with the parties. The United States therefore requested the 
Panels to adopt additional working procedures that would authorize each part y and third party to 
lift the confidentiality of its statements made during the Panels' meeting, including its answers to 
questions. Mexico objected to the United States' request, arguing that the Panels could only open 
their substantive meetings with the parties to public viewing with the consent of both parties.  
1.19.   On 22 December 2016, after consulting with the parties, the Panels adopted Additional 
Working Procedur es on Partially Open Meetings (Additional Working Procedures ).11 On the same 
day, the Panels se nt a copy of the Additional Working Procedures to the parties and the third 
parties, and indicated, pursuant to paragraphs 3.1 and 4.1 of the Additional Working Procedures, 
that the deadline for a party or third party to indicate its intention to participa te in the Panels' 
meetings with the parties and third parties as a disclosing party or a disclosing third party would 
be 9 January 2017. In its request of 13 December 2016, the United States had indicated its 
intention to participate in the Panels' meeting s as a disclosing party. Additionally, on 9 January 
2017, Australia, Canada, the European Union, Japan, Korea, Norway, and New Zealand indicated 
their intention to participate in the Panels' meetings as disclosing third parties.  
1.20.   As noted above, the Panels  met with the parties and thi rd parties on 24 and 
25 January  2017. The statements12 of the United States and disclosing third parties were video -
recorded, pursuant to the Additional Working Procedures. Following the meeting, the Panels 
consulted with the pa rties and third parties and redacted the video -recording to ensure that the 
positions of Mexico and non -disclosing third parties were not inadvertently contained in the final 
version of the video -recording. At Mexico's request, the Panels held a preview sc reening of the 
redacted video -recording for the parties on 8 March 2017, which both parties attended. The 
delayed public broadcast was held at the WTO Headquarters in Geneva on 24 March 2017 . 
1.21.   Further discussion of the Panels' Additional Working Procedures,  including the Panels' 
reasons for granting the United States' request to adopt such procedures, is provided in 
Section  7.2 of these Reports.  
1.3.3   Additional working procedures on Business Confidential Information (B CI) 
1.22.   At the Panels' organizational meeting  with the parties,  both parties requested that the  
Panels  adopt additional  working procedures to protect the confidentiality of BCI submitted in the 
course of the proceedings. The Panels  adopted such ad ditional work ing procedures on 4 July 2016 
(in the proceedings brought by the United States) and 3 August 2016 (in the proceedings brought 
by Mexico). Both Panels adopted identical additional working procedures.  
1.23.   The Additional Working Procedures of the Panels  Concernin g Business Confidential 
Information ( BCI Working Procedures) are annexed to these Reports .13  
                                                
10 Panels' and Arbitrator's  letter of 29 July 2016.  
11 Annex A -4. 
12 As defined in p aragraph 1.1(e) of the Additional Working Procedures on Partially Open Meetings.  
13 Annex A -3. WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  2  FACTUAL ASPECTS  
2.1  The measure at issue  
2.1.  Both the proceedings brought by the United States and those brought by Mexico concern the 
United States' labelling regime for dolphin -safe tuna products14 (the 2016 Tuna Measure). Both 
parties consider that the 2016 Tuna Measure comprise s the following instruments:  
a. Section 1385 (Dolphin Protection Consumer Information Act), as contained in 
Subchapter II (Conservation and Protectio n of Marine Mammals) of Chapter 31 (Marine 
Mammal Protection), in Title 16 of the United States Code (the DPCIA);  
b. Code of Federal Regulations, Title 50, Part 216, Subpart H (Dolphin Safe Tuna Labeling), 
as amended by the Enhanced Document Requirements to S upport Use of the Dolphin 
Safe Label on Tuna Products, 78 Fed. Reg. 40,997 (July 9, 2013)  (the 2013 Rule) and 
the Enhanced Document Requirements and Captain Training Requirements to Support 
Use of the Dolphin Safe Label on Tuna Products, 81 Fed. Reg. 15,44 4 (Mar ch 23, 2016) 
(the 2016 Rule) (collectively, the 2016 implementing regulations);  and 
c. The court ruling in Earth Island Institute v. Hogarth , 494 F.3d 757 (9th Cir. 2007) (the 
Hogarth  ruling) . 
2.2.  Mexico argues that the Measure also includes the following:   
a. Any implementing guidance, directives, policy announcements or any other document 
issued in relation to instruments (a) through (c) above, including any modifications or 
amendments in relation to those instruments.  
2.3.  The Panels' findings on the scope of the  measure at issue are contained in Section 7.4.1 of 
these Reports.  
2.4.  The 2016 Tuna Measure specif ies the conditions to be fulfilled in order for tuna products sold 
in the United States to be labelled "dolphin -safe" or to make sim ilar claims on their labels. Use of 
the term "dolphin -safe", or any other term that claims or suggests that the tuna contained in a 
tuna product was harvested using a method of fishing that is not harmful to dolphins, is prohibited 
if the tuna contained in  the product was not harvested and processed in compliance with the 
applicable labelling conditions.15 A more detailed description of the applicable labelling 
requirements is contained in the Section  7.4 of these Reports.  
3  PARTIE S' REQUESTS FOR FIND INGS AND RECOMMENDAT IONS  
3.1.   The United States requests the Panels in both Article 21.5 proceedings to find that the 
United  States has brought itself into compliance with the DSB recommendations and rulings and 
that the 2016 Tuna Measure  is consistent with Article 2.1 of the TBT Agreement and  justified under 
Article XX of  the GATT 1994 .16 
3.2.  Mexico requests that the Panels in both proceedings reject the United States'  claims in their 
entirety and find that the 2016 Tuna Measure  is inconsistent with Article 2.1 of the TBT Agreement 
                                                
14 The Dolphin Protection Consumer Information Act of 1990, Section 1385(c)(5), defines the term "tuna 
product" as a "food item which contains tuna and which has b een processed for retail sale, except perishable 
sandwiches, salads, or other products with a shelf life of less than 3 days"  (Exhibits MEX -01 and USA -01). 
Additionally, for purposes of the United States Code of Federal Regulations , Title 50, Section 216, "tuna 
product" means "any food product processed for retail sale and intended for human or animal consumption" 
containing one of the species of tuna listed in Section 216.24(f)(2)(i) and (ii) of the United States Code of 
Federal Regulations , Title 50, but excluding "perishable items with a shelf life of less than 3 days"  (Exhibits 
MEX-02 and USA -02).  
15 Section 1385(d) of the DPCIA, (Exhibits MEX -01 and USA -01); and Section 216.91(a) of the 2016 
implementing regulations, (Exhibits MEX -02 and USA -02).  
16 United States' first written submission, para. 224; second written submission, para. 180; third written 
submission, para. 151.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  and Articles I:1 and III:4 of the GATT 1994, and cannot be justified under Article XX of the GATT 
1994.17 
4  ARGUMENTS OF THE PAR TIES  
4.1.  The arguments of the parties are reflected in their executive summaries, provided to the  
Panel s in accordance with paragraph 18 of the Working Procedures adopted by the Panel s (see 
Annexes B -1 and B -2). 
5  ARGUMENTS OF THE THI RD PARTIES  
5.1.  The arguments of Australia, Brazil, Canada, the European Union, Japan, New Zealand, and 
Norway  are reflected i n their executive summaries, provided in accordance with paragraph 19 of 
the Working Procedures adopted by the Panel s (see Annexes C -1, C-2, C-3, C-4, C-5, C-6, and 
C 7). Additionally, Ecuador  requested that the  final written versions of its  oral statement s at the 
Panels' third party sessi ons be treated as constituting its  executive summary (see Annex C -8). 
China, Guatemala, India, and Korea did not submit written or oral arguments to the Panel s. 
6  INTERIM REVIEW  
6.1.  On 15 April 201 7, the Panels issued their Inte rim Reports to the parties. On 20 June 2017, 
Mexico and the United States each submitted written requests for the Panels to review aspects of 
the Interim Reports. On 27 June 2017, both parties submitted comments on the other's requests 
for review. Neither party requested an interim review meeting.  
6.2.  In accordance with Article 15.3 of the DSU, this section of the  Panels'  Reports sets out the 
Panels' response s to the parties' requests made at the interim review stage. The numbering of 
some of the paragraphs and  footnotes in the Final Reports has changed from the numbering in the 
Interim Reports. The discussion below refers to the numbering in the Final Reports and, where it 
differs, includes the corresponding numbering in the Interim  Reports  (in brackets) . 
6.3.   The parties' requests for substantive modifications are discussed below. In addition to the 
requests discussed below, corrections were made for typographical and other non -substantive 
errors in the Reports, including those identified by the parties.  This secti on of the  Panels'  Report s 
constitute s an integral part of the Panel s' findings.  
6.1  Requests from the United States  
6.4.  The United States requests, with respect to paragraphs 7.3, 7.48, 7.56, 7.613  (paragraph 
7.611 in the Interim Reports) and 7.636  (paragraph 7 .634 in the Interim Reports) that we replace 
the term "CFR" with the term "implementing regulations". According to  the United States, this 
change would increase the clarity and consistency of the Reports, as the term "CFR" could be 
misunderstood as referring to the entire US Code of Federal Regulations. Mexico makes no 
comments on this request.  We agree with the Unite d States that the term "implementing 
regulations" is clearer than the term "CFR", and accordingly have made the changes requested.  
6.5.  The United States requests that we delete a statement contained in paragraph 7.6 that refers 
to the possibility, under Article 17 of the DSU, of appealing these Panel Reports. According to the 
United States, because the provisions of the DSU cited in the statement in question do not address 
the scope of appeal proceedings, the statement is not necess ary to assist the DSB in making the 
recommendations provided for in the covered agreements, and could itself create an issue for 
appeal, which would not contribute to finding a positive solution to the dispute. Mexico asks us to 
reject this request. Accord ing to Mexico, the United States' request would edit the reasoning of the 
Panels and interrupt the logic of the paragraph.  In our view, it is important to recall in the context 
of the statement in question that appeal from panel reports is possible under t he DSU. However, 
to avoid any misunderstanding, we have modified the statement in question to make clear that we 
take no position on the scope of appeal proceedings.  
6.6.  The United States requests that we insert additional footnote references in paragraphs 7.45, 
7.63, 7.64, 7.66, 7.208  (paragraph 7.207 in the Interim Reports) , and 7.259  (paragraph 7.258 in 
                                                
17 Mexico's first written submission, para. 340; second written submission, para. 117.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  the Interim Reports).  According to the United States, these additional citations would further 
clarify the basis of the Panels' reasoning. Mexico asks the Panels to reject the United States' 
request in respect of paragraph 7.45, and states that it objects to all edits proposed by the United 
States that would modify the Panels' descriptions or characterizations of Mexico's evidence. With 
respect to paragraph 7.63, Mexico argues that t he citation requested by the United States would 
be superfluous, as the paragraph already contains a footnote reference. Finally, with respect to 
paragraphs 7.64 and 7.66, Mexico objects  to the Unit ed States' requests  on the basis that these 
requests constitute an attempt by the United States to instruct the Panels as to the evidence on 
which they should rely for their findings. We note, however, that Mexico does not argue that the 
additional footnot e references requested by the United States are incorrect. We also note that 
Mexico did not make any comments concerning the United States' requests in respect of 
paragraphs 7.208  or 7.259 . In our v iew, the footnote references requested by the United States in 
respect of paragraphs 7.45, 7.63, 7.64, 7.66, 7.208, and  7.259  are accurate, and their addition 
clarifies the basis of our reasoning. The addition of the references in no way changes the  Panels'  
reasoning or "instructs" the Panels as to which evidence they should use or how that evidence 
should be interpreted. We have therefore made the requested additions  by inserting footnotes 75, 
116, 118, 119, 123, 124, 351, and 422.  
6.7.  The United States requests that, in paragraph 7.56 we delete the reference to the "original"  
Tuna Measure to enhance the accuracy of the text. Mexico does not comment on this request. We 
accept this request, which increases the accuracy of the paragraph in question.  
6.8.  The United States requests that we modify certain language in paragraph 7.137  which 
concerns the relationship between the DSU Article 21.5 proceedings brought by the United States 
and th ose brought by Mexico. According to the United States, the language in the mentioned 
parag raph is not completely accurate,  because it fails to fully reflect certain differences in the 
positions of the parties in the two proceedings, and overstates the extent of the overlap between 
the two proceedings. Thus, the United States proposes alternative language to more accurately 
reflect the relationship between the two proceedings. Mexico makes no comment on this request.  
In our view, the alternative language proposed by the United States accurately reflects the 
relationship between the  two proceedings and enhances the clarity of th e paragraph in question. 
Accordingly, we have made the requested modification.  
6.9.  The United States requests that we modify certain language in paragraph 7.151  which 
concerns our decision not to have recourse to external experts to assist us in understanding  the 
evidence on the record. According to the United States, the language in the third sentence of this 
paragraph could be misread to suggest that the role of experts in WTO dispute settlement 
proceedings could be to provide evi dence to support or refute the claims of one or other of the 
parties, rather than to assist a panel in understanding the evidence that the parties have 
presented. The United States requests that we delete this sentence and add a new sentence at the 
end of the paragraph noting our decision not to have recourse to experts. Mexico argues that the 
requested  change would interrupt the logic of the paragraph in question. We are not convinced 
that the identified language could be misread in the way suggested by th e United States. 
Therefore, in our view, the deletion requested by the United States is not necessary. Nevertheless, 
in the interest of clarity, we have modified the language of the third sentence of paragraph 7.151  
in order to  make clear that we could only have had recourse to experts for the purpose of 
enhancing our understanding of the evidence presented by the parties.  
6.10.   With respect to footnote 368 in paragraph  7.222  (footnote 352 in the Interim Reports) , the 
United States requests that the figures relating to dolphin mortalities and serious injuries be 
corrected because there was a typographical error in the underlying footnote 12 of the United 
States' comments on Mex ico's response to Panels' question 57. Mexico does not comment on this 
request. We have made the requested modification to ensure the accuracy of our findings.  
6.11.   The United States requests the Panels to modify the text of footnote 385 in paragraph 7.230  
(footnote 369 in the Interim Reports ) in order to ensure that it adequately reflects the United 
States' arguments. Mexico does not comment on this request. Given that this request relates to 
the Panels ' description of the United States' own arguments, we accept the request and have 
made the requested modification in order to better reflect the United States' position.  
6.12.   The United States requests that, in paragraph 7.271  (para graph 7.270 in the Interim 
Reports) we add the words "on average" to qualify the sentence that reads "…every dolphin set, by WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  its nature, poses a risk to several hundred dolphins". According to the United States, the addition 
of this qualification would inc rease the accuracy of the sentence, as well as its consistency with 
other sentences on the same issue in other parts of the Reports . Mexico makes  no comment on 
this request.  We agree that the addition of this qualification increases the accuracy and 
consis tency of the sentence, and have therefore inserted the requested words.  
6.13.   The United States requests that, with respect to paragraph 7.292  (paragraph 7.291 in the 
Interim Reports) we modify our description of Exhibit MEX -53 to mo re accurately reflect its 
contents. The United States proposes alternative language that, in its view, better captures the 
finding of that Exhibit . Mexico argues that this  request should be rejected, because it attempts to 
edit and re -word the reasoning of  the Panels.  We consider that the alternative language proposed 
by the United States accurately reflects the contents of the relevant Exhibit, and have therefore 
made the requested modification.  
6.14.   The United States requests, with respect to paragraph 7.311  (paragraph 7.310 in the 
Interim Reports) that we modify our description of the information contained in Exhibit USA -44 to 
more accurately reflect its contents. The United States proposes alternative language that, in its 
view, b etter captures the finding of that Exhibit. Mexico argues that this request  should be 
rejected, since it attempts to modify the Panels' interpretation of the evidence.  We consider that 
the alternative language proposed by the United States accurately refle cts the c ontents of the 
relevant Exhibit. In our view, the proposed wording does not change the Panels' interpretation of 
the evidence but rather explains the interpretation in a clearer way. Accordingly,  we have made 
the requested modification.  
6.15.   With respe ct to paragraph 7.321  (paragraph 7.320 in the Interim Reports) , the United 
States requests that the figure "397" in the table in this paragraph be corrected to "144" . The 
United States argues that, as noted in the last sentence  of this paragraph, the figure "397", which 
was submitted in the United States' first written submission, was subsequently  corrected to "144" 
through Exhibit USA -179 Rev. The United States therefore requests this modification to be 
reflected in the table i n paragraph 7.321 . Mexico opposes the United States' request, arguing that 
paragraph 7.321  contains an exact copy of the information in the table contained in paragraph 51 
of the United States'  first written submis sion. We note that, as the United States argues, this 
correction was introduced in Exhibit USA-179 Rev. after the United States' first written submission. 
Therefore, we accept the United States' request and have made the requested modificat ion in 
order to ensure the accuracy of our findings. We have also introduced  footnote 545 explaining the 
modification that we have made and the reasons therefor.  
6.16.   With respect to paragraph 7.344  (paragraph 7.343  in the Interim Reports ), the United 
States' requests  us to make  modifications to the final sentence of this paragraph in order to clarify  
that, except for 2014, the number of dolphins referred to represents the number of dolphins 
released ali ve in observed sets , and thus represents the maximum possible number of observed 
serious injuries, not the number of serio us injuries actually documented. Mexico requests that the 
proposed edits to this paragraph be rejected on the ground that the United S tates'  proposa l 
attempts to modify the Panels'  interpretation of the evidence.  We note that the tables presented in 
Exhibit USA-179 Rev., in particular the ones concerning purse seine fishing without setting on 
dolphins in the WCPO, contain data either on direct dolphin mortality or on events in which 
dolphins were captured but subsequently released alive. Similarly, we note that  the numbers 
discussed in the last sentence of paragraph 7.344 , which relate to dolphins released ali ve, 
represent the upper limit of the serious injuries that could have been observed. For these reasons, 
and in order to further clarify our findings, we accept the United States' request, and have  made  
the requested modifi cation  to the text of the last sen tence of the paragraph at issue.  
6.17.   With respect to paragraph 7.365  (paragraph 7.364 in the Interim Reports), the United 
States requests that we modify the first sentence of this paragraph in order to clarify that the 
rates referr ed to are based on a representative subset of all sets in the fishery. Mexico opposes the 
United States' request, arguing that the proposed modification attempts to edit and re -word the 
reasoning of the Panels. The United States' request is to add the phrase "data shows that" to the 
part of the first sentence of the mentioned paragraph where the Panels discuss the e vidence on 
the record , and, in our view, this is not an attempt to edit or re -word our reasoning . We thus 
accept the United States' request, and  have made the requested modification . WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  6.18.   With respect to paragraph  7.385  (paragraph  7.384  in the Interim Reports) , the United 
States requests that, for reasons of clarity and consistency, the first sentence of this paragraph be 
modified. Mexico does not comment on this request. We note that the proposed modification 
improves the quality of the text as it gives the equivalent, on a per 1,000 sets basis, of the 
numbers presented in the paragraph. For this reason, we accept this requ est, and have made the 
requested modification.  
6.19.   With respect to paragraphs 7.386  and 7.399  (paragraphs 7.385 and 7.398  in the Interim 
Reports) , the United States request that a footnote be added at t he end of these paragraphs for 
the purposes of adding clarity to the text. Mexico opposes the United States' request, arguing that 
the proposed citations to a Mexican submission do not support the sentences to which the United 
States proposes adding  them.  Mexico also contends that granting this request would amount to 
modifying the Panels' characterization of Mexico's arguments. Given that the proposed 
modification concerns our description of Mexico's arguments, and that Mexico disagrees with it, we 
decline  the United States' request.  
6.20.   With respect to paragraphs  7.390  and 7.396  (pargraphs  7.389 and 7.395  in the Interim 
Reports) , the United States requests the Panels to modify the last sentences of thes e paragraphs 
to make it clear that the numbers given therein refer to potential serious injuries, and not serious 
injuries actually documented. Mexico opposes this request, arguing that the proposed modification 
attempts to edit and re -word the reasoning o f the Panels . We disagree with Mexico's argument 
since the requested modification in no way affects our reasoning. We therefore accept the United 
States' request, and have modified the last sentences of paragraphs 7.390  and 7.396  in order to 
clarify the basis of our findings.  
6.21.   With respect to paragraph  7.394  (paragraph  7.393  in the Interim Reports) , the Unite d 
States requests that we add a  footnote reference at the end of the last sentence of this paragraph, 
to provide further clarity. Mexico argues that the United States' request should be rejected 
because the proposed text attempts to edit the reasoning of the Panels by adding the phrase 
"showing no bycatch of marine mamm als", which represents the United States' interpretation of 
the relevant exhibit. We agree with the United States that the requested footnote adds clarity to 
the text, and have added footnote 657 to the text of the paragraph a t issue . In doing so, however, 
we did not include the phrase "showing no bycatch of marine mammals" suggested by the United 
States  in parenthesis.  
6.22.   With respect to paragraph 7.400  (paragraph 7.399  in the Interim Reports) , the Un ited 
States requests us to revise the last sentence of this paragraph to clarify the relationship between 
the first and second clauses. Mexico argues that the proposed modification should be rejected 
because the United States' proposal attempts to edit and  re-word the reasoning of the Panels. In 
our view, the proposed textual modification improves  and clarifies  the text and does not entail any 
change in the Panels' reasoning. We thus accept the United States' request and have modified the 
text of paragraph 7.400 . 
6.23.   The United States requests that we add a  parenthetical  to footnote 685 to paragraph 7.408  
(footnote 664  to paragraph 7.407  in the Interim Reports) , which address es an argument of the 
United States concerning the direct dolphin mortalities caused by gillnet fishing. According to the 
United States, the parenthetical would more clearly spell out one element of its argument which 
was not expressly included in the ment ioned footnote, namely that " gillnet fishing does not, 
necessarily or as a general matter, cause direct dolphin mortalities at a rate on par with that 
caused by dolphin sets in the ETP ". Mexico has not commented on this request by the United 
States.  We agr ee with the United States that the additi on of this parenthetical  provides more 
clarity  as to the argument made by the United States , and have therefore made the requested 
modification . 
6.24.   The United States requests that we substitute the phrase "at the same level of risks to 
dolphins as in the ETP" in paragraph  7.417  (paragraph 7.416 in the Interim Reports) with the 
phrase "under the determination provisions " to clarify that the "regular and significant mortality or 
serious injury " standard does not encompass the overall level of "risks" to dolphins in the ETP. 
Mexico disagree s with the United States' request . According to Mexico, the United States' request  
attempts to edit and re -word the reasoning of the Panels. Mexico further po ints out that the 
statement, as drafted in the Interim Reports, finds support in the United States' second written 
submission, paragraph 157, cited in  footnote  714 of the Reports. We have made the requested WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  modification to par agraph 7.417  because it serves to clarify our reasoning and avoids potential 
confusion.  
6.25.   The United States requests the Panels to make certain modifications and insert two footnote 
references to paragraph 7.454  (paragraph 7.453 in the Interim Reports) in order to clarify the 
basis for our findings regarding the potential stress effects dolphins might suffer as a consequence 
of entanglement in fishing nets. Mexico argues that the United States’ proposa l attempts to modify 
the Panels ' interpretation of the evidence and should therefore be rejected. We disagree with 
Mexico's view that the United States' request represents an attempt to modify our interpretation of 
the evidence, because the requested modif ication would not, in our view, modify our reasoning or 
add a new argument to the paragraph. We have therefore modified paragraph 7.454  and inserted 
footnotes 814 and 815 as requested by the United States in order to enhance the clarity of our 
findings.  
6.26.   The United States requests  that we add a conclu ding paragraph at the end of section 
7.7.2. 3.3 summarizing our  findings concerning both the observable and unobservable ha rms to 
dolphins caused by gillnet fishing . According to the United States, such a paragraph would ensure 
consistency with the structure of the sections of the Reports containing our findings regarding 
other fishing methods . To that end, the United States p roposes a detailed concluding paragraph 
drawing from different parts of section 7.7.2.3 .3. Mexico objects to  the United States' proposal on 
the ground that it would amount to the United States being allowed to write the Panels' findings or 
reasoning.  We no te that we summarize our findings regarding the observable and unobservable 
harms caused to dolphins by gillnet fishing in paragraphs 7.444  (paragraph 7.443 in the Interim 
Reports) and 7.456  (paragraph 7.455 in the Interim Reports) of the Reports, respectively. 
Nonetheless, we are of the view that adding an overall conclusion paragraph at the end of Section 
7.7.2.3 .3 concerning gillnet  fishing would add clarity to the text of the Reports. We have therefore 
inserted paragraph 7.457  for this purpose. In drafting that paragraph, however, we have modified 
the language  proposed by the United States, so as to ensure consistency with the analogous 
sections in the Reports  concerning other fishing methods . 
6.27.   With respect to the heading of the fifth column in the last table in paragraph 7.469  
(paragraph 7.467 in the Interim Reports) , as well as the texts of paragraphs 7.470  and 7.523  
(paragraph s 7.468 and  7.521 in the Interim Reports) , the United States requests the Panels to 
replace the references to dolphin mortality per set in the Australia Eastern Tuna and Billfish 
Longline fishery with the words  "possible dolphin mortalities " or, alternately, "dolphin captures ". 
This is because, according to the United States, the available per set data  for this particular fishery 
refers to dolphin captures , but not necessarily dolp hin mortalities. Mexico requests the Panels to 
reject the United States' request on the ground that it amount s to revis ing or adding to  the Panels ' 
factual findings  by arguing that the "capture " of a dolphin by hooking it and pulling it onboard 
should not be counted as mortality . 
6.28.   We first note that the table heading in the Interim Reports referred to by the United States 
was reproduced directly from Exhibit US A-179 Rev. We further note that the table contained in 
Exhibit US A-179 Rev. indicates that the data  under the heading " Mortality per 1,000 Sets ", as it 
pertains to the Australia Eastern Tuna and Billfish Longline fishery, is an estimate from the dolphin 
captures in longline hooks, by including the word "est." after each data point and by explaining 
what "est." means in footnote 5 of the mentioned Exhibit. We also note that in paragraph 58 of its 
first written submission, the United States explains that, for this particular fishery, the mortality 
data provided by the United States in connection with the m entioned submission is based on the 
total number of dolphins captured. It is therefore clear that the heading of the fifth column in the  
last table in paragraph 7.469 , as well as the texts of paragraphs 7.470  and 7.523  of our Reports , 
should be modified to reflect this fact. To this end , we have added the word "possible" before 
"mortality" in the heading of the fifth column in the  last table in paragraph  7.469  and before 
"dolphin mortalities" in paragraphs 7.470  and 7.523 . 
6.29.   The United States requests the Panels to modify the text of the third sentence in paragraph 
7.475  of these Reports  (paragraph 7.473 in the Interim Reports)  to clarify it, and to insert a 
footnote to this sentence in order to explain the basis of the statement that some longline fisheries 
present no known risk of observable harm to dolphins. Mexico contends that the United States 
should not instruct the Panels regarding  the evidence on which they should base their findings.  In 
our view, neither of the two requests from the United States modifies the evidence on which we 
base our findings or our reasoning set out in paragraph 7.475  We consider that both aspects of the WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  United States' request serve to improve the quality of the text of paragraph 7.475  We have thus 
made the textual  modificat ions requested by the United States  and inserted footnote 857. 
6.30.   With respect to paragraph 7.541  (paragraph 7.539 in the Interim Reports), the United 
States requests that we add certain language to t he third sentence of the paragraph in order to 
clarify and ensure the accuracy of the figures relating to the WCPO purse seine fishery. Mexico 
does not comment on this request.  In our view, the proposed language improves the quality of the 
text by clarifyi ng that the number mentioned in this paragraph is an annual average on a per 
1,000 sets basis. We thus accept the United States' request, and have modified the third sentence 
of the paragraph at issue.  
6.31.   The United States requests that we insert additional f ootnote references  in paragraphs 
7.683  (paragraph 7.681 in the Interim Reports) and 7.698  (paragraph  7.696  in the Interim 
Reports). The references proposed by the United States include citations fol lowed by bracketed 
descriptions of the exhibits referenced in the citations (for example, "Dolphin Mortalities to ETP 
Dolphin Sets and in Other Fisheries" (Exhibit USA -111) (showing that the ETP benchmark, i.e. the 
level of per set mortalities caused by do lphin sets in the ETP between 1997 and 2015 was 0.1265 
dolphin mortalities per set)"). According to the United States , the addition of these footnote 
references would more completely reflect the arguments of the United States. Mexico makes no 
comment regar ding the United States' request in respect of paragraph 7.683 . Regarding the 
United States' request in respect of paragraph 7.698 , Mexico argues that this request should be 
rejected because it is an  attempt to instruct the Panels as to the evidence on which they should 
base their findings. We agree with the United States that clarity and completeness is enhanced by 
adding the citations indicated b y the United States in respect o f both paragraphs 7.698  and 7.683 . 
Accordingly, we have inserted additional references in footnotes 1176 and 1177 and added a new 
footnote 1195. Concerning Mexico's argument regarding paragraph 7.698 , we do not consider that 
the United States' request "instructs" us as to the evidence on which we should rely .  Rather , the 
reference clarifies the basis of our reasoning. However, although we accept the United States' 
requests in respect of paragraphs 7.698  and 7.683 , in the interests of style and consistency, we do 
not consider it necessary to add the  bracketed descriptions of the exhibits referenced in the 
citations, as requested by the United States. Having said that, it would in our view aid reader 
comprehension if the numerical value of the benchmark, which the United States proposes to add 
in brac kets in the additional footnote references, were included in the body text of the paragraphs 
in question. Accordingly, at the end of the last sentence of paragraph 7.683 , and at the end of the 
second sentence of paragraph 7.698 , we have inserted the words "which the United States 
calculates as 0.1265 mortalities per set".  
6.2  Requests from Mexico  
6.32.   With respect to paragraph 7.46 Mexico requests that the Panels delete their stat ement that 
Mexico did not respond to the United States' argument that Mexico's allegations concerning 
pressure allegedly applied by the United States to certain US tuna retailers was outside the  Panels'  
terms of the reference. According to Mexico, Mexico w as not afforded an opportunity by the Panels 
to address this issue. Mexico suggests that the Panels did not include any question about the 
terms of reference in their post -hearing questions. The United States respond s that Mexico's  
request is based on an i ncorrect premise, since Mexico did have an opportunity to comment on this 
issue. We note that, contrary to Mexico's suggestion, the Panels did indeed ask Mexico a question 
about terms of reference following the Panels' joint meetings with the parties. Ques tion No. 72 to 
Mexico explicitly ask Mexico whether "such alleged action is within the Panels'  terms of reference ". 
In its response to this question, Mexico did not respond to this aspect of the Panels' question. 
Moreover, Mexico had the opportunity to com ment on the United States' response to a question 
from the Panels on precisely this issue, and chose not to do so.18 Accordingly, we reject Mexico's 
request and retain the accurate statement that Mexico did not respond to this argument.  
6.33.   With respect to para graph 7.60 which contains a description of the AIDCP Tracking and 
Verification System, Mexico requests that we delete the sentence "However, it does not provide 
specific legal requirements as to audits or inter -party co -operati on". According to Mexico, this 
statement is inaccurate, and may be read as suggesting that audits and inter -party cooperation 
have not been implemented under the AIDCP system. Mexico also points to evidence on the record 
                                                
18 Panels' question No. 32 (" Please respond to Mexico's argument, in paragraph 149 of its first written 
submission, regarding commitments by retailers not to purchase Mexican tuna products "); Mexico's comments 
on the United States' response to Panels' question No. 32, para. 70.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  showing that co operation does occur  in the context or under the auspices of the AIDCP. The United 
States argues that this request should be rejected, since the statement is accurate as drafted by 
the Panels. We note that  the statement to which Mexico objects concerns the apparent absence in  
the ADICP Tracking and Verification System of any detailed legal requirements concerning audits 
and inter -party cooperation. The statement says nothing about whether or not parties to the 
AIDCP, in their own domestic legislation or through arrangements co ncluded separately from, 
although in the context of, the AIDCP, do engage in auditing and cooperation. Nevertheless, to 
avoid confusion, and because we consider that the sentence in question is not essential to the 
Panels' description, we accept Mexico's r equest and have deleted the sentence.  
6.34.   With respect to paragraph 7.64 which contains the Panels' description of the NOAA Tracking 
and Verification Regime, Mexico argues that the text does not reflect a "key point" made by 
Mexico , namely, that US agencies lack authority to audit non -US fishing vessels, carrier vessels, 
and processors. Mexico requests that we therefore add a sentence reflecting this argument. The 
United States argues that this request should be rejected, first beca use the paragraph in question 
is a description of the measure at issue, rather than a summary of Mexico's arguments, second 
because the scope of the United States'  authority is clear from the paragraph as drafted by the 
Panels, and finally because the issu e of the scope of the United States'  authority is dealt with in 
detail at paragraphs 7.633  and 7.675  of these Reports  (paragraphs 7.631 and 7.673 in the Interim 
Reports) . We note, however, that the United States does not argue that the statement proposed 
by Mexico is substantively  incorrect. Accordingly, we accept this request and have inserted a 
statement reflecting Mexico's view, which in our view brings into sharper relief a point that is 
already reflected in the paragraph as drafted by the Panels.  
6.35.   With respect to paragraph 7.85 which deals with the Panels' identification of the applicable 
legal test under Article 2.1 of the TBT Agreement, Mexico argues that the Panels'  description omits 
an important element of the calibration test as described by the Appellate Body, namely, that the 
calibration analysis must be conducted "taking account of the objectives of the measure". 
According to Mexico, a reference to this element of the test should be included in the paragraph in 
question. The United States responds that the sentence as drafted by the Panels is accurate. 
According to the United States, the sentence as drafted correctly identifies the area of agreement 
between the p arties as to the applicable legal standard, but accepting Mexico's request would lead 
to this paragraph inaccurately describing the parties as being in agreement on the role that "the 
objectives of the measure" should play in the calibration  analysis  when in fact the parties disagree 
on this point. We note that, as we describe in detail in Section 7.5.2 of our Reports, the Appellate 
Body used a variety of similar formulations to describe the calibration analysis, only one of which 
referred to the objectives  of the measure. The relevance and meaning of the Appellate Body's 
reference to the objectives of the measure was a major issue in dispute between the parties. We 
consider that Mexico's proposed alternative language could mislead the reader into believing that 
both parties had the same understanding of the relevance and meaning of this formulation, which, 
as noted above, was not the case. Additionally, we recall that we discuss our view of the meaning 
and relevance of the Appellate Body's reference to the o bjectives of the measure, including 
Mexico's arguments, in detail in paragraphs 7.114  to 7.126  of these Reports. We consider that that 
discussion is sufficiently detailed, and therefore the addition  requested by Mexico is unnecessary, 
and would not increase either the accuracy or the clarity of the paragraph. Accordingly, we reject 
Mexico's request.  
6.36.   With respect to paragraph 7.87 in which the Panels describe Mexico's argu ments concerning 
the applicable legal test under Article 2.1 of the TBT Agreement, Mexico argues that the text, and 
in particular the reference to "other factors of the even -handedness standard", does not accurately 
reflect Mexico's position. Mexico reques ts that the Panels delete this reference and insert 
alternative text that more closely tracks Mexico's arguments in its written submissions. The United 
States argues that the paragraph  as drafted accurately reflects Mexico's position, since Mexico did 
refer in its submissions to different "factors" or "elements" of the applicable legal standard. 
Bearing in mind that this request relates to the Panels' description of Mexico's own arguments, we 
accept Mexico's request and have made the requested change in ord er to better reflect Mexico's 
position.  
6.37.   With respect to paragraph 7.107  Mexico requests that, in order to more accurately reflect its 
arguments, we delete the word "legal" from the phrase "Mexico argues that the reliability of the 
applicable legal systems ..." . Mexico argues that it did not use the term "legal" in its submissions, 
and that this word unduly narrow the scope of the word "systems" in a way that was not intended WT/DS381/RW/USA • WT/DS381/RW 2 
 
- 25 - 
 
  by Mexico. The United States makes no  comment on this request. Bearing  in mind that this 
request relates to the Panels' description of Mexico's own arguments, we accept Mexico's request 
and have made the requested change in order to better reflect Mexico's position.  
6.38.   With respect to paragraph 7.130  which describes Mexico's arguments concerning the 
relevance of the preamble to the WTO Agreement in the interpretation of the covered agreements, 
Mexico objects to the Panels' statement that Mexico's argument entails the conclusion that a  
measure may be found to be inconsistent with a particular provision of the covered agreements 
"because it does not further one of the goals referenced in the preamble". According to Mexico, 
this statement does not accurately reflect Mexico's argument, whi ch was that "[m]easures that 
discriminate in a manner that goes against the objective of sustainable development … can be 
found to be inconsistent".19 Mexico therefore requests that this statement be deleted and replaced 
with alternative language that more accurately reflects Mexico's argumen ts. The United States 
makes no comment  on this request.  We accept Mexico's request in order to better reflect Mexico's 
argument.  
6.39.   With regard to paragraph 7.183  (paragraph 7.182  in the Interim  Reports) , Mexico contends 
that the paragraph omits key elements of Mexico's argument regarding the US regulations adopted 
under the Marine Mammal Protection Act, and requests the Panels to make the necessary 
modifications in order to fully reflect such ar guments. Among others, Mexico requests that the 
Panels use the word "explains", instead of "contends", in characterizing Mexico's description of the 
regulations, because the United States does not contest the accuracy of Mexico's description. The 
United St ates does not object to certain proposed changes to the last sentence  of the paragraph at 
issue but requests the Panels to deny other aspects of Mexico 's request. With respect to the 
proposed changes to the first sentence, the United States requests that t he Panels deny Mexico 's 
request, as the text Mexico suggests is inaccurate  in that it gives the wrong impression that 
Mexico's argument was made in response to an argument by the United States . With respect to 
the proposed changes to the last sentence, the  United States contends that Mexico did not argue 
that "the regulations require the United States to ban seafood imports entirely " from countries that 
do not "create assessments that estimate population abundance for marine mammal stocks that 
are killed or  seriously injured in their territorial waters ". To the contrary, in the view of the United 
States, the Marine Mammal Protection Act is a fishery -specific, as opposed to country -specific, 
measure. We note that Mexico's request is composed of two parts, one  asking  us to include a 
contextual description of the argument contained in the first sentence of the paragraph at issue , 
and another requesting further expansion of one of Mexico's arguments in the last sentence of th at 
paragraph. Regarding the first part , we agree with the United States that characterising Mexico's  
argument as being a response to the United States' argument on the impracticability of collecting 
information in the context of the PBR methodology is not entirely accurate. Further, we note th at, 
as it stands, the first sentence correctly reflects Mexico's argument. We therefore reject the first 
part of Mexico's request. Regarding the second part, we agree with Mexico and therefore have 
modified the last sentence of the paragraph at issue . Finally, we have replaced the word  
"contends" with "submits" . 
6.40.   Mexico also requests  that the Panels introduce a new paragraph following the existing 
paragraph 7.183  (paragraph 7.182 in the Interim Reports) of the Reports because the  Interim 
Reports omit to mention two of Mexico 's arguments regarding the use of PBR , namely,  that (i) the 
United States used the PBR methodology to evaluate the impact of the dolphin encirclement 
fishing methods on dolphins in the ETP in implementing the Measure, and that (ii) the use of PBR 
protects smaller dolphin stocks from total extinction in circumstances where a relatively low 
number of mortalities can erode the ability of members of the stock to reproduce. The United 
States argues that the addition of these details is unnecessary because the explanation at 
paragraph 7.175  is sufficient to accurately describe Mexico's arguments concerning PBR. If, 
however, the Panels decide to include the details requested by Mexico, the U nited States points 
out that the place where Mexico requests that this new paragraph be introduced is not 
appropriate, and that the appropriate place would be in the context of paragraph 7.175  which sets 
out Mexico's arguments.  We agree with Mexico's request and , have included the details of Mexico's 
arguments in the new paragraph 7.176 . We have, however, modified the language proposed by 
Mexico in drafting this paragraph. In choosing the place of th is paragraph, we have taken the 
United States' comment into account.  
                                                
19 Mexico's response to P anels' question No. 84, para. 125.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  6.41.   Regarding paragraph  7.217  (paragraph  7.216  in the Interim Reports) , Mexico argues that 
this paragraph sets forth the United States' argument regarding the pro bity of Exhibit USA -179 
Rev. but not that of Mexico. Mexico therefore requests that a sentence be added at the end of the 
paragraph in order to properly describe Mexico's position in this regard. The United States opposes 
Mexico's request, arguing that thi s paragraph does not set forth the arguments of either party but 
rather the Panels' description of Exhibit USA -179 Rev. If Mexico meant to refer to paragraph 7.216  
(paragraph 7.215 in the Interim Reports) of the Reports, the Un ited States maintains that that 
paragraph already addresses, in its second and third sentences, the arguments that Mexico 
requests the Panels to add. We note that, as the United States argues, paragraph 7.217  contains 
our descr iption of Exhibits USA -179 and USA -179 Rev., rather than  the parties' arguments on 
those Exhibits. We also note that the comments that Mexico requests us to add to paragraph 
7.217  convey Mexico's views on Exhibit USA -179, and n ot Exhibit USA -179 Rev. We have 
nevertheless revised the text of paragraph  7.216 , where we note  the parties' arguments on 
Exhibits USA -179 and USA -179 Rev., to provide a more thorough description of Mexico's 
arguments on Exhib it USA -179. 
6.42.   Mexico requests that the Panels include a new paragraph , before or after paragraph 7.238  
(pargraph 7.237  in the Interim Reports) , to reflect Mexico 's arguments on whether observer 
coverage of less than 10% provides scientifically valid data. The United States argues that 
Mexico 's proposed new paragraph is unnecessary and inappropriate, as the Interim Reports 
already fully summarize Mexico 's arguments on this issue. We note that the  new paragraph  
requested by Mexico c ontains arguments  whose thrust ha s already been described in these 
Reports, such as in paragraph  7.236  (paragraph 7.235 in the Interim Reports) . In fact, the 
proposed new text makes reference to Mexico's interpretation of some exhibits on the record 
submitted in support of Mexico's main argument that observer coverage of less than 10%  does not  
provide scientifically valid data . We thus reject Mexico's request.  
6.43.   Regarding paragraph 7.250  (paragraph 7.2 49 in the Interim Reports), Mexico requests that 
the Panels modify this paragraph which indicates that Mexico did not submit any arguments 
regarding the meaning of the terms " observed, " "unobserved, " "observable, " "unobservable, " 
"direct " and "indirect " harms. Mexico argues that it did address this issue, and suggests specific 
language to reflect this in the paragraph at issue. The United States requests that the  Panels deny 
Mexico's request. The United States recalls that at the hearing, Mexico, in respons e to this 
question, stated that  it would respond to the question fully in writing, but that subsequently 
Mexico provided no specific arguments on the matter at issue, nor any reference to statements 
made at the hearing. We note that although Mexico address ed some of the issues regarding the 
meaning of the terms mentioned in the paragraph at issue, it also stated that it would "submit 
more detailed information in [its] written reply". However, in response to Panels' question  No. 116, 
sent to the parties afte r the Panels' substantive meeting with the parties , asking them to explain 
their understand ing of  the terms "direct", "indirect", "observed", "observable", "unobserved" and 
"unobservable" harms or risks, Mexico did not provide any further elaboration on th e conceptual 
differences between these terms. For these reasons, we have modified the text of paragraph 7.250  
to reflect Mexico's statements during the meeting as well as its response to Panels' question no. 
116. 
6.44.   With respect t o paragraph 7.276  (paragraph 7.275 in the Interim Reports) which describes 
Mexico's arguments concerning the ETP large purse seine fishery, Mexico requests that we add 
certain language to more accurately reflect Mexico's positi on. In particular, Mexico requests, first, 
that we clarify that Mexico does not dispute the recent  data on dolphin mortalities caused by 
setting on dolphins in the ETP, and second, that we reflect Mexico's argument concerning the 
impact of the La Jolla Agr eement on the mortality levels in that fishery. The United States does not 
oppose Mexico's request entirely, but does oppose the addition of the word "recent" in the first 
sentence. According to the United States, this addition would not accurately reflect  Mexico's 
arguments . In our view, the addition of the word "recent" as requested by Mexico is unnecessary, 
since the sentence already indicates that Mexico does not contest evidence "collected and 
published by the AIDCP". This reference to the AIDCP makes clear the extent of the evidence that 
Mexico does not contest, as the AIDCP only came into existence (in its earliest form) following the 
entry into force of the La Jolla Agreement in 1992. Thus, we do not accept Mexico's request to add 
the word "recent". However, we accept the remainder of Mexico's request, which accurately 
describes Mexico's position, except that we have not accepted the word "emphasizes", which 
Mexico proposes and which could be read as an endorsement by the Panels of Mexico's argument. 
Such an endorsement would be inappropriate in the context of the paragraph in question, which is WT/DS381/RW/USA • WT/DS381/RW 2 
 
- 27 - 
 
  simply a description of Mexico's arguments. We have therefore changed this word to " argues", but 
have accepted Mexico's request in all other respects.  
6.45.   With res pect to p aragraph 7.277  (paragraph 7.276 in the Interim Reports), Mexico requests 
that we modify the text to more accurately reflect Mexico's arguments concerning the  extent of 
unobservable harms caused by setting on dolphins i n the ETP. The United States does not object 
to this request, but argues that some of the alternative language proposed by Mexico does not 
accurately reflect Mexico's written submissions. Bearing in mind that this request relates to the 
Panels' description  of Mexico's own arguments, we accept Mexico's request and have made the 
requested change, which in our view reflects Mexico's position during the proceedings.  
6.46.   With respect to paragraph 7.284  (paragraph 7.283 in the Interim Re ports) in which the 
Panels note that the World Wildlife Fund (WWF), inter alia , has expressed concerns that mortalities 
in the ETP large purse seine fishery may be understated, Mexico requests the Panels to explicitly 
recall Mexico's position that the WWF document to which the Panels refer in this paragraph 
"provides no evidence of mortalities, but simply makes an allegation without support". The United 
States argues that this request should be rejected for two reasons: first, because the paragraph in  
quest ion describes the Panels' assessment of the evidence rather than the parties' arguments; and 
second, because the argument that Mexico requests to be inserted was made by Mexico not in 
respect of the Exhibit discussed in this paragraph, but in respect of a different WWF document 
discussed in a subsequent paragraph. Like the United States, we note that the argument that 
Mexico requests us to include was not made in respect of the Exhibit at issue in this paragraph, 
but rather in respect of a different WWF doc ument. Additionally, we note that the paragraph in 
question describes the Panels' own assessment of the evidence having taken into account both 
parties' arguments, and therefore does not summarize the arguments of either  of the parties. We 
therefore consid er that it would be inappropriate to insert a summary of Mexico's argument into 
this paragraph. In this connection, we recall that panels are not required to explicitly address 
every argument advanced by the parties to a dispute.20 Moreover, we recall that a panel does not 
commit error simply because it declines to accord to the evidence the weight that one of the 
parties believes should be accorded to it .21 
6.47.   With respect to paragraph 7.289  (paragraph 7.288 in the Interim Reports) Mexico requests 
that the Panels delete the statement indicating that Mexico did not dispute the existence of 
unobservable harms in either of the preceding stages of this dispute (i.e. the original proceedings 
or the first Article 21.5 proceedings). Accordi ng to Mexico, this statement is incorrect, as Mexico's 
position has been consistent throughout the different proceedings in this dispute. The United 
States requests that  the Panels retain the language as drafted because, in the United States' view, 
the lan guage as drafted correctly reflects that Mexico has changed its position over the course of 
this dispute with regard to the existence of unobservable harms. In our view, the sentence in 
question is not essential to the Panels' reasoning in the current Arti cle 21.5 proceedings, as the 
Panels' findings about the existence of unobservable harms are based on the previous panel and 
Appellate Body reports in this dispute and the evidence submitted by the parties in the present 
proceedings, and not on whether eith er of the parties has changed its position regarding such 
harms during the course of this dispute. Accordingly, we accept this request and have deleted the 
sentence in question.  
6.48.   With respect to paragraph 7.295  (paragraph 7.294 in the Interim Reports) Mexico argues 
that the Panels "decided to agree with the US position" on Exhibit USA -43, but omitted to mention 
arguments made by Mexico in respect of this Exhibit. Mexico therefore requests that a sentence be 
added to the end of th e paragraph in question recalling Mexico's argument. The United States does  
not oppose this request, but suggests that the appropriate place to note Mexico's argument would 
be in the paragraphs describing the parties' arguments, rather than the paragraphs where the 
Panels explain their reasoning. The United States also requests that, if the Panels accept Mexico's 
request, they adopt verbs that convey that the sentences reflect Mexico's arguments and not 
uncontested facts or findings by the Panels. We begin by observing that, in the paragraph in 
question, the Panels do not "agree" with the United States, as Mexico suggests. Rather, in that 
paragraph, the Panels record their own assessment of the Exhibit in question, based on their own 
reading of it and inform ed by the arguments of both parties. This is entirely in keeping with the 
Panels' obligation under Article  11 of the DSU to carry out an "objective" assessment of the 
matter. As this paragraph contains the Panels' own assessment, it does not repeat the arg uments 
                                                
20 Appellate Body Report, Dominican Republic — Import and Sale of Cigarettes , para. 125.  
21 Appellate Body Report, Chile — Price Band System (Article 21.5 — Argentina),  para. 229.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
- 28 - 
 
  of either of the parties. We therefore consider that it would be inappropriate to insert a summary 
of Mexico's argument into this paragraph. Nevertheless, to try to accommodate M exico's concern, 
we have added  new text to  footnote  503 in the paragraph in question , in which we describe 
Mexico's argument using Mexico's proposed text. We have also provided in the same footnote an 
explanation as to why we do not accept Mexico's argument concerning the meaning and 
evidentiary value of Exhibit USA -43. 
6.49.   With respect to paragraph 7.296  (paragraph 7.295 in the Interim Reports) Mexico argues 
that the Panels "decided to agree with the US position" on Exhibit USA -45, but omitted to mention 
arguments made by  Mexico in respect of this Exhibit. Mexico therefore requests that a sentence be 
added to the end of the paragraph in question recalling Mexico's argument. The United States22 
does not oppose this request, but suggests that the appropriate place to note Mex ico's argument 
would be in the paragraphs describing the parties' arguments, rather than the paragraphs where 
the Panels explain their reasoning. The United States also requests that, if the Panels accept 
Mexico's request, they adopt verbs that convey that  the sentences reflect Mexico's arguments and 
not uncontested facts or findings by the Panels. We begin by observing that, in the paragraph in 
question, the Panels do not "agree" with the United States, as Mexico suggests. Rather, in that 
paragraph, the Pa nels record their own assessment of the Exhibit in question, based on their own 
reading of it and informed by the arguments of both parties. This is entirely in keeping with the 
Panels' obligation under Article  11 of the DSU to carry out an "objective" ass essment of the 
matter. As this paragraph contains the Panels' own assessment, it does not repeat the arguments 
of either of the parties. We therefore consider that it would be inappropriate to insert a summary 
of Mexico's argument into this paragraph. Neve rtheless, to try to accommodate Mexico's concern, 
we have added new  text to  footnote  506 in the paragraph in question , in which we describe 
Mexico's argument using Mexico's proposed text. We have also provided in the same foot note an 
explanation as to why we do not accept Mexico's argument concerning the meaning and 
evidentiary value of Exhibit USA -45. 
6.50.   With respect to paragraph 7.300  (paragraph 7.299 in the Interim Reports) Mexico argues 
that the Pa nels "decided to agree with the US position" on Exhibit MEX -14, but omitted to mention 
arguments made by Mexico in respect of this Exhibit. Mexico therefore requests that a sentence be 
added to the end of the paragraph in question recalling Mexico's argume nt. The United States does  
not oppose this request, but suggests that the appropriate place to note Mexico's argument would 
be in the paragraphs describing the parties' arguments, rather than the paragraphs where the 
Panels explain their reasoning. The Uni ted States also requests that, if the Panels accept Mexico's 
request, they modify the alternative language proposed by Mexico in order to more accurately 
convey the limited nature of Mexico's argument on this Exhibit. We begin by observing that, in the 
paragraph in question, the Panels do not "agree" with the United States, as Mexico suggests. 
Rather, in that paragraph, the Panels record their own assessment of the Exhibit in question, 
based on their own reading of it and informed by the arguments of both p arties. This is entirely in 
keeping with the Panels' obligation under Article 11 of the DSU to carry out an "objective" 
assessment of the matter. As this paragraph contains the Panels' own assessment, it does not 
repeat the arguments of either of the parti es. We therefore consider that it would be inappropriate 
to insert a summary of Mexico's argument into this paragraph. Nevertheless, to try to 
accommodate Mexico's concern, we have added  new text to footnote 515 in the paragra ph in 
question , in which we describe Mexico's argument using Mexico's proposed text, including the 
modification suggested by the United States, which seems to us to increase the accuracy of the 
text. We have also provided in the same footnote an explanatio n as to why we do not accept 
Mexico's argument concerning the meaning and evidentiary value of Exhibit MEX -14. 
6.51.   With respect to paragraph 7.301  (paragraph 7.300 in the Interim Reports) Mexico argues 
that the Panels "decided to a gree with the US position" on Exhibit USA -47, but omitted to mention 
arguments made by Mexico in respect of this Exhibit. Mexico therefore requests that a sentence be 
added to the end of the paragraph in question recalling Mexico's argument. The United Sta tes does  
not oppose this request, but suggests that the appropriate place to note Mexico's argument would 
be in the paragraphs describing the parties' arguments, rather than the paragraphs  where the 
Panels explain their reasoning. The United States also re quests that, if the Panels accept Mexico's 
request, they adopt verbs that convey that the sentences reflect Mexico's arguments and not 
uncontested facts or findings by the Panels. We begin by observing that, in the paragraph in 
question, the Panels do not "agree" with the United States, as Mexico suggests. Rather, in that 
                                                
22 We observe that, in its comments on Mexic o's requests, the United States appears to refer to this 
paragraph mistakenly as 7.294.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  paragraph, the Panels record their own assessment of the Exhibit in question, based on their own 
reading of it and informed by the arguments of both parties. This is entirely in keeping wi th the 
Panels' obligation under Article  11 of the DSU to carry out an "objective" assessment of the 
matter. As this paragraph contains the Panels' own assessment, it does not repeat the arguments 
of either of the parties. We therefore consider that it woul d be inappropriate to insert a summary 
of Mexico's argument into this paragraph. Nevertheless, to try to accommodate Mexico's concern, 
we have added a new footnote  517 to the paragraph in question in which we describe Mexico's  
argument using Mexico's proposed text. We have also provided in the same footnote an 
explanation as to why we do not accept Mexico's argument concerning the meaning and 
evidentiary value of Exhibit USA -47. We have also added the full title of the Exhibit into the text of 
the paragraph in question in the interests of consistency.  
6.52.   With respect to paragraph 7.305  (paragraph 7.304 in the Interim Reports) Mexico argues 
that the Panels "decided to agree with the US position" on Exhib it USA -140, but omitted to 
mention arguments made by Mexico in respect of this Exhibit. Mexico therefore requests that a 
sentence be added to the end of the paragraph in question recalling Mexico's argument. The 
United States does not make  any comment on t his request. We begin by observing that, in the 
paragraph in question, the Panels do not "agree" with the United States, as Mexico suggests. 
Rather, in that paragraph, the Panels record their own assessment of the Exhibit in question, 
based on their own re ading of it and informed by the arguments of both parties. This is entirely in 
keeping with the Panels' obligation under Article 11 of the DSU to carry out an "objective" 
assessment of the matter. As this paragraph contains the Panels' own assessment, it d oes not 
repeat the arguments of either of the parties. We therefore consider that it would be inappropriate 
to insert a summary of Mexico's argument into this paragraph. Nevertheless, to try to 
accommodate Mexico's concern, we have added a new footnote  522 to the paragraph in question 
in which we describe Mexico's argument using Mexico's proposed text. We have also provided in 
the same footnote an explanation as to why we do not accept Mexico's argument concerning the 
meaning a nd evidentiary value of Exhibit USA -140. 
6.53.   With respect to paragraph 7.307  (paragraph 7.306 in the Interim Reports) Mexico argues 
that the Panels "decided to agree with the US position" on Exhibit USA -142, but omitted to 
mention arguments made by Mexico in respect of this Exhibit. Mexico therefore requests that a 
sentence be added to the end of the paragraph in question recalling Mexico's argument. The 
United States does not object to the idea of the Panels adding a summary of Mex ico's argument 
concerning this Exhibit . However, the United States argues that the Panels should not use the 
words "Mexico observed", which could be read as suggesting that Mexico's argument was 
uncontested by the United States. Moreover, the United States  argues that the Panels should not 
accept Mexico's request to include language to the effect that Mexico argued that Exhibit USA -142 
"is not probative evidence", since, in the United States' view, this would not be an accurate 
reflection of Mexico's argume nt in its submissions. We begin by observing that, in the paragraph in 
question, the Panels do not "agree" with the United States, as Mexico suggests. Rather, in that 
paragraph, the Panels record their own assessment of the Exhibit in question, based on th eir own 
reading of it and informed by the arguments of both parties. This is entirely in keeping with the 
Panels' obligation under Article 11 of the DSU to carry out an "objective" assessment of the 
matter. As this paragraph contains the Panels' own assess ment, it does not repeat the arguments 
of either of the parties. We therefore consider that it would be inappropriate to insert a summary 
of Mexico's argument into this paragraph. Nevertheless, to try to accommodate Mexico's concern, 
we have added  new text to footnote 524 in the paragraph in question , in which we describe 
Mexico's argument using Mexico's proposed text. We accept the wording proposed by the United 
States, since although it is true that Mexico did not use the wor ds "is not probative evidence" in its 
submissions, the phrase nevertheless accurately reflects Mexico's position. In the same footnote, 
we have also inserted an explanation as to why we do not accept Mexico's argument concerning 
the meaning and evidentiary  value of Exhibit USA -142. 
6.54.   Regarding paragraph 7.323  (paragraph 7.322  in the Interim Reports) , Mexico requests that 
some modifications are introduced to reflect further Mexico's arguments. The United States argues 
that if the P anels were to  accept Mexico's  request concerning this paragraph, the verbs Mexico 
proposes should be replaced to accurately convey that the sentences summarize Mexico's 
arguments and are not factual findings by the Panels. We have accepted Mexico's request  but 
made some textual modifications to the language Mexico proposed.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
- 30 - 
 
  6.55.   Regarding paragraph  7.347  (paragraph  7.346  in the Interim Reports) , Mexico requests that 
we change the figure 6% to 65%. The United States supports Mexico's request. We have made the 
requested modification.  
6.56.   With respect to paragraph 7.584  (paragraph 7.582 in the Interim Reports) which concerns 
the parties' arguments regarding the new captain training course introduced by the 2016 T una 
Measure, Mexico argues that the description is incomplete because it does not include Mexico's 
response to the United States' argument. Mexico therefore requests that we insert language 
summarizing this response. The United States does not object to th is request, but argues that the 
description of Mexico's argument would be better placed in an earlier paragraph where the Panels 
describe Mexico's argument. The United States also suggests that the Panels should use the words 
"Mexico also argues" rather th an the words "Mexico responds", to more accurately describe the 
context on which Mexico's argument was made. We accept this request and have inserted Mexico's 
proposed language, with the change suggested by the United States, which adds to the 
completeness  and accuracy of the description of the parties' arguments. We have also accepted 
the United States' suggestion to put this language in paragraph 7.583  (paragraph 7.581 in the 
Interim Reports) rather than paragraph  7.584 , since it is the former rather than the latter that 
describes Mexico's arguments.  
6.57.   Regarding paragraph 7.634  (paragraph 7.632  in the Interim Reports) , Mexico requests that 
a sentence be added at the end of  this paragraph to better describe Mexico's argument regarding 
the complex supply chain for tuna by referring to evidence submitted by Mexico on this point, 
namely, a recent report of the International Seafood Sustainability Foundation. The United States 
argues that the exhibit that Mexico requests the Panels to cite in the paragraph at issue was 
submitted in Mexico's comments on the United States response to the Panels' questions and that, 
therefore, the United States did not have the opportunity to commen t on it. The United States also 
contends that the mentioned exhibit is not relevant to the measure at issue in these proceedings, 
and that therefore  its meaning  is not uncontested. Therefore, the United States asks the Panels to 
make clear that the languag e proposed by Mexico represents what Mexico argues in this regard, 
and not an uncontested fact. Finally, should the Panels accept Mexico's request, the United States 
also requests that another paragraph be inserted in order to provide a summary of the Unit ed 
States' arguments on the same issue. We note that the argument that Mexico requests the Panels 
to reflect in paragraph 7.634  pertains to the issue of whether tuna companies are able to track a 
particular catch to the individ ual vessel that caught it and to other points in the supply chain. The 
present proceedings, however, concern whether the 2016 Tuna Measure is calibrated to different 
levels of risks posed to dolphins by different fishing methods in different parts of the o cean, among 
others, in terms of its tracking and verification requirements. Therefore, the argument that Mexico 
requests us to reflect in the paragraph at issue is not  directly  relevant to our inquiry. We therefore 
deny Mexico's request.  
6.58.   Regarding  paragra ph 7.635  (paragraphs 7.633 in the Interim Reports), Mexico requests that 
a sentence be added at the end of the paragraph in order to reflect Mexico's argument  regarding 
the unreliability of tracking systems in Thailand, the Philippines and Chinese Taipei at the same 
level of detail as that at which the arguments of the United States are explained in the same 
paragraph. The United States argues that the Interim Reports provide a complete summary of 
Mexico's argume nts concerning the tracking and verification regimes of certain Asian countries , 
and that the summaries of both the United States' and Mexico's arguments are otherwise 
comparable in terms of the level of detail . If the  Panels decide to accept Mexico's requ est, the 
United States requests that some modifications be introduced to the language proposed by Mexico 
to underline that what is said represents Mexico's arguments. Bearing in mind that this request 
relates to the Panels' description of Mexico's own argu ments, we accept Mexico's request and have 
made the requested change in order to better reflect Mexico's position. In doing so, however, we 
have modified the language proposed by Mexico in certain regards, to underline that the added 
text represents Mexico 's arguments.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7  FINDINGS  
7.1  Introduction  
7.1.1   Procedural overview  
7.1.  The current proceedings are the latest in the long -running dispute between Mexico and the 
United States over the WTO -consistency of the United States' labelling regime for "dolphin -safe" 
tuna products .23 The procedural history of the dispute is summarized in the Appellate Body's report 
in the first compliance proceedings24 and in the Decision by the Arbitrator in this dispute25, and 
need not be repeated in detail here.  
7.2.  On 20 November 2015, the Appellate B ody circulated its report in the first compliance 
proceedings brought by Mexico against the measure taken by the United States to comply with the 
DSB recommendations and rulings in the original proceedings. In these Reports, the Panels refer 
to that measur e as the "2013 Tuna Measure".26 The Appellate Body found that the 2013 Tuna 
Measure modified the conditions of competition to the detriment of Mexican tuna products in the 
US market; that such detrimental impact did not stem exclusively from a legitimate re gulatory 
distinction, and, thus, that the 2013 Tuna Measure accorded less favourable treatment to Mexican 
tuna products as compared to like tuna products from the United States and other countries and 
was therefore inconsistent with Article 2.1 of the TBT Agreement. The Appellate Body also found 
that the 2013 Tuna Measure was inconsistent with Articles I:1 and III:4 of the  GATT 1994, and 
that the United States had not demonstrated that it was applied in a manner that did not 
constitute arbitrary or unjustif iable discrimination as required by the chapeau of Article XX of the 
GATT 1994.27 The findings of the Appellate Body are described in more detail later in these 
Reports.  
7.3.  On 3 December 2015, the DSB adopted the panel and Appellate Body reports in the first 
compliance proceedings. In response, on 22 March 2016, the United States National Oceanic and 
Atmospheric Administration (NOAA) issued an interim final rule with the aim of bringing the 
labelling regime for dolphin -safe tuna products into compliance with th e United States' obligations 
under the WTO Agreement. As discussed in further detail below, this interim rule (the 2016 Rule) 
made certain changes to the implementing regulations , but did not affect either the DPCIA or the 
Hogarth  ruling. In these Reports,  the DPCIA, the implementing regulations  as amended by the 
2016 Rule, and the Hogarth  ruling are collectively referred to as the "2016 Tuna Measure".  
7.1.2   Format of these Reports  
7.4.  As described above, these proceedings are somewhat unusual in that two compliance panels 
have been established – one at the request of the original complaining party and the other at the 
request of the original responding party – to determine the WTO -consistency of the same 
measure.28 The unusual nature of the proceedings gives rise to c ertain complications, the most 
important of which, concerning the burden of proof, is discussed below.29 It also raises the 
question of how the two Panels should present their findings, given that both are charged with 
assessing the WTO -consistency of the s ame measure. After consulting with the parties, the Panels 
have decided to issue their findings in a single document, with separate conclusions for each of the 
two proceedings. This is justified by the close interrelation of the two proceedings. Indeed, in sofar 
                                                
23 In the original proceedings, Mexico challenged the Dolphin Protection Consumer Information Act of 
1990, codified in United States Code , Title 16, Section 1385 (the D PCIA) , (Exhibits USA -01, MEX -01); sections 
216.91 and 216.92 of Title 50 of the United States Code of Federal Regulations  (the implementing regulations 
or CFR ), (Exhibits USA -02, MEX -02); and the ruling by the United States Court of Appeals for the Ninth C ircuit 
in Earth Island Institute et al v William T. Hogarth , 494 F.3d 757 (9th Cir. 2007) ( Hogarth  ruling) , (Exhibit MEX -
03). 
24 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , paras. 1.2 –1.6. 
25 Decision by the Arbitrator, US – Tuna II  (Mexico) , paras. 1.1 –1.4. 
26 See Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , paras. 1.7 and 6.8. The 
2013 Tuna Measure consisted of the DPCIA; the implementing regulations  as amended by the "Enhanced 
Document Requirements to Suppo rt Use of the Dolphin Safe La bel on Tuna Products" (the 2013  Rule), 
published in the United States Federal Register  on 9 July 2013; and the Hogarth  ruling.  
27 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 8.1. 
28 The parties de fine the measur e at issue slightly differently: see  Section 7.4.1below.  
29 See Section 7.6below.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  as the same questions are raised about the same measure in both proceedings, it would be 
inefficient and unnecessarily duplicative to deal with each of the proceedings separately.  
7.2  Preliminary Issue: United States' request to lift the confidentiality of its statements 
at the Panels' substantive meetings with the parties and third parties  
7.2.1   Procedural background  
7.5.  As reflected in Section 1.3.2, following  an initial request by the United States and subsequent 
requests by certain third parties, the Panels in these proceedings authorize d the United States and 
the relevant third parties  to lift the confidentialit y of their statements at the  Panels'  consolidated 
substantive meeting with the parties  and at the third par ty session . The Panels  permitted the  
partial public observation of their meeting through delayed viewing, to ensure that the 
confidentiality of Mexico's statements  or the statements of non-disclosing third parties  was not 
breached.  The parties were informe d that the reasons supporting th e Panels' decision on the 
United States' request would be elaborated by the Panels in their Reports.  
7.2.2   Merits of the United States' request for a partially open meeting  
7.6.  The Panels  note that US – Tuna II (Mexico)  is the first dispute in which a WTO adjudicator  at 
the request of a party  organize d a partially open meeting with the parties. An identical request was 
made by the United States in the  arbitration conducted under  Article 22.6 in this dispute.30 The 
arbitrator granted tha t request in the light of the particular circumstances of that proceeding.31 
The arbitrator who granted the United States' request in this dispute was composed of the same 
individuals as these Panels. Unlike the arbitrator, however, the Panels also benefite d from, and 
took into account, the views expressed by the third parties participating in these compliance panel 
proceedings. Moreover, we recall that  panel  reports  are subject to appeal. In the light of this, and 
bearing in mind our responsibility under Ar ticle 12.7 of the DSU to explain the basic rationale 
behind our findings, it is appropriate to set out in these Reports the Panels' full legal analysis even 
if the arbitrator has already provided a full legal analysis of essentially the same issue in its 
decision.32  
7.7.  Accordingly, we set out below the detailed reasons supporting our decision to grant  the 
United States' request  in the light of the specific circumstances of these proceedings. We begin by 
summarizing the parties' and third parties' arguments .  
7.8.  The United States submits that it is not asking the Panels to mandate the opening of the 
meeting over Mexico's objection. Instead, the United States seeks to exercise its right to disclose 
to the public its own statements at the Panels'  consolidated substan tive meeting, and to that end 
requests that the Panels  facilitate this disclosure by adopting appropriate procedures. The United 
States argues that it is possible for  the Panels to authorize the United States  to disclose its own 
statements and at the same time to maintain the confidentiality of Mexico's statements. In the 
United States' view, meetings opened for public observation enhance understan ding of the dispute 
settlement system and promote confidence in its objectivity and professionalism.  
7.9.  The United  States submits that its request is supported by the Appellate Body report in US – 
Continued Suspension . According to the United States, the Appellate Body in that dispute agreed 
that each party has the right to maintain the confidentiality of its own stat ements and therefore 
provided each party and third party a possibility to lift the confidentiality of their statements at the 
Appellate Body's hearing. The United States notes that it is possible to protect Mexico's right to 
maintain the confidentiality of  its statements while also protecting the United States' right to 
disclose its own statements to the public.  
7.10.   Mexico observes  at the outset that it is not in a position to accept open meetings in this 
dispute. Mexico recalls that even in those disputes wher e it did not object to open meetings, it had 
indicated that this was without prejudice to its systemic position on public observation of meetings 
in dispute settlement proceedings. Mexico also notes that the meetings in the original and first 
compliance pr oceedings in this dispute were not open for public observation.  
                                                
30 Decision of the Arbitrator, US – Tuna II (Mexico) (Article 22.6 – US), para s. 2.6 and 2.11 . 
31 Decision of the Arbitrator,  US – Tuna II (Mexico) (Article 22.6 – US), para. 2.34 . 
32 Decision of the Arbitrator, US – Tuna II (Mexico) (Article 22.6 – US), para s. 2.13-2.34. WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.11.   In Mexico's view, the Panels should reject the United States' request. For Mexico , it is clear 
from the DSU that panel meetings are confidential, except if all parties agree otherwise. Mexico 
considers that Appendix 3 of the DSU indicates that deliberations must be kept confidential. Mexico 
recalls in this connection that it was a third party in US – Continued Suspension , and that it was 
among the Members that criticized the approach taken in t hat dispute at the DSB meeting at which 
the panel and Appellate Body reports were adopted. Mexico notes that unlike in that dispute, in 
this dispute there has been no agreement by the parties on holding a public meeting. In Mexico's 
view, there is in the p resent dispute a relationship of confidentiality between the parties and the 
Panels , not between each party and the Panels . According to Mexico,  the Appellate Body in EU – 
Biodiesel (Argentina) declined the European Union's request to allow public observat ion of the oral 
hearing, noting that the other party expressed a preference against doing so.  
7.12.   In Mexico's view, proceeding as the United States requests would affect the rights of Mexico 
and those of other Members that have systemic concerns about open mee tings. Mexico submits in 
this regard that acceding to the United States' request could force other Members to accept open 
meeting s because otherwise only one party's  views are ventilated. Mexico suggests that the DSU 
already gives the United States the pos sibility to make its statements available on the website of 
the United States Trade Representative , as is its practice. Mexico considers that the United States' 
right to disclose its own positions and statements to the public does not have to be exercised 
through an open meeting.  
7.13.   Mexico is therefore of the view that the Panels  should deny the United States' request for a 
partially open meeting. Mexico also clarifies that it is not prepared to waive its right to 
confidentiality and  that it  therefore designa tes all information submitted by it in this dispute as 
confidential. Mexico considers that all statements and documents  submitted by the parties and 
third parties  are confidential until the Panels ' Reports  are circulated.  
7.14.   Brazil, China, Ecuador, Guatemala,  Korea, and India are opposed to the United States' 
request. Brazil, China, Ecuador, Guatemala, and Korea consider that panels may not hold open 
meetings, except with the agreement of all parties. Brazil, Ecuador, and Korea are of the view that 
this is cle ar from, inter alia , Article 14 of the DSU on panel deliberations.33 China, Ecuador, 
Guatemala, and India submit that the United States is free to increase transparency by releasing 
its statements to the public without the assistance of the Panels pursuant to Article 18.2 of the 
DSU. Moreover, Brazil, China, and Guatemala question whether a partially open panel meeting 
would meaningfully improve transparency. Brazil and India also observe that the issue of open 
hearings is a systemic and sensitive one on whi ch Members have not reached consensus.  
7.15.   Australia notes that it supports transparency and that it therefore , in principle, also supports 
the United States' request in this dispute, noting that panel meetings have been opened in the 
past with necessary safeg uards to protect confidentiality. Norway considers that the DSU does not 
prevent panels from holding a partially open meeting as the United States suggests and notes that 
Article 12.1 of the DSU permits panels to depart from the working procedures in Appen dix 3 after 
consulting with the parties. Japan is of the view that a partially open meeting would require 
additional work of the Panels and parties, but that the Panels can properly conduct a partially open 
meeting through delayed broadcasting without disc losing statements of WTO Members that do not 
wish to make them in public. In Japan's view, the only novelty in the United States' request is that 
it is one party, rather than all parties, that wishes to disclose its statements to the public.   
7.16.   The Panels  begin their analysis  by noting that numerous WTO adjudicators, including the 
Appellate Body, panels and Article 22.6 arbitrators, have on request opened meetings with parties 
for public observation in their entirety, except for any parts of meetings during w hich BCI was 
addressed.34 If a WTO adjudicator has the power to accede to a request to fully open a hearing or 
meeting with the parties, then a fortiori  it must in principle also have the power to go less far, 
including by opening only parts of a meeting wi th the parties.  
                                                
33 India considers that it would certainly be inconsiste nt with the DSU if a panel were to open a panel 
meeting, fully or partially, without the agreement of all parties. India does not wish to comment, however, on 
whether it would in its view be consistent with the DSU if a panel were to open a panel meeting b y agreement 
of the parties.  
34 The United States in this dispute is not seeking authorization to disclose BCI to the public. Indeed, the 
United States requested the Panels  to adopt additional working procedures for the protection of BCI.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.17.   The meetings with parties  in previous WTO dispute settlement proceedings  that have been 
opened for public observation in their entirety have been opened with the agreement of all parties. 
At those fully open meetings, the parties were autho rized to disclose not only statements of their 
own positions, but also statements of the positions of the other party or parties. The situation in 
the present proceedings is different, however. The United States is seeking authorization to 
disclose stateme nts of its own positions only.  
7.18.   We observe in this regard that, according to Article 18.2 of the DSU, nothing in the DSU 
precludes a party "from disclosing statements of its own positions to the public".35 According to the 
Appellate Body, this provision allo ws a party to forego confidentiality protection in respect of 
statements of its own positions.36 The Appellate Body has further confirmed that Article 18.2 
covers not just statements in written form, but also oral statements and responses to questions at 
Appellate Body hearings.37 The same holds true, in our view, for oral statements and responses 
given at meetings of panels . We further observe that Article 18.2 does not stipulate that a party 
may disclose its statements only once, or only after any meetings of a WTO adjudicator with the 
parties.38 
7.19.   Mexico , supported by  several  third parties , nevertheless considers that we cannot authorize 
the United States to forego confidentiality protection in respect of its statements of its own 
positions, except with Mexico 's agreement. Mexico bases this contention on the Appellate Body's 
procedural ruling in EU – Biodiesel (Argentina) .39 In our view, Mexico's reliance on this procedural 
ruling is misplaced. In EU – Biodiesel (Argentina) , the Appellate Body rejected a unilate ral request 
by the European Union that the Appellate Body conduct a fully open hearing even though the other 
party, Argentina , was not supportive of that request.40 This is not the situation we are facing, since 
the United States in this dispute requests au thorization to disclose statements of its own positions, 
not those of Mexico.41 
7.20.   Mexico further seems to consider that in respect of meetings or hearings , the DSU protects 
the confidentiality of the relationship between the parties taken as a group and a WTO  adjudicator, 
rather than between each of the parties and a WTO adjudicator. We note, however, that 
Article  18.2 gives each party individually the right to disclose statements of its own positions. 
Where a fully open meeting is to be held, it is clear that  all parties need to request authorization to 
disclose the statements of their own positions that they wish to make at the meeting. This does 
not imply, however, that one party can simply veto another party's request that it be authorized to 
disclose state ments of its own positions. Indeed, this is also the approach taken by the Appellate 
Body in respect of third parties participating in its hearings  (which the Appellate Body refers to as 
"third participants") . Although the Appellate Body has referred to a relationship of confidentiality 
between "the third participants"42 and itself, it has authorized those third participants  that so 
wished to lift the confidentiality of their statements at the hearing, despite objections by other 
third participants .43 Thus, t he Appellate Body did not impose an inflexible "all-or-none" rule for the 
lifting of confidentiality. In our view, this approach is equally appropriate in respect of the 
relationship between the parties and a ny WTO adjudicator. Indeed, it would be incongru ous to 
permit individual third parties to forego confidentiality protection in respect of their statements (in 
those disputes where the parties have requested the same) even as other third parties wish to 
hold on to that protection, but to withhold that sa me opportunity from a party merely because 
                                                
35 We note that the immediate context of Article 18.2 of the DSU suggests that it relates to statements 
of positions made to panels or the Appellate Body.  
36 Appellate Body Report, US – Continued Suspension , Annex IV, paras. 4 and 11.  
37 Appellate Body Report, US – Continued Suspension , Annex IV, para. 4.  
38 As we address below, Article 18.2 of the DSU does not mean that we must automatically authorize 
the United States to disclose to the public an oral statement of its own positions made during our meeting. 
Indeed, we recall i n this respect that even if we were to deny the United States' request, the United States 
could still exercise its right to disclose statements of its own positions in a different form or on a different 
occasion.  
39 Mexico refers to Appellate Body Report, EU – Biodiesel (Argentina) , Annex D -2 (procedural ruling of 
11 July 2016).  
40 Appellate Body Report, EU – Biodiesel (Argentina) , Annex D -2, paras. 2 and 3.  
41 We emphasize that we are not suggesting that a fully open meeting could be conducted in the 
absence of an agreement between the parties. Nor is this the position of the United States in this dispute. 
Indeed, the United States initially sought Mexico's agreement to conduct a fully open panel  meeting. When 
Mexico expressed its opposition, the United States  did not pursue its proposal. The United States proceeded 
instead to request that we allow the United States to disclose statements of its own positions at our meeting.  
42 Appellate Body Report,  US – Continued Suspension , Annex IV, para. 6.  
43 Appellate Body  Report,  US – Continued Suspension , Annex IV, paras. 1 and 11.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  another party objects to the granting of such an opportunity . Put another way, when it comes to 
authorizing the lifting of confidentiality protection for their statements, we consider that we should 
treat parties no less favourably than third parties.  
7.21.   Mexico has also referred to Article 14.1 of the DSU and Paragraph 3 of Appendix 3 of the 
DSU, which provide that panel "deliberations" are to be confidential. We do not agree that the se 
provisions  imply that  we cannot  authorize  the United States to lift the confidentiality of its 
statements. These provisions relate to a panel's internal work, not the meetings with the parties 
and third parties.44 Moreover, just like the Appellate Body, panels have authorized third parti es 
that so wished to lift the confidentiality of their statements even as some third parties objected.45 
This approach necessarily assumes that Article 14.1 does not prescribe closed panel meetings with 
parties or third parties.  
7.22.   In our view, the confidentia lity of panel meetings is covered by Paragraph 2 of Appendix 3  
of the DSU , which says that panels shall meet in closed session. However, this paragraph forms 
part of those provisions from which panels may depart pursuant to Article 12.1 of the DSU, after 
consulting the parties and provided that such departure is not contrary to another provision of the 
DSU.46 In any event, Paragraph 2 in our view does not preclude a party or third party from 
foregoing confidentiality protection for its statements at a  panel  meeting, provided that another 
party  (hereafter a "non -disclosing party")  or other third parties  (hereafter "non -disclosing third 
parties")  can maintain confidentiality protection for their statements. Indeed, as already explained, 
this is the approach fol lowed by those panels that held partially open third party sessions. We 
consider that Paragraph 2 permits the same approach in the present proceedings with regard to 
the parties.  
7.23.   In the light of the foregoing, we consider that in principle we have the powe r to authorize 
the United States to disclose statements of its own positions (but not those of Mexico  or a non -
disclosing third party ) to the public through a partially open panel  meeting, even if Mexico opposes 
the United States' request. However, it does  not follow that we must automatically grant the 
United States' request. We thus proceed to provide  the main considerations that underpin our 
decision to grant the United States' request in the  particular circumstances of the se proceedings.  
7.24.   Although the Un ited States has an autonomous right to disclose statements of its own 
positions to the public, that right is not absolute. In the context of this dispute, it notably finds its 
limitation in Mexico's right not to have statements of its own positions disclos ed by the United 
States during any public parts of the Panels ' consolidated meeting.47 Mexico indicated in this 
regard that it wished to maintain the confidentiality of its own positions and information submitted 
to the Panels . It is therefore necessary to provide for a review process prior to  any public viewing 
of a partially open meeting, to allow the Panels  and the parties to ensure that any statements 
disclosed by the United States do not inadvertently disclose, directly or indirectly, statements of 
Mexico's positions. It follows that we may authorize the United States to disclose in a partially 
open meeting only those parts of its statements that do not disclose statements of Mexico's 
positions, and that we must therefore reserve the right to appropriate ly redact the statements that 
the United States wishes to be open for public observation.48 
7.25.   For the same reason, we  consider that we  may authorize the United States to disclose in a 
partially open meeting only those parts of its statements that do not discl ose statements of non -
disclosing third parties . Likewise, we  consider that we  may authorize disclosing third parties to 
disclose in a partially open third party session only those parts of their statements that do not 
disclose statements of Mexico or non -disclosing third parties . Consequently, we must also reserve 
the right to  redact  (i) the statements of the United States to ensure that they do not disclose , 
                                                
44 We note that in US – Continued Suspension , the Appellate Body used the term "deliberations" in the 
same sense, in relation to the internal work of the Appellate Body. Appellate Body Report,  US – Continued 
Suspension , Annex IV, para. 8. See also Panel Report, US – Continued Suspension , para. 7.49.  
45 See, for instance, US – Tax Incentives , para. 1.20; Canada — Feed-In Tariff Program/Canada – 
Renewable Energy , para. 1.9; US – COOL (Article 21.5 – Canada and Mexico) , para. 1.10; US – Continued 
Zeroing , para. 1.9.  
46 Panel Report, US – Continued Suspension , paras. 7.46 -7.47. 
47 Consistent with para . 1.1(e) of our Additional Working Procedures  on Partially Open Meetings  (Annex 
A-4), we use the term "po sitions" in this Section of our Findings  to encompass also the exhibits submitted and 
the arguments put forward by a party.  
48 We note that this type of redaction is already routinely u sed in open meetings whenever the 
statements made by the parties or thi rd parties address BCI.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  directly or indirectly, statements of non-disclosing third parties' positions , and (ii) the stateme nts 
of disclosing third parties to ensure that they do not disclose, directly or indirectly, statements of 
Mexico's or non-disclosing third parties' positions.  
7.26.   A further limitation arises from the requirements of due process. These requirements mean , 
inter alia, that all parties must be given the opportunity to lift the confidentiality of statements of 
their own positions at partially open meetings. In these proceedings, Mexico chose not to avail 
itself of that opportunity. Further, these requirements mean that the implementation of any 
additional working procedures for partially open meetings, including the associated redaction 
process, must not impair the ability of any party that opposes partially open meetings to present 
its case or defence effectively . 
7.27.   We note, in addition, Mexico's argument that if a partially open meeting is conducted, 
viewers will by definition be exposed to only one party's statements. In our view, however, this 
does not compromise due process. First, a party that does not wish its s tatements at a WTO 
adjudicator's meeting to be open for public observation is not thereby deprived of the possibility to 
otherwise disclose statements of its positions to the public. More importantly, Article 18.2 already 
allows each party to disclose stat ements of its own positions to the public independently of 
whether another party does the same. A partially open meeting thus does not create a new 
situation. The media, for instance, can (and does) already report to the public based on 
statements of only one party's positions where only that party has made available its statements 
on its government's website. Finally, we recall that in disputes where the meetings with the parties 
were opened for public observation, both the Appellate Body and panels have a uthorized third 
parties that so wished to lift the confidentiality of their statements at the relevant hearing or third -
party session. Under this practice, it is accepted that viewers of those meetings are exposed to the 
views of only some third parties, e ven though the Appellate Body and panels are required to take 
all third parties' views into account.49 
7.28.   Another factor that in our view should be taken into account when assessing a request for a 
partially open meeting is the importance, articulated in Artic le 3.3 of the DSU, of the prompt 
settlement of disputes. This suggests to us that the conduct of a partially open meeting should not 
significantly delay a WTO adjudicator's proceedings. In our view, one way to fulfil this objective is 
to devise additional working procedures governing partially open meetings that put appropriate 
emphasis on workability and efficiency.  
7.29.   In addition, we must bear in mind our primary duty, which is to carefully assess the matter 
before us and resolve the dispute between the part ies. Partially open meetings impose a greater 
burden on a WTO adjudicator than fully open meetings, owing to the need to make sure that there 
is no disclosure of statements of any party that wishes to maintain the confidentiality of its 
statements. In deci ding whether to authorize a request for a partially open meeting, it therefore 
appears appropriate that a WTO adjudicator assess at the outset whether it has access to the 
requisite resources, in technical, logistical and human terms, to conduct a partiall y open meeting 
and any associated redaction process. Otherwise, the conduct of a partially open meeting could 
potentially have an adverse impact on the proper discharge of the adjudicative function and could 
thus also be detrimental to due process or the p rompt settlement of disputes.  
7.30.   We note, finally, the Appellate Body's view that any authorization to forego the 
confidentiality protection for statements of a party's or third party's positions  must not undermine 
the integrity of the adjudicative function. The Appellate Body has already clarified in this regard 
that the mere fact of permitting public observation of a meeting does not have an adverse impact 
on the integrity of the adjudicative function.50 
7.31.   In sum, it is in our view permissible for a WTO adjudic ator to authorize a request for a 
partially open meeting if the conduct of such a meeting does  not impair or interfere with (a ) a non -
disclosing party's  or non-disclosing  third party's  right to confidentiality protection of sta tements of 
its own position, (b) due process, (c ) the promp t settlement of disputes, or (d ) the careful and 
efficient discharge, or the integrity, of the adjudicative function. Beyond that, we consider that it 
falls within the sound discretion of each WTO adjudicator considering a req uest for a partially open 
meeting to decide whether it is appropriate in the particular circumstances of its case to accede to 
                                                
49 See, for instance, Article 10.1 of the DSU.  
50 Appellate Body Report, US – Continued Suspension , Annex IV, paras. 7 and 10.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  that request.51 We observe in this respect that the rejection of such a request by a WTO 
adjudicator would not in and of itself de prive the requesting party of its right to disclose 
statements of its own positions to the public, since it would still have available to it other ways of 
exercising that right.  
7.32.   Guided by the foregoing considerations, in the present proceedings we devised additional 
working procedures in consultation with the parties that we think fully protect Mexico's and non -
disclosing third parties'  right to confidentiality protection, satisfy the requirements of due process , 
and are sufficiently workable and efficient to safeguard the promptness of dispute settlement and 
the proper discharge and integrity of our adjudicative function.52 
7.33.   In granting the United States' request we notably also t ake into account the following four 
circumstances. First, the present dispute co ncerns the protection of dolphins and thus a 
conservation -related measure. In this kind of dispute, even a partially open meeting is apt to 
enhance understanding of, and confidence in, the WTO dispute settlement process.53 Second, 
there was in these proceed ings only one relatively short  and consolidated  substantive meeting with 
the Panels  that was requested to be partially opened for public observation. Third, the parallel 
conduct of a n arbitration under Article 22.6 of the DSU  in this dispute required the a ssembly of a 
substantial Secretariat support team. We were thus in a position where we could conduct a 
partially open meeting and carry out the associated redaction process without this compromising 
our substantive work.  Finally, in granting the United Sta tes' request, we also seek to ensure 
consistency, since the arbitrator in this dispute has already authorized an identical request by the 
United States.  
7.34.   On the basis of these considerations, we therefore conclude that in the particular 
circumstances of these compliance panel proceedings  it is, on balance, appropriate for us to accept 
the United States' request that it be permitted to disclose through public viewing the statements of 
its own positions made during the Panels ' meeting.  We likewise permit any t hird parties that so 
request to disclose through public viewing the statements of their own positions made during the 
Panels ' third party session.54 Our authorization s are subject to the dual condition that the public 
viewing take the form of delayed (rathe r than simultaneous) viewing, and that any parts of the 
meeting , including the third party session , opened for  partial  public observation not disclose 
statements of Mexico's positions , or positions of non -disclosing third parties,  and hence be subject 
to redaction  prior to the public viewing  as necessary.  
7.3  Preliminary Issue: United States' failure to request consultations  
7.35.   In its first written submission, Mexico argues that the United States did not request to hold 
consultations with Mexico in relation to the  Article 21.5 proceedings it initiated, and thereby 
violated its obligations under Articles 4, 6, and 21.5 of the DSU. According to Mexico, as a legal 
matter, consultations must be held in Article 21.5 proceedings unless explicitly agreed otherwise in 
a sequencing agreement between the disputing parties. In Mexico's view, in normal circumstances, 
the United States' failure to request consultations prior to requesting the establishment of a panel 
under Article 21.5 would undermine the jurisdiction of the pan el established pursuant to that 
request. However, given the specific circumstances of these proceedings, wherein the subject 
matters of the two proceedings substantially overlap and consultations were held in the 
proceedings brought by Mexico55, Mexico does  not challenge the jurisdiction of the Panel 
established pursuant to the request of the United States. Mexico does, however, request that the 
Panels set forth guidance for future cases, especially as to whether, in the absence of an 
agreement with the othe r party, a Member may initiate Article 21.5 proceedings without first 
                                                
51 See Appellate Body Report, EC – Hormones , para. 154.  
52 See the Panels' A dditional Working Procedures  on Partially Open Meetings (Annex A-4), in particular 
paras 3.5, 3.10-3.20, 4.5, and 4.10 -4.19.  
53 The United States indicated that it was pursuing these objectives in requesting the opening of our 
meeting. We also note in this connection that in our Additiona l Working Procedures  on Partially Open Meetings 
(Annex A -4), at paras. 3.11 and 4.11, we have sought to avoid unnecessary discontinuity in the delayed 
viewing by inviting  the United States  and disclosing third parties to structure their statements in such a way as 
to separate those statements that disclose statements of positions of Mexico  or non -disclosing third parties 
from those that do not .  
54 As indicated at para. 1.19, seven  third parties sought and were gi ven permission to disclose 
statements of their own positions during the Panels' third party session (Australia, Canada, the European 
Union, Japan, Korea, Norway, and New Zealand).  
55 See WT/DS381/36 and WT/DS381/36/Corr.1.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  requesting consultations. In Mexico's view, there is nothing in the DSU or in the jurisprudence that 
prevents the Panel s from providing the requested guidance on this important systemic issue.56 
7.36.   In response to Mexico's request for guidance, the United States submits that the Panels 
should not issue the guidance requested by Mexico given that there is no live controversy behind 
Mexico's request. In the view of the United States, the guidanc e requested by Mexico would 
amount to an advisory opinion that would not contribute to resolving the dispute and would 
therefore be outside the mandate of the Panels. Moreover, the United States argues that there is 
in fact no requirement to request consul tations under Article 4 of the DSU as a condition for 
requesting the establishment of a compliance panel pursuant to Article 21.5 of the DSU. According 
to the United States, the Appellate Body has already confirmed this point. Further, in the view of 
the U nited States, Article 4 of the DSU is, according to its own terms, inapplicable in situations 
where the original responding party initiates Article 21.5 proceedings.57 
7.37.   The Panels begin by observing that, as Mexico acknowledges, consultations were held 
betwe en the parties in the context of the compliance proceedings brought by Mexico. As we have 
already noted, those proceedings are closely connected to the proceedings brought by the United 
States, in the context of which Mexico alleges that the United States failed to request to hold 
consultations. The consultations held in the context of the proceedings brought by Mexico would 
certainly have enabled the parties to "exchange information, assess the strengths and weaknesses 
of their respective cases, [and] narr ow the scope of the differences between them"58 with respect 
to both the proceedings brought by Mexico and those brought by the United States. Indeed, 
Mexico also acknowledges that "in the circumstances of this dispute the holding of consultations in 
the pa rallel proceeding mitigates the failure of the United States to consult[.]"59 We do not see, 
therefore, that the United States' failure to consult could, in the specific circumstances of these 
proceedings, have had any practical effect on the parties' abili ty to understand, prepare for, or 
even narrow their dispute.  
7.38.   Moreover, we note that in Mexico – Corn Syrup , the Appellate Body declined to decide 
whether the general obligations in the DSU regarding prior consultations were applicable in 
proceedings under Article 21.5 of the DSU. The Appellate Body nevertheless held that, even if  
those obligations were applicable, non-compliance therewith – that is, failure to engage in 
consultations - would not deprive  a panel  of its authority to deal with and dispose of a dispute 
before it .60 Accordingly, we do not agree with Mexico that in normal circumstances, failure to 
request consultations would vitiate the jurisdiction of a panel established pursuant to Article 21.5 
of the DSU. Consequently, in the specific context of  these proceedings, even if the United States 
were required to have requested consultations prior to requesting the establishment of a panel 
under Article 21.5 of the DSU, its failure to do so would not negate our jurisdiction. Therefore, we 
do not conside r that the "guidance" Mexico requests would have any legal implications in the 
present circumstances (even if Mexico were challenging the jurisdiction of the Panel established at 
the request of the United States, which, as we noted above, it is not). In ou r view, therefore, the 
United States' characterization of Mexico's request for guidance as a request for an "advisory 
opinion" appears to be accurate.  
7.39.   In this respect, we are mindful that no provision of the DSU explicitly gives panels the 
power to issue a dvisory opinions or, indeed, to make any findings other than those required to 
resolve the dispute before them. Indeed, a number of provisions of the DSU suggest that panels 
should not make findings in respect of issues that are not in dispute.61 For exampl e, Article 3.7 of 
the DSU provides that the "aim of the dispute settlement mechanism is to secure a positive 
solution to a dispute". Similarly, Article 3.4 of the DSU stipulates that "[r]ecommendations or 
rulings made by the DSB shall be aimed at achieving  a satisfactory settlement of the matter in 
accordance with the rights and obligations under this Understanding and under the covered 
agreements". Additionally, Article 7.1 of the DSU charges panels with making  "such findings as will 
assist the DSB in maki ng the recommendations or in giving the rulings provided for in that/those 
                                                
56 Mexico's first written submissio n, paras. 25 -29; response to Panels' question No. 74, para. 81.  
57 United States' second written submission, paras. 8 -10; comments on Mexico's response to Panels' 
question No. 74, para. 86.  
58 Appellate Body Report, Mexico – Corn Syrup (Article 21.5 – US), para. 54.  
59 Mexico's response to Panels' question No. 74.  
60 Appellate Body Report, Mexico – Corn Syrup (Article 21.5 – US), para. 65.  
61 See Appellate Body Report, US – Wool Shirts and Blouses , p. 19.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  agreement(s) ". In our view, these provisions make clear that the purpose of the dispute 
settlement system is to resolve disputes between Members.  
7.40.   This understanding of the scope of WTO dispute settlement has been confirmed by the 
Appellate Body. In US – Wool Shirts and Blouses , after noting that Article 3.2 of the DSU indicates 
that one of the functions of dispute settlement is to "clarify the existing provisions of [the covered] 
agreements in accordance with customary rules of interpretation of public international law", the 
Appellate Body explained that this provision is not meant "to encourage either panels or the 
Appellate Body to 'make law' by clarifying existing provisions of th e WTO Agreement outside the  
context of resolving a particular dispute. A panel need only address those claims which must be 
addressed in order to resolve the matter in issue in the dispute".62 This statement indicates that 
panels are generally not required or, indeed, empowered to engage with issues that are not in 
dispute between the parties and whose resolution would accordingly not contribute to the "prompt 
settlement"63 of disputes.  
7.41.   In our view, given that Mexico has indicated that it is not challenging t he jurisdiction of the 
Panel established pursuant to the United States' request, and given the Appellate Body's 
clarification that failure to consult would not in any event deprive a panel established pursuant to 
Article 21.5 of the DSU of its authority, t he question on which Mexico seeks "guidance", that is, 
whether in the absence of agreement with the other party a Member is allowed to initiate an 
Article 21.5 compliance proceeding without requesting consultations, is not one which must be 
addressed in or der to resolve the matter before us . Accordingly, we decline to set forth the 
guidance requested by Mexico.  
7.4  The measure at issue  
7.4.1   Elements of the measure at issue  
7.42.   The Panels now turn to describe in more detail the measure at issue in these proceedings. 
In this context, we will first identify the elements that constitute the measure at issue, and then 
proceed to describe them as relevant for the purposes of these proceedings.  
7.43.   We recall that in the original and the first compliance proceedings, the Tuna Measur e was 
described as consisting of three elements, namely, (a) the DPCIA; (b) the relevant implementing 
regulations; and (c) the Hogarth ruling.64 In the  present  proceedings, the United States' 
description of the 2016 Tuna Measure refers to the same three ele ments.65 The only difference  
between the Tuna Measure as described in the original and first compliance proceedings and as 
described by the United States in the present proceedings  is that  in these proceedings  the United 
States' reference to the implementin g regulations includes the amendments made by the 2016 
Rule.66 Mexico's description of the components of the Measure, however, is less clear. Although in 
certain parts of its submissions, Mexico, like the United States, refers to the 2016 Tuna Measure as 
comprising the same three elements mentioned above67, in other parts of its submissions, Mexico 
refers,  in addition to th ose three elements , to two additional elements. First, i n its panel request in 
these proceedings, Mexico refers, to "[a]ny implementing gu idance, directives, policy 
announcements or any other document issued in relation to instruments [(a)] through [(c)] above, 
including any modifications or amendments in relation to those instruments".68 Second, in certain 
parts of its submissions, Mexico re fers to the alleged action of the United States in pressuring US 
retailers not to distribute Mexican tuna products .69 
7.44.   With respect to the first additional element cited in Mexico's panel request, that is, "[a] ny 
implementing guidance, directives, policy ann ouncements or any other document issued in relation 
to instruments [(a)] through [(c)] above, including any modifications or amendments in relation to 
                                                
62 Appellate Body Report, US – Wool Shirts and Blouses , p. 19. 
63 Article 3.3 of the DSU.  
64 Panel Report, US – Tuna II (Mexico) , para. 2.1; Appellate Body Report, US – Tuna II (Mexico) , para. 
172; Panel Report , US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 3.1; Appellate Body Report, US – Tuna 
II (Mexico) ( Article 21.5 – Mexico) , para s. 6.7-6.8. 
65 United States' first written submission, para. 19 . 
66 United States' first written submission, para s. 22-29. 
67 Mexico's first written submission, para. 118.  
68 WT/DS381/38, p. 2. See also Mexico's first written submi ssion, para. 2.  
69 Mexico's first written submission, para. 149.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  those instruments ", we note that Mexico does not argue that, as a measure taken to comply with 
DSB recomm endations and rulings within the meaning of Article 21.5 of the DSU, the 2016 Tuna 
Measure includes, in addition to the three elements cited above, "[a] ny implementing guidance, 
directives, policy announcements or any other document issued in relation to i nstruments [(a)] 
through [(c)] above, including any modifications or amendments in relation to those instruments " 
that the Panels would need to take into account in their analysis in these proceedings. Neither has 
Mexico presented any evidence of such dire ctives, announcements, modifications or amendments 
to the Panels. As such, Mexico's description refers to this additional element in the abstract, 
without arguing that in fact there exists such an element which is subsumed within the definition 
of the meas ure taken to comply subject to these proceedings. Further, the claims and arguments 
that Mexico has presented in these proceedings do not in any way pertain to this alleged additional 
element of the 2016 Tuna Measure.  
7.45.   With regard to the  second additional e lement, namely, the  alleged action of the United 
States in pressuring US retailers not to distribute Mexican tuna products, we note, first, that, 
unlike the fourth element discussed above, this element is not included in the description of the 
measure at i ssue in Mexico's panel request. We also note that it is not clear whether Mexico is 
arguing that this element is, in the jurisdictional sense, part of the measure taken to comply in 
these proceedings. In response to a question from the Panels concerning wh ether Mexico was 
seeking separate findings from the Panels in respect of this alleged element of the Measure, 
Mexico stated that it was not.70 Rather, Mexico explain s that "[t]he action of the United States in 
pressuring retailers not to distribute Mexican tuna products is itself a measure implemented under 
and in relation to the 2016 tuna measure with the specific intent to impede the marketing of 
Mexican tuna products in the US market".71 Although this argument suggests that Mexico sees this 
element as a me asure, or as a part of the 2016 Tuna Measure, in the same response, Mexico also 
argue s that these letters constitute additional evidence of the detrimental effect of the 2016 Tuna 
Measure. However, Mexico also state s that since the United States acknowledg es that the 2016 
Tuna Measure has a detrimental effect on Mexican tuna products, "it is not necessary for the 
Panels to consider this evidence to rule on the issues before them".72 For its part, at the Panels' 
joint substantive meeting with the parties, the United States argue d that this alleged additional 
element falls outside the Panels' terms of reference. Moreover, the United States  disagrees with 
Mexico's allegation that the US government has pressured US retailers no t to sell Mexican 
products. The Unit ed States indicates that it invited US retailers to submit statements to be used 
in the context of the arbitration proceedings under Article 22.6 of the DSU in this dispute.73 We 
note that the statements cited by Mexico were submitted to, and taken into acc ount by, the 
Arbitrator in the mentioned arbitration proceedings.74 As Mexico also acknowledges, none of the 
claims or arguments presented by Mexico in these compliance proceedings in any way pertain to 
this alleged additional element of the  2016 Tuna Measu re.75 Mexico has not explained how this 
alleged additional element interacts with the other elements of the 2016 Tuna Measure, and 
neither has it advanced any arguments concerning whether the alleged additional element stems 
exclusively from a legitimate re gulatory distinction.  
7.46.   We recall that  this second additional element of the 2016 Tuna Measure is not included in 
Mexico's panel request . We also note that Mexico did not respond to the United States' argument 
that this alleged additional element is not with in the Panels' terms of reference . In the light of  
Mexico's own statement that the Panels need not consider this aspect of Mexico's claim in the light 
of the United States' concession that the 2016 Tuna Measure has a detrimental impact on Mexican 
tuna prod ucts, it would , in our view , at any rate  be unnecessary to deal with this alleged additional 
element of the Measure in order to fulfil our functions under the DSU.  
7.47.   On the basis of the foregoing, we will  assess parties' claims and arguments in relation to t he 
2016 Tuna Measure defined as consisting of (a) the DPCIA, (b) the relevant implementing 
regulations; and (c) the Hogarth ruling, which are the three elements of the Measure  on which 
both parties agree, and to which both parties' claims and arguments per tain. We now turn to a 
detailed description of each of these three elements.  
                                                
70 Mexico's response to Panels' question No. 72.  
71 Mexico's response to Panels' question No. 72.  
72 Mexico's response to Panels' question No. 72.  
73 United States' response to Panels' question No . 32. 
74 Decision of the Arbitrator, US – Tuna II (Mexico) (Article 22.6 – US), paras.  5.73 - 5.85. 
75 Mexico's response to Panels' question No. 72, para. 74.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.4.2   Description of the measure at issue  
7.48.   As noted above, the 2016 Tuna Measure consists of (a) the DPCIA, (b) the implementing 
regulations as amended by the 2016 Rule, and (c) the Hogarth ruling. The panels and the 
Appellate Body in previous stages of this dispute have described the original and the 2013 Tuna 
Measure in detail.76 In this section, the Panels describe the 2016 Tuna Measure only insofar as 
relevant for the purposes of resol ving the claims raised in the present proceedings.  
7.49.   The 2016 Tuna Measure, like the previous versions of the Tuna Measure, pursues two 
objectives: first, to ensure  that consumers are not misled or deceived about whether tuna 
products contain tuna that was c aught in a manner that adversely affects dolphins ; and, second,  
to contribute  to the protection of dolphins, by ensuring that the US  market is not used to 
encourage fishing fleets to catch tuna in a manner that adversely affects dolphins .77 To this end, it 
conditions the use on a tuna product78 of a dolphin -safe label upon certain requirements that vary 
depending on the fishing method by which tuna contained in the tuna product was harvested, the 
ocean area where it was caught, and the type of vessel used. Th e Measure also prohibits any 
reference to dolphins, porpoises, or marine mammals on the label of a tuna product if the tuna 
contained in that product does not comply with the labelling conditions provided for in the 
measure.79 
7.50.   The 2016 Tuna M easure sets out  several substantive conditions for access to a dolphin -safe 
label. First, it disqualifies from being labelled all tuna products containing tuna harvested by two 
methods of fishing: (i) large -scale driftnet fishing on the high seas80; and (ii) vessels using  purse 
seine nets to encircle or "set on" dolphins anywhere in the world81. Although the DPCIA's 
disqualification of tuna products derived from tuna caught by setting on dolphins was suspended in 
2002 by virt ue of administrative action82, the Hogarth ruling overturned that action shortly 
thereafter83, thereby restoring this condition of access to the US dolphin -safe labelling regime. The 
disqualification of tuna products containing tuna caught by setting on dolphins thus formed part of, 
and is unchanged as com pared to, both the original  and the 2013 Tuna M easure. Second, all other 
tuna products, that is, those containing tuna harvested by all other fishing methods, are  
potentially  eligible for the dolphin -safe label, but become ineligible if they contain tuna c aught in a 
                                                
76 Panel Report, US – Tuna II (Mexico) , paras. 2.1 -2.33; Appellate Body Report, US – Tuna II (Mexico ), 
paras. 172 -177; Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , paras. 3.1 -3.52; Appellate Body 
Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , paras. 6.7 -6.34. 
77 Appellate Body Report, US – Tuna II  (Mexico)  (Article 21.5 – Mexico) , para. 7.16;  Panel Report,  US – 
Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.525; Appellate Body Report,  US – Tuna II (Mexico) , para. 
325; Panel Report,  US – Tuna II (Mexico) , paras.  7.401, 7.413, and 7.425.  
78 The DPCIA defines "tuna product" in Sectio n 1385(c)(5) as a "food item which contains tuna and 
which has been processed for retail sale, except perishable sandwiches, salads, or other products with a shelf 
life of less than 3 days". In addition, for purposes of 50  CFR Section 216, "tuna product" m eans "any food 
product processed for retail sale and intended for human or animal consumption" containing one of the species 
of tuna listed in 50 CFR Section s 216.24(f)(2)(i) and (ii), and not including "perishable items with a shelf life of 
less than 3 da ys", (Exhibits MEX -02 and USA -02). Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – 
Mexico) , fn. 101 (citing Panel Report, US – Tuna II (Mexico) , paras. 7.60 -7.61).  
79 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 6.8. 
80 DPCIA, 16 USC Section 1385(d)(1)(A) , (Exhibit USA-1), 50 CFR Section 216.91(a)(2) , (Exhibit s USA-
02, MEX -02); see also  Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 6.9.  
81 50 CFR Section s 216.91(a)(1)(iii), (a)(3)(i) and  (a)(3)(ii)(A) , (Exhibit s USA-02, MEX -02). See also  
Appellate  Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 6.9.  
82 According to Section 1385(h) of the DPCIA, the type of certification required for tuna products 
containing tuna harvested  by large purse sein e vessels in the ETP was subject to a finding by the US Secretary 
of Commerce on whether the intentional deployment on or encirclement of dolphins with purse sein e nets was 
having a significant adverse impact on any depleted dolphin sto ck in the ETP. The US Secretary of Commerce 
initially found that setting on dolphins was not having a significant adverse effect on any depleted dolphin stock 
in the ETP. The effect of this finding was that tuna products containing tuna caught by setting o n dolphins 
could be labelled dolphin -safe provided that the other conditions for access to the label were satisfied . Panel 
Report, US – Tuna II (Mexico) , para. 2.18; Appellate Body Report, US – Tuna II (Mexico) , para. 176. 
83 The finding of the US Secretary  of Commerce was overruled in Earth Island Institute v. Evans , on the 
basis that the Secretary failed to conduct statutorily -mandated studies and that the best available scientific 
evidence did not support the Secretary's finding. The ruling was affirmed o n appeal in the Hogarth  ruling. As a 
result, Section 1385(h) requires that tuna products derived from tuna harvested by large purse sein e vessels in 
the ETP may be labelled dolphin -safe only if the captain and an AIDCP -approved  observer certify both that 
there was "no setting on dolphins" and that there were "no dolphins killed or seriously injured" . Panel Report, 
US – Tuna II (Mexico) , paras. 2.15 -2.20; Appellate Body Report, US – Tuna II (Mexico) , paras. 175 -176).  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  set or other gear deployment during which a dolphin was killed or seriously injured.84 The 2016 
Tuna Measure also prescribes a number of certification and tracking and verification requirements 
relating to the substantive conditions.  
7.51.   With respect  to certification , the 2016 Tuna Measure provides that, for a tuna product to be 
labelled dolphin -safe, it must be accompanied by certain certifications that the eligibility 
requirements were met. Under 50 CFR Section 216.91(a)(3), for fishing trips that b egan on or 
after 21 May 2016, captains85 of all vessels in all fisheries other than the large purse seine86 
fishery in the Eastern Tropical Pacific Ocean (ETP)87 and a large -scale driftnet fishery88 must 
certify, that:  
No purse seine net or other fishing gear was intentionally deployed on or used to 
encircle dolphins during the fishing trip in which the tuna were caught, and that no 
dolphins were killed or seriously injured in the sets or other gear deployments in 
which the tuna were caught.89 
7.52.   In these fisheries , certification by an independent observer may also be required, under 
certain circumstances described below.90 
7.53.   Additionally, under the 2016 Tuna Measure, captains of vessels operating outside the ETP 
large purse seine fishery (and high seas driftnet fisher ies) must certify, in addition to the above, 
that they have completed the National Marine Fisheries Service (NMFS) Tuna Tracking and 
Verification Program (TTVP) dolphin -safe training course (the Captain Training Course).91 The 
course, which can be accessed on the Internet in English, Mandarin Chinese, Indonesian, 
Japanese, Korean, Spanish, Tagalog, Thai, and Vietnamese, covers four main topics: identifying 
dolphins of the taxonomic family Delphinidae ; identifying intentional gear deployment on or 
encirclemen t of dolphins; identifying dolphin mortality and serious injury; and physically 
separating dolphin -safe tuna from non -dolphin -safe tuna from the time of capture through 
unloading.92 The contents of the Captain Training Course are discussed further below.93 
7.54.   For large purse seine vessels in the ETP, certification is required from both the vessel 
captain and an International Dolphin Conservation Program (IDCP) -approved observer94 that (a) 
no dolphins were killed or seriously injured during the sets in which the t una was caught, and (b) 
none of the tuna was caught on a trip using a purse seine net intentionally on or to encircle 
dolphins.95 
7.55.   With respect to tracking and verification , tuna products are eligible to receive a dolphin -safe 
label only if they meet the tra cking and verification requirements provided for in the 2016 Tuna 
Measure.  
7.56.   The 2016 Tuna Measure, like the 2013 Tuna Measure, requires that dolphin -safe and non -
dolphin -safe tuna, wherever and however caught, be segregated from the moment of catch 
through the entire processing chain.96 However, the requirements pursuant to which tuna must be 
                                                
84 See 50 CFR Sections 216.91(a)(1)(ii), ( a)(3)(ii)(A) -(B), (a)(3)(iii)(A) , (Exhibit s USA-02, MEX -02); 
Appellate Body Report, US – Tuna II  (Mexico)  (Article 21.5 – Mexico) , para. 6.9.   
85 50 CFR Section 216.91(a)(3)(A), (Exhibits USA -02, MEX -02). 
86 Large purse sein e vessels are defined as vessels with a carrying capacity greater than 400 st (362.8 
mt). 50 CFR Section 216.91(a), (Exhibits USA -02, MEX -02). 
87 Pursuant to Section 1385(c)(2) of the DPCIA, the Eastern Tropical Pacific Ocean  means "the area of 
the Pacific Ocean  bounded by 40 degrees north  latitude, 40 degrees  south latitude, 160 degrees west 
longitude,  and the western coastlines of North,  Central, and South America".  
88 In the 2016 Tuna Measure, these fisheries are combined in the category "Other fisheries". 50 CFR 
216.91(a)(3), (Exhibits U SA-02, MEX -02). 
89 Under the 2013 Tuna Measure, captains were only required to certify that no dolphins were killed or 
seriously injured in the gear deployment(s) in which the tuna was caught. Appellate Body Report, US – Tuna II 
(Mexico) (Article 21.5 – Mexico), para. 6.10. 
90 See paras. 7.67to 7.69below.  
91 50 CFR Section 216.91(a)(3)(iii)(B), (Exhibits USA -02, MEX -02). 
92 See NOAA, Dolphin -Safe Captain 's Training Course  (March  23, 2016) , (Exhibits USA -10, MEX -56). 
93 See paras . 7.585  to 7.588  below.  
94 50 CFR Section 216.92(b)(2)(iii), (Exhibits USA -02, MEX -02). 
95 50 CFR Section 216.91(a)(1), (Exhibits USA -02, MEX -02). 
96 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 6.12; 50 CFR Section 
216.92(c)(1) -(3), (Exhibit s USA-02, MEX -02). WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  segregated, tracked, and verified differ as between tuna caught in the ETP large purse seine 
fishery, on the one hand, and other fisheries, on the other hand. This is be cause the tracking and 
verification of tuna caught in the ETP large purse seine fishery must be conducted consistently with 
the Agreement on the International Dolphin Conservation Program (AIDCP) Resolution to Adopt 
the Modified System for Tracking and Ver ification of Tuna (AIDCP Tracking and Verification 
System).97 However, the tracking and verification of tuna caught in other fisheries must be 
conducted according to different regulations established principally  in the implementing 
regulations . 
7.57.   The AIDCP Tr acking and Verification System is based on the use of Tuna Tracking Forms 
(TTFs). Every TTF has a unique number. On every fishing trip, ETP large purse seine vessels must 
maintain two forms, one to record tuna harvested in dolphin -safe sets, and one to rec ord tuna 
harvested in non -dolphin -safe sets.98 Under the AIDCP, the determination of the dolphin -safe 
status of tuna is made at the end of each set.99 The IDCP-approved observer and the vessel 
engineer are required to initial each entry following each set.100 Once the tuna harvested  in a 
particular set is on board the fishing vessel, it is loaded into wells designated as either dolphin -safe 
or non -dolphin -safe, and recorded on the trip TTF.101 Tuna from one set can be loaded into a well 
containing tuna from anoth er set and tuna from one set can be loaded into multiple wells, provided 
that the designations are correct (that is, that tuna harvested in dolphin -safe sets is stored only in 
wells designated as dolphin -safe, and tuna harvested in non -dolphin -safe sets is  stored only in 
wells designated as non -dolphin -safe).102 At the end of each fishing trip, the IDCP -observer and 
the captain of the fishing vessel sign both TTFs to certify that the information on the forms is 
accurate.103 Trans -shipments of tuna (i.e. transfe r of tuna at sea before completion of the fishing 
trip) are permitted, but must be documented on the TTFs of both the transferring and the 
receiving vessels.104 
7.58.   When tuna is unloaded at port, dolphin -safe and non -dolphin safe tuna must be unloaded 
into separ ate bins, and each bin must be identified with the corresponding TTF number. The AIDCP 
Tracking and Verification System does not prohibit tuna stored in different wells on -board the 
vessel from being comingled in individual bins, or tuna stored in the same  well on -board the vessel 
from being separated into different bins. The only requirement is that dolphin -safe and non -
dolphin -safe tuna be stored in separate bins.105 
7.59.   At the time of unloading, the relevant TTF must be transmitted to the competent authority 
of an AIDCP party.106 The relevant TTF number must then accompany the tuna through sales of 
portions of the catch, and through every step of processing of those portions.107 The relevant 
national authority must report any subsequent transfer of ownership to the  AIDCP Secretariat, 
specifying,  inter alia , the TTF number(s).108 During storage and processing, dolphin -safe and non -
dolphin -safe tuna cannot be processed on the same lines at the same time, and processors must 
maintain records complete enough to allow the lot numbers of processed tuna to be traced back to 
                                                
97 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 6.12. 
98 International Dolphin Conservation Program, System for Tracking and Verifying Tuna, as amended 
(2015) , Section 3(2), (Exhibit USA -90); Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , 
para. 6.19.  
99 International Dolphin Conservation Program, System for Tracking and Verifying Tuna, as amend ed 
(2015) , Section 4(1), (Exhibit USA -90). 
100 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 6.19. 
101 International Dolphin Conservation Program, System for Tracking and Verifying Tuna, as amended 
(2015) , Section 4(3), (Exhibit U SA-90). 
102 International Dolphin Conservation Program, System for Tracking and Verifying Tuna, as amended 
(2015) , (Exhibit USA -90). 
103 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 6.19. 
104 International Dolphin Conservation Prog ram, System for Tracking and Verifying Tuna, as amended 
(2015) , Section 4(5), (Exhibit USA -90). 
105 International Dolphin Conservation Program, System for Tracking and Verifying Tuna, as amended 
(2015) , Section 5(6), (Exhibit USA -90). 
106 International Dolphin  Conservation Program, System for Tracking and Verifying Tuna, as amended 
(2015) , Section 5(2) -(5), (Exhibit USA -90). 
107 International Dolphin Conservation Program, System for Tracking and Verifying Tuna, as amended 
(2015) , Section 5(7), (Exhibit USA -90). 
108 International Dolphin Conservation Program, System for Tracking and Verifying Tuna, as amended 
(2015) , Section 5(7), (Exhibit USA -90). WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  the corresponding TTF number.109 Tuna exported as AIDCP dolphin -safe must be accompanied by 
a certificate of its dolphin -safe status issued by a competent authority, which must also include a 
reference to th e relevant TTF number.110 
7.60.   The AIDCP Tracking and Verification System also provides that the national programs 
established by the parties to the AIDCP should include periodic audits and spot checks for tuna 
products, as well as mechanisms for cooperation amon g national authorities.111 
7.61.   The AIDCP Tracking and Verification System is directly applicable to US -flagged large purse 
seine vessels in the ETP by virtue of 50 CFR Section 216.93. Foreign -flagged large purse seine 
vessels catching tuna in the ETP are also re quired to comply with the System. Under the 2016 
Tuna Measure, tuna products containing tuna harvested in the ETP by non -US-flagged large purse 
seine vessels may be labelled dolphin -safe only if the vessel belongs to a nation that is a party to 
the AIDCP a nd is therefore subject to the AIDCP Tracking and Verification System.112 Additionally, 
the NOAA Form  370 requires that imports of tuna harvested by non -US-flagged ETP large purse 
seine vessels, or of tuna products derived from the same, be accompanied by do cumentation from 
the appropriate AIDCP member country certifying that there was an IDCP -approved observer on 
board the vessel at all times, and listing the numbers of the associated TTFs. Thus, under the 
Measure, tuna products containing tuna caught by bot h US -flagged and non -US-flagged  large 
purse seine vessels in the ETP have access to the dolphin -safe label only if the handling of the 
TTFs and the tracking and verification of tuna are conducted consistent with the AIDCP Tracking 
and Verification System.113 
7.62.   Under the 2016 Tuna Measure, tuna caught in a fishery other than the ETP large purse seine 
fishery is not required to comply with the requirements of the AIDCP Tracking and Verification 
System. Rather, it is subject to what the United States refers to as the "NOAA regime".114 To be 
eligible for a dolphin -safe label under the NOAA regime, tuna caught outside the ETP large purse 
seine fishery must be kept physically separate from non -dolphin -safe tuna from the time of catch, 
through offloading and processing.115 
7.63.   Under the NOAA regime, all tuna product imported into the United States, regardless of 
where the tuna was caught and whether the dolphin -safe label is used, must be accompanied by a 
NOAA Form 370 (Form 370), which designates, inter alia , whether the tuna is dolphin -safe.116 
Dolphin -safe and non -dolphin -safe tuna products must have separate Form 370s. For tuna product 
designated dolphin -safe, Form 370 contains the necessary certifications, and requires identification 
of the harvesting vessel, the fishing gear  used, and the trip on which the tuna was caught.117 
7.64.   The NOAA regime requires US tuna processors to submit monthly reports to the US Tuna 
Tracking and Verification Program for all tuna received at their processing facilities.118 These 
reports contain the same information as is contained in the Form 370, as well as certain additional 
information, such as unloading dates and the condition of the tuna products.119 Additionally, NMFS 
is empowered to undertake verification activities, including dockside inspections of  vessels, 
monitoring of Form 370s, monitoring of cannery reports, audits of US canneries, and retail market 
spot checks.120 Other US agencies may conduct on -board inspections on the high seas and in US 
                                                
109 International Dolphin Conservation Program, System for Tracking and Verifying Tuna, as amended 
(2015) , Section 6(b) -(c), (Exhibit USA -90). 
110 International Dolphin Conservation Program, System for Tracking and Verifying Tuna, as amended 
(2015) , Section 6(d), (Exhibit USA -90). 
111 International Dolphin Conservation Program, System for Tracking and Verifying Tuna, as amended 
(2015) , Section 7, (Exhibit USA -90). 
112 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 6.20. 
113 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 6.20. 
114 United States' first written submission, para. 143 . 
115 50 CFR Sections 219.93(c)(2) -(3) and d(4), (Exhibits USA -02, MEX -02). 
116 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 6.13; 50 CFR Sections 
216.24(f)(2)(i) -(ii) (Exhibit US A-03); 50 CFR Section 216.93(f) (Exhibits USA -02, MEX-02); Form 370 (Exhibit 
USA-04) 
117 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 6.25. 
118 Panel Report, US – Tuna II (Mexico) , para. 2.32; 50 CFR Section 216.93(d) -(e) (Exhibits USA -02, 
MEX-02). 
119 Panel Report, US – Tuna II ( Mexico) , para. 2.32; 50 CFR Section 216.93(d) -(e) (Exhibits USA -02, 
MEX-02). 
120 50 CFR Section 216.93(g)(3); see also 50 CFR Sections 216.93(d)(1) -(3) and 216.93(f) 
(Exhibits  USA-02, MEX -02). WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  waters.  In its submissions on this aspect of the Measure , Mexico noted that US agencies lack 
authority to audit non -US fishing vessels, carrier vessels, and processors (i.e. canneries).121 
7.65.   Additionally, the 2016 Tuna Measure establishes new chain of custody requirements for tuna 
products produced from tuna caught  outside the ETP large purse seine fishery, and which are to be 
marketed as dolphin -safe. Specifically, US processors and importers of such tuna products must 
collect and retain for two years information on each point in the chain of custody of the tuna or  
tuna product, including information on all storage facilities, trans -shippers, processors, and 
wholesalers/distributors.122 The retained information must be provided to NMFS upon request, and 
must be sufficient for NMFS to conduct a trace -back of any tuna p roduct marketed as dolphin -safe 
to verify that the tuna product in fact meets the dolphin -safe labelling requirements. The 
information must also be sufficient to enable NMFS to trace back any non -dolphin -safe tuna loaded 
onto the harvesting vessel back to one or more storage wells or other storage locations for a 
particular fishing trip to prove that such non -dolphin -safe tuna was kept physically separate from 
dolphin -safe tuna through unloading. These new requirements apply to all tuna products labelled 
dolphin-safe if those products contain tuna harvested on a fishing trip beginning on or after 
21 May 2016.  
7.66.   Breach of these requirements may lead to the imposition of sanctions. In particular, 
sanctions for offering for sale or export tuna products falsely la belled dolphin -safe may be 
assessed against any producer, importer, exporter, distributor, or seller who is subject to the 
jurisdiction of the United States.123 Violators may be prosecuted under the DPCIA provisions 
directly, under federal provisions prohibi ting false statements and smuggling, or under federal 
labelling standards.124 
7.67.   Additional certification and tracking and verification requirements may be imposed on tuna 
and tuna products made from tuna caught outside the ETP large purse seine fishery pursuan t to 
the so -called "determination provisions". In the 2016 Tuna Measure, there are two relevant 
determination provisions: one concerning certification125, and one concerning tracking and 
verification.126 
7.68.   With respect to certification , under 50 CFR Section 216. 91(a)(3)(v) provisions, NOAA may 
require an observer certification in addition to the captain certification where the Assistant 
Administrator has determined that a fishery other than the ETP large purse seine fishery has either 
a regular and significant as sociation between dolphins and tuna (similar to the association between 
dolphins and tuna in the ETP) or a regular and significant mortality or serious injury of dolphins is 
occurring. The observer must be a participant in a national or international progr am acceptable to 
the Assistant Administrator. The Assistant Administrator retains the discretion to determine that an 
observer certification is unnecessary.  
7.69.   With respect to tracking and verification , the determination provisions state that, where the 
Assistant Administrator has made a certification of regular and significant association or regular 
and significant mortality or serious injury under 50 CFR Section  216.91 (a)(3)(v), any imported 
tuna or tuna product made from tuna caught on a trip beginning on o r more than 60 days after the 
publication of a notice of the determination in the Federal Register, and which is intended to be 
labelled as dolphin -safe, must be accompanied by valid documentation signed by a representative 
of the vessel flag nation or the  processing nation (if processed in another nation) certifying that 
(a) the catch documentation recorded on the Form 370 is correct; (b) the tuna or tuna products 
meet the US dolphin -safe labelling standards; and (c) the chain of custody information is 
                                                
121 Mexico's first written submission, para.  297. 
122 50 CFR Section 216.91(a)(5) , (Exhibit s USA-02, MEX -02). 
123 50 CFR Section 216.93(g)(3) ( Exhibits USA -02, MEX -02); Form 3 70 (Exhibit USA -04); United States' 
response to Panels' question No. 29, paras. 148 -149. 
124 NOAA Form 37 0 (Exhibit USA -04); 16 USC. § 1375(a)(1) (Exhibit  USA-174); 16 USC Section 3372(d) 
(Exhibit USA -169); 16 USC Section 1375(b) (Exhibit USA -174); 18 USC Section 3571 (Exhibit USA -167); US 
Department of Commerce, Civil Monetary Penalty Adjustments for Inflation, 81 Fed. Reg. 36,454 (June 7, 
2016) (Exhibit U SA-170); 16 USC Section 3373(d)(3) (Exhibit USA -171); 16 USC Section 3374(a)(1) 
(Exhibit  USA-172); 18 USC Section 3571 (Exhibit USA -167); 18 USC Section 545 (Exhibit USA -166); 18 USC 
Section 1001(a) (Exhibit USA -173).  
125 50 CFR Section 216.91(a)(3)(v), (Exh ibits USA -02, MEX -02). 
126 50 CFR Section 216.91(a)(5)(ii), (Exhibits USA -02, MEX -02). WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  correct.127 The Panels examine these additional requirements in more detail later in these 
Reports.128 
7.70.   In summary, there are four central elements or aspects of the 2016 Tuna Measure:129  
a. The "eligibility criteria", pursuant to which tuna produc ts made from tuna ca ught by 
(a) setting on dolphins and (b) driftnets in the high seas are disqualified from accessing 
a dolphin -safe label, while tuna products made from tuna caught by other fishing 
methods are provisionally eligible;  
b. The "certification requirements", which require certain documentation to accompany 
tuna intended to be labelled as dolphin -safe; 
c. The "tracking and verification requirements", which impose certain conditions concerning 
the segregation of dolphin -safe and non -dolphin -safe tuna from the time of cat ch 
through off -loading, processing, and sale;  
d. The "determination provisions", which allow for additional certification and tracking and 
verification requirements to be imposed in respect of tuna caught outside the ETP large 
purse seine fishery under certai n circumstances.  
7.71.   Of course, these elements form part of a single measure and thus work together towards 
the same objectives.130 They are highly interconnected and interrelated. For example, as the 
Appellate Body emphasized in the first compliance proceedings , the two substantive conditions for 
access to the dolphin -safe label – namely, the conditions of "no setting on dolphins" and "no 
dolphins killed or seriously injured" – are both defined by, and verified through, the associated 
certification and tracking and verification requirements .131 Accordingly, in conducting our 
assessment of the WTO -consistency of the 2016 Tuna Measure, we will carefully consider both the 
individual elements of the 2016 Tuna Measure and the way in which these elements work together 
and mutually reinforce one another.132 We will examine the Measure as a whole, in an integrated 
manner133, taking account of the overall architecture of the dolphin -safe labelling regime.134 
7.5  Claim under Article 2.1 of the TBT Agreement  
7.5.1   Introduction: "technical reg ulation", "like products", and "detrimental impact"  
7.72.   As noted above, the United States asks the Panels to find that the 2016 Tuna Measure 
brings the United States into compliance with its WTO obligations, including Article 2.1 of the TBT 
Agreement. Mexico, however, asks the Panels to find that the 2016 Tuna Measure is WTO -
inconsistent, including under Article 2.1 of the TBT Agreement.  
7.73.   In its report in the first compliance proceedings in this dispute, the Appellate Body 
confirmed that in order to establish a violation of Article 2.1 of the TBT Agreement, a complainant 
must establish that (a) the measure at issue is a technical regulation within the meaning of Annex 
1.1 to the TBT Agreement; (b) the relevant products are "like" products; and (c) the measure at 
issue accords less favourable treatment to imported products than to the relevant group of like 
products.135 Moreover, the Appellate Body stated that the "treatment no less favourable" element 
of the analysis must be addressed in two distinct steps. First, a  panel must determine whether the 
challenged measure modifies the conditions of competition to the detriment of the relevant 
imported products vis-à-vis like products of domestic origin and/or like products originating in any 
other country.136 If the panel m akes such a finding, then it must proceed to determine whether the 
                                                
127 50 CFR 216.91(a)(5)(ii), (Exhibits USA -02, MEX -02). 
128 See Section 7.8.4 below.  
129 We note that these same four elements or as pects were also central in the first compliance 
proceedings.  
130 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para.  7.105.  
131 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para.  7.17. 
132 See e.g. Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para.  7.265. 
133 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para.  7.20. 
134 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para.  7.20. 
135 Appellate Body Rep ort, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.25.  
136 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.26.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  detrimental impact on imports stems exclusively from a legitimate regulatory distinction rather 
than reflecting discrimination against the group of imported products.137 
7.74.   The parties agree tha t the 2016 Tuna Measure, like the previous versions of the Tuna 
Measure, is a technical regulation within the meaning of Annex 1.1 to the TBT Agreement. They 
also agree that the relevant products, i.e. Mexican tuna products on the one hand and tuna 
product s produced by the United States and other countries on the other hand, are "like".138 We do 
not see that the facts, including the overall architecture and structure of either the original or the 
2013 Tuna Measure, or the nature of the products at issue have changed in any way that would 
call these conclusions into doubt. The parties have not suggested that this would be the case. 
Accordingly, we agree with the parties that the 2016 Tuna Measure is a technical regulation, and 
that the relevant products are "li ke". 
7.75.    The parties also agree that the 2016 Tuna Measure modifies the conditions of competition 
to the detriment of Mexican tuna products in the US market.139 Specifically, the parties agree that 
the key elements of the original and 2013 Tuna Measure s – in particular the disqualification of all 
tuna caught by setting on dolphins from using a dolphin -safe label, and the provisional 
qualification of tuna caught by other fishing methods to use such a label – and the relevant 
features of the US market for tuna rem ain unchanged, so that most Mexican tuna products are still 
being excluded from access to the dolphin -safe label, whereas most like products from the United 
States and other Members are still eligible for such label.140 
7.76.   In this connection, we recall that in the first compliance proceedings, the Appellate Body 
explained that:  
[A]ccess to the dolphin -safe label constitutes an advantage on the US  market for tuna 
products by virtue of that label's significant commercial value. We further recall that, 
in the origi nal proceedings, the Appellate Body relied on the following factual findings 
by the original panel: (i) the Mexican tuna cannery industry is vertically integrated, 
and the major Mexican tuna products producers and canneries own their vessels, 
which operate  in the ETP; (ii)  at least two  thirds of Mexico's purse seine tuna fleet 
fishes in the ETP by setting on dolphins and is therefore fishing for tuna that would not 
be eligible to be contained in a dolphin -safe tuna product under the US dolphin -safe 
labellin g provisions; (iii) the US fleet currently does not practice setting on dolphins in 
the ETP; and (iv) as the practices of the US  and Mexican tuna fleets currently stand, 
most tuna caught by Mexican vessels, being caught in the ETP by setting on dolphins, 
would not be eligible for inclusion in a dolphin -safe product under the US dolphin -safe 
labelling provisions, while most tuna caught by US vessels is potentially eligible for the 
label. These various factual elements thus supplied the foundation for the App ellate 
Body's finding of detrimental impact.141 
7.77.    Like the parties, we do not see that there has been any relevant change in these factual 
circumstances. Indeed, we agree with the parties that the 2016 Tuna Measure maintains the 
overall architecture and struc ture of the original and 2013 Tuna Measure s – in particular, it 
maintains the regulatory distinction between tuna products derived from tuna caught by setting on 
dolphins and tuna products derived from tuna caught by other fishing methods. Thus, although t he 
2016 Tuna Measure has introduced new requirements in respect of tuna products made from tuna 
caught outside the ETP, the distinction between tuna caught by setting on dolphins, which 
(together with tuna caught by high seas driftnet fishing) is ineligibl e to receive a dolphin -safe 
                                                
137 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.26.  
138 Panel Report, US – Tuna II (Mexico) , para. 7.251; Appellate Body Report, US – Tuna II (Mexico) , 
paras. 199; Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.71. The Appellate Body in the 
first compliance proceedings observed that the United States' appeal wi th respect to the interpretation of 
Article 2.1 of the TBT Agreement did not concern these issues, and accordingly treated them as settled. 
Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.25. 
139 United States' first written sub mission, para. 69; Mexico's first written submission, para. 203.  
140 United States' response to Panels' question  No. 109, para. 381; Mexico's response to Panels' 
question No. 109, para. 217.  
141 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico), para. 7.236 (internal citations 
omitted).  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  label, and tuna caught by other fishing methods, which is provisionally eligible for a dolphin -safe 
label, remains in effect.142 
7.78.   In the light of this, and given the parties' agreement that the relevant factual situation has 
not ch anged from the original or the first compliance proceedings, we find that, by excluding most 
Mexican tuna products from access to the dolphin -safe label, while granting conditional access to 
such label to like  products from the United States and other coun tries, the 2016 Tuna Measure, 
similar to the original and the 2013 Tuna Measure, modifies the conditions of competition to the 
detriment of Mexican tuna products in the US market .143 
7.79.   The parties' disagreement as to the WTO -consistency of the 2016 Tuna Measur e centres on 
the question of whether the detrimental impact caused by the 2016 Tuna Measure nevertheless 
does not accord treatment less favourable to Mexico within the meaning of Article 2.1 of the TBT 
Agreement, because such detrimental impact stems exclu sively from a legitimate regulatory 
distinction. This question is at the heart of these proceedings. The parties, however, have very 
different understandings of the legal standard to be applied in this part of the analysis under 
Article 2.1 of the TBT Agre ement. Accordingly, we now turn to consider the proper meaning of the 
"legitimate regulatory distinction" test on the basis of the text of Article 2.1 and the Appellate 
Body's guidance in the previous stages of this dispute.  
7.5.2   "Legitimate regulatory distinct ion": the applicable legal standard  
7.80.   As noted above, the Appellate Body has clarified that the existence of detrimental impact is 
not sufficient to establish a violation of Article 2.1 of the TBT Agreement. Rather, if a panel 
determines that a measure has m odified the conditions of competition to the detriment of 
imported products vis-à-vis like products of domestic origin and/or like products originating in any 
other country, then the panel must proceed to determine whether the detrimental impact on 
imports  stems exclusively from a legitimate regulatory distinction rather than reflecting 
discrimination against the group of imported products.144 
7.81.   In this connection, the Appellate Body has repeatedly emphasized that the specific context 
provided by other provisio ns of the TBT Agreement is instructive in understanding the expression 
"treatment no less favourable" in Article 2.1. According to the Appellate Body, the specific context 
provided by, in particular, Annex 1.1, Article 2.2, and the second, fifth, and sixth  recitals of the 
preamble, supports the view that Article 2.1 does not operate to prohibit a priori  any and every  
restriction on international trade. Moreover, in the Appellate Body's view, the sixth recital sheds 
light on the meaning and ambit of the "tre atment no less favourable" requirement in Article 2.1 by 
making clear that technical regulations may pursue legitimate objectives but must not be applied 
in a manner that would constitute a means of arbitrary or unjustifiable discrimination. On the basis 
of these considerations, the Appellate Body has clarified that Article 2.1 should not be read to 
mean that all regulatory distinctions would per se  constitute less favourable treatment within the 
meaning of Article 2.1.145 Rather, some distinctions that entai l detrimental impact may not give 
rise to less favourable treatment under Article 2.1. This would be the case, in particular, where the 
detrimental impact on imports stems exclusively from a legitimate regulatory distinction.146 
7.82.   The Appellate Body has stated  that in determining whether the detrimental impact on 
imports stems exclusively from a legitimate regulatory distinction, a panel must carefully scrutinize 
whether the technical regulation at issue is even -handed in its design, architecture, revealing 
structure, operation, and application in the light of the particular circumstances of the case. The 
Appellate Body has pointed out that where a regulatory distinction is not designed and applied in 
an even -handed manner – because, for example, it is designed or applied in a manner that 
constitutes a means of arbitrary or unjustifiable discrimination – that distinction cannot be 
considered "legitimate", and thus the detrimental impact will reflect discrimination proscribed 
under Article 2.1. Therefore, a measur e that involves "arbitrary or unjustifiable discrimination" 
would not be designed and applied in an "even -handed manner". At the same time, according to 
the Appellate Body, the fact that a measure is designed in a manner that constitutes a means of 
                                                
142 The United States acknowledges this point. United States' first written submission, para. 29. 
143 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.238.  
144 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.26.  
145 Appellate Body Reports, US – Clove Cigarettes , para. 169; US – Tuna II (Mexico) , para. 211;   
US – COOL , para. 268.  
146 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.30.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  arbitra ry or unjustifiable discrimination is not the only way in which a measure may lack even -
handedness, such that the detrimental impact cannot be said to stem exclusively from legitimate 
regulatory distinctions.147 Rather, it is one of the ways to determine whe ther the measure is 
even-handed and therefore its detrimental impact stems exclusively from a legitimate regulatory 
distinction.148 
7.83.   The Panels note that, in the first compliance proceedings in this dispute, the Appellate Body 
explained that, in interpreting and applying the "treatment no less favourable" element of Article 
2.1 of the TBT Agreement, and in particular in assessing whether the identified detrimental impact 
stems exclusively from a legitimate regulatory distinction, a panel does not err by assess ing 
whether the detrimental impact can be reconciled with, or is rationally related to, the policy 
objective pursued by the measure at issue, so long as, in doing so, it does not preclude 
consideration of other factors that may also be relevant to the anal ysis.149 Similarly, the Appellate 
Body stated that "depending on the nature of the measure at issue and the circumstances of the 
case at hand, additional factors – beyond the question of whether the discrimination can be 
reconciled with the policy objective – could also be relevant to the analysis of whether the 
discrimination is arbitrary or unjustifiable".150 We understand the Appellate Body as meaning that, 
in assessing whether a measure is "even -handed", a panel may consider whether the 
measure/regulatory d istinction causing the detrimental impact is designed or applied in a manner 
that constitutes a means of "arbitrary or unjustifiable discrimination". One way of assessing this is 
by considering whether there is a rational relationship between the discrimin ation and the 
objectives pursued by the measure. However, this is not the only way in which "arbitrary or 
unjustifiable discrimination" may be assessed.  
7.84.   Having made these observations, the Appellate Body in the first compliance proceedings 
went on to recal l that in the original proceedings in this dispute, the United  States sought to 
explain that the original Tuna Measure was even -handed, and that the detrimental impact did stem 
exclusively from a legitimate regulatory distinction by introducing the notion of "calibration". In 
particular, the United States contended that the original Tuna Measure was even -handed because 
the distinctions that it drew between different tuna fishing methods and different areas of the 
ocean could be explained or justified by dif ferences in the risks to dolphins associated with such 
fishing methods and areas of the ocean. This, in turn, led the Appellate Body in the original 
proceedings to examine the legitimacy of the original Tuna M easure's regulatory distinctions 
through the le ns of the concept of "calibration".151 While emphasizing that "calibration" does not 
constitute a separate legal test, the Appellate Body in the first compliance proceedings 
nevertheless held that there was a special relevance in those Article 21.5 proceedin gs in 
conducting an assessment of whether, under the 2013 Tuna Measure, the differences in labelling 
conditions for tuna products containing tuna caught by large purse -seine vessels in the ETP, on the 
one hand, and for tuna products containing tuna caught by other fishing methods in other 
fisheries, on the other hand, are "calibrated" to the differences in the likelihood that dolphins will 
be adversely affected in the course of tuna fishing operations by different vessels, using different 
fishing methods, i n different areas of the ocean.152 The Appellate Body then repeatedly 
emphasized that, in its view, the appropriate way, in the context of this dispute, for a panel to 
assess whether the detrimental impact caused by the Tuna Measure stems exclusively from a 
legitimate regulatory distinction is to assess whether the Measure is properly "calibrated" to the 
risks to dolphins arising from different fishing methods in different areas of the ocean.153 To this 
end, the Appellate Body explained that a panel should cond uct an analysis involving: first, an 
identification of whether different tuna fishing methods in different areas of the oceans pose 
different risks to dolphins; and, second, an examination of whether, in the light of these risks, the 
different treatment cr eated by the relevant regulatory distinctions show that, as between different 
groups of tuna products, the treatment accorded to each group is commensurate with the relevant 
risks, taking account of the objectives of the Measure.154 
                                                
147 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.31.  
148 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.94.  
149 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.95.  
150 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.93 (citing Appellate 
Body Report, EC – Seal Products , para. 5.321 ). 
151 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.98.  
152 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.101.  
153 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.155.  
154 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.155.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.85.   In the light of these sta tements of the Appellate Body, both parties have argued, and we 
agree, that the question whether the 2016 Tuna Measure is "calibrated" to the risks to dolphins 
arising from different fishing methods in different areas of the ocean is central to our analysi s in 
these proceedings.155 However, the parties have very different views about how the calibration 
analysis should be understood and applied. Indeed, as the United States has noted, the parties 
appear to read the Appellate Body's report in the first complia nce proceedings, and the legal test 
set out therein, "very differently".156 In particular, although the parties agree that "calibrated" 
means "appropriately tailored to " or "commensurate with " the relevant risks157, they 
fundamentally disagree about how that t est should be applied, and in particular as to what the 
2016 Tuna Measure must be calibrated  to. 
7.86.   In the United States' view, the calibration analysis essentially requires the Panels to assess 
whether, under the 2016 Tuna Measure, the differences in labelli ng conditions for tuna products 
containing tuna caught by large purse -seine vessels in the ETP, on the one hand, and for tuna 
products containing tuna caught by other fishing methods in other areas of the ocean, on the other 
hand, are calibrated to the dif ferences in the likelihood that dolphins will be adversely affected in 
the course of tuna fishing operations by different vessels, using different fishing methods, in 
different areas of the ocean.158 According to the United States, the Appellate Body has exp licitly 
recognized that the United States' tuna labelling regime will not violate Article 2.1 of the TBT 
Agreement if it is properly calibrated to the risks to dolphins arising from different fishing methods 
in different areas of the ocean.159 The United Sta tes contends that under the applicable legal 
standard, the Panels must analyse the relative harms in respect of observed mortality or serious 
injury, as well as a comparative assessment of unobserved harms, caused by different fishing 
methods in different areas of the world's oceans.160 The Panels must then evaluate the relevant 
regulatory distinctions in light of the risks of overall harm to dolphins, and determine whether 
those distinctions are explained by, and appropriately tailored to, the relevant risks .161 In other 
words, the Panels, having analysed the different risks to dolphins caused by different fishing 
methods in different areas of the ocean, should assess whether the relevant regulatory distinctions 
address these risks in a way that is commensurate  with the respective risk profiles of the different 
fisheries.162 In this regard , the United States submits that if the risks to dolphins across fisheries 
were the same, but the requirements imposed by the 2016 Tuna Measure were different, then the 
Panels co uld conclude that the relevant regulatory distinctions are not calibrated.163 
7.87.   Mexico has a different understanding of the applicable legal standard. According to Mexico, 
even-handedness is the central concept for determining whether detrimental treatment cau sed by 
a measure stems exclusively from a legitimate regulatory distinction.164 In Mexico's view, the 
"even -handedness" standard should be applied through a "multi -factor legal test".165 For Mexico, 
calibration, while important, is not a synonym for even -hande dness, but rather only one "factor" of 
the applicable legal test.166 Thus, according to Mexico, the calibration test complements, but does 
not replace the assessment of whether the regulatory distinctions are applied in a manner that 
constitutes a means of a rbitrary or unjustifiable discrimination, for example, on the basis of 
whether or not they can be reconciled with, or are rationally related to, the policy objectives of the 
measure.167 
                                                
155 Mexico's first written sub mission, para. 212; United States' first written submission, para. 67.  
156 United States' comments on Mexico's response to Panels' question No. 86, para. 145. Mexico also 
acknowledges that "Mexico and the United States disagree on the appropriate role of ca libration in this 
dispute". Mexico's second written submission, para. 15.  
157 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , paras. 7.252 and 7.253.  
158 United States' second written submission, para. 14 (citing Appellate Body Report, US – Tuna II 
(Mexico) (Article 21.5 – Mexico) , para. 7.101).  
159 United States' third written submission, para. 10 (citing Appellate Body Report, US – Tuna II 
(Mexico) (Article 21.5 – Mexico) , para. 7.155).  
160 United States' response to Panels' question  No. 44,  para. 227.  
161 United States' response to Panels' question  No. 107, para. 377.  
162 United States' first written submission, para. 15 (citing Appellate Body Report, US – Tuna II (Mexico) 
(Article 21.5 – Mexico) , paras. 7.126 and 7.161).  
163 United States' respon se to Panels' question  No. 107, paras. 377 and 378.  
164 Mexico's second written submission, para. 20.  
165 Mexico's second written submission, para. 20.  
166 Mexico's second written submission, para. 15.  
167 Mexico's first written submission, para. 215.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.88.   Mexico therefore urges the Panels to take into account a number of facto rs in applying the 
legal test for even -handedness.168 Certainly, one of these factors is whether or not the 
discriminatory effects of the Tuna Measure's regulatory distinctions can be justified on the basis 
that they are calibrated to different relevant circ umstances.169 However, another question is 
whether or not the discriminatory effects constitute arbitrary or unjustifiable discrimination on the 
basis that the regulatory distinctions cannot be reconciled with, or rationally connected to, the 
measure's polic y objectives (what we, for brevity, call the "rational connection" test).170 In 
Mexico's view, these questions do not create independent or discrete legal tests; rather, they are 
elements within the overall analysis of whether or not the Tuna Measure is even -handed, and they 
must be assessed cumulatively, in relation to one another, on a common record of facts and 
circumstances.171 In response to a question from the Panels, Mexico contends that the calibration 
analysis "can and must" occur within the "constrain ts" of the rational connection test for arbitrary 
and unjustifiable discrimination.172 
7.89.   In this respect, Mexico considers that the United States is incorrect to the extent that it 
attempts to narrow the legal analysis to a single -factor test, i.e., the questi on of whether or not 
the 2016 Tuna Measure is calibrated to the relative risks to dolphins in different fisheries.173 
Mexico also considers that the United States is incorrect insofar as its proposed legal test would 
preclude the Panels from assessing the re lationship between the detrimental impact caused by the 
relevant regulatory distinctions and the objectives purs ued by the measure.174 In this connection, 
Mexico observes that it is only if consumers are able to accurately distinguish between tuna caught 
in conditions that are harmful to dolphins from tuna caught in conditions that are not harmful to 
dolphins that the use of harmful fishing techniques could be discouraged in the US market through 
the use of the dolphin -safe label.175 For Mexico, it follows from  this that the accuracy of the 
dolphin -safe label, as a consumer information measure, is essential to the objective of protecting 
dolphins from adverse effects arising in different fisheries.176 Therefore, in Mexico's view, the 
accuracy of the dolphin -safe i nformation provided to consumers on the US label is a central factor 
in the assessment of whether the regulatory distinctions drawn by the measure are calibrated to 
the relative risks of overall harms to dolphins posed by different fishing methods in diffe rent ocean 
regions.177 Indeed, according to Mexico, the reliability of different certification and tracking and 
verification systems is an integral element of the risk profiles of different fisheries.178 In practical 
terms, this means that while the calibratio n analysis should analyse the different risk profiles of 
different fishing methods in different areas of the ocean, it must also take into account the 
reliability of the record -keeping and reporting — that is, the accuracy of the information provided 
— by the tuna suppliers in different countries, including the level and effectiveness of 
governmental oversight over the fishers and trans -shippers of the tuna and the producers of the 
product, and the existence of illegal, unreported and unregulated fishing (I UU).179 Such 
considerations would, in Mexico's view, be especially relevant to the Panels' assessment of any 
differences in the certification and tracking and verification requirements.180 
7.90.   Finally, Mexico argues that, in the context of these proceedings, the P anels' assessment of 
even-handedness should encompass consideration of whether the 2016 Tuna Measure gives rise to 
"unjustifiable discrimination" for reasons other than  the relationship (or lack thereof) between the 
detrimental impact and the objectives pu rsued by the 201 6 Tuna Measure. Specifically, Mexico 
argues that the Panels should determine whether the 2016 Tuna Measure gives rise to 
"unjustifiable discrimination" because the differences in labelling conditions "discriminate against 
an environmentally  sustainable fis hing method … in favour of an environmentally unsustainable 
fishing practice".181 In Mexico's view, while WTO Members are free to choose their own objectives, 
                                                
168 Mexico's f irst second written submission, para. 22.  
169 Mexico's first written submission, para. 4.  
170 Mexico's second written submission, para. 22.  
171 Mexico's second written submission, para. 24.  
172 Mexico's response to Panels' question  No. 73, para. 79.  
173 Mexico's sec ond written submission, para. 23.  
174 Mexico's second written submission, para. 24.  
175 Mexico's second written submission, para. 42 (citing Panel  Report, US – Tuna II (Mexico) , paras. 
7.426 -7.427) (emphasis in original).  
176 Mexico's second written submission, para. 42.  
177 Mexico's second written submission, para. 44.  
178 Mexico's first written submission, para. 114.  
179 Mexico's first written submission, para. 221.  
180 Mexico's second written submission, para. 50.  
181 Mexico's second written submission, paras. 30 -31. WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  they cannot employ means that are inconsistent with the objective of sustainable de velopment. 
Accor ding to Mexico, because the 2016 Tuna Measure discriminates against an environmentally 
sustainable fishing method in favour of one that is unsustainable, the Measure is inconsistent with 
the principle of sustainable development and can be f ound to be incon sistent with the WTO 
Agreement on this ground.182 
7.91.   The United States disagrees with Mexico's understanding of the applicable legal standard. 
First, the United States argues that Mexico' s proposed test for arbitrary or unjustifiable 
discriminat ion, and its contention that the even -handedness analysis is a multi -factor test, is 
incompatible with the approach adopted by the Appellate Body in the first compliance proceedings. 
According to the United States, Mexico's argument seeks to divert the Pan els from conducting the 
required risk -based analysis, and would lead the Panels to consider factors other than the risks to 
dolphins – factors not relied on by the Appellate Body in either its original or first compliance 
reports – thus improperly minimizi ng the importance in the analysis of the relative overall risks to 
dolphins resulting from the use of different fishing methods in different fisheries.183 In the United 
States' view, the fact that there may, in theory, be different ways to test for even -handedness 
does not detract from the fact that, in this dispute, the Appellate Body has clarified that the 
appropriate analysis is whether the Measure is properly calibrated to the risks to dolphins arising 
from different fishing methods in different areas of the ocean.184 
7.92.   The United States further contends that Mexico is incorrect in arguing that the Panels should 
assess whether the relevant regulatory distinctions in the 2016 Tuna Measure are calibrated to the 
relative risks of inaccurate dolphin -safe certifica tion, reporting, and/or record -keeping.185 In the 
United States' view, this is not the test that was articulated by the Appellate Body186, and the 
United States  finds no support in either of the Appellate Body's previous reports in this dispute.187 
Rather, accor ding to the United States, the Appellate Body has made clear that the relevant test is 
whether the relevant regulatory distinctions are calibrated to the risks to dolphins arising from 
different fishing methods in different areas of the ocean.  
7.93.   Moreover, th e United States argues that Mexico's approach would require the Panels to 
apply one calibration test to the eligibility criteria (that is, calibration to the risks to dolphins 
caused by different fishing methods in different areas of the ocean), and an ent irely different 
calibration test to assess the certification and tracking and verification requirements (that is, 
calibration to the risks of inaccurate dolphin -safe certification, reporting, and/or record -keeping). 
According to the United States, in the f irst compliance proceedings, the Appellate Body faulted the 
compliance panel for applying one test to the eligibility criteria and a different test to the 
certification requirements and tracking and verification requirements, emphasizing that the same 
test must be applied to each of these cumulative and highly interrelated regulatory distinctio ns. In 
the view of the United States, applying different tests to different regulatory distinctions would 
lead to the type of segmented analysis that the Appellate Bo dy criticized in the previous 
proceedings. Thus, adopting Mexico's proposed legal test would amount to "reversible error".188 
7.94.   In sum, we understand the United States' position to be that the applicable legal standard 
under Article 2.1 of the TBT Agreement is  whether the relevant regulatory distinctions in the 2016 
Tuna Measure are calibrated to the risks to dolphins arising from the use of different fishing 
methods in different areas of the ocean. On the other hand, Mexico's view is that the Panels must 
asses s whether the 2016 Tuna Measure is "even -handed" by applying a "multi -factor" legal test 
that asks a number of questions, including whether the Measure is calibrated to both the risks to 
dolphins arising from the use of different fishing methods in differe nt areas of the ocean and the 
risks of inaccurate labelling, as well as whether there is a rational relationship between the 
relevant regulatory distinctions and the objectives pursued by the 2016 Tuna Measure.  
7.95.   We not e that the  present  proceedings form par t of a continuum that includes the original 
and first compliance proceedings in this dispute. We must therefore accord due cognizance to the 
recommendations and rulings made by the DSB in the original and first compliance proceedings, 
                                                
182 Mexico's second written submission, paras. 31 -32. 
183 United States' third written submission, para. 25.  
184 United States' third written submission, para. 19.  
185 United States' second written submission, para. 39.  
186 United States' first written submission, par a. 41.  
187 United States' second written submission, para. 41.  
188 United States' response to Panels ' question No. 44, para. 229. WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  based on the findings  of the Appellate Body and original and first compliance panels.189 In our 
view, the Appellate Body's report in the first compliance proceedings is particularly instructive on 
the question of the applicable legal standard. We note, however, that the parties have very 
different understandings of the parts of this report that set out the applicable legal standard. 
Accordingly, we will summarize our understanding of the key legal findings in that report before 
explaining their implications for our task in the pr esent proceedings.  
7.96.   In our view, the Appellate Body's report in the first compliance proceedings contains a 
number of passages that clarify the legal test that we should apply in these proceedings.  
7.97.   We first observe that, the Appellate Body in the first comp liance proceedings did indeed 
state, in the section of its report containing "Preliminary Observations" on "Whether the Panel 
erred in its interpretation of Article 2.1 and its articulation of the legal standard for determining 
whether the detrimental impa ct on imported products stems exclusively from a legitimate 
regulatory distinction", that "a panel does not err by assessing whether the detrimental impact can 
be reconciled with, or is rationally related to, the policy pursued by the measure at issue, so long 
as, in doing so, it does not preclude consideration of other factors that may also be relevant to the 
analysis".190 In stating this, the Appellate Body was reiterating its view  that factors other than the 
question of whether discrimination can be reconc iled with the policy objective of the measure at 
issue may be relevant to an analysis of whether discrimination is arbitrary or unjustifiable.191 
7.98.   However, immediately after making these general observations, the Appellate Body recalled 
that in the original p roceedings in this dispute, the United States sought to explain that its 
measure was even -handed by introducing the notion of "calibration". The Appellate Body explained 
that in those proceedings, the United States contended that its measure was even -hande d because 
the distinctions that it drew between different tuna fishing methods and different areas of the 
ocean could be explained or justified by differences in the risks associated with such fishing 
methods and areas of the ocean.192 The Appellate Body obs erved that this line of argument led the 
Appellate Body in those proceedings to examine the legitimacy of the original Tuna M easure's 
regulatory distinctions through the lens of the concept of calibration.193 
7.99.   In the light of this background, and bearing in m ind that in the first compliance proceedings 
the United States had again made arguments concerning the calibration of its tuna labelling 
regime, the Appellate Body in th e first  compliance proceedings found that:  
[T]here is a special relevance in these Arti cle 21.5 proceedings in conducting an 
assessment of whether, under the amended tuna measure, the differences in labelling 
conditions for tuna products containing tuna caught by large purse -seine vessels in 
the ETP, on the one hand, and for tuna products co ntaining tuna caught in other 
fisheries, on the other hand, are "calibrated" to the differences in the likelihood that 
dolphins will be adversely affected in the course of tuna fishing operations by different 
vessels, using different fishing methods, in di fferent areas of the oceans.194 
7.100.   The Appellate Body then proceeded to consider the first compliance panel's application of 
the legal standard it had articulated. In this context, the Appellate Body found that the panel had 
erred because, in the light of the c ircumstances of the dispute and the nature of the distinctions 
drawn under the 2013 Tuna Measure, the panel was required to assess whether the certification 
and tracking and verification requirements were calibrated to the risks to dolphins arising from 
different fishing methods in different areas of the ocean.195 In this respect,  as we have noted 
above,  the Appellate Body noted that "the Appellate Body's assessment of even -handedness in the 
original proceedings was focused on the question of whether the orig inal tuna measure was 
calibrated to the risks to dolphins arising from different fishing methods in different areas of the 
oceans", and emphasized that the Appellate Body had accepted the premise that the United 
States' tuna labelling regime "will not viol ate Article  2.1 if it is properly calibrated to the risks to 
                                                
189 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.112.  
190 Appellate Body Report, US – Tuna II (Mexico ) (Article 21.5 – Mexico) , para. 7.95.  
191 Appellate Body Report, EC – Seal Products , para. 5.321.  
192 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.98.  
193 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.98.  
194 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.101.  
195 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.169.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  dolphins arising from different fishing methods in different areas of the oceans".196 Thus, in 
concluding its review of the first compliance panel's analysis under Article 2.1 of the TBT 
Agreement,  the Appellate Body stated:  
[W]e have not found error in the Panel's articulation of the legal standard. However … 
We have further found that, in the light of the circumstances of this dispute and the 
nature of the distinctions drawn under the amended tun a measure, the Panel erred by 
failing to consider whether differences in the relative risks of harm to dolphins from 
different fishing techniques in different areas of the oceans explain or justify the 
differences in the certification requirements and the tracking and verification 
requirements applied inside and outside the ETP large purse -seine fishery.197 
7.101.   The Appellate Body thus found that while the first compliance panel did not err in its 
articulation  of the applicable legal standard (which focused on the  existence of a rational 
connection between detrimental treatment and the objectives pursued by a challenged measure, 
but also recognized that the existence of such rational relationship was not the only element that 
could be taken into account), it nevert heless erred in its application  of that standard in this 
particular dispute by failing to assess whether the measure was "calibrated" to the risks posed to 
dolphins by different fishing methods in different areas of the ocean. As noted above, the Appellate  
Body emphasized that in the original proceedings, the Appellate Body had found that the United 
States' labelling regime would not be inconsistent with Article 2.1 of the TBT Agreement if it were 
calibrated to the risks to dolphins arising from the use of different fishing methods in different 
areas of the ocean.198 
7.102.   In our view, these statements make clear that, while there may in theory be a number of 
ways in which a panel could assess the "even -handedness" of a measure challenged under Article 
2.1 of the TB T Agreement, in the specific context of these proceedings , the appropriate legal 
standard for the Panels to apply is one that focuses on the relationship between the risks posed to 
dolphins by different fishing methods in different areas of the ocean, on t he one hand, and the 
relevant regulatory distinctions, on the other hand. In this connection, we note that, as in both the 
original and first compliance proceedings, the United States has once again based its arguments 
on the notion that the 2016 Tuna Meas ure is calibrated to the risks to dolphins arising from the 
use of different fishing methods in different areas of the ocean. Mexico has also engaged in 
extensive argumentation on the question of whether the Measure is properly calibrated. In our 
view, the  parties' continued reliance on an analysis of calibration supports our view that, in these 
proceedings, it is appropriate for us to assess the even -handedness of the 2016 Tuna Measure by 
analysing it through the "lens" of calibration.199 
7.103.   As we understand it , the Appellate Body's reasoning indicates that, in the context of this 
dispute , and without prejudice to the ways in which the "even -handed ness" could be applied in 
other cases, the "even -handedness" of the Tuna Measure can be determined by assessing whet her 
its relevant regulatory distinctions are calibrated to the risks to dolphins arising from the use of 
different fishing methods in different areas of the ocean. Accordingly, we read these passages as 
indicating that our task in these proceedings is to a scertain whether the relevant regulatory 
distinctions are appropriately "calibrated" and "tailored" to, and commensurate with200, the 
different risks to dolphins arising in different fisheries. If the relevant regulatory distinctions are so 
calibrated, this will indicate that the 2016 Tuna Measure is not inconsistent with  Article 2.1 of the 
TBT Agreement.201 
7.104.   In this connection, we note Mexico's argument that "the Panels need not undertake such a 
comparison [i.e. the calibration analysis]. Rather, it is the Unit ed States that must demonstrate 
that such a comparison was undertaken".202 Insofar as Mexico is arguing that the calibration 
analysis imposes a process obligation on the United States, and that what the United States must 
prove is not (or not only) that the 2016 Tuna Measure is calibrated , but also that the United States 
actually undertook a calibration analysis prior to establishing the Measure, we disagree. We find no 
                                                
196 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para.  7.155.  
197 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.229.  
198 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.155.  
199 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.98. 
200 See e.g. Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.252.  
201 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.155.  
202 Mexico's response to Panels' question No. 79, para. 109.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  support for this notion in either the text of Article 2.1 of the TBT Agreement or in the panel or 
Appellate Body reports in the prior proceedings  of this dispute . As we understand it, Article 2.1 of 
the TBT Agreement does not impose a particular process or set of procedures that should be 
applied by WTO  Members  before adopting technical regulat ions. Rather, it requires Members to 
ensure that technical regulations accord  treatment no less favourable to the products of a Member 
than to like products of national origin or originating in any other country. In other words, it is a 
particular treatmen t to be accorded to imported products (i.e. one that is no less favourable than 
that accorded to domestic or foreign like products), rather than a specific process of adoption that 
is imposed by Article 2.1 of the TBT Agreement. Moreover, we understand the  Appellate Body's 
report in the first compliance proceedings as indicating that the panels themselves must undertake 
an assessment of whether the Tuna Measure is calibrated.203 
7.105.   In thus finding, we must emphasize that we do not mean to imply that the process through 
which a technical regulation is adopted has no place in, or bears no consequence to, our analysis 
under Article 2.1 of the TBT Agreement. Indeed, the process of adoption can be relevant for a 
panel to determine whether a technical regulation is eve n-handed in light of the " particular 
circumstances of the case, that is, the design, architecture, revealing structure, operation,  and 
application of the technical regulation at issue ".204 In this sense, insofar as the process of adoption 
of the 2016 Tuna Me asure could help demonstrate its (lack of) even -handedness, it will form part 
of our analysis.205 However, as we noted above, Article 2.1 is explicitly concerned with the nature 
of treatment accorded  by technical regulations, and accordingly we do not unders tand Article 2.1 
to establish a separate or distinct obligation relating to the process by which the 2016 Tuna 
Measure was adopted.  
7.106.   Two issues related to  the legal standard outlined above (i.e. calibration to the risks to 
dolphins arising from the use of d ifferent fishing methods in different areas of the ocean)  must 
now be clarified further. First, we must determine if we should focus our calibration analysis on the 
question of whether the 2016 Tuna Measure is calibrated only to the risks to dolphins arisi ng from 
the use of different fishing methods in different areas of the ocean, as the United States argues, or 
if our calibration analysis should also consider whether the relevant regulatory distinctions are 
calibrated to risks relating to inaccurate certi fication and tracking and verification, as Mexico 
argues. Second, we must further consider the relationship between the calibration analysis and the 
question of whether there is a rational connection between the regulatory distinctions and the 
objectives o f the 2016 Tuna Measure.  
7.107.   The first issue concerns the scope of the calibration analysis. As we have explained above, 
Mexico argues that the reliability of the applicable systems in different fisheries for certification, 
tracking and verification are integr al elements of the 'risk profile' of different fisheries.206 In 
Mexico's view, this means that, in addition to analysing whether the relevant regulatory 
distinctions are calibrated to the risks to dolphins, we must conduct an "additional examination"207 
of whe ther the relevant regulatory distinctions are calibrated to the different relative risks (i.e. 
likelihood) of inaccurate dolphin -safe certification, reporting, and/or record -keeping with respect to 
the tuna caught in different fisheries and different areas  of the ocean.208 As we noted above, the 
United States rejects Mexico's view, arguing that the standard articulated by Mexico is "not the 
test applied by the Appellate Body"209, and that applying the standard articulated by Mexico would 
result in the Panels ap plying different legal tests in respect of different regulatory distinctions, 
contrary to the Appellate Body's guidance in the first compliance proceedings.210 
                                                
203 See e.g. A ppellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.155 
(indicating what, in the Appellate Body's view, would  have been an "appropriate … analysis" for the first 
compliance  panel  to have undertaken .) 
204 Appellate Body Report, US – Clove Cigarettes , para. 182.  
205 We note, for instance, that in some previous disputes brought before the WTO dispute settlement 
system, the manner in which the measures under review were adopted was taken into consideration by the 
Appellate Body in its deter mination of whether they constituted "arbitrary or unjustifiable discrimination". See 
Appellate Body Report,  US – Shrimp , para s. 171-172. See also Appellate Body Report,  US – Gasoline , pp. 27-
29. 
206 Mexico's first written submission, para. 114.  
207 Mexico's f irst written submission, para. 218.  
208 Mexico's first written submission, para. 218.  
209 United States' second written submission, para. 41.  
210 United States' second written submission, para. 42.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.108.   In determining the proper scope of the calibration analysis, we look to the guidance 
provided by t he Appellate Body in previous stages of this dispute. Of particular importance, in our 
view, is that the Appellate Body, in both its original and first compliance reports, repeatedly 
referred to the importance of assessing whe ther the measure is calibrated  to "the different risks to 
dolphins arising from different fishing methods in different areas of the oceans"211, "the risk that 
dolphins may be killed or seriously injured when tuna was caught"212, "the likelihood that dolphins 
would be adversely affected in the course of tuna fishing operations in the different fisheries"213, 
the "differences in the likelihood that dolphins will be adversely affected in the course of tuna 
fishing operations by different vessels, using different fishing methods, in different are as of the 
oceans"214, "the relative adverse effects on dolphins arising outside the ETP large purse -seine 
fishery as compared to those inside that fishery"215,"the differing risk profiles of the different 
fisheries"216, "the differences in risks in different fis heries"217, and "the different risk profiles in 
different fisheries".218 We have not found any reference in either of the Appellate Body reports in 
this dispute suggesting that the proper analysis is whether the 2016 Tuna Measure is calibrated to 
anything othe r than the risks posed to dolphins by the use of different fishing methods in different 
areas of the ocean.  
7.109.   With respect to Mexico's specific argument that risks relating to inaccurate certification, 
reporting, and/or record -keeping  form an "integral part"  of the risk profiles of different fisheries, in 
our view, the Appellate Body's reasoning in the preceding reports in this dispute does not support 
this view. As noted above, the Appellate Body has repeatedly stated that the applicable legal 
standard is ca libration to the risks to dolphins arising from the use of different fishing methods in 
different areas of the ocean. To us, this suggests that the relevant inquiry is one that focuses on 
the risks that dolphins face as a result of the use, in different ar eas of the ocean, of different 
fishing methods. In particular, the inquiry is one that centres on the risks that dolphins will be 
killed or injured by the use of different fishing techniques in different fishing grounds.219 Indeed, 
this is how the Appellate Body appears to have understood the expression "risk profile". For 
example, at paragraph 7.165 of its report in the first compliance proceedings, the Appellate Body 
notes that the compliance panel "gave some consideration to the respective risk profiles as sociated 
with different fishing methods in different areas of the ocean" by noting that "setting on dolphins is 
inherently dangerous to dolphins even where no dolphin is seen to be killed or seriously 
injured".220 
7.110.   As we see it, the risks of inaccurate certification, reporting, and/or record -keeping  are not 
risks that affect dolphins themselves, though they may, as Mexico alleges221, have an indirect 
influence on the extent to which different fishing methods are used to catch tuna intended for the 
US market.222 Nor are they  risks that arise from the use of different fishing methods in different 
areas of the ocean, even though fish caught in different areas of the ocean through the use of 
different fishing methods  may be associated with a greater or smaller risk of inaccurate labelling 
depending on a range of interconnected factors , including the persons involved in the catch, 
available technology, and applicable domestic and international regulatory requirements.223 
Accordingly, we do not think the Appellate Body in e ither the original or the first compliance 
                                                
211 See e.g. Appellate Body Report, US – Tuna II (Mexico) , paras. 283 and 297; US – Tuna II (Mexico) 
(Article 21.5 – Mexico) , paras. 7.33, 7.78, 7.98, 7.108, 7.109, 7.111, 7.119, 7.123, 7.144, 7.146, 7.152, 
7.156, 7.169, 7.266, 7.327, and 7.347.  
212 See e.g. Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico), paras. 7.80 and 
7.121.  
213 See e.g. Appellate Body Report, US – Tuna II (Mexico) , para. 286; US – Tuna II (Mexico) (Article 
21.5 – Mexico) , paras. 7.157, 7.239, and 7.330.  
214 See e.g. Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.101.  
215 See e.g. Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.242.  
216 See e.g. Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.144.  
217 See e.g. Appellate Body Report, US – Tuna II (Mexico)  (Article 21.5 – Mexico) , para. 7.344.  
218 See e.g. Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , paras. 7.334 and 
7.350.  
219 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , paras. 7.80 and 7.121.  
220 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.165.  
221 Mexico's response to Panels' question No. 78, para. 101. 
222 This is because one of the objectives of the label is to provide consumers with information as to the 
dolphin -safe status of tu na products in order to ensure "that the US  market is not used to encourage fishing 
fleets to catch tuna in a manner that adversely affects dolphins". Appellate Body Report, US – Tuna II (Mexico) 
(Article 21.5 – Mexico) , para. 6.3. 
223 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , paras. 7.169 and 7.372 and fn. 464, 
681 and 711.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  proceedings intended subsequent compliance panels to include risks relating to inaccurate 
certification, reporting, and/or record -keeping  within the "risk profiles" that it instructed those 
panels to assess and co mpare. Rather, the Appellate Body's focus was clearly on the risks of  
observable and unobservable  mortality and injury caused to dolphins as a result of the use of 
different fishing methods  in different areas of the ocean.  
7.111.   In order to explore this issue fu rther with the parties, we asked Mexico to clarify whether 
there is support in either of the Appellate Body's reports for its view that the reliability of different 
systems for certification and tracking and verification are integral elements of the risk p rofile in 
different fisheries.224 Mexico responded  that the Appellate Body's reports in the original and first 
compliance proceedings "do not directly address" whether the Tuna Measure must be calibrated to 
the relative risks of inaccurate dolphin -safe infor mation being passed on to US consumers , or 
whether the reliability of the applicable systems for certification, tracking and verification are 
integral elements of the risk profile of different fisheries. In Mexico's view, however, "the 
maintenance of label  accuracy is part of the Appellate Body's reasoning".225 
7.112.   As we discuss in more detail later in these Reports, we agree with Mexico that the question 
of the accuracy  of certification, and tracking and verification  was relevant to  the Appellate Body's 
analysis  in the original and the first compliance proceedings. That, however, is different from 
saying that the applicable legal standard, as clarified by the Appellate Body, requires the Panels to 
determine whether the 2016 Tuna Measure is calibrated, inter alia , to the risk of inaccurate 
dolphin -safe information being passed to consumers , or that risks relating to inaccurate labelling 
are an integral part of the risk profiles of different fisheries.  In our view, Mexico's 
acknowledgement that the Appellate Body re ports "do not directly address" this point also confirms 
our reading of those reports.  Given the importance placed by the Appellate Body on the calibration 
test, and the detail with which it described that test, we believe that, if the Appellate Body had 
considered risks of inaccurate labelling to be part of the "risk profile" of a fishery, such that a 
subsequent compliance panel would need to assess whether the relevant regulatory distinctions 
were calibrated to the risks of inaccurate labelling , it would have said so explicitly. However, as 
Mexico acknowledges, it did not. Rather, it repeatedly referred to the risks to dolphins arising from 
the use of different fishing methods in different areas of the ocean.  
7.113.   Therefore,  those risks are not part of the risk  profiles of different fisheries, and accordingly 
the applicable legal standard does not require us to assess whether the different regulatory 
distinctions are calibrated to  the different risks of inaccurate certification or tracking and 
verification that may exist in different fisheries.  That said, such risks are relevant to the application 
of the legal test to the facts, as we explain in detail below.226 
7.114.   We now turn to consider the second issue requiring further clarification  with regard to the 
legal test , namely the relationship between the calibration analysis and the question of whether 
there is a rational connection between the regulatory distinctions and the objectives of the 2016 
Tuna Measure. As noted above, Mexico argues that the calibration analysis  "can and must" occur 
within the constraints of the rational connection test for arbitrary and unjustifiable 
discrimination.227 In particular, Mexico argues that "the accuracy of the dolphin -safe label, as a 
consumer information measure, is essential to the objective of protecting dolphins from adverse 
effects arising in different fisheries"228, and that the calibration analysis must take into account the 
nexus between the regulatory distinctions and this objective.229 Mexico argues that this position is 
confirme d by the Appellate Body's statement in the first compliance proceedings that the 
calibration analysis must be undertaken "taking account of the objectives of the measure".230 
7.115.   Insofar as Mexico's argument suggests that we should assess the existence of a rati onal 
relationship between the detrimental impact and the objectives of the 2016 Tuna Measure as a 
separate or distinct step in our analysis, w e are not convinced that Mexico's approach is supported 
by the Appellate Body's reports in the original or the  first compliance proceedings. In the first 
place, we note that although the Appellate Body in the first compliance proceedings found that the 
                                                
224 Panels' question No. 78.  
225 Mexico's response to Panels' question  No. 78, para. 96.  
226 See paras. 7.119  to 7.124  below.  
227 Mexico's response to Panels' questions Nos. 73, para. 79 and 76, para. 85.   
228 Mexico's second written submission, para. 42 (internal citations omitted).  
229 Mexico's second written submission, para. 27. 
230 Appellate  Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.155.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  first compliance panel had not erred in its articulation of the applicable legal standard, including in 
its emphasis of the importance of assessing whether the detrimental impact c ould be reconciled 
with, or was rationally related to, the policy pursued by the measure at issue231, it nevertheless 
held that there was a "special relevance" in this dispute in conducting a pro per calibration analysis. 
In the light of this holding, the Appellate Body proceeded to find that the first compliance panel 
had erred by failing to conduct such an analysis.232 As we have explained above, in our view, these 
findings of the Appellate Body es tablish that in this dispute , the question of whether the 2016 Tuna 
Measure is consistent with Article 2.1 of the TBT Agreement can be answered by assessing 
whether that Measure is calibrated to the risks to dolphins arising from the use of different fishi ng 
methods in different areas of the ocean.233 We do not read the Appellate Body as requiring any 
additional , separate analysis of, for example, the abstract relationship between the objectives of 
the Measure and the detrimental impact.  
7.116.   Additionally , we do n ot agree with Mexico that the Appellate Body's statement that the 
calibration analysis must be conducted taking account of the objectives of the Measure indicates 
that the calibration analysis should be "constrained" by an analysis of whether the detriment al 
impact is rationally related to the objectives of the measure, insofar as "constraint" in this context 
suggests an external benchmark against which the calibration analysis described above must be 
checked and with which it must be reconciled. Rather, we  understand this statement to mean  that 
(a) the form and content  of the calibration test must be appropriately informed by the objectives 
pursued by the measure , and (b) the calibration test should itself be applied  taking account of the 
measure's objectiv es. 
7.117.   With respect to (a), we understand the Appellate Body's reference to the objectives of the 
Measure to mean that  those  objectives inform the criteria in respect of which calibration is to be 
assessed. For example, it is conceivable that the Panels could  assess whether the relevant 
regulatory distinctions of the 2016 Tuna Measure were calibrated to the different  depth of the  
ocean floor in different regions . Such an analysis, however, would have no connection to the 
objectives pursued by the Measure  based  on the evidence on the record , and accordingly would fall 
foul of the Appellate Body's guidance. On the other hand, calibration to the risks to dolphins 
arising from the use of different fishing methods in different areas  of the ocean would take account 
of the objectives of the 2016 Tuna Measure, which, as noted above, are "contributing to the 
protection of dolphins, by ensuring that the US  market is not used to encourage fishing fleets to 
catch tuna in a manner that adversely affects dolphins" and "ensuri ng that consumers are not 
misled or deceived about whether tuna products contain tuna that was caught in a manner that 
adversely affects dolphins".234 Accordingly, because the form and content of the legal standard 
articulated by the Appellate Body are infor med and shaped by the Measure's objectives, we take 
those objectives into account in applying the legal standard articulated by the Appellate Body . 
7.118.   With respect to (b), we also understand the Appellate Body's reference to mean that, in 
applying the calibra tion test to the facts, and in particular in developing an appropriate 
methodology for assessing calibration and in assessing whether the relevant regulatory distinctions 
are in fact calibrated to the risks to dolphins arising from the use of different fis hing methods in 
different areas of the ocean , we should bear in mind the objectives of the 2016 Tuna Measure.  In 
this regard,  we consider that  although, as we have explained above, the calibration test does not 
require us to consider whether the 2016 Tuna Measure is calibrated to the risks of inaccurate 
certification, reporting, and/or record -keeping , those risks are nevertheless central to our 
application  of the calibration test, precisely because in applying the calibration test we must take 
the objective s of the Measure into account.  
7.119.    In this connection, we note that by the expression "risk of inaccuracy", we understand the 
first compliance panel, the Appellate Body, and the parties to mean the risk that, as a result of an 
error in the certification,  and tracking and verification processes , the information recorded and 
reported at any stage of the tuna catch and processing chain could misrepresent the actual 
dolphin -safe status of a batch of tuna. In other words, we understand it to mean the risk that an 
error in the recording and reporting of information somewhere in the catch and processing chain 
could result in a batch of tuna being designated as dolphin -safe while in fact containing tuna that 
should have been designated as non-dolphin -safe. 
                                                
231 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.95.  
232 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.169.  
233 Appellate B ody Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.155.  
234 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.16.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.120.   In this rega rd, we find it important to note that , as we understand it, the existence of a 
margin of error in certification,  and tracking and verification requirements does not necessarily 
equate or give rise to a risk that the information ultimately conveyed to a con sumer by a dolphin -
safe label will itself be incorrect. In our view, t he risk of inaccurate information being passed to 
consumers by the label will depend not only on the referred margin of error, but also , and 
importantly, on the extent of events that req uire recording whether a dolphin mortality or serious 
injury was observed  in a given fishery.  
7.121.   To give an example , it is possible to think of a situation where the margin of error is high 
but where , due to a low  occurrence of events that require recording w hether a dolphin mortality or 
serious injury was observed, the risk of  incorrect information ultimately conveyed to a consumer 
by a dolphin -safe label would be low. Conversely, there might be a situation where the margin of 
error is low but the extent of e vents that require recording whether a dolphin mortality  or serious 
injury was observed  is so high that there is a higher risk of incorrect information ultimately 
conveyed to a consumer by a dolphin -safe label. In our view, the  risk profile is a good proxy  to 
measure the extent of events that require recording235 whether  a dolphin mortality or serious 
injury was observed.  
7.122.    Thus, in applying the calibration test and taking into account the objectives of the 2016 
Tuna Measure, we cannot assume that the mere exi stence of margins of error in certification,  and 
tracking and verification  requirements  is necessarily inconsistent with the objectives of the 
Measure. Rather, in our view, the central question is whether any margins of error in certification, 
tracking and  verification , and any differences in the  margins of error tolerated by different 
certification, and tracking and verification  requirements , are calibrated to the risks to dolphins 
arising from the use of different fishing methods in different areas of the  ocean.  
7.123.   To put this another way, we consider that, in applying the calibration test, it is appropriate 
for us to consider whether the certification,  and tracking and verification requirements applied in 
different fisheries are commensurate with, and tailor ed to, the particular risk profiles of those 
fisheries. In our view, in a fishery where the risks to dolphins are low, it may be calibrated to apply 
certification,  and tracking and verification  requirements that tolerate a higher margin of error than 
the certification, reporting, and/or record -keeping  requirements that apply in respect of fisheries 
with a high risk profile. This is because the risk that the dolphin -safe label will communicate 
inaccurate information is a function of numerous factors, includi ng not only the regulations in 
place, but also  the different levels of dolphin interaction, mortality, and serious injury in different 
fisheries . Thus, in fisheries with high dolphin interactions and harms, more sensitive certification, 
and tracking and ve rification requirements may be needed to ensure the ultimate accuracy of the 
dolphin -safe label, whereas in fisheries with low dolphin interactions and harms, less sensitive 
requirements  may be sufficient. Thus, the extent to which margins of error in certification,  and 
tracking and verification requirements, or any differences in the margins of error in different 
certification,  and tracking and verification requirements, are consistent with the objectives of the 
2016 Tuna Measure cannot be answered by look ing at the regulations in isolation. Rather, it is 
necessary to examine them in the light of the relevant risk profiles in different fisheries, in 
particular by assessing whether any margins of error in certification,  and tracking and verification 
requirem ents are themselves calibrated to, tailored to, and commensurate with the different risk 
profiles in different fisheries.  
7.124.   Thus, we consider that  the objectives of the 2016 Tuna Measure can  and should  be taken 
into account in the application of the calibrat ion test to the facts , in particular in assessing whether 
any margins of error in certification, and tracking and verification requirements, or any differences 
in the margins of error in different certification, and tracking and verification  requirements, are 
calibrated to the risks to dolphins arising from the use of different fishing methods in different 
areas of the ocean . This, however, is not the same as requiring that the relevant regulatory 
distinctions themselves be calibrated to the different risks  of inaccurate certification and tracking 
and verification , nor is it the same as "constraining" the calibration analysis by reference to a 
separate analysis of the relationship between the Measure's objectives and the detrimental 
treatment . 
                                                
235 By "events that require recording", we mean not only the events, such as death or serious injury o f 
dolphins, which make up the risk profile of the relevant fishery, but also other events, such as the fact that 
dolphins were observed by the vessel captain or independent observer; whether or not dolphin -safe and non -
dolphin -safe tuna were segregated in the wells on board the vessel; and whether that segregation was 
maintained during the trans -shipment and unloading of the tuna.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.125.   We further not e that, as we understand it, Mexico's argument that the calibration analysis 
should be constrained by the rational relationship test appears to  create an artificial distinction 
between the consumer information and the dolphin protection objectives of the Measure. As we 
understand it, the 2016 Tuna Measure does not pursue two distinct objectives. Rather, the two 
objectives are mutually complementary and reinforcing, and work together to "address [the effects 
of] adverse of fishing techniques on dolphins".236 In this connection, while it is certainly true that 
the 2016 Tuna Measure "is a labelling measure which, by its nature and design, is primarily 
focused on conveying accurate information to consumers"237, we agree with the United States that 
"that information is not provided simply for the sake of informing consumers".238 Rather, the 
Measure aims to convey accurate information to consumers in order to ensure that the US tuna 
market is not used to encourage fishing fleets to catch tuna in a manner that adversely a ffects 
dolphins.239 The objective of providing information to consumers is therefore a part of, rather than 
separate from, the objective of protecting dolphins.240 
7.126.   Finally on this point, we note Mexico's argument that conducting a calibration analysis that 
is constrained by an examination of the existence of a rational connection between the detrimental 
impact and the objectives of the Measure is necessary in order to "ensure[] symmetry between 
Article 2.1 of the TBT Agreement and the chapeau of Article XX of t he GATT 1994".241 In the 
context of this dispute, it is unnecessary for us to opine on the existence of a systemic "symmetry" 
between the two provisions. We would simply note that the calibration analysis we have described 
is fully consistent with the legal standard applicable under the chapeau of Article XX of the 
GATT  1994, as clarified by the Appellate Body. The calibration test looks precisely at whether the 
relevant regulatory distinctions are "tailored to", "commensurate with", or "explained" by 
differe nces in the underlying situation to which the 2016 Tuna Measure seeks to respond.242 As we 
see it, this is similar to the inquiry under Article XX of the chapeau, which considers,  inter alia , 
whether the measure is "applied in a manner which would constitute  a means of arbitrary or 
unjustifiable discrimination".  
7.127.   In sum, we find that in these proceedings, there is a "special relevance" to an analysis of 
whether the 2016 Tuna Measure is calibrated to the risks to dolphins arising from the use of 
different fishi ng methods in different areas of the ocean. In particular, we recall the Appellate 
Body's statement in the first compliance proceedings that the Measure will not be inconsistent with 
Article 2.1 of the TBT Agreement if it is properly calibrated to those ri sks. For the reasons given 
above, we conclude that the risk of inaccurate labelling does not  form part of the "risk profiles" of 
different fisheries . Additionally, we disagree with Mexico's argument that  the calibration analysis 
must be "constrained by" a distinct analysis of the relationship between the detrimental impact 
and the objectives of the Measure.  Having said that, in our view the calibration analysis "takes 
account of the objectives of the Measure" insofar as those objectives inform the shape and  content 
of the calibration test. Moreover, as we explain in more detail below, the objectives of the Measure 
will also be taken into account in the application  of the legal standard to the facts at issue.  
7.128.   Before concluding our discussion of the applicable  legal test, we briefly note Mexico's 
argument that WTO "Members are of course free to choose their own objectives. But if the means 
they use to achieve those ends are inconsistent with the objectives of sustainable development, 
then they are likewise inco nsistent with their WTO obligations".243 In response to a question from 
the Panels concerning the legal basis for this argument, Mexico argue s that while the reference to 
sustainable development in the preamble of the WTO Agreement does not itself create any  
obligations, nevertheless the text of all WTO obligations that in any way relate to the objective of 
sustainable development  or environmental protection  must be interpreted and clarified within this 
textual context.244 Moreover, Mexico contends that the pri nciple of sustainable development has 
                                                
236 Panel Report, US – Tuna II , para. 7.550 . 
237 Mexico's response to Panels' question No. 115, para. 231.  
238 United States' response  to Panels' question No. 115, para. 402. 
239 Panel Report, US – Tuna II , para. 7.427.  
240 We note that the Appellate Body appears to have confirmed this understanding in its report in the 
first compliance proceedings, where it stated that the panel had failed to conduct the required calibration 
analysis "in the light of the objective of protecting dolphins from adverse effects arising in different fisheries".  
Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.253.  
241 Mexico's comments on United States' response to Panels' question No. 117, para. 173. 
242 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.253.  
243 Mexico's second written submission, para. 32. 
244 Mexico's response to Panels' question No. 84, para. 13 0. WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  risen to the status of a principle of international law applicable to all countries245, and accordingly 
should be taken into account by the Panels when interpreting Article 2.1 of the TBT Agreement in 
accordance with cus tomary rules of interpretation of public international law246, including the rule 
codified at Article 31(3)(c) of the Vienna Convention on the Law of Treaties . Finally, Mexico refers 
to the "17 global goals and the 169 global targets of the Sustainable Devel opment Goals approved 
by the United Nations in September of 2015 – with the support of both Mexico and the United 
States" and posits that, although not binding, they should "provide helpful guidance as context 
from broader public international law in this dispute for the purposes of interpreting and clarifying 
the relevant obligations in the WTO covered agreements in a manner that is consistent with the 
objective of sustainable development".247 In particular, Mexico argues that the Sustainable 
Development Goa l 14, and its targets 14.2 and 14.4, on sustainable management of marine 
ecosystems and effective regulation of fishing practices, respectively, provide "useful context" for 
this dispute.248 
7.129.   As we understand it, Mexico's argument is that the Panels should, a t the least, interpret 
Article 2.1 of the TBT Agreement in the light of the principle of sustainable development. This is so 
because (a) the preamble of the WTO Agreement refers to s ustainable development, and 
(b) sustainable development has risen to the s tatus of a principle of international law applicable in 
the relations between all countries.  
7.130.   It is not entirely clear to us what, in Mexico's view, would be the result of interpreting 
Article 2.1 in the light of the principle of sustainable development. In  its response to the Panels' 
question, Mexico suggest s that "[m]easures that discriminate in a manner that goes against the 
objective of sustainable development are inconsistent with this important context [i.e. the context 
provided by the preamble of the WTO Agreement] and, therefore, can be found to be inconsistent 
with the obligations and requirements in Article 2.1 and the chapeau to Article XX".249 This 
argument, however, does appear to elevate the preambular language to the level of substantive 
obligati on, despite Mexico's assertion to the contrary. As Mexico itself acknowledges, however, the 
preamble to the WTO Agreement does not of itself create substantive obligations.  We of course 
recognize that the preamble of the WTO Agreement  "add[s] colour, textu re and shading to [the] 
interpretation of the agreements annexed to the WTO Agreement ".250 In our view,  however,  to 
accept, as Mexico proposes, that a measure may be found to be inconsistent with a particular 
provision of one of the covered agreements becaus e it discriminates in a manner that  goes again st 
one of the goals referenced in the preamble to the WTO Agreement would go far beyond 
recognizing that the preamble informs the interpretation of the covered agreements.251 Rather, it 
would elevate the language  of the preamble to the level of a norm, and accord it more weight than 
the language used by the Members in framing the obligations contained in the covered 
agreements.  
7.131.   In our view, Article 2.1 is essentially concerned with ensuring that technical regulati ons are 
designed and applied in a manner that affords national treatment and most favoured nation 
treatment to all WTO Members.252 That Article 2.1  may apply in respect of technical regulations 
that themselves pursue the objective of sustainable development is beside the point, since it may 
just as well apply in respect of technical regulations that have nothing whatsoever to do with 
sustainable development. At any rate, we note that, we do not consider that the 2016 Tuna 
Measure is concerned with sustainable  development. Rather, it is concerned with the protection 
and well -being of dolphins.253 While the protection of dolphins of course has an impact on the 
conservation and therefore the sustainability of dolphin populations, that does not render the 2016 
Tuna Measure a "sustainability" measure, nor does it turn a dolphin -safe label into a 
"sustainability" label. The WTO Agreement does not obligate the United States or any other 
Member to regulate only for the objective of "sustainable development", and in our v iew a 
measure is not inconsistent with Article 2.1 of the TBT Agreement merely because it pursues some 
other objective.  
                                                
245 Mexico's response to Panels' question No. 84, para. 132.  
246 Article 3.2 of the DSU.  
247 Mexico's response to Panels' question No. 84, para. 133.  
248 Mexico's response to Panels' question No. 84, para. 134.  
249 Mexico's response to Panels' question No. 84, pa ra. 125. Also , Mexico's response to Panels' question 
No. 84, paras. 135 and 139.  
250 Appellate Body Report, US – Shrimp , para. 153. 
251 Appellate Body Report, US – Shrimp , para. 129. 
252 Appellate Body Report, US – COOL , para. 267.  
253 Panel Report, US – Tuna II ( Mexico) (Article 21.5 – Mexico) , para. 7.527.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.6  Burden and standard of proof  
7.132.   Before proceeding, it is convenient to say something about the burden of proof. The Panels 
note that t he ge neral principles applicable to burden of proof in WTO dispute settlement require 
that a party claiming a violation of a provision of the WTO Agreement by another Member must 
prove its claim.254 Further, it is generally for each party asserting a fact, whethe r complainant or 
respondent, to provide proof thereof.255 We also note that the fact that proceedings initiated under 
Article 21.5 of the DSU concern measures taken to comply with DSB recommendations and rulings 
does not alter the allocation of burden of pro of.256 We will be guided by these principles with 
regard to burden of proof in these proceedings.  
7.133.   However, we note that these proceedings are somewhat unusual, in that both the original 
complaining party and the original responding party have requested the e stablishment of panels 
under Article 21.5 of the DSU to determine the consistency with the WTO Agreement of a measure 
taken to comply by the original responding party. The parties' written and oral submissions have 
not clearly distinguished between claims and arguments made in respect of the proceedings 
brought by the United States, on the one hand, and those made in respect of the proceedings 
brought by Mexico, on the other hand. This is perhaps inevitable given that the parties agree as to 
what is the mea sure taken to comply, namely the 2016 Tuna Measure, and both proceedings focus 
on two issues, namely, whether the 2016 Tuna Measure (a) complies with the requirement to 
provide "treatment no less favourable" under Article 2.1 of the TBT Agreement and (b) m eets the 
conditions laid down in the chapeau of Article XX of the GATT 1994.  
7.134.   Although, technically speaking, these Panels deal with two disputes, in terms of their 
practical dynamics, these proceedings resemble very much proceedings dealing with a single 
dispute, except with respect to the issue of burden of proof. The allocation of the burden of proof 
requires special attention in these proceedings because both the original complainant (Mexico) and 
the original respondent (United States) are at the same ti me both complainant and respondent in 
these proceedings. Further, the claims and arguments of both parties presented in the proceedings 
brought by Mexico are the mirror image of their claims and arguments presented in the 
proceedings brought by the United States. Thus, in the proceedings brought by the United States, 
the United States, as complaining party, argues that the 2016 Tuna Measure brings the United 
States into compliance with the WTO Agreement because it complies with the requirement to 
provide "t reatment no less favourable" under Article 2.1 of the TBT Agreement and meets the 
conditions laid down in the chapeau of Article XX of the GATT 1994. Mexico as the responding 
party argues the opposite. In the proceedings brought by Mexico, Mexico as compla ining party 
argues that the 2016 Tuna Measure fails to bring the United States into compliance with the WTO 
Agreement, because it neither complies with the requirement to provide "treatment no less 
favourable" under Article 2.1 of the TBT Agreement nor mee ts the conditions laid down in the 
chapeau of Article XX of the GATT 1994. The United States as the responding party argues the 
opposite. Accordingly, the United States' claim that the 2016 Tuna Measure brings the United 
States into compliance with the WTO  Agreement is a claim that is made both as a complaint and 
as a response. The same is true of Mexico's claim.  
7.135.   Given this situation, it is not entirely clear how in practice we should apply the principles 
on burden of proof cited above. While the parties ap pear to agree on these principles, neither has 
explained how those principles could actually be applied in the light of the consolidated way in 
which the parties presented their arguments. In this regard, we note that, in its first written 
submission, Mexi co explains that "[t]his submission presents Mexico's prima facie  case that the 
measure violates [Article 2.1 of the TBT Agreement and the chapeau of Article XX of the GATT 
1994] in the Article 21.5 – Mexico II  proceeding. It also responds to the first wri tten submission of 
the United States in the Article 21.5 – United States  proceeding".257 The submission does not, 
however, distinguish between those arguments made as part of Mexico's prima facie  case, and 
those made in response to the United States' submiss ion. The United States similarly argues in its 
second written submission that "[t]he United States agrees that with respect to the matter brought 
by the United States, the United States has the burden of proof, and with respect to the matter 
                                                
254 Appellate Body Report, US – Wool Shirts and Blouses , p. 14.  
255 Appellate Body Report, US – Wool Shirts and Blouses , p. 14.  
256 Appellate Body Report, Brazil – Aircraft (Article 21.5 – Canada) , para. 66; Panel R eport, Canada – 
Dairy (Article 21.5 – New Zealand and US) , para. 6.4.  
257 Mexico's first written submission, para. 4.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  brought by Mex ico, Mexico has the burden of proof". The United States does not, however, make 
any distinction in its submissions between the two matters.258 
7.136.   In its third party statement, Norway argues that "the burden of proof does not shift 
depending on who initiated the  Article 21.5 proceedings".259 In Norway's view, the principles 
outlined by the Appellate Body and quoted above apply regardless of whether the United States or 
Mexico initiated proceedings under Article 21.5 of the DSU. In order to explore this issue with t he 
parties, we asked them to comment on Norway's argument. In response, Mexico maintains that 
"[i]n both Article 21.5 proceedings, the burden of proof under the chapeau of Article XX is on the 
United States. In the case of Article 2.1, the initial burden i s on the United States and Mexico 
respectively".260 The United States responds by arguing that "Mexico carries the burden of proof 
for its claims that the measure taken to comply is inconsistent with a covered agreement in the 
matter brought by it, and the U nited States carries the burden of proof with respect to the 
existence of a measure taken to comply in the matter brought by it".261 Again, however, neither 
party explains how, in practice, both parties could bear the burden of proof in respect of their own 
proceedings, given that neither party distinguished between the arguments it made in the 
proceedings brought by the United States and those it made in the proceedings brought by Mexico.  
7.137.   Given the special nature of these proceedings, while we will follow th e basic principles on 
burden of proof that have emerged from WTO dispute settlement, we will avoid applying those 
principles in a mechanistic fashion, because doing so would not only cause unnecessary confusion, 
but would also risk not respecting parties' due process rights. Given that both parties address 
overlapping legal issues  and present  the same set s of exhibits, in both proceedings, and given the 
narrowly -defined nature of the claims before us, we find it appropriate to apply the above -
referenced pri nciples on burden of proof in a cumulative or holistic fashion. That is, since both 
parties are at the same time the complainant and the respondent in these proceedings, in 
resolving these issues, we will assess both parties' claims and arguments in a holi stic fashion.  
7.138.   With respect to standard of proof, we recall that the principle in WTO dispute settlement is 
that the complainant who has the initial burden of proof has to make a prima facie  case for the 
burden to shift to the respondent to rebut that case.  In this regard, we recall that a prima facie 
case is one which, in the absence of effective refutation by the other party, requires a panel, as a 
matter of law, to rule in favour of the party presenting the prima facie case.262 Since we will 
evaluate holist ically the parties' submissions in these proceedings, with respect to the issues that 
we will assess, we will find for the party that overall presents a more convincing case in terms of 
arguments and evidence.  
7.139.   Independently of our explanations above regard ing the allocation of the burden of proof, 
and the issue of the standard of proof, in reviewing the parties' arguments in support of their 
claims, we will be guided by the principle that " the party that asserts a fact is responsib le for 
providing proof the reof".263 In this regard , we recall that " [i]t is important to distinguish, on the 
one hand, the principle that the complainant must establish a prima facie case of inconsistency 
with a provision of a covered agreement from, on the  other hand, the principle that the party that 
asserts a fact is responsible for providing proof thereof ".264 We note that the parties also agree 
with this point. In both its second written submission and its response to the Panels' question, the 
United States argues that "regardless of which party has the general burden of proof, the party 
that asserts a fact is responsib le for providing proof thereof".265 Mexico similarly recognizes that, 
as the Appellate Body explained in the first compliance proceedings in this dispute, " each party 
bears the burden of substantiating the assertions that it makes ".266 
7.140.   We note that the approach we have laid out above is consistent with the statement by the 
Appellate Body in the first compliance proceedings in this dispute that the burden of proof is not 
                                                
258 United States' second written submission, para. 11.  
259 Norway's third party submission, para. 8.  
260 Mexico's response to Panels' question N o. 122, para. 248.  
261 United States' response to Panel' question No. 122, para. 441.  
262 Appellate Body Report, EC – Hormones , paras. 98, 104.  
263 Appellate Body Report, US – Tuna II (Mexico) , para. 283.  
264 Appellate Body Report, Japan – Apples , para. 157.  
265 United States' response to Panels' question No. 122, para. 442 (internal citations omitted). See also 
United States' second written submission, para. 11.  
266 Mexico's response to Panels' question No. 104, para. 205 (citing Appellate Body Report, US – Tuna II 
(Mexico) (Article 21.5 – Mexico) , para. 7.33 ). WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  "an entirely binary issue".267 The Appellate Body in those proceedings further explained that both 
parties in a claim under Article 2.1 have "responsibilities" to substantiate their claims and 
arguments, and that the burden of proof should not be appli ed "mech anistically".268 We also find 
support in the reasoning of the panel in EC and certain member States – Large Civil Aircraft 
(Article 21.5 – US) that "WTO dispute settlement proceedings  do not involve any particular 
temporal sequence of proof. Both parties wil l adduce evidence in support of their own arguments 
or to rebut the arguments made by the other at various stages of a dispute, sometimes 
simultaneously, throughout the entirety of a proceeding ".269 
7.141.   Finally, we also consider our approach to be consistent wit h our obligation under Article 11 
of the DSU to conduct an objective assessment of the matter before us, "including an objective 
assessment of the facts of the case and the applicability of and conformity with the relevant 
covered agreements".  
7.7  Factual findings 
7.7.1   Introduction  
7.142.   The Panels now turn to assess the evidence on the record relating to the risks to dolphins 
arising from  the use of  different fishing methods in different areas of the ocean . This will enable us 
to identify the risk profiles of different f isheries, on the basis of which we will then determine 
whether the 2016 Tuna Measure  is calibrated to the risks to dolphins arising from  the use of  
different fishing methods in different areas of the ocean.270 
7.143.   In this section, we (i)  outline the findings mad e by the Appellate Body and the panels in 
previous stages of this dispute regarding the appropriate methodology to be used in assessing the 
evidence on the risk profiles of different fishing methods , as well as their factual findings regarding 
the nature o f the risks posed and harms done to dolphins by such methods; (ii) discuss certain 
preliminary issues on the methodology that we will use in assessing the evidence on the record; 
(iii) make findings about the risk profiles of individual fishing methods; an d finally (iv) provide a 
comparative assessment of the results of the method -specific findings.  
7.7.1.1   Findings made in previous proceedings  
7.144.   We recall  that these compliance proceedings are not occurring in a vacuum, but rather 
form part of a continuum  of events, beginning with the original panel proceedings . In this 
connection, we note that numerous findings on the methodology to assess evidence and on the 
facts have been made over the course of this dispute. Such findings are relevant to our task of 
analyzing  the evidence and assessing the risks posed to dolphins by the use of different fishing 
methods in different parts of the ocean. In our view, these factual findings must be taken into 
account in our analysis of the factual record in order to avoid any doubts a s to the objectivity  of 
these compliance proceedings .271 In this  Section, we will discuss these existing findings and our 
interpretation of how they should be applied in the context of the present proceedings.  
7.7.1.1.1   Previous  findings regarding the appropriate meth odology to be used  
7.145.   We observe that in previous  stages of this dispute, the Appellate Body has provided 
guidance on the nature of the assessment that should be undertaken in determining if the Tuna 
Measure is adequately calibrated to the relative risks to d olphins  arising from the use of  different 
fishing methods in different parts of the ocean.  
7.146.   In the first compliance proceedings and in the context of completing the legal analysis 
after having reversed some of the legal findings made by the compliance panel  regarding Article 
                                                
267 Appellate Body Report, US – Tuna II  (Mexico)  (Article 21.5 – Mexico) , para. 7.34. 
268 Appellate Body Report, US – Tuna II  (Mexico ) (Article 21.5 – Mexico) , para. 7.34. 
269 Panel Report, EC and certain member Stat es – Large Civil Aircraft (Article 21.5 – US), para. 6.50.  
270 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.169.  
271 See Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 5.9 (referring to 
Appellate B ody Report s, US – Softwood Lumber VI (Article  21.5 – Canada) , para.  103; US – Upland Cotton 
(Article  21.5 – Brazil) , para.  386). WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  2.1 of the TBT Agreement272, the Appellate Body found that the panel had not put itself in a 
position to conduct an  assessment of whether the  2013 Tuna Measure was even-handed in 
addressing the respective risks of setting on dolphins in th e ETP large purse -seine fishery versus 
other fishing methods outside that fishery .273 The Appellate Body explained that this was because, 
in the panel's  assessment of the relative harms posed  to dolphins  by setting on dolphins versus 
other fishing methods, t he compliance p anel focused almost exclusively  on the unobserved harms 
associated with different fishing methods .274 The Appellate Body explained that although there was 
considerable evidence on the record concerning the nature and scope of the relative risk s 
associated with different fishing methods  in different areas of the ocean275, the compliance panel 
did not address what th at evidence indicated in respect of the overall levels of risks in different 
fisheries , and how the se fisheries  compared to each other . The Appellate Body also held  that it 
failed to consider the relative risks posed by different fishing methods in respect of observed  
mortality or serious injury, while focusing solely on the narrower difference in the respective risks 
attributable to unobserved  harms .276 In other words, the Appellate Body faulted the first 
compliance panel for conducting a narrow assessment of the relative risks posed by different 
fishing methods, in particular, because it failed to consider the relative risks arising from observed 
mortalities and serious injuries to dolphins.  
7.147.   As we understand it, the Appellate Body's finding in this connection indicates that, in our 
factual assessment, we need to undertake an evaluation of the overall  levels of  relative  risks or 
levels of h arms277 attributable to different fisheries, including in respect of both observ able and 
unobserv able harms. We note, however, that the nature of the concept of "overall levels of relative 
risks", and what it entails in practical terms , is not immediately  clear. 
7.148.   In this regard, we observe that both parties presented arguments on how the Panels 
should understand the concept of "overall relative levels of harm". Mexico argues they can be 
understood as the aggregate of direct and observed dolphin mortality and s erious injury together 
with the indirect and unobserved harms to dolphins caused by a particular fishing method .278 For 
its part, t he United States considers that the expression "overall relative levels of harm" conveys 
two concepts: (i) the use of the words  "overall " and "harms" conveys the scope of harms that the 
Panels should examine, i.e. mortalities and serious injuries, as well as those unobservable harms 
that are "a result of the chase itself"279, and (ii) the inclusion of the word "relative" conveys tha t 
the Panels should compare  these harms across fishing methods and fisheries.280 
7.149.    In our view, an assessment  of the overall  levels of  relative  risks attributable to different 
fisheries, including in respect of both observ able and unobserv able harms , entails a comparison of 
the different risks to dolphins arising from the use of different fishing methods in different parts of 
the ocean. In particular, it entails an assessment of the risks to dolphins posed by the fishing 
method predominately used by Mexico ( i.e. setting on dolphins in the large purse seine fishery in 
the ETP), which is ineligible for the dolphin -safe label, in comparison with  the risks to dolphins 
                                                
272 We observe that the Appellate Body stated that, in applying the legal test under Article 2.1 of the 
TBT Agreement, the " Panel  was required to assess whether the certification and tracking and verification 
requirements [were] 'calibrated'  to the risks to dolphins arising from different fishing methods in different 
areas of the oceans " and concluded that, the first compliance pane l's analysis "failed to encompass 
consideration of the relative risks to dolphins from different fishing techniques in different areas of the oceans, 
and of whether the distinctions that the amended tuna measure draws in terms of the different conditions o f 
access to the dolphin -safe label are explained in the light of the relative profiles" . Appellate Body Report, US – 
Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.169.  
273 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.249 . 
274 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , paras. 7.245 and 7.249.  
275 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.243.  
276 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.248.  
277 We note that in its report in the first compliance proceedings, the Appellate Body did not use 
necessarily the same terminology when referring to the concept of "overall relative risks". While it used the 
expression "overall relative  harms" in  para. 7.246, it used the expression " overall relative risks or levels of 
harm" in paras. 7.252 and 7.3 53. To us, there is a relationship between the concepts of relative risks and 
relative harms insofar as the determination of the levels of risks  can be s een as an analysis where the 
likelihood of occurrence of an adverse event, in this case, observable and unobservable harms to dolphins, is 
assessed. Consequently, an assessment of the levels of risks  involves an assessment of the levels of harms . 
278 Mexico' s response to Panels' question No. 96.  
279 United States' response to Panels' question No.  96 (referring to  Appellate Body Report, US – Tuna II 
(Mexico) (Article 21.5 – Mexico) , para. 7.116; Panel Report, US – Tuna II  (Mexico)  (Article 21.5 – Mexico) , 
para. 7.122 ). 
280 United States' response to Panels' question No. 96.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  posed by other fishing methods in different parts of the ocean.281 As a basis to conduct this 
compar ison, we observe that we will need to establish the risk profiles of the relevant fishing 
method s in different areas of the ocean, taking into account data on both observable and 
unobservable harms.  
7.150.   In this regard, we are mindful of the difficulty posed by  the scientific and technical nature 
of the information needed to undertake this task and the inherent difficulties associated with this 
type of data. Indeed,  we note that in the first compliance proceedings, the Appellate Body itself 
recognized " the diffi culty associated with making such an assessment of the respective risks, 
particularly in the light of the highly contested evidence adduced by the parties", and also stated 
that "the panel was [not] necessarily in a position to come to a definitive or prec ise view as to the 
extent to which the relevant risk profiles differed".282 In this vein, we asked the parties during the 
course of our substantive meeting whether, in their view, the Panels should consult with external 
experts to better understand the diffe rent risk profiles in different fisheries. Both parties agreed 
that it was in the Panels' discretion to seek such guidance from independent and qualified experts.  
The United States submitted that even if the Panels' have this discretion, they could still c ome to a 
determination on this issue based on the evidence on the record.  
7.151.   In our view, the difficulties  that the Appellate Body recognized in the first compliance 
proceedings are equally present in these proceedings. Indeed, we are not  necessarily in a pos ition 
to come to a definitive or precise view as to the extent of relevant risk s and how precisely they 
may differ across different fisheries in different parts of the ocean.  Nevertheless, we decided not to 
consult with external experts  for the purpose of enhancing our understanding of the evidence 
presented by the parties . This is because  our ultimate  task in these proceedings  is to establish 
whether the 2016 Tuna Measure is consistent with the United States' obligations under Article 2.1 
of the TBT  Agreem ent, and not to conduct a fully -fledged scientific evaluation of the different risks 
that dolphins face across the globe. While our analysis under Article 2.1 of the TBT Agreement 
requires a determination of the different risk profiles of different fishing  methods in different parts 
of the ocean, we consider that this can and should be done on the basis of the available scientific 
information that has already been produced by experts on the matter and that has been submitted 
as evidence by the parties. In t his connection, our task is to conduct a thorough and objective 
review of the evidence on the record, and not necessarily to come to conclusions aiming to 
establish scientific or environmental truth. We note that, as the evidentiary record and the 
argument s of the parties show, the relevant scientific and environmental issues are still highly 
debated by experts in the field of marine biology  and fisheries management. We will therefore 
conduct our assessment  in light of such inherent difficulties and limitat ions in the evidence on the 
record, and the divergence in the arguments presented by the parties on the basis of that 
evidence.  
7.152.   With these caveats in mind,  and in the light of the Appellate Body's finding on the relevant 
analysis,  we will  undertake an eval uation of the overall levels of relative risks attributable to 
different fisheries, including  in respect of both observ able and unobserv able harms.  
7.7.1.1.2   Previous factual findings: observable and unobservable harms to dolphins  
7.153.   In the previous stages of these pro ceedings, both the panels and the Appellate Body made 
a number of factual findings relevant to our current examination, in particular, regarding the 
harms caused to dolphins by different fishing methods in different areas of the ocean. In this 
section, we will briefly discuss those findings.  
7.154.   In doing so, we are mindful that the Appellate Body has stated that "doubts could arise 
about the objective nature of an Article  21.5 panel's assessment" if, on a specific issue, that panel 
were to "deviate from the rea soning" in the original report "in the absence of any change in the 
underlying evidence in the record" .283 In other words,  in conducting the factual assessment 
described above, we consider that we  should take due account of the relevant reasoning  and 
                                                
281 We observe that neither party has submitted evidence concerning high -seas driftnet fishing.  
282 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.252.  
283 Appellate Bod y Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 5.9 (referring to 
Appellate Body Report s, US – Softwood Lumber VI (Article  21.5 – Canada) , para.  103; US – Upland Cotton 
(Article  21.5 – Brazil) , para.  386). Although these cited statements may  not directly refer to the context of our 
current proceedings, i.e. because they refer to the nature of the assessment of a first compliance panel, we 
consider them to be applicable mutatis mutandis  in our current situation . WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  finding s that led to the original  and 2013 Tuna M easure s being found to be WTO -inconsistent.  We 
will thus take account of this reasoning, unless we find that there has been a relevant  change in 
the underlying evidence in the record . 
7.155.    We now move to discuss those previous relevant factual findings  concerning harms to 
dolphins in the ETP large purse -seine fishery  and other fisheries . We note that such harms can be 
broadly categorized as relating to (i) observable harms , both observed and unobserved,  and 
(ii) unobser vable harms.  
7.156.   Regarding observable harms, the first compliance panel found that these are "the kind of 
interactions that can and, under the amended tuna measure, must be certified, and whose 
occurrence renders ineligible for the dolphin -safe label any tuna caught in the set in which the 
harmful interaction (i.e. the death or serious injury) occurred".284 The first compliance panel also 
described observable harms as "perceptible during fishing operations"285, but also  found that the 
concept  extend ed beyond certif ied serious injuries or mortalities,  and could  includ e dolphin 
mortality or serious injury occurring after the end of the fishing operation. In this vein, the 
compliance panel stated that " [w]hile it may be that dolphins injured in gillnets die at some lat er 
time, injuries such as those leading to gillnet p arts 'protruding from the mouth'  of dolphins would 
seem clearly to  be the kind of 'serious injury'  that is observable" .286 
7.157.   Regarding unobserved harms, the original panel broadly described these  as "negative  
impacts on dolphins beyond observed deaths and serious injuries" .287 It also explained that it 
understood "the United States' use of the terms 'observed mortalities and injuries' as referring to 
dolphin killings or serious injuries that are reported during (or immediately after the conclusion of) 
dolphin -setting operations. Thus, to the extent that setting on dolphins also result s in dolphin 
deaths or injuries that are not observed or taken into account as observed killings or serious 
injuries, the other adv erse effects identified by the United States may be described as unobserved 
deaths o r injuries of dolphins" .288 Moreover , in concluding on the  issue of unobserved harms  
caused by  setting on dolphins, the original panel found "a degree of uncertainty in relat ion to the 
extent to which setting on dolphins may have an adverse impact on dolphins beyond observed 
mortality" .289 Nonetheless, the original panel considered that sufficient evidence had been put 
forward by the United States to raise a presumption that gen uine concerns exist in this respect.290 
7.158.   The concept of uno bserved harms was also discussed in the  first compliance proceedings. 
In this co nnection, we note that the first compliance panel recalled  the findings made in the 
original proceedings, including that  setting on dolphins causes unobservable harms to dolphins 
beyond mortality and serious injury, that these harms arise "as a result of the chase itself".291 The 
first compliance panel described unobservable effects as " negatively impacting the health and wel l-
being of dolphin populations "292 and also clarified that "[n]o ne of […] fishing methods other than 
setting on dolphins inflict the same kinds of unobservable harms that are caused by net sets ".293 
In relation to  ETP large  purse seine  fishing  by setting on do lphins, the compliance panel noted that 
"even if there are tuna fisheries using … gear types that produce the same number of dolphin 
mortalities and serious injuries allowed or caused in the ETP  … it is simply not the case that such 
fisheries are producing  the same level of unobserved harms, such as cow -calf separation, muscular 
damage, immune and reproductive system failures, which arise as a result of the chase in 
itself".294 
7.159.   We note that in drawing further distinction s between the unobservable harms of set ting on 
dolphins and other fishing methods, the first compliance panel introduced the notion of "direct" 
and "indirect" harms, clarifying that " indirect and unobservable harms may follow consequentially 
                                                
284 Panel Report, US – Tuna II  (Mexico) ( Article 21.5 – Mexico),  para. 7.132.  
285 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico), para. 7.579.  
286 Panel Report, US – Tuna II (Mexico) para. 7.736,  US – Tuna II (Mexico) (Article 21.5 – Mexico), para. 
7.130.  
287 Panel Report, US – Tuna II (Mexico), para. 7.484. 
288 Panel Report, US – Tuna II (Mexico), fn. 675.  
289 Panel Report, US – Tuna II (Mexico), para. 7.504. 
290 Panel Report, US – Tuna II (Mexico), para. 7.504. 
291 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico), para. 7.579 (referring to Appellate Body 
Report, US – Tuna II (Mexico) , paras.  246 and  289). 
292 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico), para.  7.132.  
293 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico), para. 7.132.  
294 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico), para. 7.581.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  from observable harms caused by tuna fishing methods other than setting on dolphins"295, thus 
constituting a broader concept, not necessarily involving the element of chase.  
7.160.   Regarding the types of unobservable harms caused by setting on dolphins, the first 
compliance panel stated that, w hile the evidence on th e record "clearly establishes that tuna 
fishing methods other than setting on dolphins pose serious threats to dolphins, we have been 
unable to find any indication in this evidence that fishing methods other than setting on dolphins 
cause the kinds of unob servable harms that are caused by setting on dolphins" .296 Hence, despite 
the "degree of uncertainty " noted  by the original panel "in relation to the extent to which  setting 
on dolphins may have an adverse impact on dolphins beyond the observed mortality"297, the first 
compliance panel noted the same genuine concerns regarding setting on dolphins. The first 
compliance panel also stated that "unlike the kinds of unobservable harms caused by setting on 
dolphins, these types of indirect harms are thus qualitativel y different from the kind of 
unobservable harms caused by setting on dolphins" and  that these "are harms whose occurrence 
cannot be recorded ".298 
7.161.   We are mindful that during the appeal in the first compliance proceedings, Mexico claimed 
that the panel  had erred in finding that fishing methods other than setting on dolphins have no 
unobservable adverse effects.299 In essence, Mexico claimed that the first compliance panel  had 
found that all of the effects on dolphins caused by fishing methods other than setting o n dolphins 
would be "observable" if a trai ned person were watching for them , but that  this was a factual error  
given that Mexico  had submitted evidence that not all adverse effects  of fishing methods other 
than setting on dolphins  are observable.300 The Appe llate Body found that Mexico had  not properly 
substantiated its claim nor established that the compliance panel found that fishing methods other 
than setting on dolphins have no unobservable adverse effects301, in particular because it did not 
read the compl iance p anel's reasoning to include any finding that all of the adverse effects on 
dolphins caused by other fishing methods would be "observable" if a trained person were watching 
for them.302 According to the Appellate Body, the compliance panel had rather f ound that no 
fishing method inflict s the same  kinds of unobservable harms  as the ones caused by purse seine 
fishing by  setting on dolphins.303 
7.162.   With respect to fishing methods other than setting on dolphins , we note that there are a 
number of factual findings  that have been made in previous stages of these proceedings regarding 
the adverse effects of particular fishing methods in different parts of the ocean. We will discuss 
these findings  when we examine each fishing method below, and take them into account u nless 
any new evidence presented in these proceedings requires us not to do so.  
7.7.1.2   Preliminary issues about the methodology to assess evidence  
7.163.   As we mentioned in paragraph 7.150 above  above, there are a number of difficulties 
associated with our task of evaluating the  overall levels of relative risks  of different fisheries and 
the assessment of the evidence  on the record. In particular, we note that there are three 
preliminary issues that must be dealt with before  moving into ou r evidential assessment: (i) the 
methodology that we should use to conduct the assessment of the different risk profiles of the 
relevant fisheries ; (ii) the differences between different kinds of harms posed to dolphins ; and 
(iii) certain difficulties pert aining to the assessment of the evidence on the record . We will discuss 
each of these matters in turn.  
7.7.1.2.1   The methodology that we should use to conduct the assessment of the 
different risk profiles of the relevant fisheries  
7.164.   Although the Appellate Body has pro vided guidance as to the general nature of the task of 
assessing the evidence, namely, that we should undertake an evaluation of the overall levels of 
                                                
295 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico), para  7.134.  
296 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico), para. 7.131.  
297 Panel Report, US – Tuna II (Mexico), para. 7.504 . 
298 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico), para. 7.134.  
299 Appellate Body Report , US – Tuna II (Mexico) (Article 21.5 – Mexico), para. 7.198.  
300 Appellate Body Report , US – Tuna II (Mexico) (Article 21.5 – Mexico), para. 7.198.  
301 Appel late Body Report , US – Tuna II (Mexico) (Article 21.5 – Mexico), para. 7.202.  
302 Appellate Body Report , US – Tuna II (Mexico) (Article 21.5 – Mexico), para. 7.200.  
303 Appellate Body Report, US – Tuna II  (Mexico)  (Article 21.5 – Mexico) , para. 7.200.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  relative risks  associated with  different fisheries, including in respect of both observ able and 
unobserva ble harms, it is not clear how this assessment should be conducted. In our view, this is a 
crucial issue, and its resolution  will determine , in concrete and practical terms, the way in which 
we should parse through the evidence in order to determine the di fferent risk profiles necessary 
for our analysis under Article 2.1 of the TBT Agreement.  
7.165.   We note that there are two dimensions to this issue: one relating to the general approach 
that should be used, including whether the Panels' assessment should be quali tative, quantitative, 
or a mix of the two, and which relevant indicators or variables should be taken into account when 
comparing risk levels as between different fisheries; and another relating to the use of a 
standardized benchmark or metric, so that the  results from the different scientific studies can be 
adequately contrasted and compared. We note that the parties have significant disagreements 
particularly concerning th e second dimension.  
7.7.1.2.1.1    General approach  
7.166.   The United States argues that the Panels shou ld undertake a mixed qualitative and 
quantitative assessment of the different risks to dolphins arising from the use of different fishing 
methods in diffe rent areas of the ocean. The United States contends that unobservable harms 
must be part of the assess ment of the overall relative risk posed by setting on dolphins, compared 
to other fishing methods, but that due to their nature, these harms are not susceptible of precise 
quantification. Consequently, the United States submits that this aspect of the Pane ls' assessment 
must be qualitative. Regarding observable harms arising from dolphin mortalities and serious 
injuries and the frequency of interactions  with fishing vessels that are dangerous to dolphins, the 
United States argues that they can be measured q uantitatively.304 
7.167.   Regarding the variables or indicators that should be used, the United States contends that 
the Appellate Body in the first compliance proceedings made clear that any subsequent compliance 
panel should assess the overall relative risk profil e for dolphins of different fishing methods in 
different fisheries , and that, consequently,  any indicators or variables that are relevant to the 
overall risk profile of a fishery or fishing method should be included in the Panels' analysis, and no 
relevant  indicators or variables should be excluded from the analysis. In particular, the United 
States submits that three relevant indicators or variables should be taken into account: (i) the fact 
that setting on dolphins intentionally targets dolphins and there fore involves dangerous 
interactions with dolphins every time it is used, whereas other fishing methods do not; (ii) the fact 
that setting on dolphins causes a unique category of unobservable harms not caused by other 
fishing methods; and (iii) the relativ e levels of dolphin mortalities caused by the different fishing 
methods in different fisheries. F or the United States, the Panel s' analysis should balance these 
three factors, with unobservable harms being taken into account on a qualitative basis, and lev els 
of dolphin interaction and dolphin mortalities caused by different fishing methods in different 
fisheries being considered quantitatively.305 
7.168.   Mexico argues that a calibration analysis requires a relative assessment of risks to dolphins 
arising from the u se of different fishing methods in different  areas of the ocean . For Mexico, a 
relative assessment requires that a standardized benchmark, i.e. a consistent method of 
comparison, be used to assess relative risks.306 In Mexico's view, "d irect harms " are at least 
potentially measurable  if there is data available of a sufficient quality.307 Mexico maintains that in 
this case , the absence of comprehensive data  on some  fisheries makes the application of a 
quantitative evaluation very chal lenging, but that a t the sam e time a purely qualitative analysis 
may be overly su bjective and arbitrary. Mexico argues that, b y definition, unobservable harms 
cannot be measured, and consequently t he Panels can only speculate  on their existence. Mexico 
also submits that  presumptions  the Panels may make about the existence of risks, including of 
unobservable harm  must be made in a consistent manner across all fisheries.308 
7.169.   We agree with the United States that, as the Appellate Body has already clarified that the 
nature of our task is to assess the overall relative risk profiles for dolphins of different fishing 
                                                
304 United  States' response to Panels' question No. 116.  
305 United States' response to Panels' question No. 116. See also United States' first written submission, 
paras. 97 -103; second written submission, para. 77.  
306 Mexico's response to Panels' question No. 79.  
307 Mexico's response to Panels' question No. 116.  
308 Mexico's response to Panels' question No. 116.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  methods in different areas of the ocean, all variables apt for measuring the nature and degree of 
observed and unobserved harms are in principle relevant to the determination of th e risk profiles. 
These variables would include the number of observed mortalities and serious injuries, the nature 
and extent of any unobservable harms caused by different fishing methods in different areas of the 
ocean, the nature and extent of the intera ction with dolphins of the fishing method in a given area 
of the ocean, if any, and any other indicators that are helpful in describing the risks to dolphins 
arising from the use of different fishing methods in different areas of the ocean.  
7.170.   In relation to the issue of whether our analysis should be qualitative, quantitative, or a mix 
of the two, we agree with the parties that, given the inherent difficulties of quantifying 
unobservable harms, our approach should encompass both a quantitative and a qualitati ve 
dimension. Bearing in mind our obligation to conduct an objective assessment of the matter, we 
will rely to the greatest extent possible on a quantitative analysis, and recur to a qualitative 
assessment in cases where this seems to be the most reasonabl e avenue to properly gauge and 
describe the risks at issue.  
7.7.1.2.1.2   Use of a standardized benchmark  
7.171.   We now turn to the issue of the use of a standardized benchmark or metric when 
determining and comparing the different risk profiles. The importance of this issue c annot be 
understated. Because the different scientific evidence on the record does not necessarily follow the 
same methodology or present its results in a homogeneous and consistent manner, there is a need 
to use a standardized benchmark so that comparison s across studies are meaningful and 
adequate. In other words, there is a need to use a standard metric to assess the risks posed to 
dolphins so that the relevant information can be extracted in a coherent and comparable manner 
from the evidence on the reco rd. As noted above, the parties disagree significantly on what would 
be an appropriate benchmark . In particular, they disagree on whet her the Panels should use a 
(i) Potential Biological Removal (PBR) methodology or a (ii) per set  comparison of dolphin 
mortalities.  
7.172.   Mexico  argues  that the Panels  should assess the risks to dolphins in a given fishery by  
apply ing the PBR methodology , which measures the maximum number of animals that may be 
removed from an animal stock (such as dolphins) without affecting that stock's optimum 
sustainable population.309 Mexico contends that the PBR level can first be determined for an ocean 
area and then compared to the level of animal stock removal to assess the level of risk to the 
sustainability of the stock.310 Alternatively, Mex ico requests the Panels to use an "absolute levels 
of adverse effects on dolphins" methodology, whereby the Panels would examine the absolute 
levels of dolphin mortalities and serious injury caused by different fishing methods in different 
areas of the oce an.311 
7.173.   The United States disagrees with both of Mexico's proposed approaches . It argues instead 
for a per set methodology that would measure and compare the level of harm caused to dolphins 
by units of effort across different fishing methods. According to th e United States,  both 
methodologies  proposed by Mexico  are inconsistent with the calibration analysis articulated  by the 
Appellate Body. Regarding the first methodology, the United States argues that Mexico's metric 
misunderstands the purpose  of the eligib ility criteria, which do not adopt a fishery -by-fishery 
approach but rather a fishing method -by-fishing method approach312, and disregards the fact that 
the Measure at issue is a dolphin -safe label rather than a dolphin -sustainability label .313 Regarding 
the second method proposed by Mexico, the United States contends that Mexico's metric invites 
the Panels to conduct an analysis that does not address all aspects of the harms of different fishing 
methods and does not take a relative approach.314 
                                                
309 Mexico's first written submission, para. 240. Mexico notes that the Appellate Body  has commented 
on this method by stating: "We do not exclude that reference to  such objective indicators might assist in an 
assessment of whether regulatory differences in the treatment of different fisheries can be explained on the 
basis that such treatment is calibrated to, or commensurate with, the relative risks to dolphins aris ing from 
different fishing methods in different areas of the oceans". Appellate Body Report, US - Tuna II (Mexico) 
(Article 21.5 – Mexico) , fn. 827. 
310 Mexico's first written submission, para. 242. 
311 Mexico's first written submission, para. 247. 
312 United St ates' second written submission, para. 119.  
313 United States' second written submission, para. 122. 
314 United States' second written submission, para. 126.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.174.   We will begin our  analysis by addressing the methodologies proposed by Mexico, namely, 
the PBR methodology and the "absolute levels of adverse effects on dolphins"  methodology. We 
will then proceed to assess the per set methodology proposed by the United States.  
7.7.1.2.1.3   PBR method ology  
7.175.   As noted above , Mexico argues that the Panels should use the PBR methodology, which 
measures the maximum number of animals that may be removed from an animal stock (such as 
dolphins) without affecting that stock's optimum sustainable population.315 For Mexico, the use of 
the PBR methodology would capture all of  the relevant factors that need to be taken into account 
by the Panels, and it provides a common benchmark against which to measure  the different risk 
profiles of different fisheries . Mexico conte nds that there is  sufficient  information on the record to  
enable the Panels to find, on the basis of the PBR methodology,  that the 2016 Tuna M easure is not 
calibrated.316 
7.176.   Mexico submits  that the Department of Commerce used the PBR methodology to evaluate 
the dolphin stocks that interact with the dolphin encircl ement fishing method in the ETP.317 Mexico 
also contends that, where only a small absolute number of mortalities could result in the extinction 
of a dolphin stock, such potential extinctions are harmful t o dolphins.318  
7.177.   Mexico also  notes  that in the first compliance proceedings, the Appellate Body stated  that 
it did "not exclude that reference to such objective indicators [such as the PBR] might assist in an 
assessment of whether regulatory differences in th e treatment of different fisheries can be 
explained on the basis that such treatment is calibrated to, or commensurate with, the relative 
risks to dolphins arising from different fishing methods in different areas of the oceans".319 
According to Mexico, this  statement lends support to the idea of using the PBR methodology in our 
assessment.  
7.178.   The United States opposes the use of the PBR methodology  for four reasons . First, the 
United States contends that the 2016 Tuna Measure is not a sustainability measure, as  its 
objectives make clear, and that as such, the PBR methodology  is inconsistent with the design of 
the Measure, which tracks harm to individual dolphins on a per set basis. The United States argues 
that under the PBR methodology , mortality in a fishery m ay be sustainable even if there are many 
deaths, on a per set basis, and may be unsustainable even if there are only very few dolphins 
killed on a per set basis , as it depends on the population and reproduction rates of the relevant  
dolphin stocks. For the  United States, Mexico's claim that a PBR methodology  must be used to 
assess whether the Tuna M easure is calibrated is akin to concluding that the objective  of the  Tuna 
Measure has to  become sustainability in order to be WTO -consistent . The United States n otes, 
however,  that the previous DSB recommendations and rulings confirm that this is not the case.320 
The United States claims that the findings underlying the DSB recommendations and rulings 
establish that "t he preservation of individual dolphin lives is j ust as much an act of conservation as 
is a program to encourage reco very of a particular population" , and that the objective of the Tuna 
Measure of protecting "the well -being of individual dolphins" is legitimate.321 
7.179.   Second, the United States claims that Mex ico's argument conflicts with the very structure 
of the Tuna Measure , as the eligibility criteria make a distinction based on fishing methods on the 
one hand (setting on dolphins compared to other fishing methods), and sets or gear deployments 
on the other  hand (sets where a dolphin was killed or seriously injured compared to sets where no 
such harm took place). For the United States, the eligibility criteria do not draw distinctions on a 
fishery -by-fishery basis.  The United States clarifies this point by a rguing that, f or example, the 
eligibility criteria do not deny access to the label for just th e tuna product produced from setting 
                                                
315 Mexico's first written submission, para. 240.  
316 Mexico's response to Panels' question No. 116.  
317 Mexico's first written submission, para. 41.  
318 Mexico's responses to the Panels' questions, para. 41; second written submission, para. 64.  
319 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , fn. 827.  
320 United States' response to Panels' question No. 33. See also United States' third written submission, 
paras. 36 -39; second written submission, paras. 36 -38. 
321 United States' response to Panels' question No. 33 (referring to Panel Report, US – Tuna II  (Mexico)  
(Article 21.5 – Mexico) , para. 7.527 ). WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  on dolphins in the  ETP large purse seine fishery, but rather,  they deny access to the label for all 
tuna product produced fro m setting on dolphins, no matter where the set occurs.322 
7.180.   Third, the United States contends that a PBR cannot be created for an entire fishing  
method because it is an inherently area -specific methodology . The United States argues that the 
PBR methodology  concerns particular stocks of dolphins that may be  affected by one or more 
fisheries . The United States claims that this means that the effects on a particular population of a 
particular fishing method cannot be disassociated from the effects on the same popu lation of a 
different fishing method , and that a single fishery could have multiple PBRs if there are multiple 
species of dolphins living in proximity with one another.  In the United States' view, these 
considerations render the PBR methodology inappropria te for the assessment called for by the 
Appellate Body.323 
7.181.   Finally , the United States contends that th e PBR methodology  is unworkable as there is 
simply not enough data  on the record  to conduct the required evaluation using this 
methodology.324 
7.182.   In response to the United States, Mexico  argues that, in accordance with the reasoning of 
the Appellate Body  in the first compliance proceedings , calibration must be undertaken in 
reference to the risks to dolphins  arising  from the use of different fishing methods in dif ferent 
ocean areas, and thus, for the purpose of calibration, the United States is incorrect in arguing that 
Mexico's approach is "inconsistent with the fishing method approach of the eligibility criteria". 
Mexico also contends that the United States is fa ctually incorrect when it characterizes the 
eligibility criteria under the Tuna M easure as having a fishing method approach because the 
designation of driftnet fishing as ineligible applies only to high seas driftnet fishing. Mexico thus 
submits that the T una Measure's eligibility criteria apply to both fishing method and ocean area s 
and that therefore the analysis of calibration must take into account both the method and the 
area.325 
7.183.   Mexico further notes the existence of a different US law, administered  by the same agency 
that administers the Tuna Measure,  which makes reference to the PBR methodology. According to 
Mexico, this law is evidence that  the United States  believes the PBR can and should be used  to 
determine the risks that dolphins face in different parts of the ocean . Additionally, Mexico argues 
that, on 15  August  2016, the  US Department of Commerce  issued regulations for evaluating the 
regulatory programs of other countries for reducing marine mammal mortality and injury in their 
export fisheries.326 Mexico submits that under those regulations , foreign countries  are required  to 
create assessments that estimate population abundance for marine mammal stocks that are killed 
or seriously injured in their territorial waters , and that, b ased on an evaluation  of data submitted 
by each harvesting nation, the Commerce Department will either issue a comparability finding or 
deny a comparability finding with  an explanation for such denial , and it will also specify the fish 
and fish product subject to the denial. Mexico further submits that i f a comparability finding is 
denied or is terminated, imports of fish and fish products from the fishery in question wil l be 
subject to an import ban.327 
7.184.   The Panels begin by noting that the PBR methodology enables calculation of t he maximum 
possible number of animals, in this case dolphins, which can be removed from an animal stock 
without affecting the population or its sustainability. We observe that in the context of the present 
proceedings, if this methodology were to be used, it would result in an estimation of the maximum 
numbers of dolphins  in a particular stock  that could be killed, while allowing that stock  of dolphins  
to reach or maintain its optimum sustainable population.328 In this regard, use of a PBR 
                                                
322 United States' response to Panels' question No. 33.  
323 United States' response to Panels' question No. 33.  
324 United States' second written submission, para. 120; response to Panels' question No. 33.  
325 Mexico's response to Panels' question No. 80.  
326 Mexico's first written submission, para. 151 (referring to US Department of Commerce, Fish and Fish 
Product Import Provisions of the Marine Mammal Protection Act; Final Rule, 81 Fed. Reg. 54390 (August 15, 
2016), (Exhibit MEX -49). 
327 Mexico's first writte n submission, paras. 152 -158. 
328 In this connection, we  note that under the US Marine Mammal Protection Act (MMPA), PBR is defined 
as the maximum number of animals, not including natural mortalities , that may be removed from a marine 
mammal stock while allo wing that stock to reach or maintain its optimum sustainable population. The PBR level 
is the product of the following factor s: (a) The minimum population estimate of the stock; (b) one -half of the 
maximum theoretical or estimated net productivity rate of the stock at a small population size; and (c) a WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  methodology seems t o us to be suitable in the context of policies that concern the sustainability of 
marine mammal stocks  and where a certain level of mortalities  or serious injury is tolerated . 
Indeed, Mexico itself characterises this methodology as involving a comparison b etween the  levels 
of animal stock removal to assess the level of risk to the sustainability of the stock.329 Thus, to us, 
a PBR methodology is more concerned with the sustainability of a stock of animals than with the 
well-being of the individual animals com posing that stock , as it would tolerate a certain number of 
deaths.  
7.185.   We observe, however, that because of the very nature of the PBR methodology, and in 
particular because it is more concerned with the sustainability of a stock than with the effects of 
fishing on individual dolphins, using it in the context of these proceedings would not be useful, 
given the objectives pursued by the Tuna Measure, as well as with our task of evaluati ng the 
overall levels of  relative  risks attributable to different fisheries,  and the subsequent determination 
of the different risk profiles.  
7.186.   We recall  that the objectives of the Tuna Measure are, first, ensuring  that consumers are 
not misled or deceived about whether tuna products contain tuna that was caught in a manner 
that adv ersely affects dolphins ; and, second,  contributing  to the protection of dolphins by ensuring 
that the US  market is not used to encourage fishing fleets to catch tuna in a manner that 
adversely affects dolphins .330 In this connection, we note that there is no  particular indication that 
the Tuna Measure is  directly  concerned with the protection of the population levels of dolphins. 
Rather, it seems to us to be concerned with the protection of the well -being of dolphins, and with 
informing consumers whether the tuna used in the production of particular tuna products was 
caught in a set that harmed dolphins. In this sense, we understand the Tuna Measure to be 
concerned with the risks facing dolphins at an individual level, rather than at a population level. 
Having  said that, we recognize that mortality or serious injury suffered by individual dolphins may 
also have population -level consequences. That, however, is not directly relevant to the findings 
that we will make about the overall levels of relative risks pose d to dolphins by different fishing 
methods in different areas of the ocean.  
7.187.   In this connection, the  first compliance panel found that the 2013 T una Measure was more 
concerned with the effects of tuna fishing on the well -being of individual dolphins than on  the state 
of a particular dolphin population consi dered globally or statistically.331 The original panel also 
came to a similar conclusion when it stated that it was " not persuaded that the objective of 
protecting dolphins through the US  dolphin -safe provis ions is to be understood exclusively, or even 
primarily, in terms of dolphin population recovery ".332 
7.188.   In this vein, we are not persuaded that a methodology that is primarily aimed at assessing 
the sustainability of an animal stock but that nonetheless tolera tes the existence of mortalities is in 
line with the objectives of the Tuna Measure, and consequently, is appropriate for an assessment 
of the overall levels of relative risks  posed to dolphins for  the purposes of the present proceedings . 
By allowing the e xistence of some dolphin mortalities and focusing primarily on the population 
levels, the PBR methodology prioritizes the sustainability of the population rather than the well -
                                                                                                                                                  
recovery factor of between 0.1 and 1.0.  (Exhibit MEX -49), p. 54400 and Earth Island Institute v. Hogarth , 484 
F.3d 1123 (9th Cir. 2007) , (Exhibit MEX -3), p. 8.  See also Panel Report, US – Tuna II (Mexico) , fn. 716.   
329 Mexico's first written submission, para. 242. We note that this characterization was also argued by 
Mexico during the first compliance proceedings: " On appeal, M exico argues for the use of an ' object ive, 
scientifically -established'  benchmark – such as potential biological removal (PBR) levels – that could be used to 
compare how different fishing methods each affect the sustainability of dolphin populations ". Appellate Body 
Report, US – Tuna II  (Mexico)  (Article 21.5 – Mexico), fn. 827.  
330 Appellate  Body Report, US – Tuna II  (Mexico)  (Article 21.5 – Mexico), para. 7.16; Panel Report, US – 
Tuna II  (Mexico)  (Article 21.5 – Mexico) , para. 7.525;  Appellate Body Report,  US – Tuna II (Mexico) , para. 
325; Panel Report,  US – Tuna II (Mexico) , paras.  7.401, 7 .413, and 7.425.  
331 Panel Report, US – Tuna II (Mexico)  (Article 21.5 – Mexico) , para. 7.527.  We are nonetheless 
mindful that the original panel itself recognized that the conservation of dolphin populations might be one of 
the objectives of the Tuna Measur e by stating that the "US  objectives in relation to dolphin protection are not 
limited to the conservation of dolphin populations or to the avoidance of direct mortality ". Panel Report, US – 
Tuna II (Mexico) , para. 7.596. Although the first compliance pane l took note that the original panel recognized 
that to the extent that addressing adverse effects  arising from observed and unobserved mortalities and 
serious injuries to individual dolphins  might also be considered as seeking to conserve dolphin populatio ns, and 
that, consequently,  the US  objectives also incorporate  considerations regarding the conservation of dolphin 
stocks , it was clear in stating that, in their view, the Tuna Measure was more concerned with the " well-being of 
individual dolphins ". 
332 Panel Report, US – Tuna II (Mexico) , para s. 7.550 and 7.735.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  being of individual dolphins. To us, this is difficult to reconcile with the obj ectives of the Tuna 
Measure.  
7.189.   We also consider that the PBR methodology would not enable us to fully carry out the 
inquiry entrusted to us by the Appellate Body. We recall that the Appellate Body has instructed us 
to assess the overall levels of relative ri sks posed by different fishing methods in different areas of 
the ocean. In our view, such an inquiry requires us to consider both mortalities and serious 
injuries, and both observable and unobservable harms. However, under the PBR methodology, we 
would pot entially have to overlook mortalities that do not endanger the population of dolphins in a 
particular fishery. Additionally, we could not have regard to  serious injuries,  or to unobservable 
effects that do not have population -level consequences. In our vie w, this would be inconsistent 
with the Appellate Body's guidance.  
7.190.   In our view, the PBR methodology also sits uncomfortably with the design and structure of 
the 2016 Tuna Measure. We recall that, under the eligibility criteria, tuna caught outside the ETP 
large purse seine fishery or a large scale high seas driftnet fishery is ineligible for a dolphin -safe 
label if it was caught in a set or gear deployment in which dolphins were killed or seriously injured. 
Similarly, under the certification requirements, th e 2016 Tuna Measure provides that, for a tuna 
product to be labelled dolphin -safe, it must be accompanied by certain certifications that the 
eligibility requirements were met, in particular that "no purse seine net or other fishing gear was 
intentionally d eployed on or used to encircle dolphins …  and that no dolphins were killed or 
seriously injured in the sets or other gear deployments in which the tuna were caught".333 Thus, 
disregarding mortalities with the view to prioritizing population levels, and ignor ing non -fatal 
serious injuries, would be difficult to reconcile with the architecture of the measure, which by its 
own terms is concerned with the mortality and serious injury of individual dolphins, on a per set 
basis, rather than with the overall sustain ability of dolphin stocks.  
7.191.   Finally, we find inapposite Mexico's argument that the PBR methodology is employed in a 
different US law administered by the same agency that administers the Tuna Measure . The fact 
that the United States, in a different regulator y context and for a different measure, has decided 
to use a PBR methodology, has no relevance to our assessment of the 2016 Tuna Measure, whose 
objectives and structure, as we have noted above, are difficult to reconcile  with a PBR 
methodology.  
7.192.   For the for egoing reasons, the Panels reject Mexico's argument that in our assessment, we 
should use a PBR methodology to assess the overall levels of relative risks attributable to different 
fisheries, including in respect of both observ able and unobserv able harms.  
7.7.1.2.1.4   Absolute levels of adverse effects  
7.193.   We now turn to assess Mexico's contention regarding a methodology that focuses on the 
absolute levels of adverse effects. We recall that Mexico claims that the Panels should use an 
"absolute levels of adverse effects on d olphins" methodology whereby the Panels would examine 
the absolute levels of dolphin mortalities and serious injury caused by different fishing methods in 
different areas of the ocean.334 
7.194.   The United States disagrees with Mexico's position and  contends that M exico's metric 
invites the Panels to conduct an analysis that does not address all aspects of the harms of different 
fishing methods and does not take a relative approach.335 
7.195.   We note that, as discussed in section 7.7.1.1.1 above , the Appellate Body has already 
clarified the nature of our task, namely that in our factual assessment we need to undertake an 
evaluation of the overall levels of  relative  risks attributable to different fisheries, including in 
respect of both observable and unobservable harms. Because we need to undertake a comparative 
assessment of the different risk profiles , we do not find it appropriate to primarily use a 
methodology that takes the absolute levels of adverse effects on dolphins into  account . This is 
because such a methodology would not necessarily deal with the issue of how to compare the 
                                                
333 Under the 2013 Tuna Measure, captains were only required to certify that no dolphins were killed or 
seriously injured in the gear deployment(s) in which the tuna was caught. Appellate Body Report,  US – Tuna II 
(Mexico) (Article 21.5 – Mexico) , para. 6.10. 
334 Mexico's first written submission, para. 247. 
335 United States' second written submission, para. 126.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  levels of adverse effects on dolphins aris ing from different fis hing methods in different areas of the 
ocean , or contextualize them in the light of  the relative  extent and intensity to which different 
fishing methods are used,  in such a way as to allow an apples -to-apples  assessment of the relative 
harmfulness of different fishing methods as used i n different areas of the oceans . 
7.7.1.2.1.5   Per set methodology  
7.196.   We turn now to analyse the parties' arguments regarding the per set methodology.  The 
United States claims that a per set methodology  is a scientifically accepted metric widely used by 
regional fisheries management organizations (RMFOs), national regulators , and scientists around 
the world for assessing risk levels in various fisheries. For the United States, one of the most 
widely accepted and commonly used methods of estimating overall risk based on observer data is 
by "multiplying catch rates determined f rom observer data by estimates of total fishing effort"336, 
and that a set is one of the most widely used and accepted units of fishing effort in this regard. 
Consequently, the United States submits that using a per set bycatch rate metric is a well -
establis hed way to measure and compare risks to bycatch species in different f isheries based on 
data from those fisheries .337 
7.197.    The United States contends that with respect to the analysis of direct, observable dolphin 
mortalities and injuries caused by tuna fishing,  sets or gear deployments are comparable across 
fisheries for purposes of assessing the relative risk to dolphins posed by different fishing methods . 
In this connection, the United States clarifies its understanding of the terms "gear deployment" 
and "set" , which it uses interchangeably.  The United States contends that  these terms  refer to a 
unit of fishing effort consisting of a single operation of the fishing gear used in the particular 
fishery. The  precise  definition of  a "set", or what a set consists of , varies according to the fishing 
method used.338 
7.198.   The United States argues that sets or gear deployments are comparable between fishing 
methods because gear deployment represents the same thing, this is, a unit of effort, across 
different methods. The United  States thus contends that a per set or gear deployment 
methodology  shows how often, relative to fishing effort, a dolphin is directly killed or injured in a 
particular fishery and how likely any particular fishing operation in that fishery is, on average,  to 
directly kill or injure a dolphin.339 
7.199.   The United States further contends that in the context of the Tuna Measure, sets or gear 
deployments are also comparable across fisheries, because the Measure is generally applied on a 
per gear deployment basis, and thus, for purposes of determining what portion of the tuna 
produced by a fishery is non -dolphin safe, how often captains have to make non -dolphin safe 
certifications, or how frequently non -dolphin safe tuna must be segregated from dolphin -safe tuna, 
sets o r gear deployments are comparable between different fishing methods.340 
7.200.   Mexico argues that to apply the United States' per set comparison based on the inadequate 
data available would be unscientific and arbitrary. Mexico contends that if data is collected fr om 
within the same fishery in a consistent manner on a year -by-year basis, per set  or per gear 
deployment data can be used to evaluate whether fishery conditions (such as population 
abundance or level of interactions) or the performance of vessels has chan ged over time. 
However, Mexico argues that there is no precedent for using per set  or per gear deployment 
methodology  to compare the dolphin mortality rates of different fisheries, using different 
equipment and/or methods in different ocean regions. Mexico  submits that comprehensive data is 
not collected for any fishery except the large purse seine fishery in the ETP , and that purse seine 
sets are different in nature and length than longline, gillnet and trawl deployments. Mexico notes 
                                                
336 United States' response to Panel s' question No. 100 (referring to Tim Lawson, Secretariat o f the 
Pacific Community, Methods for Analysing Bycatches with Observer Data (Aug ust 2001) , (Exhibit USA -227)).  
337 United States' response to Panel s' question No. 100 (referring to Tim Lawson, Secretariat of the 
Pacific Community, Methods for Analysing Bycat ches with Observer Data (Aug ust 2001) , (Exhibit USA -227)).  
338 For purse seine fisheries, the United States argues a set consists of the deploying and pursing of the 
purse seine net, pulling it aboard the seiner, and harvesting the catch. For longline fisher ies, a set consists of 
the baiting, setting, and hauling in of longlines and the landing of the catch. For pole and line and handline 
fisheries, it consists of the locating of the tuna, the chumming of the bait or baiting hooks, and the ensuing 
fishing on the tuna school from the vessel. For trawl and gillnet fisheries, it consists of the setting, fishing or 
soaking, and hauling in of the net. United States' response to Panel's question No. 93.  
339 United States' response to Panel s' question No. 93.  
340 United States' response to Panel s' question No. 93.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  that the United State s itself has declined to use a per set  methodology in evaluating the Indian 
Ocean gillnet fisheries.341 
7.201.   Mexico also argues that there are  problems beyond the lack of quality data outside the 
ETP. For Mexico, the United States' approach lacks any scientifical ly-based measuring stick. Mexico 
also argues that the quantitative approach proposed by the United States seems inconsistent with 
its claim that the Measure is not intended to protect dolphin populations, but rather discourage 
harms to dolphins on an indiv idual basis , because  gillnets, longlines, purse seine nets and trawls 
have all been shown to harm dolphins.342 
7.202.   Regarding the comparability of sets or gear deployments across fishing methods, Mexico 
argues that they are not comparable. For Mexico, the differe nces between  different fishing gear 
and techniques in different fishing methods are significant. Mexico submits that, for example, a 
longline fishing set can take as long as 10 -12 hours or more , and the lengths of the lines and the 
number of hooks can vary  greatly. Mexico also contends that other fishing methods, such as pole -
and-line fishing, have a shorter duration. A gillnet deployment can last anywhere between a few 
hours and several days, again with varying sizes of nets. There is also variability in p urse seine 
sets.343 
7.203.   Mexico also contends that a comparison of the relative overall risks of harm to individual 
dolphins posed by different fishing methods on a per set basis is further complicated by the fact 
that dolphins exist in all tuna fisheries, and th at there is a recognized absence of reliable data on 
interactions  with dolphins.344 
7.204.   We begin by setting out our understanding of what using a per set methodology would 
imply in the context of our assessment of the overall levels of  relative risks posed to do lphins. As 
suggested by the United States, a per set or per gear deployment comparison entails averaging 
some of the relevant indicators identified in paragraph 7.169 above , including observed 
mortalities, se rious injuries , and interactions, by the number of operations of the fishing gear used 
in a particular fishery in a given time period. For instance, in the case of the large purse seine 
fishery in the ETP, we understand that using this methodology would en tail dividing the total 
number of observed mortalities or serious injury by the number of sets, with the latter consisting 
of each operation of deploying and pursing of the purse seine net, pulling it aboard the seiner, and 
harvesting the catch. The result ing number would then be compared to the number obtained by 
using the same methodology for a different fishery, e.g. gillnet fishery in the Indian Ocean. Thus, 
the use of this methodology would control for the intensity of a given fishing operation in a gi ven 
area of the ocean so that the number of observed mortalities or serious injuries to dolphins would 
be a proportion of the number  of times a fishing activity may put dolphins in harm occurs.  
7.205.   It is important to note that, in our view, the numbers resulti ng from the use of a per set 
methodology could only be  an input to establish the risk profile of a particular fishery, as they do 
not describe all the relevant aspects of the risks posed to dolphins by a particular fishing method 
in that fishery . This is s o for several reasons, including the fact that the number of mortalities or 
serious injuries per set is a description of observed, past events, and does not necessarily describe 
the likelihood of that same event happening in the future. Thus, although the occurrence of past 
dolphin mortalities or serious injuries might be a good predictor of those same events happening 
at some point in the future, other variables might have to be taken into account to complete this 
assessment. Additionally, and as a consequ ence of the very nature of this methodology, which 
relies on quantitative information, we are mindful that the per set methodology would only be 
suitable to describe and compare observable harm s, which can be quantified, but not necessarily 
adequate for th e assessment of  unobservable harm s. Therefore, in our view, this methodology 
would only  be able to  assist us in describing a part of the risk profile of a fishery, observable harm, 
but not necessarily the risks of unobservable harm.  
7.206.   Moving now to the scien tific basis of using a per set methodology, we observe that there 
are a number of studies on the record on this matter. Of particular i mportance  is a study by the 
Food and Agriculture Organization of the United Nations (FAO) on bycatch and non -tuna catch i n 
                                                
341 Mexico's responses to Panels' question No. 100. 
342 Mexico's responses to Panels' question No. 116. 
343 Mexico's responses to Panels' question No. 93. 
344 Mexico's responses to Panels' question No. 93. WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  the tropical tuna purse seine fisheries of the world from 2013345, which mentions that in order to 
estimate the total bycatch of a fleet in a period , there are four  main options: (i) estimate a ratio 
expressing the bycatch per unit of effort (BPUE) (set), or per tonnes of tuna captured or retained, 
and extrapolate it to the total amount of effort by the fleet in sets, or the total tonnage captured or 
retained; (ii) develop a model from observer data to predict the by catch in unobserved sets; 
(iii) estimate total mortality of a population, and subtract an estimate of natural mortality where 
available, with the traditional fisheries methods; and (iv) use tagging methods.346 The study also 
mentions that due to costs and logistic difficulties, the most used method s are either the 
estimation of a ratio expressing the bycatch per unit of effort and the development of a model 
from observer data to predict the bycatch in unobserved sets, with extrapolation based on 
observer data being the most common method in use in t he tuna fisheries.347 In our view, this 
study lends support to the United States' contention that the per set methodology is commonly 
used in scientific assessment. Although it might not be the sole methodology to describe risks 
posed to dolphins  by tuna fis hing, we believe that it would be  appropriate for us to use the per set 
methodology, particularly  because it is one of the most commonly used  methodologies . 
7.207.   We also note that the evidence on the record  shows that several RM FOs use a per set 
methodology whe n reporting bycatch rates of certain marine mammals, including dolphins. In this 
regard, a report of the International Dolphin Conservation Program under the purview of the 
Agreement on the International Dolphin Conservation Program and the Inter -American Tropical 
Tuna Commission (IATTC) from 2013 reports dolphin mortalities using a per set approach.348 In 
this context, we also  note that the per set methodology has been used to assess the bycatch of 
other animals, such as the silky shark.349 
7.208.   The Western and Central Pacific Fisheries Commissio n (WCPFC) also seems to follow this 
approach. As evidenced in several of its reports, the per set methodology is used routinely. For 
instance, in Exhibit USA -17, which contains summary information on whale shark and cetacean  
interactions in the tropical WCPFC purse seine fishery, prepared by the Secretariat of the Pacific 
Community -Oceanic Fisheries Programme, from November 2011, reports dolphin, baleen whale 
and whale sharks mortalities using a per set methodology .350 This met hodology is also used in 
Exhibit USA -228, containing a report of Integrated Shark Conservation and Management Measure 
for the Western and Central Pacific Ocean.351 
7.209.   A study on marine turtle bycatch prepared for the Indian Ocean Tuna Commission (IOTC) 
also rep orts some of its figures using a per set methodology. In particular, we note that the report 
mentions that "[t]he by -catches of marine turtles per unit of observation effort (i.e. observed sets) 
from 1995 to 2011 are shown in figure 11ab (see annexes 13a -d and 14a -d for the same maps per 
quarter). The mean number of by -caught turtles per observed set, where a capture occurred, is 
1.14 (SD=0.46) in the AO and 1.11 (SD=0.31) in the IO, meaning that most of the time, captures 
per set rarely account to more tha n a single individual" .352 It also mentions that "[t]o obtain the 
number of observed turtles  per observed set or per object observation per year, we divided the 
                                                
345 Martin Hall  and Marlon Roman, Bycatch and Non -Tuna Catch in the Tropical Tuna Purse Seine 
Fisheries of the World (2013) , (Exhibit USA -200).  
346 Martin Hall and Marlon Roman, Bycatch and Non -Tuna Catch in the Tropical Tuna Purse Seine 
Fisheries of the World (2013) , (Exhibit USA -200), p. 63.  
347 Martin Hall and Marlon Roman, Bycatch and Non -Tuna Catch in the Tropical Tuna Purse Seine 
Fisheries of the World (2013) , (Exhibit USA -200), p. 63.  
348 AIDCP, Report on the International Dolphin Conservation Program, Document MOP -28-05 (October 
18, 2013) (Exhibit MEX -08). "The average mortality per set was 0.094 dolphins in 2012 and  0.10 dolphins in 
2011. The trends in the numbers of sets on dolphin -associated fish, mortality per set, and  total mortality in 
recent years are shown in Fig ure 3 ". Seep. 3. See also Table 13, which contains the annual estimates of 
dolphin mortality, by species and stock, 1979 -2012, where the estimates for 1979 -1992 are based on a 
mortality -per-set ratio. See p. 15 . See also the  report from the  32nd Mee ting of  the Parties , Document MOP-
32-05, (Exhibit USA -15). 
349 IATTC, Tuna, Billfishes and Other Pelagic Species in the Eastern Pacific Ocean in 2014, Doc. IATTC -
89-04a, IATTC 89th Meeting (June 29 -July 3, 2015) , (Exhibits USA -14) and IATTC, Fishery Status Report N o. 
14 (2016)  (2016) , (Exhibit MEX-06). 
350 Summary Information on Whale Shark and Cetacean Interactions in the Tropical WCPFC Purse Seine 
Fishery, Paper prepared by SPC -OFP, 8th Reg ular Session, Koror, Palau (November  2011) , (Exhibit USA -17), 
tables 2a and 2 b. 
351 Shelley Clarke, Towards an Integrated Shark Conservation and Management Measure for the 
Western and Central Pacific Ocean, WCPFC -SC9-2013/EB -WP-08 (August 2013) (Exhibit USA -228), p. 15.  
352 Sandra Clermont et al., IOTC, EU Purse Seine Fishery Interacti on with Marine Turtles in the Atlantic 
and Indian Oceans: A 15 Years Analysis  (Sept ember  2012) , (Exhibit USA -230), p. 11.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  total number of observed turtles by the total observed sets or object observations per year. The 
annual mean of observed turtles per observed set or object and respective standard deviation 
were then calculated per Ocean and per fishing mode" .353  
7.210.   To us, the mentioned scientific evidence on the record provides ample support for the 
United States' conten tion that a per set methodology is a scientifically accepted metric widely used 
by RMFOs and scientists around the world for assessing risk levels in various fisheries.354 In this 
connection, we note that Mexico itself recognizes the viability of using this methodology to 
evaluate whether fishery conditions ha ve changed over time, given that information is collected 
from within the same fishery in a consistent manner on a year -by-year basis.355 We are 
nonetheless mindful that , according to Mexico , there is no p recedent for using per set  or per gear 
deployment metrics to compare the dolphin mortality rates of different fisheries, using different 
equipment and/or methods in different ocean regions, and that comprehensive data is not 
collected for any fishery excep t the large purse seine fishery in the ETP .356 In other words, Mexico 
claims that due  to possible lack of information for some fisheries and the differences between  the 
fishing methods, the use of a per set methodology would be inadequate.  
7.211.    Regarding Mexico' s contention that there is no precedent for using a per set methodology  
to compare different fisheries, we note that the mere fact that this might not have happened in the 
past is not enough to conclude that it would be inappropriate to do so in this parti cular case. 
Mexico has summited no evidence showing that the differences between fisheries have an 
important impact on the comparison of dolphin mortalities or serious injuries on a per set basis, 
which would render such comparison scientifically unsound o r would lead to an unreasonable 
result. We are mindful that the different fishing methods conducted in different ways do not 
necessarily use the same type of gear and may differ in duration. These differences might, in our 
view,  have an impact on the risks  posed to dolphins. However, imperfect as it may be , the per set 
methodology uses a standard metric, that is, a unit of effort in each of the fisheries, that may 
contribute in controlling for the differences across fishing methods. In this connection, we agree 
with the United States that observable dolphin mortalities and injuries caused by tuna sets are 
comparable across fisheries for purposes of assessing the relative risk to dolphins posed by 
different fishing methods in different parts of the ocean and the operation  of the Tuna Measure 
because they refer to the same unit of fishing effort consisting of a single operation of the fishing 
gear used in the particular fishery. Thus, regardless of the duration, type of gear or other variables 
that may describe  a fishing method, a per set comparison focuses on a common denominator  
among fishing methods:  a unit of effort.  
7.212.    In any case, we recall that as  we mentioned above,  the results of using a per set 
methodology are only one of the inputs in establishing the r isk profile of a fishery, as they do not 
describe all the relevant aspects of the risk posed to dolphins by a particular fishing method in a 
particular part of the ocean. Consequently, other factors, such as the level of interactions with 
dolphins, the nec essity for a particular method to interact with dolphins,  and the existence and 
extent of unobservable harms,  which  might affect the comparability across fishing methods, can 
still be adequately taken into account when constructing a risk profile.  
7.213.   Finally,  contrary to our findings regarding the PBR methodology, we consider that the per 
set methodology sits comfortably with the design and structure of the 2016 Tuna Measure, as the 
latter is generally applied on a per gear deployment basis  in respect of how o ften captains have to 
make non -dolphin safe certifications, or how frequently non -dolphin safe tuna must be segregated 
from dolphin -safe tuna . 
7.214.   We therefore conclude that using the per set methodology is appropriate for our 
assessment of the overall levels of relative risks attributable to different fisheries . However, where 
there is no information provided on a per set basis for a particular fishing method in a particular 
area of the ocean, we will naturally base our determination on the available data.  
                                                
353 Sandra Clermont et al., IOTC, EU Purse Seine Fishery Interaction with Marine Turtles in the Atlantic 
and Indian Oceans: A 15 Years A nalysis  (Sept ember  2012) , (Exhibit USA -230), p. 6.  
354 United States' response to Panel's question No. 100 (referring to Tim Lawson, Secretariat of the 
Pacific Community, Methods for Analysing Bycatches with Observer Data (Aug ust 2001) , (Exhibit USA -227)).  
355 Mexico's responses to Panels' question No. 100.  
356 Mexico's responses to Panels' question No. 100.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.7.1.2.1.6   Per set data contained in Exhibit USA -179 Rev.  
7.215.   Having concluded that it is appropriate for us to use per set data in our assessment of the 
overall levels of relative risks posed to dolphins by different fishing methods in different areas of 
the ocean, it is a pposite to make a number of observations about the per set data presented by 
the parties in the current proceedings.  
7.216.   During the course of the Panels' meeting with the parties357, the United States submitted 
Exhibit USA -179, which contains a compilation of th e data presented, on a per set basis, in various 
other exhibits submitted in the current proceedings. We asked Mexico to comment on the 
completeness and accuracy of the informat ion contained in Exhibit USA -179. In response, Mexico 
states that the data from  outside the ETP is incomplete and based on unverified captains' logs and 
information from observer programs that the United States itself does not consider reliable. In 
Mexcio's view, the United States compounds these problems by making unsupported assump tions 
and calculation errors. Mexico also argues that Exhibit USA -179 does not provide information that 
can reasonably be relied upon to compare the relative risks posed by different fishing methods in 
different fisheries, especially because the United Sta tes is purporting to apply a per set metric that 
requires comprehensive and precise data.358 In response to this comment, t he United States 
updated Exhibit USA -179 in Exhibit US A-179 Rev., and argues that this Exhibit sets out the best 
available scientific e vidence as to the levels of dolphin mortalities occurring in the major tuna 
fisheries around the world. The United States further argues that Mexico has not refuted this 
conclusion in general or with respect to any particular fisheries.359 
7.217.   As noted above, Exhibit USA -179 contains a compilation of the data of the main exhibits on 
the record regarding harms caused to dolphins by different fishing methods in different areas of 
the ocean. Exhibit USA -179 Rev., in turn, revises some of the numbers  presented in Exh ibit USA -
179, but essentially follows the same structure and contains the same information, but for some 
modifications, as is contained in the former Exhibit. For the purposes of our analysis in this 
section, we will focus on Exhibit USA -179 Rev.  
7.218.    We note that Exhibit USA -179 Rev. consists of three tables concerning (i) the  association  
and interactions of dolphins and tuna in various fisheries, (ii) the observed mortality, per set, of 
dolphins in various fisheries, and (iii) the marine mammal interactions i n US Longline Fisheries.360 
7.219.   In what follows, we address the points raised by Mexico regarding Exhibit USA -179 Rev.361 
In general, they can be categorized in two groups, one relating to the accuracy of numerical 
                                                
357 See United States' response to Panels' question No. 3.  
358 Mexico's response to Panels' question No. 57, paras. 1 -3. 
359 United States' comments on Mexico's re sponse to Panels' question No. 57.  
360 Exhibit USA -179 Rev., titled "Tables Summarizing the Fishery -by-Fishery Evidence on the Record" 
consists of 3 tables: Table 1  describes the association  between tuna and dolphins in purse seine fisheries 
across different  areas of the ocean. It incorporates annual or periodical data according to nine criteria namely, 
the overall number of observed sets, positive sets (defined as sets with observed dolphin interactions and 
mortalities) and their rate expressed in the form o f percentage together with the overall number of dolphins 
chased and encircled and dolphin mortalities. The last two criteria reflect a summary of all dolphins' 
interactions and mortalities according to the per set methodology in the ETP large purse seine and purse seine 
fisheries without setting on dolphins  in the  WCPO, the Eastern Tropical Atlantic and the Indian Ocean.  
 
Table  2 contains data on mortality  of dolphins in various fisheries across different areas of the ocean. It 
describes the reported dolp hin mortalities in the purse sein e fishery, longline and trawl  on the basis of observer 
reports in , among others,  the ETP, the Pacific, the Atlantic and Indian Ocean, including the scope of coverage 
by the observers. This table contains data reported on an nual or periodical. The table also contains a summary 
of all dolphins' mortalities reported in different areas of the ocean, using the per set methodology.  
 
Table  3 contains data on m arine mammal interactions in US  longline fisheries, namely in American 
Samoa, Hawaii Deep -set longline and Atlantic Pelagic longline, collected on annual basis, mostly between 2004 
and 2015. This table includes information on the total number of observed trips, including those with dolphin 
interactions, and  general rate of int eractions observed  during these trips and expressed in a percentage. The 
table also incorporates data on the total number of sets, the number  of positive sets, the rate of interactions in 
the sets expressed in percentage rate as well as summary information  on the total amount of dolphin 
interactions per 1,000 sets.  
361 Although Mexico presented these comments with respect to Exhibit USA -179, such comments apply, 
mutatis mutandis , to Exhibit USA -179 Rev.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  calculations and the other relating to the reliab ility of the exhibits supporting such numerical 
calculations.  
Issues regarding the numerical calculations  
7.220.   Mexico contends that on page 3 of Exhibit USA -179 Rev., the United States has entered 
the number 31 as the aggregate number of mortalities and serious  injuries caused by purse seine 
vessels of the listed countries in 2010. Based on the individual numbers listed by the United 
States, Mexico contends that the correct number is 335. Mexico also argues that in the same table 
for the year 2015, the United St ates entered a total of 65, when the numbers it listed in fact add 
up to 119.362 
7.221.   The United States contends that these figures, which concern  the levels o f dolphin 
mortality in the WCPO  purse seine fi shery overall, are not incorrect, because the overall fish ery 
data reflects 15% (for 2007 -2009) and 40 -60% (for 2010, 2014, and 2015) observer coverage  of 
that purse seine fishery .363 The WCPFC members'  annual reports, on the other hand, reflect 100 % 
coverage of their purse seine vessels  (except for Philippine vess els in national waters).364 The 
United States thus contends that  one would not expect the numbers for  dolphin mortalities in the 
fishery overall for 2014 and 2015 to equal the sum of those in the annual reports365, as they 
should be about 40 -60% of the sum of those figures  because the WCPFC -wide data reflects 40 -
60% of the trips in the fishery in that year . 
7.222.   We note that  the United States presented overall data from the WCPO  fishery for the years 
2007-2009, 2010, 2014, and 2015, as well as data from the individu al members'  annual reports 
for 2014 and 2015.366 In reporting the overall numbers for this fishery, including the per set 
mortalities and the observed sets, we note that the United States used the WCPFC, 7th Annual 
Report for the Regional Observer Programme,  in Exhibit USA -109, which has a different observer 
coverage than the individual country reports. In fact, we note that f or 2015, there were a total of 
111 observed dolphin mortalities in the annual reports and a total of 66 i n the WCPFC report, 
based on 6 3% observer coverage.367 We observe that f or 2014, the result is similar except  with 
respect to  the data from the PNG annual report.368 
7.223.   We thus accept the United States' explanation  of the difference between the overall and 
member -specific data, and reject Mex ico's argument on this issue.  
7.224.   Mexico also contends that the WCPFC itself estimated that its purse seine fishery had 
1,195 dolphin mortalities in 2009, but that the United States omits this information.369 The United 
States argues that that the reason why it  did not include the 1,195 dolphin mortality figure is 
because it was not relevant to the purpose of Exhibit US A-179 Rev., which was to present data on 
levels of dolphin mortality per set  and not in absolute terms.370 
7.225.   We find merit in the United States' expla nation, as it is consistent with our finding that the 
use of per set data is appropriate for our assessment of the overall levels of relative risks posed to 
dolphins by different fishing methods in different areas of the ocean. For this reason, we agree 
that the number of 1,195 dolphin mortalities in 2009 was not apposite for the purposes of Exhibit 
USA-179 Rev.371 
                                                
362 Mexico's response to Panels' question No. 57.  
363 We not e that the United States contends that the reason the 2014 and 2015 reports do not reflect 
the 100% observer coverage required in the purse seine fishery is that not all data is entered by the time the 
reports are published. WCPFC, 7th Annual Report for th e Regional Observer Programme (Sept ember  3, 2015) , 
pp. 4-5.  
364 Exhibit USA -179 Rev., table 2.  
365 Mexico's Response to Panels' question No. 57.  
366 Exhibit USA -179 Rev., table 2.  
367 Exhibit USA-179 Rev.  
368 Exhibit USA -179 Rev., table 2. The United States contend s that this table shows that a WCPFC report 
covered 46% of trips and documented 31 dolphin mortalities, and the 2015 annual countries' reports except for 
PNG showed 67 dolphin mortalities (plus 13 cetacean interactions on US vessels), meaning that the WCPF C 
report covered 46.26% of dolphin mortalities (31/67 = 0.4626) outside of the PNG fishery.  
369 Mexico's response to Panels' question No. 57.   
370 United States' comments on Mexico's response to Panels' question No. 57.  
371 We will nonetheless discuss this in fu rther detail below in  Section  7.7.2.2  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.226.   Mexico additionally argues that Exhibit USA -179 Rev. averages data from national fisheries 
with more forthright and reliable reports (e.g., Papua New Guinea (PNG)) with those of other 
countries, in order to avoid providing a (higher) per set number for the more reliable fisheries, and 
especially PNG.372  
7.227.   The United States argues that  Mexico' s argument is incorrect because, f irst, Mexico has no 
basis, and never cites to any  source, for the assertion that the PNG report is more "forthright and 
reliable " than the other annual reports.373 The United States argues that these reports are 
submitted under t he same Conservation and Management Measure and generall y based on data 
from the same Parties to the Nauru Agreement observer program for all WCPFC members.374 
Second, the United States contends that it  has calculated the p er set number for the PNG alone for 
2014 and 2015, and the numbers are 23.1375 and 8.1376 dolph in mortalities per 1,000 sets, 
respectively.377 Thus,  the United States contends that  both figures are significantly lower than 
even the lowest ever level of dolphin mortalities caused by dolphin sets in the ETP.378 
7.228.   We note that Exhibit US A-179 Rev . contains b oth the individual information for PNG purse 
seine fishery and the overall information for the WCPO purse seine tropical fishery. We will 
therefore use both of these sets of information in our determination of the relative risk profiles.  
                                                
372 Mexico's response to Panels' question No. 57.   
373 United States' comments on Mexico's response to Panels' question No. 57.  
374 United States' comments on Mexico's response  to Panels' question No. 57; third written submission, 
para. 80, fn. 181.  
375 United States' comments on Mexico's response to Panels' question No. 57. The United States argues 
that in 2014, PNG national vessels and foreign vessels in PNG waters caught 403,31 6 mt. of tuna ( referring to  
Papua New Guinea, Annual Report to the Commission, WCPFC -SC12/AR/CMM -19 (Aug ust 2016) , (Exhibit USA -
107), pp. 5, 9). According to the United States, this was  19.7% of all tuna caught in the WCPFC purse seine 
fishery  (referring t o Peter Williams and  Peter Terawasi, WCPFC, Overview of Tuna Fisheries in the Western and 
Central Pacific Ocean, Inclu ding Economic Conditions – 2015 (August 30, 2016) , (Exhibit US A-108), p. 2; and 
United States' response to Panels' Question 31(c)). For th e United States, assuming that vessels covered by 
the PNG observer program conducted a consistent percentage of the 56 ,000 t otal sets in the fishery in 2014 
(referring to Peter Williams and  Peter Terawasi, WCPFC, Overview of Tuna Fisheries in the Western a nd Central 
Pacific Ocean, Including Economic Conditions – 2015 (August 30, 2016) , (Exhibit USA -108), p. 55), this 
suggests that such vessels engaged in 11,032 sets. For the United States,  this suggests that the per set 
mortality rate was 23.1 mortalities p er 1,000 sets ( i.e., 255 / 11,032 * 1,000).  
376 United States' comments on Mexico's response to Panels' question No. 57. The United States argues 
that in  2015, PNG national vessels and foreign vessels in PNG waters caught 249,072 mt. of tuna (referring to 
Papua New Guinea, Annual Report to the Commission, WCPFC -SC12/AR/CMM -19 (Aug ust 2016) , (Exhibit USA -
107), pp. 5, 9). For the United States, this was 14% of the 1,766,070 mt of tuna caught in the WCPO purse 
seine fishery . Peter Williams and  Peter Terawasi, WC PFC, Overview of Tuna Fisheries in the Western and 
Central Pacific Ocean, Inclu ding Economic Conditions – 2015 (August 30, 2016) , (Exhibit  USA-108), p. 5. The 
United States contends that, assuming a consistent percentage of the approximately 48,000 total s ets in the 
fishery in 2015  (referring to  Peter Williams and  Peter Terawasi, WCPFC, Overview of Tuna Fisheries in the 
Western and Central Pacific Ocean, Inclu ding Economic Conditions – 2015 (August  30, 2016) , (Exhibit USA -
108), p.55), this suggests that the  covered vessels conducted approximately 6,768 sets. For the United States, 
this suggests a per set dolphin mortality rate of 8.1 mortalities per 1,000 sets  (i.e. 55 / 6768 * 1,000).  
377 The United States argues that the figures in this sentence are based on  the natural meaning of the 
PNG report as encompassing observer reports covering " the vessels based out of PNG and foreign vessels 
fishing the PNG waters " (United States' response to Panels' Question No. 31(c); Papua New Guinea, Annual 
Report to the Commis sion, WCPFC -SC11 -AR/CCM -19 (August  2015) , (Exhibit  MEX-23), p. 2 ). According to the 
United States,  under the other possible interpretation – that only the PNG "national fleet" is covered - the 
United States contends that the analogous figures would be 43.4  dolphin mortalities per 1,000 sets for 2014 
and 9.9 dolphin mortalities per 1,000 sets for 2015. For 2015, the United States argues that the PNG national 
vessels caught 204,517 mt. of tuna in 2015. Papua New Guinea, Annual Report to the Commission, WCPFC -
SC12/AR/CMM -19 (Aug ust 2016) , (Exhibit USA -107), pp. 4 -5, 9, which was 11.6% of the 1,766,070 mt of tuna 
caught in the WCPO purse seine fishery in 2015 . Peter Williams and  Peter Terawasi, WCPFC, Overview of Tuna 
Fisheries in the Western and Central Pacific  Ocean, Inclu ding Economic Conditions – 2015 (August  30, 2016) , 
(Exhibit USA -108), p. 2. The United States thus contends that, assuming a consistent percentage of the 48,000 
sets that occurred in the fishery in 2015, this suggests that PNG national fleet v essels engaged in 5,568 sets in 
2015, with a per set dolphin mortality rate of 9.9 dolphin mortalities per 1,000 sets ( i.e. 55 / 5,568 sets * 
1,000).  
378 United States' comments on Mexico's response to Panels' question No. 57 . WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  Issues regarding t he reliability of the exhibits supporting the numerical 
calculations  
7.229.   Mexico argues that the observer data available from the WCPFC is much more limited than 
the United States seeks to suggest because the WCPFC itself has reported that for purse seine 
vesse ls, "the coverage of 2014 observer data submitted to SPC is very low for Japan, China, Spain 
and Chinese Taipei".379 For Mexico, the WCPFC's data indicates, for example, that observer data 
for 107 out of the estimated  359 purse seine trips made by Chinese Ta ipei's purse seine fleet in 
2014 were still missing as of September 2015.380 With respect to longline vessels, Korea and 
Chinese Taipei had provided no observer data at all for 2013 and 2014.381 
7.230.   We agree with the United States that the observer coverage is  transparently reported by 
the United States, as evidenced in  the tables and citations included in Exhibit USA -179 Rev.  The 
WCPFC annual report for 2010 states how many sets are covered by the report, and a subsequent 
WCPFC report identifie s the total number o f sets in 2010.382 Similarly, the 2014 and 2015 reports 
are explicit as to the number of trips covered by the reports, and the 2015 annual re port identifies 
the total number of trips in both years.383 We also note that , while Exhibit MEX -116 refers to the 
level of observer reports submitted to the Secretariat of the Pacific Comm unity as "very low " for 
certain countries384, Table 2 of the exhibit shows that, in fact, the countries in question had 
submitted obse rver data for between 69% and 78%  of all trips by thei r flagged vessels in 2014.385 
7.231.   In addition, we agree with the United States' contention that there is no minimum 
threshold of observer coverage below which the resulting observations are necessarily 
unreliable.386 We note that d ifferent levels of observer cover age may be required for different 
purposes , but that did not preclude the authors of the reports on the record  from drawing 
conclusions about whether bycatch is a problem , and about the level s of bycatch , based on the  
observer  coverage underlying the  repor ts.387 For these reasons, we reject Mexico's arguments on 
this point.  
7.232.   Mexico also contends that, according to the United States, the United States' data from the 
Philippines are representative of all of the Philippines purse seine fishing.388 However, for Mexi co, 
the Philippines report addresses fishing efforts only in "High Seas Pocket 1", which is a limited area 
that happens to be subject to strict conservation measures of the WCPFC.389 Mexico also argues 
that the United States omits other relevant evidence, su ch as reports that a particular fleet of five 
purse seine vessels in the Philippines using FADs killed 2,000 dolphins per year, and a 2012 report 
that in the Philippines, FAD vessels fish at night with lights that attract dolphins and lead to their 
deaths.390 
                                                
379 WCPFC, Status of ROP Data Man agement, WCPFC -TCC11 -2015-IP05_rev1 (10 September 2015), 
(Exhibit MEX -116), p. 7.  
380 WCPFC, Status of ROP Data Management, WCPFC -TCC11 -2015-IP05_rev1 (10 September 2015), 
(Exhibit MEX -116), p. 13, Table 2.  
381 WCPFC, Status of ROP Data Management, WCPFC -TCC11-2015-IP05_rev1 (10 September 2015), 
(Exhibit MEX -116), p.8.  
382 Exhibit USA -179 Rev., table 2. WCPFC Cetacean Interactions Paper, Table s 2a, 2b (Exhibit USA -58); 
Peter Williams and  Peter Terawasi, WCPFC, Overview of Tuna Fisheries in the Western and Centra l Pacific 
Ocean, Inclu ding Economic Conditions – 2015 (August  30, 2016) , (Exhibit USA -108), p. 55.  
383 Exhibit USA -179 Rev., table 2. W CPFC, 7th Annual Report for the Regional Observer Programme  
(Sept ember  2015) , (Exhibit USA -109), pp. 4-5; WCPFC, 8th Annual  Report for the Regional Observer  
Programme, (September  2016) , (Exhibit USA -110), pp. 2, 5 -6. 
384 Mexico's Response to Panels' question No. 57.  
385 WCPFC, Status of ROP Data Management  (September 10,  2015) , (Exhibit MEX-116), pp. 13 -14. The 
United States argue s that these figures may underestimate the percentage of trips covered by the observer 
data, as fishing may not have occurred in all of the estimated trips. The United States further argues that 
based on the WCPFC Annual Report for 2015, published in Septe mber 2016, this was the case, as the estimate 
of trips in the purse seine fishery had been revised down to 1,830. WCPFC, 8th Annual Report for the Regional 
Observer  Programme (September  2016) , (Exhibit USA -110), p. 2.  
386 United States' response to Panels' q uestion No. 95.  
387 United States' response to Panels' question No. 95.  
388 United States' third written submission, para. 80.  
389 Philippines, Annual Report to the Commission, WCPFC -SC11/AR/CCM -20 (September 28, 2015), 
(Exhibit USA -38), p. 2.  
390 Mexico's respons e to Panels' question No. 57 (referring to Mexico's first written submission, paras. 
74-75). WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.233.   In the view of the United States, Mexico's argument implies  that the Panels should ignore 
the evidence of the levels of dolphin mortality caused by  the Philippine vessels in recent years and 
instead rely on anecdo tal data from the early 1990s.391  
7.234.   We note that one of the pieces of evidence submitted by the United States, Exhibit US A-38, 
shows that, based on 100% observer coverage , in the 35 Philippine purse seine vessels fishing  on 
the high seas , there were  "18 instances that a cetacean was unintentionally encircled by a purse 
seine net and these were all  released alive but subsequently died"  in 2014.392 We observe that on 
a per set basis, based on the number of fishing days in 2014 and the average number of sets per 
day, this would be approximately 2.3 dolphi n mortalities  per 1,000 sets.393 We are also mindful 
that Mexico  has submitted its own evidence on this matter, namely "Incidental Takes of Small 
Cetaceans in Fisheries in Palawan, Central Visayas and Northern Mindanao in the Philippines", from 
1994, in Exhi bit MEX -117 and " Convention on Migratory Species, Report of the Third Southeast 
Asian Marine Mammal Symposium ", from 2015, in Exhibit MEX -22. We see no reason to disregard 
a priori  any of these Exhibits in our assessment of  the relevant  risk profiles.  
7.235.   We nonetheless note that, regarding Mexico's  claims that the ac tivities of Philippine vessels 
on the high seas in 2014 -2015 are not representative of other Philippine vessels , we agree with 
the United States  that the  vessels fishing on the high seas are simply  a subset of the Philippine 
commercial purse seine and ringnet fleet .394 We also note that the Philippine s annual reports show 
that catches on the high seas account for a substantial portion of the Philippine s purse seine catch 
outside PNG waters, namely, 36 .6% in 2014 and 39%  in 2015.395 Therefore, it is reasonable to 
conclude that the activities of the vessels on the high seas are representative of the Philippine 
purse seine fleet . For these reasons, we reject Mexico's arguments.  
7.236.   Mexico also contends that eve n putting aside the issue of the reliability of observers 
outside the ETP, the United States lists observer coverage rates such as 3 to 6% (e.g., Australia 
longline, Chinese Taipei longline fisheries); 3% (e.g., Japanese longline fisheries), 7.8% of "vesse l 
activities" (Indian Ocean purse seine fisheries), and that coverage rates at those levels do not 
produce reliable data.396 
7.237.   In this regard, we agree with the United States that Mexico's argument on this point does 
not seem to be a balanced reflection of the  body of evidence on the record. We note that  the 
majority of the evidence on the record  summarized in E xhibit  USA-179 Rev.  is based on observer 
coverage of more than 10% of the fishing effort in the fishery at issue, including the reports from 
WCPFC purse  seine fisheries, WCPFC longline fisheries, Atlantic longline fisheries, Indian Ocean 
longline fisheries, and others.397 We also observe that other RFMOs, national regulators, and 
scientists that conducted these studies drew conclusions from them about overa ll levels of bycatch 
even with low observer coverage. This indicates to us that they considered it appropriate 
statistically sound to do so.398 Where experts in the field of fisheries management consider that 
                                                
391 L. Dolar, Incidental Takes of Small Cetaceans i n Fisheries in Palawan, Central Visayas and Northern 
Mindanao in the Philippines, in Report of International  Whali ng Commission (Special Issue 15) (1994) , (Exhibit 
MEX-117), p. 355 (explaining that information was collected "opportunistically" from "fishermen and other 
knowledgeable  local people"). According to the United States' comments on Mexico's resp onse to Panel s' 
question No. 57, it is also notable that the author clarified that the vessels examined in the paper were not 
producing for the global tuna product market but "for local markets". See p. 357.  
392 Philippines, Annual Report to the Commission, WCPFC -SC11/AR /CCM -20 (Sept ember  28, 2015) , 
(Exhibit USA -38) pp. 1,  9. The United States argues that the area of the high seas where Philippine purse seine 
vessels fish is known as High Seas Pocket 1 (HSP1) and that Philippine vessels do not fish in the other high 
seas areas of the WCPFC convention area. WCPFC, Conservation and Management Measure 2011 -01 for 
Temporary Extension of CMM 2008 -01, (Exhibit USA -238), pp. 1, 3.  
393 See fn. 21 in United States' comments on Mexico's response to Panels' question No. 57. See also 
Value of Philippine Tuna Exports Drops in 2014, The Freeman  (12 August 2015), (Exhibit USA -236); 
Philippines, Annual Report to the Commission, WCPFC -SC11/AR/CCM -20 (Sept ember  28, 2015) , (Exhibit USA -
38), p. 5.  
394 High Seas Pocket Fishing Rules Released, Bus. World  (March  4, 2014) , (Exhibit USA -237); 
Philippines, 2014 Annual Report, (Exhibit USA -38), p. 7.  
395 Philippines, Annual Report to the Commission, WCPFC SC12 -AR/CCM -20 (June 2016) , (Exhibit USA -
38), p.5; Philippines, 2015 Annual Report, (Exhibit USA -105),  p. 5. 
396 Mexico's second written submission, para. 79; Mexico's first written submission, paras. 82 -85. 
397 Exhibit USA -179 Rev., table 2.  
398 See William A. Karp, Lisa L. Desfosse, and  Samantha G. Brooke (eds.), NM FS, US National Bycatch 
Report (2011) , (Exhib it USA -61), pp 391, Table 4.6.C.1 and  394, Table 4.6.D.1; US National Bycatch Report 
First Edition Update , (Exhibit USA -62), Table 8.3; US National Bycatch Report First Edition Update,  (Exhibit WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  certain evidence is reliable and provides a suffi cient basis from which to draw conclusions, we 
consider this to be a strong indicator that the evidence is in fact reliable and provides a sufficient 
basis from which we can also draw conclusions.  
7.238.   Furthermore , we are not of the view that 10% observer cover age is some minimum 
threshold below which the relevant evidence would lose its probative value. As underlined by the 
Appellate Body in the first compliance proceedings399, collection and assessment of data regarding 
harms caused by the use of different fishi ng methods in different areas of the ocean is generally 
very difficult. In our view, the sampling coverage used in a particular study does not necessarily 
need to meet a pre -established threshold for it to be taken into account by a WTO panel, other 
than w hat is considered to be the standard statistical practice in  the field the study touches upon. 
With respect to the Exhibits at issue here, we consider that the fact that  many of  these are 
scientific studies published in a peer review journal suggests that their results may be deemed to 
provide an adequate assessment of the risks to dolphins.  
7.239.   We thus reject Mexico's contention on this issue of  observer coverage rates.  
7.240.   Finally, Mexico contends that the United States uses the word "interaction" in an 
inconsist ent fashion, as it shows figures for estimates of all dolphins involved in any way in dolphin 
sets in the ETP, but does not include, for example, the many thousands of dolphins that feed off of 
longline hooks (i.e., depredation), or dolphins that are in th e vicinity of purse seine net settings 
outside the ETP. For Mexico, the United States simply asserts that there are zero or minimal 
"interactions" for other types of fishing methods, as though that were a proven fact.400 
7.241.   We note that the United States has cl arified, in response to questioning from the Panels, 
that, for purposes of table 1 of Exhibit USA -179 Rev., "interaction" includes any set where there 
was an observed interaction between the fishing vessel and its gear and one or more dolphins.401 
We also no te the United States' explanation that where it listed "0" under "interaction" in any of 
the tables, it is because the RFMO or scientific, peer -reviewed report referred to in the associated 
footnote supported that data point. Moreover, the Panels do not ac cept assertions, but rather 
make their assessment based on the evidence before them, as is required by Article 11 of the 
DSU. 
7.242.   We thus reject Mexico's arguments in this respect.  
7.7.1.2.1.7   Overall conclusion  
7.243.   Having addressed all of Mexico's criticisms regarding the in formation contained in Exhibit 
USA-179 Rev., we conclude that, as a general matter, we can rely on the information therein in 
our assessment of the overall levels of relative risks posed to dolphins by different fishing methods 
in different areas of the oc ean. We will of course assess the relevance of particular piece s of 
information contained in that Exhibit in  the light of the fishing method s and the area s of the ocean 
that we will analyse in the following parts of our Reports.  
7.7.1.2.2   Differences between differe nt kinds of harms posed to dolphins  
7.244.   We are mindful that over the course  of this dispute, several categories  of harms posed to 
dolphins have been discussed and assessed by the panels and the Appellate Body , but they have 
not always been clearly distinguishe d. Before we begin our factual analysis, it is useful to explain 
these different categories, as they will structure our assessment of the evidence on the record and 
facilitate our comparison of the risks to dolphins  arising from  the use of different fishin g methods 
in different areas of the ocean. It is in our view particularly important to draw a proper distinction 
                                                                                                                                                  
USA-63), Table 8.4 ; Summary Information on Whale Shark and Cet acean Interactions in the Tropical WCPFC 
Purse Seine Fishery, Paper prepared by SPC -OFP, 8th Reg ular Session, Koror, Palau (November  2011) , (Exhibit 
USA-17), pp.5-6; NOAA Fisheries, 2015 Stock Assessment and Fishery Evaluation (SAFE) Report for Atlantic 
Highly Migratory Species (2015) , (Exhibit USA -39), pp. 43, 50 -51, Tables 4.3, 4.9 ; Hsiang -Wen Huang and  
Kwang -Ming Liu, Bycatch and Discards by Taiwanese Large -Scale Tuna Longline Fleets in the Indian Ocean, 
106 Fish. Res. 261, (2010) , (Exhibit USA -189), pp. 263-265. 
399 See Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.252.  
400 Mexico's response to Panels' question No. 57.  
401 United States' Response to Panels' Question 2.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  between the concepts of observed, unobserved, observable, unobservable, direct  and indirect 
harms . 
7.245.   We begin by noting that the first compliance  panel began this process of clarification by 
drawing a distinction between the type of unobservable harms caused by setting on dolphins, on 
the one hand, and the kinds of harm caused by other fishing methods , which would, at least in 
theory, be observable  (although they may not, in fact, be observed, for a variety of reasons). 
According to the first compliance panel, certain  harms caused by setting on dolphins  are 
unobservable in the sense that no evidence of their occurrence is produced during the set. Th ey 
may be inflicted even in cases where no dolphin is caught in the net, or where a caught dolphin is 
released without apparent injury. Accordingly, they are harms whose occurrence cannot be 
recorded .402 The first compliance panel found that this differentia tes them from harms caused by 
other fishing methods, which at least in theory are observable to the human eye (even if they are 
not, in fact, observed).  
7.246.   The first compliance panel also introduced  the notion of "direct" and "indirect" harms, 
clarifying that  "indirect and unobservable harms may follow consequentially from observable 
harms caused by tuna fishing methods other than setting on dolphins" .403 The panel explained that 
where, for example, a mother dolphin is killed or seriously injured in a gear set, her calf may also 
suffer as a result of her (the mother's) inability to provide care, including food and prot ection, but 
that the key point was  that these harms flow from mortalities or injuries that are themselves 
observable , and whose occurrence would render non -dolphin -safe all tuna caught in the set or 
gear deploy ment in which the injury or mortality was inflicted . These  indirect  harms may be 
serious. However, because they flow from observable  harms, such as serious injury, all of which 
could  in theory  be detected and reported, unlike the kinds of unobservable harm s caused by 
setting on dolphins which are not visible to the human eye,  these types of indirect harms are 
different from the kind of unobservable harms caused by setting on dolphins .404 
7.247.   In an eff ort to clarify our understanding  of the different categories of harms caused by 
tuna fishing, we asked the parties for their views on the difference between observed, unobserved, 
observable, unobservable, direct  and indirect harms . In response, the United States argues that  
both the original panel and the first compliance panel identified two distinct categories of harms to 
dolphins, i.e. those stemming from direct, harmful interactions with fishing gear, and those caused 
by the "chase itself" in dolphin se ts.405 With respect to the first category, "observable" harms, the 
United States contends that the first compliance panel explained that they "flow from mortalities or 
injuries that are themselves observable, and whose occurrence renders non -dolphin -safe all  tuna 
caught in the set or gear deployment in which the injury or mortality was sustained"406, and that 
the second category, "unobservable" harms, by contrast, occur "as a result of the chase itself" in 
dolphin sets and would thus "continue to exist even if measures are taken in order to avoid the 
taking and killing of dolphins in the nets" .407 
7.248.   The United States also contends that " unobserved " harms encompass "unobservable" 
harms as well as potential instances or consequences of " observable " harms that are not,  in fact, 
observed.408 The United States argues that an example of such an "unobserved" harm would be a 
dolphin caught in a purse seine net that was released dead but was unseen by an observer or 
captain.409 In this regard,  the United States contends that  the frequency of dolphin interactions  
and number of dolphins generally involved  would be t he best quantitative proxy for unobserved 
                                                
402 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico ), para. 7.134.  
403 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico), para. 7.134.  
404 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico), para. 7.134.  
405 United States' response to Panels' questio n No. 116 (referring to  Panel Report, US – Tuna II  (Mexico)  
(Article 21.5 – Mexico) , paras. 7.120 -135).  
406 United States'  response to Panels' question No. 116 (referring to Panel Report,  US – Tuna II  (Mexico) 
(Article 21.5 – Mexico) , para. 7.134).  
407 United States'  response to Panels' question No. 116 (referring to Panel Report,  US – Tuna II  (Mexico)  
(Article 21.5 – Mexico) , para. 7.122 ). 
408 United States'  response to Panels' question No. 116 (referring to Panel Report,  US – Tuna II  (Mexico)  
(Article 21.5 – Mexico) , para. 7.134) . 
409 United States'  respo nse to Panels' question s No. 105 and  116.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  but observable harms , as these figures give a picture  of how frequently dolphins are endangered 
by the fishing method.410 
7.249.   Regardin g "direct" and " indirect " harms , the United States contends that they  refer, on the 
one hand, to harms inflicted on a dolphin directly and, on the other, to harms that are derivative 
of a direct harm. The United States argues that t he primary example of th e latter is calves who are 
orphaned  when their mother is killed in a fishing set411, but clarifies that this is a different type of 
harm than the cow -calf separation that can occur in dolphin sets due to the chase itself, regardless 
of whether a dolphin is d irectly killed or seriously injured.412 
7.250.   During the course of the Panels ' meeting  with the parties, Mexico argued  that the concepts 
of "unobservable" and "observable" and "direct" and "indirect" were developed in the first 
compliance proceedings to address th e fact that, outside the ETP, there is no program requiring 
100% coverage by observers trained to watch for and report on interactions with dolphins, and 
that direct and indirect are synomys for observable and unobservable harms .We note that Mexico 
also st ated that it would  submit more detailed information in its written reply , but did not do so, in 
particular , as to the differences between these various terms .413 
7.251.   In light of the previous panel and Appellate Body reports in this dispute, and taking into 
accou nt the parties'  response s to our question, we understand that tuna fishing may cause the 
following categories of harm to dolphins:  
a. observable  harm. This is any type of harm that can be detected and reported, such as 
serious injury  sustained during the cond uct of a set. We note that not all observable 
harms are in fact observed.   
b. unobservable harm. This is the type of harm in respect of which no evidence of their 
occurrence is produced during the set . 
c. observed  harm. This is harm that is observable and that h as, as matter of fact, been 
detected and reported  during the conduct of a set.  
d. unobserved  harm. This is the type of harm that is observable but that  has not, as matter 
of fact, been detected or reported  during the conduct of a set, even if it was in princi ple 
capable of being detected and reported . 
e. direct  harm.  This is the type of harm caused by direct interaction with fishing gear.  
f. indirect harm. This is harm consequent upon harm sustained as a result of direct 
interaction with a fishing gear.  
7.7.1.2.3   Difficulties  in assessing the data on the record  
7.252.   To conclude this introductory section, we find it important to mention some of the other 
issues that arise in respect of  our task of assessing the evidence on the record. Although we will 
not address them here, but rath er when we establish the risk profiles of the different fisheries, we 
find it useful to identify them in this part of these  Report s. 
7.253.   The first issue concerns the completeness and availability of data. Although the parties 
agree that there is an abundance o f data and studies on the harms caused to dolphins in some 
areas of the ocean, for instance in the ETP, there are other areas where the amount and quality of 
data is scant. This will invariably complicate our assessment of the risk profiles of different 
fisheries. One specific context in which this issue presents itself is the assessment of observable 
harms that in fact are not observed. With respect to different fishing methods, the record contains 
                                                
410 United States response to Panels' question No. 116 (referring to Panel Report,  US – Tuna II  (Mexico)  
(Article 21.5 – Mexico) , para. 7.134).  
411 United States'  response to Panels' question No. 116 (referring to Pan el Report,  US – Tuna II  (Mexico)  
(Article 21.5 – Mexico) , para. 7.134) . 
412 United States'  response to Panels' question No. 116 (referring to Panel Report,  US – Tuna II  (Mexico)  
(Article 21.5 – Mexico) , para. 7.134).  
413 Mexico's  response to Panels' question N o. 116 (referring to Panel Report,  US – Tuna II  (Mexico)  (Article 
21.5 – Mexico) , para. 7.134).  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  no direct evidence regarding the existence and level of su ch harms. In such instances, we consider 
that it may be possible to use the frequency of interactions with dolphins as a proxy to measure 
the maximum potential level of unobserved harms. This is so because the number of dolphins that 
interact with a vessel  represents the maximum number of dolphins that could suffer unobserved 
harms. In this sense, the magnitude of interactions does not indicate the number of dolphins that 
actually do suffer unobserved harms, but rather, the upper bound of dolphins that coul d suffer 
such harms. The lower the interaction the less likely it is for the relevant fishing method to cause 
harms to dolphins. In this regard, we also keep in mind that the level of interaction with dolphins 
depends on the fishing method as well as the a rea of the ocean where the method is used to catch 
tuna. 
7.254.   The second issue is related to the time range of some of the data on the record.  The 
different scientific studies in the record have different time ranges. This may complicate the 
comparison between the results across studies since the time difference may have a substantial 
impact on the conclusions about mortalities and injuries to dolphins. We note that in some cases, 
the parties contest the probative value of evidence on this ground.  
7.255.   The third issu e relates to statistical and data -gathering biases. Several studies discuss the 
existence of important statistical  issues, such as sampling. In this regard, we note that  "[p]otential 
biases to consider in observer programmes include non -representative prac tices in the presence of 
the observer (an "observer effect" ), and pressures on the observer to affect reports ".414 
7.7.2   Findings on the risk profiles of individual fishing methods  
7.7.2.1   Setting on dolphins  
7.7.2.1.1   Introduction  
7.256.   The Panels now turn to review the evidence concern ing the risks to dolphins caused by 
setting on dolphins. It is vital that we have a clear understanding of the risks to dolphins arising 
from the use of setting on dolphins, because, as we have noted above, under the 2016 Tuna 
Measure the risks of setting on dolphins provide a kind of benchmark against which the degree of 
risk caused by other fishing methods in other areas of the ocean is assessed.  
7.257.   We will commence our analysis  by recalling the characteristics of the fishing method of 
setting on dolphins. N ext, we will underline the existing findings  made in the previous proceedings 
in this dispute  concerning the risks to dolphins posed  by setting on dolphins. We will then 
summarize the parties ' arguments in these proceedings, before moving on to examine the  
evidence submitted by the parties in support of their positions. In this connection, we recall again 
the Appellate Body's statement that a compliance panel should not deviate from the reasoning 
contained in an earlier report on the same matter in the same  dispute "in the absence of any 
change in the underlying evidence in the record".415 In the light of this statement, we will not 
conduct a de novo  review  of the evidence concerning the effects of setting on dolphins. Rather, 
after summarizing the findings made in the previous proceedings in this dispute , we will examine 
the evidence submitted by the parties in order to determine whether there has been any change in 
the underlying record that would justify our revising the existing findings.  
7.7.2.1.2   Findings made in t he previous proceedings  
7.258.   The fishing method of setting on dolphins has been the subject of extensive discussion and 
analysis in the previous stages of this dispute. Its characteristics were considered in both the 
original and the first compliance proceeding s. We recall that, because of the unique association 
between tuna and dolphins in the ETP416, setting on dolphins is only practiced in a "widespread" 
and "systematic" manner in the ETP.417 Moreover, we recall that the Encyclopedia of Marine 
Mammals  describes s etting on dolphins as follows:  
                                                
414 Martin Hall and Marlon Roman, Bycatch and Non -Tuna Catch in the Tropical Tuna Purse Seine 
Fisheries of the World (2013)  (Exhibit USA -200). 
415 Appellate Body Re port, US – Upland Cotton (Article 21.5 – Brazil) , para. 386. 
416 Appellate Body Report, US – Tuna II (Mexico) , para. 287.  
417 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , paras. 7.241 -242. WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  Purse -seining for tuna in the ETP can be conducted in one of three ways: the net may 
be set around schools of tuna associated with dolphins ("dolphin sets" which catch 
large yellow -fin tuna) … Dolphins are killed almost exclu sively in dolphin sets. During 
"porpoise fishing" (the fishermen's term), schools of tuna are located by first spotting 
the dolphins or the seabird flocks which are also associated with the fish. Speedboats 
are used to chase down the dolphins and herd them  into a tight group; then the net is 
set around them. The tuna -dolphin bond is so strong that the tuna stay with the 
dolphins during this process, and tuna and dolphins are captured together in the net. 
Dolphins are released from the net during the backdow n procedure. If all goes well, 
the dolphins are released alive, but the process requires skill by the captain and crew, 
proper operation of gear, and conducive wind and sea conditions. As with any 
complicated procedure at sea, things can go wrong, and when  they do, dolphins may 
be killed.418 
7.259.   We recall that, in the original proceedings, the Appellate Body noted that the original panel 
accepted that, while all tuna  fishing methods may pose risks to dolphins, "setting on dolphins is 
particularly harmful to dolph ins".419 The Appellate Body then accepted that "the fishing method of 
setting on dolphins causes observed and unobserved adverse effects on dolphins"420, and noted 
that the original panel found that these "unobserved" harms include "cow -calf separation; potent ial 
muscle injury resulting from the chase; immune and reproductive systems failures; and other 
adverse health consequences for dolphins, such as continuous acute stress".421 The Appellate Body 
also observed that these unobserved harms would exist " even unde r the restrictions contained in 
the AIDCP  rules", because they are caused "as a result of the chase itself", which is an essential 
part of the process of setting on dolphins.422 Finally, the Appellate Body recognized that "certain 
environmental conditions in  the ETP (such as the intensity of tuna -dolphin association)" are 
unique".423 
7.260.   In the first compliance proceedings, the panel reviewed the findings of the original panel 
and the Appellate Body, and also analysed the new evidence submitted by the parties. It f ound 
that the fishing method of setting on dolphins "targets" dolphins424, and interacts "with dolphins in 
100% of dolphin sets".425 It also accepted that "the particular nature of the interaction is itself 
inherently dangerous to dolphins, even where no dolph in is seen to be killed or seriously injured, 
because it has unobservable deleterious effects on dolphins' physical and emotional well -being".426 
And it noted that "[w]her e dolphins associate with tuna  … they are more likely to interact with 
tuna fishing gea r, even if such interaction is accidental or unintentional. This is simply a question 
of numbers: the more dolphins there are in the vicinity, the more likely that one or more dolphins 
will be killed or seriously injured".427 
7.261.   Reiterating the original panel 's finding that setting on dolphins is "particularly harmful to 
dolphins"428, the first compliance panel observed that "the chase itself "429, which is an essential 
part of the process of setting on dolphins, may cause:  
 [V]arious adverse impacts … beyond observe d mortalities, including cow -calf 
separation during the chasing and encirclement, threatening the subsistence of the 
calf and adding casualties to the number of observed moralities, as well as muscular 
damage, immune and reproductive system failures, and o ther adverse health 
consequences.430 
                                                
418 Tim Gerrodette, The Tuna -Dolphin Issue, in Perrin, Wu rsig and  Thewissen (eds.)  Encyclopedia of 
Marine Mammals  (2d ed. 2009) , (Exhibit USA -12), p. 1192.  
419 Appellate Body Report, US – Tuna II (Mexico) , para. 289. 
420 Appellate Body Report, US – Tuna II (Mexico) , para.  288. 
421 Appellate Body Report, US – Tuna II ( Mexico) , para. 330, fn. 663.  
422 Appellate Body Report, US – Tuna II (Mexico) , para. 287 (citing Panel Report, US – Tuna II (Mexico) , 
para. 7.504 ). 
423 Appellate Body Report, US – Tuna II (Mexico) , para. 287.  
424 Panel Report, US – Tuna II (Mexico) (Article 21.5  – Mexico) , para. 7.261 . 
425 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.244 (internal citations omitted).  
426 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.244 (internal citations omitted).  
427 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.261 . 
428 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.120.  
429 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.122.  
430 Panel Report, US – Tuna II (Mexico) (Article 21 .5 – Mexico) , para. 7.120.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.262.   According to the first compliance panel, these harms "cannot be mitigated by measures to 
avoid killing and injuring dolphins".431 
7.263.   The first compliance panel also conducted a review of the  evidence submitted by the 
parties c oncerning the question whether fishing methods other than setting on dolphins cause 
unobservable harms similar to those caused by setting on dolphins. On the basis of this evidence, 
the compliance panel found that "no fishing method other than setting on d olphins has effects on 
dolphins as consistently harmful as those caused by setting on dolphins".432 It also rejected 
Mexico's arguments that other fishing methods cause similar unobservable harms.433 
7.264.   The first compliance panel therefore concluded that "setting  on dolphins does … cause 
observed and unobserved harms to dolphins", and that "other tuna fishing methods  [do not] 
consistently cause similar harms".434 Moreover, it accepted the United States' argument that " even 
if there are tuna fisheries using  … gear ty pes that produce the same number of dolphin mortalities 
and serious injuries allowed or caused in the ETP  … it is simply not the case that such fisheries are 
producing the same level of unobserved harms, such as cow -calf separation, muscular damage, 
immune  and reproductive system failures, which arise as a result of the chase in itself".435 
7.265.   We note, moreover, that in a separate opinion, one panelist, after agreeing that setting on 
dolphins is "particularly harmful to dolphins", went on to find that "[s]etting  on dolphins is the only 
tuna fishing method that deliberately targets dolphins, and so interacts with dolphins in a way that 
is uniquely intense, both in terms of the number of dolphins affected and the frequency of the 
interaction".436 
7.266.   On appeal, Mexico ch allenged three of the compliance panel's factual findings  under Article 
11 of the DSU . First, Mexico alleged that the compliance panel erred by "convert[ing] the prior 
finding that 'genuine concerns' exist regarding the extent to which setting on dolphins may have 
an adverse impact on dolphins beyond observed mortality into a finding of 'conclusive evidence'  of 
significant unobserved effects ".437 The Appellate Body rejected this argument, finding that the 
panel's references to the original Appellate Body's fi ndings "do not … mischaracterize the findings 
made in the original proceedings regarding the existence of unobserved effects on dolphins".438 
7.267.   Second, Mexico argued  that the compliance panel erred in finding that fishing methods 
other than setting on dolphins  have no unobservable effects.439 The Appellate Body also rejected 
this argument, and found that the panel had examined evidence relating to other fishing methods, 
contrary to Mexico's claim that the panel "did not even mention" this evidence.440 The Appellate  
Body also clarified that the compliance panel did not make a finding that " all of the adverse effects 
on dolphins caused by other fishing methods would be observable if a trained person were 
watching for them".441 Rather, the panel's finding, which the Appe llate Body did not reverse, was 
that none of the evidence presented by Mexico regarding the adverse effects on dolphins caused 
by other fishing methods "suggests that fishing methods other than setting on dolphins inflict the 
same kinds of unobservable har ms that are caused by net sets" (i.e. setting on dolphins) .442 
7.268.   Third, Mexico asked the Appellate Body to reverse the compliance panel's finding that the 
Appellate Body in the original proceedings had found that "dolphin sets under the rules of [the] 
                                                
431 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 6.8.  
432 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.130 (citing Appellate Body 
Report, US – Tuna II (Mexico) , para. 289 (noting that oth er fishing methods may give rise to the "same level 
of risk" only "in some circumstances")).  
433 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , paras. 7.130 -7.134.  
434 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.135. 
435 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.135. 
436 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.278.  
437 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.193.  
438 Appellate Body Report , US – Tuna II (Mexico) (Article 21.5 – Mexico) , para s. 7.19 6-7.197. 
439 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.198 . 
440 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.201 . 
441 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.200 (emphasis in 
original).  
442 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.200.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  AIDCP ar e more harmful to dolphins than other fishing methods".443 The Appellate Body rejected 
this claim also. It explained that:  
Mexico has neither established that the Panel made a finding "that the dolphin set 
method is more harmful to dolphins than other fishin g methods when the dolphin set 
method is regulated under the AIDCP", nor identified any problem with the statements 
made by the Panel regarding the Appellate  Body's use of the phrase "particularly 
harmful" in connection with the fishing method of setting o n dolphins.444 
7.269.   Accordingly, the Appellate Body rejected all of Mexico's claims under Article 11 of the DSU, 
and did not reverse the factual findings of the first compliance panel, which are therefore relevant 
to our analysis in these proceedings.  
7.7.2.1.3   Panels' assessment in the present proceedings  
7.270.   Having set out the findings concerning setting on dolphins made by the original and first 
compliance panels and the Appellate Body in the previous stages of this dispute, we now turn to 
the arguments made by the parties i n the  present  proceedings  regarding setting on dolphins . We 
note that the parties have submitted long and complex arguments about the risks associated with 
setting on dolphins. Indeed, the parties' arguments seem to be diametrically opposed about the 
safety of this fishing method. In this part of our Reports, we will provide a general summary of the 
parties' arguments . We will provide more detailed descriptions of those arguments below, when we 
examine the existing findings and the evidence submitted by the  parties in these proceedings.  
7.271.   The United States essentially requests the Panels  to reaffirm the findings concerning 
setting on dolphins made in the original and first compliance proceedings in this dispute . In 
particular, the United States asks us to find  that setting on dolphins poses relatively greater risks 
to dolphins than do other fishing methods, in terms of both observable and unobservable harms.  
In this connection, the United States contends that s etting on dolphins is the only fishing method 
in the world that systematically and intentionally targets a type of marine mammal to capture a 
commercially valuable fish. According to the United States, this  intentional targeting of dolphins is, 
by its very nature, unsafe for dolphins.  The United States exp lains that i n a dolphin set, the  fishing 
vessel (and its gear) interacts with dolphins in a way that is uniquely intense, both in terms of the 
number of dolphins affected an d the frequency of interaction.  The inherent dangerousness of this 
intense and sust ained interaction between dolphins and fishing vessels means that setting on 
dolphins is unique in terms of the level of harm it causes to dolphins.445 Moreover, the United 
States contends that since dolphins are an essential component of setting on dolphins , every 
dolphin set, by its nature, poses a risk to , on average,  several hundred dolphins.446 
7.272.   With respect to unobservable harms, the United States submits that scientific evidence 
confirms that setting on dolphins causes a unique category of unobservable ha rms that occur as a 
result of the chase and encirclement process, independent of whether a dolphin is killed or injured. 
According to the United States, these harms include calf-cow separation, muscular damage, 
immune system failures, reproductive system f ailures, and other adverse health effects .447 The 
United States notes that the extent of these harms is "almost certainly significant", although 
difficult to quantify precisely. The United States notes that between 2009 and 2013, for example, 
approximately 6 .2 million dolphins were chased and approximately 3.6 million were captured each 
year in nets.448 According to the United States, each one of these dolphins was at risk of suffering 
unobservable harms.449 
7.273.   With respect to observable harms, the United States con tends that setting on dolphins 
causes significant observable harms.450 The United States notes that, historically, setting on 
dolphins in the ETP led to the deaths of hundreds of thousands of dolphins each year. In the 
1990s, following the adoption of the Agreement for the Conservation of Dolphins  (La Jolla 
                                                
443 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7. 203. 
444 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.207.  
445 United States' first written submission, para. 36.  
446 United States' second written submission, para. 73.  
447 United States' first written submission, para. 37.  
448 United States' first written submission, para. 50, Table 2.  
449 United States' first written submission, para. 37.  
450 United States' first written submission, para. 38.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  Agreement), dolphin mortalities in the fishery dropped from the hundreds of thousands annually to 
the tens of thousands.451 The United States submits that, although dolphin mortalities have fallen 
since the introduction of the AIDCP, setting on dolphins in the ETP nevertheless continues to kill 
approximately 1000 dolphins per year.452 According to the United States, on a per set basis, 
between 2009 and 2014, the average dolphin mortality was 94.92 dolphins per 1000 sets.453 Over 
the last decade, the average dolphin mortality has ranged between 69.4 and 126.3 dolphins per 
1000 sets.454 
7.274.   With respect to serious injury, the United States argues that although there is only limited 
data available concerning the extent of serious injuries in the ETP455 (and other fisheries), it is 
possible to use the total number of dolphins, cetaceans or other marine mammals caught or 
hooked in the fishery as a proxy for the maximum possible number of injuries in a given fishery. 
Applying th is methodology, the United States observes that the figure for the ETP large purse 
seine fishery is well over three million dolphins a year, i.e. all those encircled in purse seine 
nets.456 We note that the United States is not arguing that three million dol phins are in fact 
seriously injured in the ETP large purse seine fishery, but rather that this figure represents the 
"maximum possible" number of injuries.  
7.275.   Mexico's view of the impact of setting on dolphins is diametrically opposed to that of the 
United St ates. According to Mexico, the United States' descriptions of setting on dolphins rely on 
"colourful language and exaggerations  in order  to inaccurately suggest that dolphin encirclement 
involves cruel and vicious attacks on dolphins".457 Moreover, in Mexico 's view, the United States' 
arguments improperly conflate the activities that define a fishing method and the level of adverse 
effects on dolphins caused by those activities.458 In this connection, Mexico submits that a causal 
link between encirclement of do lphins and risk of observable and unobservable harms cannot be 
assumed. Thus, the mere fact that dolphins are intentionally and routinely chased does not, by 
itself, establish the existence of risks to dolphins.459 
7.276.   With respect to observable harms, Mexico do es not dispute the mortality figures submitted 
by the United States, which are based on data collected and published by the AIDCP.460 Mexico 
argues that after the non -binding La Jolla Agreement was adopted in 1993, dolphin mortalities 
immediately dropped dra matically461, and in 2015 were 765.462  Mexico also  submit s that the direct 
mortalities are well within the limits of sustainability463, and are in fact "statistically 
insignificant".464 Indeed, in Mexico's view, AIDCP -compliant setting on dolphins is an 
environme ntally -sustainable fishing practice that causes less by -catch than other fishing 
methods.465 
7.277.   With respect to unobservable harms, Mexico argues that the evidence on which the United 
States' arguments are based is "speculative, biased, and faulty".466 According to Mexico, as 
evidence of indirect harms to dolphins, the United States cites to old reports that claim, or are 
based on the assumption, that the populations of the two dolphin stocks on which the Measure is 
based were not recovering at the expected rate. In Mexico's view, this is the "only objective 
scientific evidence" that supports the United States' arguments about the existence of 
unobservable harms.467 However, Mexico argues that that assumption has subsequently been 
                                                
451 United States' first written submission, para. 40.  
452 United States' first written submission , para. 41.  
453 United States' first written submission, para. 42.  
454 United States' second written submission, para. 75.  
455 United States' response to Panels' question No.3, para. 10. According to the United States, 
information on injuries is collected for th e ETP large purse seine fishery but not generally released by IATTC 
reports.  
456 United States' response to Panels' question No. 3, para. 11.  
457 Mexico's second written submission, para. 4.  
458 Mexico's first written submission, para. 229.  
459 Mexico's first wri tten submission, para. 230.  
460 Mexico's response to Panels' question Nos. 58, para. 5, and 63, para. 24. 
461 Mexico's first written submission, para. 37.  
462 Mexico's first written submission, para. 40.  
463 Mexico's second written submission, para. 6.  
464 Mexico's first written submission, para. 37.  
465 Mexico's second written submission, paras. 9 -12. 
466 Mexico's first written submission, para. 53.  
467 Mexico's first written submission, para. 61.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  found to be inaccurate.468 Accordingly , in Mexico's view, there is no evidentiary basis for 
extrapolating the level of unobserved harms from the extent of dolphin interactions. Such an 
approach, in Mexico's view, is based on "pure speculation".469 Relying on report submitted by the 
United States , Mexico suggests that, giving the United States the benefit of the doubt,  the extent 
of unobservable harms  could  be calculated at , at most,  approximately 14  percent  of the level of 
observed mortalities. For example, in 2015, the extent of unobservable har ms caused to dolphins 
can be measured by adding an additional 108 dolphins to the total number of observed 
mortalities.470 
7.278.   Finally, in the light of the above, Mexico asks the Panels to "carefully reconsider 
statements made by the first compliance panel that suggest encircling dolphins in an AIDCP -
compliant manner is 'particularly harmful'". In Mexico's view, Mexico's fishing method is not 
'particularly harmful'. In fact, it is less harmful to dolphins than other tuna fishing methods.471 
7.279.   We begin our assessment by observing that neither party contests the accuracy of the data 
collected and published by the AIDCP concerning the level of observed mortalities caused by 
setting on dolphins in the ETP. We note that the data in Exhibit USA -179 Rev., which we reproduce 
below, is as follows:  
YEAR  OBSERVED 
SETS  OBSERVED 
MORTALITY  MORTALITY PER 1000 SETS  
2009 10,910  1,237  113.38  
2010 11,645  1,169  100.38  
2011 9,604  976 101.62  
2012 9,220  870 94.36  
2013 10,736  800 74.49  
2014 11,382  975 85.66  
2015 11,020  765 69.42  
Total 74,517  6,792  91.15  
 
7.280.   This data confirms the United States' arguments concerning the per set mortality 
associated with setting on dolphins in the ETP. Specifically, it shows that the per set mortality 
associated with setting on dolphins in the ETP over the  last seven years has ranged between 69.42 
per 1000 sets (in 2015) and 113.38 (2009), for an average of 91.15 dolphin mortalities per 1000 
sets between 2009 and 2015. We note that, as we have explained above, the 2016 Tuna Measure 
is not a sustainability m easure, and accordingly the question of whether this per set average is 
sustainable on a population level is not directly relevant to our inquiry.  
7.281.   With respect to observable serious injury, we observe that there is limited evidence on the 
record concerning  the extent to which dolphins are seriously injured in the ETP as a result of 
setting on dolphins. Exhibit USA -16, which contains a dataset prepared by the IATTC covering the 
years 2009 -2013, appears to be the only exhibit containing relevant figures. It i ndicates the 
following concerning the number of recorded serious injuries in the covered time -period:472 
YEAR  OBSERVED SERIOUS INJURY  
2009 72 
2010 57 
2011 36 
2012 13 
2013 27 
 
7.282.   These figures suggest that serious injury is less frequent than mortality. Th e figures are 
also small when compared against the total number of dolphins chased and encircled per year. 
Exhibit USA -179 Rev. indicates that, between 2009 and 2013, on average  3,716 ,319.4 dolphins473 
                                                
468 Mexico's first written submission, para. 54.  
469 Mexico's first written sub mission, para. 62.  
470 Mexico's first written submission, para. 65.  
471 Mexico's first written submission, para. 238. 
472 IATTC, EPO Dataset 2009 -2013, (Exhibit USA -16), p.3.  
473 Exhibit USA -179 Rev., p. 1. We arrive at this figure by adding the number of "dolphin s encircled" 
between 2009 and 2013 and dividing the total by 5.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  were encircled per year. Even when compared against the highest number  of recorded injuries (79 
in 2009), it is clear that the vast majority of encircled dolphins do not suffer observed serious 
injury. These figures suggest that setting on dolphins does not pose a very high risk of observable 
serious injury.  
7.283.   No evidence on the record indicates the number of unobserved  observable mortalities or 
serious injuries suffered by dolphins in the ETP as a result of setting  on dolphins . However, as we 
have explained in paragraph 7.253  above, w e consider that the extent of dolphin interaction may 
serve as a proxy for the potential magnitude of unobserved harms. Bearing in mind that on 
average some six million dolphins are chased474 and some three and a half million dolphins are 
encircled each year , we think it is reasonable to assume that some dolphins may be killed or 
seriously injured, without this being observed.  Indeed, we note that in its Final Draft Full 
Assessment Report on the Northeastern Tropical Pacific Purse Seine Yellowfin and Skipjack  Tuna 
Fishery, the Marine Stewardship Council (MSC) considered that because " recorded data are based 
on animals that remain on the deck after the completion of a set whereas most bycatch is dumped 
overboard as soon as it is brought aboard ", observe rs likel y underestimate the number of 
individuals affected.475 The same report also notes that:  
[B]iases may result (conservatively) in under -reporting observable mortality 
associated with fishing operations by approximately 9% in half of observed trips. 
Overall, th is would result in ~5% under -reporting, or ... Results for the observer 
survey also indicated that a number of respondents cited mortalities seen by divers, or 
entanglement events as possible sources of unreported mortality (9 of 23 
respondents).476 
7.284.   Concern that dolphin mortalities and serious injuries caused by setting on dolphins in the 
ETP may be underreported appears to be shared by a number of other sources. For example, in a 
letter sent to the MSC in October 2016, the World Wildlife Fund (WWF) states th at "[t]here is a 
real concern that dolphin mortalities are actually unknown or potentially significantly 
underestimated", and questions whether full knowledge of mortalities and serious injuries can be 
gleaned even from 100% observer coverage.477 
7.285.   To us, thes e sources suggest that it is likely that dolphins are killed and seriously injured in 
the ETP in larger numbers than are observed. They also seem to be consistent with the fact, 
accepted by the panel in the first compliance proceedings, that the task of ob serving dolphin 
mortalities and serious injury in the ETP is complicated by " the intensity and length of the 
interactions in a dolphin set between the dolphins, on the one hand, and the vessel, speed boats, 
helicopter, a nd purse seine net on the other".478 We further note that, because setting on dolphins 
necessarily involves interaction with dolphins in 100% of sets479, the likelihood of unobserved 
mortality or serious injury is present in every set.  
7.286.   We now turn to assess the evidence and the parties' argument s concerning unobservable 
harms. As we explained above, the first compliance panel conducted a detailed review of both the 
panel's and Appellate Body's findings in the original proceedings and the evidence submitted by 
the parties on this issue in the firs t compliance proceedings. The compliance panel accepted that 
setting on dolphins causes unobservable harms, including "cow-calf separation; potential muscle 
injury resulting from the chase; immune and reproductive systems failures; and other adverse 
health  consequences for dolphins, s uch as continuous acute stress"480, and observed that these 
harms occur as a result of the "chase itself".481 
                                                
474 The average of the figures listed in Exhibit USA -179.Rev., p.1, is 6,260,131.8 . 
475 Sian Morgan et al., SCS Global Services, MSC Full -Assessment Report: The Northeastern Tropical 
Pacific Purse  Seine Yellowfin and Skipjack Fishery (2016) , (Exhibit USA -205), p. 52.  
476 Sian Morgan et al., SCS Global Services, MSC Full -Assessment Report: The Northeastern Tropical 
Pacific Purse Seine Yellowfin and Skipjack Fishery (2016) , (Exhibit USA -205), p. 90.  
477 Letter from Daniel Suddaby, WWF, to the Independent Adjudicator, MSC, on Notice of Objection for 
the Northeastern Tropical Pacific Purse Seine Yellowfin and Skipjack Tuna Fishery (Oct ober 24, 2016) , (Exhibit 
USA-144), p. 8.  
478 Panel Report, US – Tuna II  (Mexico) (Article 21.5 – Mexico) , paras. 7.239 -7.245.  
479 Panel Report, US – Tuna II  (Mexico) (Article 21.5 – Mexico) , para. 7.244.  
480 Appellate Body Report, US – Tuna II (Mexico) , para. 330, fn. 663.  
481 Panel Report, US – Tuna II (Mexico) , para. 7.504.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.287.   In these proceedings, Mexico essentially asks us to reconsider the evidence on the 
existence of unobservable harms. As we  noted above, Mexico argues that the evidence for the 
existence of unobservable harms is "speculative, biased, and faulty".482 However, as we also noted 
above, the Appellate Body has made clear that compliance panels should follow the reasoning of 
previous p anels and the Appellate Body, unless there has been a change in the underlying 
evidence.483 Accordingly, we will focus our assessment of this issue on whether there is new 
evidence on the record that calls into question the conclusions of the previous panels  and 
Appellate Body regarding unobservable harms caused by setting on dolphins in the ETP.  
7.288.   According to Mexico, the evidence regarding unobservable effects of setting on dolphins in 
the ETP is based on speculative hypotheses, all initially motivated by the  assumption that dolphin 
populations were not growing at expected rates.484 However, in Mexico's view, the assumption that 
dolphin populations were not recovering as expected has subsequently been found to be 
inaccurate, including by the US Department of Com merce itself.485 Accordingly, because all the 
evidence concerning unobservable harms is based on the "assumption" that dolphin stocks were 
not recovering, and because that assumption is incorrect , there remains no support for the 
proposition that setting on dolphins causes unobservable harms.486 Indeed, in Mexico's view, "the 
only objective scientific evidence of the magnitude of any unobservable harms caused by AIDCP -
compliant dolphin encirclement is the evidence related to the growth of dolphin stocks".487 Thus, 
according to Mexico, since dolphin stocks are increasing, there is no basis for concluding that 
setting on dolphins has any unobservable effects.  
7.289.   At the outset, we observe that one of the key pieces of evidence on which Mexico relies in 
support of its pr oposition that dolphin stocks are recovering – Exhibit MEX -13488 – was on the 
record in the first compliance proceedings, and accordingly does not constitute a change in the 
underlying factual record. However, we also note that Mexico has also submitted a re cent scientific 
article suggesting that dolphin stocks in the ETP have likely been underestimated, perhaps by 
more than 50%.489 
7.290.   The United States questions whether the evidence submitted by Mexico indeed shows that 
dolphin populations in the ETP are recoveri ng.490 Moreover, the United States argues that the 
various exhibits it has submitted (and that have been relied on in previous stages of this dispute) 
indicate that setting on dolphins has unobservable effects on dolphins "independent from any 
population ass essment".491 
7.291.   In our view, the evidence on the record does not unambiguously indicate that dolphin 
stocks in the ETP are recovering. We recognize that the NOAA Technical Memorandum suggests 
that "[o]bservers as a group have generally been consistent in their tendency to underestimate 
schools", and indicates that numbers may have been underestimated inter alia , due, to the failure 
to include certain data in the calculations and computer software that excluded certain dolphin 
sightings.492 Moreover, we have no rea son to doubt that, as J ay Barlow concludes in h is article 
                                                
482 Mexico' s first written submission, para. 53. 
483 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 5.9 (referring to 
Appellate Body Report, US – Softwood Lumber VI (Article 21.5 – Canada) , para. 103; Appellate Body Report, 
US – Upland Cott on (Article 21.5 – Brazil) , para. 386).  
484 Mexico's response to Panels' question No. 61, para. 22.  
485 Mexico's first written submission, para. 54.  
486 Mexico's first written submission, para. 61.  
487 Mexico's first written submission, para. 61.  
488 NOAA Technical Memorandum NMFS, Estimates of 2006 Dolphin Abundance In The Eastern Tropical 
Pacific, With Revised Estimates From 1986 -2003 (April 2008) , (Exhibit MEX -13), in the previous proceedings 
(Exhibit USA -50). 
489 J. Barlow, Inferring trackline detection probabiliti es, g(0), for cetaceans from apparent densities in 
different survey conditions ,, Marine Mammal Science (2015) , (Exhibit MEX -53). According to the article, 
underestimation may result from the fact that "animals are harder to see when sighting conditions are  worse" 
(p. 9), and therefore the number of dolphins in "rough sea conditions" appears to decline (pp. 10 -11).  
490 United States' second written submission, paras. 68 -69. 
491 United States' second written submission, para. 70.  
492 NOAA Technical Memorandum NMFS , Estimates of 2006 Dolphin Abundance In The Eastern Tropical 
Pacific, With Revised Estimates From 1986 -2003 (April 2008) , (Exhibit MEX -13), pp. 11 -12. WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  submitted by Mexico, dolphin populations may be underestimated due to the difficulty of observing 
dolphins in rough ocean conditions.493 
7.292.   That said, we note that the NOAA Technical Memorandum makes no firm conclusions as to 
the recovery of dolphin stocks in the ETP. It states that certain stocks may be beginning to 
recover494, but also notes that this "interpretation must be tempered by several caveats"495, 
including statistic uncertainty and the possibilit y that  depleted  ETP dolphin stocks are being 
increased by the migration of dolphins  across the geographic boundaries that define the 
northeastern and western/southern spotted dolphin stocks .496 Additionally, a more recent study 
suggests that dolphin stocks i n the ETP may not, in, fact, be recovering as expected.497 
7.293.   In our view, therefore, the evidence falls short of establishing that the assumption that 
dolphin stocks are not recovering at the expected rate is "inaccurate", as Mexico alleges.498 While 
the evidenc e suggests that dolphin stocks may have been underestimated in some population 
surveys, it does not establish that the stocks are necessarily recovering at the expected rate.  
7.294.   At any rate, it is in our view unnecessary in the context of these proceedings to  come to a 
definite view on this issue, because we do not agree with Mexico that all of the evidence 
concerning unobservable effects depends on an assumption that dolphin stocks are not growing at 
the expected rate. In this sense, we do not agree with Mexi co that unobservable harms would 
necessarily be reflected in dolphin stocks.499 Rather, the evidence on the record seems to support 
the view that setting on dolphins has negative unobservable effects on dolphins, even though 
these effects may not be manifest  at a population level.  
7.295.   For example, the article "Physiological and Behavioral Development in Delphinid Calves: 
Implications for Calf Separation and Mortality due to Tuna Purse Seine Nets ", written by 
Shawn  R. Noren and Elizabeth F. Edwards and published i n Marine Mammal Science in 2007, notes 
that "unobserved calf mortality could affect recovery of dolphin populations".500 It does not, 
however, suggest that the cow -calf separation is in itself a speculation based on unexpectedly slow 
recovery rates. Rather, the article clearly finds that "dolphin calves become separated from their 
mothers during tuna purse seine activities" and that "[w]ithout their mothers, calves have an 
increased risk of mortality due to starvation and predation".501 The article also finds t hat "[t]he 
fishing intensity in the ETP provides ample opportunities for mother -calf separations and 
subsequent calf mortality to occur".502 Thus, it is the possible population -level effects of cow -calf 
separation, rather than the phenomenon of cow -calf sepa ration itself, that appears to be presented 
as hypothetical in this article.503 
                                                
493 J. Barlow, Inferring trackline detection probabilities, g(0), for cetaceans from apparent densities in  
different survey conditions, Marine Mammal Science (2015) , (Exhibit MEX -53), pp. 10 -11. 
494 NOAA Technical Memorandum NMFS, Estimates of 2006 Dolphin Abundance In The Eastern Tropical 
Pacific, With Revised Estimates From 1986 -2003 (April 2008)  (Exhibit MEX -13), p. 12.  
495 NOAA Technical Memorandum NMFS, Estimates of 2006 Dolphin Abundance In The Eastern Tropical 
Pacific, With Revised Estimates From 1986 -2003 (April 2008)  (Exhibit MEX -13), p. 12.  
496 NOAA Technical Memorandum NMFS, Estimates of 2006 Dolphin Abund ance In The Eastern Tropical 
Pacific, With Revised Estimates From 1986 -2003 (April 2008)  (Exhibit MEX -13), pp. 12 -13. 
497 Andre E. Punt, Independent Review of the Eastern Pacific Ocean Dolphin Population Assessment, 
IATTC Special Report (2013) , (Exhibit USA -104), p. 7 (noting the " (possible) lack of recovery of the eastern 
stock of spinner dolphins and of the North-Eastern stock of the spotted dolphins "). 
498 Mexico's first written submission, para. 54.  
499 Mexico's first written submission, para. 61.  
500 Shawn R . Noren, and Elizabeth F. Edwards, Physiological and Behavioral Development in Delphinid 
Calves: Implications for Calf Separation and Mortality Due to Tuna Purse ‑Seine Sets, 23 Marine Mammal 
Science (2007) , (Exhibit USA -43), p. 16 (emphasis added).  
501 Shawn R . Noren, and Elizabeth F. Edwards, Physiological and Behavioral Development in Delphinid 
Calves: Implications for Calf Separation and Mortality Due to Tuna Pur se‑Seine Sets, 23 Marine Mammal 
Science (2007) , (Exhibit USA -43), p. 16.  
502 Shawn R . Noren, and Elizabeth F. Edwards, Physiological and Behavioral Development in Delphinid 
Calves: Implications for Calf Separation and Mortality Due to Tuna Purse ‑Seine Sets, 23 Marine Mammal 
Science (2007) , (Exhibit USA -43), p. 16.  
503 Shawn R . Noren, and Elizabeth F. Edwards, Physiological and Behavioral Development in Delphinid 
Calves: Implications for Calf Separation and Mortality Due to Tuna Purse ‑Seine Sets, 23 Marine Mamma l 
Science (2007) , (Exhibit USA -43), p. 24.  We note Mexico's argument that the research contained in this Exhibit 
was presented as "speculation" relying on the behavior of t errestrial herd -forming mammals , rather than on 
data concerning dolphins in the ETP.  Mexico's first written submission, para. 62. We do not read the Exhibit in WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.296.   The same is true of the article " Declines in reproductive output in two dolphin populations 
depleted by the yellowfin tuna purse seine fishery", writt en by Katie L. Cramer, 
Wayne  L. Perryman and Tim Gerrodette and published in 2008.504 This article, like the article by 
Noren and Edwards, considers that cow -calf separation could be restricting population recovery. It 
does not, however, suggest that the phenomenon of cow -calf separati on is in itself hypothetical. 
Rather, it too states unequivocally that "75 to 95% of lactating females killed in purse seines do 
not have their nursing calves with them", and that "encirclement could have negative physiological 
consequences for individual dolphins".505 It is the possible impact of these phenomena on the 
stock, rather than the phenomena themselves, that appear to be theoretical in this article.506 
7.297.   Other exhibits concerning unobservable harms similarly do not rely on the assumption that 
dolphin s tocks in the ETP are not recovering at expected rates. For example, the article 
"Adrenocortical color darkness and correlates as indicators of continuous acute premortem stress 
in chased and purse -seine capture d male dolphins" by Albert C. M yrick Jr. and P eter C. Perkin s, 
published in Pathophysiology  in 1995 , finds that "[a] dolphin fishing set subjects dolphins to many 
strong, unavoidable stimuli including forced high -speed swimming, close pursuit, gear and vessel 
noise, turbulence, confinement, and crowdi ng", and that "many set stimuli should stress dolphins 
acutely",507 with stress defined as a "condition caused by factors impairing an animal's well -being 
by forcing its systems into oscillatory instability and altering normal oscillatory performances 
("home ostasis" sensu lato)".508 The same article concludes that all animals sampled showed signs 
                                                                                                                                                  
this way. As we understand it, although the authors of the Exhibit make comparisons between dolphins and 
other terrestrial mammals, they do not rely on those comparisons in arrivin g at their conclusions, which are 
based on photographs of dolphins in the ETP as well as scientific knowledge about dolphin behaviour. The 
comparisons with other mammals are made to obtain additional "clues" as to possible dolphin behavior. 
Moreover, we no te that even if the authors had relied entirely on comparisons between dolphins and other 
terrestrial mammals, as Mexico argues, this would not of itself be reason for us to disregard or accord less 
weight to the Exhibit. Mexico has not argued or establish ed that reliance on such comparisons would be 
unscientific or unobjective, or would otherwise undermine the conclusion reached by the authors. In this 
connection, we note that the Exhibit in question is a scientific study published in a journal called Mari ne 
Mammal Science. The fact of its publication in such a journal suggests to us that the methodology used was 
objective and accepted in the relevant scientific community. Mexico has not suggested otherwise, and we have 
no basis to question the study's legi timacy. As such, even if Mexico's argument were correct, it would not 
provide a basis for us to ignore or accord less weight to the Exhibit in question.  
504 Katie L. Cramer, Wayne L. Perryman and Tim Gerrodette, Declines in Reproductive Output in Two 
Dolphin  Populations Depleted by the Yellowfin Tuna Purse Seine Fishery, 369 Marine Ecology Progress Series 
273 (2008) , (Exhibit USA -45). 
505 Katie L. Cramer, Wayne L. Perryman and Tim Gerrodette, Declines in Reproductive Output in Two 
Dolphin Populations Depleted b y the Yellowfin Tuna Purse Seine Fishery, 369 Marine Ecology Progress Series 
273 (2008) , (Exhibit USA -45), p. 274.  
506 Katie L. Cramer, Wayne L. Perryman and Tim Gerrodette, Declines in Reproductive Output in Two 
Dolphin Populations Depleted by the Yellowfin  Tuna Purse Seine Fishery, 369 Marine Ecology Progress Series 
273 (2008) , (Exhibit USA -45), p. 282. A number of other exhibits also indicate that cow -calf separation occurs 
as a result of the chase: see e.g. Paul R. Wade et al., Depletion of Spotted and Sp inner Dolphins in the Eastern 
Tropical Pacific: Modeling Hypothesis for their Lack of Recovery, 343 Marine Ecology Progress Series 1 (2007) , 
(Exhibit USA -48), p. 11; Elizabeth Edwards, Fishery Effects on Dolphins Targeted by Tuna Purse -Seiners in the 
Easte rn Tropical Pacific Ocean, 20 Int 'l J. Comp. Psychology 217 (2007) , (Exhibit USA -140), pp. 224 -225. We 
note Mexico's argument that Exhibit USA -45 itself states that its analysis only applies to the northeastern 
offshore spotted stock and that its hypothesi s is speculative. Mexico's first written submission, para. 62. We do 
not consider that Mexico's argument undermines the probative value of this Exhibit. The fact that the Exhibit 
relates only to one stock of dolphins in the ETP does not, in our view, mean that its conclusions are not 
reliable. Moreover, we do not agree that the Exhibit states its conclusions as mere hypothesis. To the contrary, 
the Exhibit announces its conclusions about the existence of unobservable harms caused by setting on dolphins 
in unequivocal terms, for example at page 282, where the Exhibit states that "the practice of setting on 
dolphins has population -level effects beyond the direct kill reported by observers on fishing vessels". Morever, 
even if the study were based on hypothesis  or some kind of speculation, Mexico has not established that this 
would invalidate the study. Mexico has not pointed to any methodological shortcomings that would render the 
Exhibit unreliable or unobjective. We note that the Exhibit in question is a scie ntific study published in a journal 
called Marine Ecology Progress Series. The fact of its publication in such a journal suggests to us that the 
methodology used was objective and accepted in the relevant scientific community. Mexico has not suggested 
otherwise.As such, even if Mexico's argument were correct, it would not provide a basis for us to ignore or 
accord less weight to the Exhibit in question.  
507 Albert C. Myrick and Peter C. Perkins, Adrenocortical Color Darkness and Correlates as Indicators of 
Continuous Acute Premortem Stress in Chased and Purse ‑Seine Captured Male Dolphins, 2 Pathophysiology 
191 (1995) , (Exhibit USA -46), p. 192.  
508 Albert C. Myrick and Peter C. Perkins, Adrenocortical Color Darkness and Correlates as Indicators of 
Continuous Acut e Premortem Stress in Chased and Purse ‑Seine Captured Male Dolphins, 2 Pathophysiology 
191 (1995) , (Exhibit USA -46), p. 191.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  of continuous acute stress prior to their deaths, but that "entanglement and death throes were not 
the primary source" of this stress, meaning that the stress was like ly caused by the chase itself.509 
Moreover, the study found that the sampled dolphins were in a state of continuous acute stress 
"for an hour or more up to the time of death".510 
7.298.   Mexico submitted a more recent academic article that, in its view, casts doubt on  the 
conclusions of the paper by Myrick and Perkin s.511 This paper, published in 2013 in Marine Mammal 
Science, is entitled "Hematological, serum, and plasma chemical constituents in pantropical 
spotted dolphins (Stenella attenuata) following chase, encircle ment, and tagging". Mexico notes 
that this paper finds that:  
It might be expected that dolphins subjected to the continuous stress of confinement 
and gradual constriction of the space around them would express these changes to an 
increasing degree over ti me. In fact, few such associations were detected statistically, 
and several of those that were detected ran counter to the anticipated direction of 
change .512 
7.299.    We note, however, that this passage appears to relate to the way in which the intensity of 
identif ied stress effects change s over the course of a particular chase. As we read it, this 
statement does not suggest that dolphins do not suffer stress effects as a result of the chase.  
7.300.   Indeed, when read as a whole, this paper supports, rather than contradict s, the findings of 
Myrick and Perkin s. The paper clearly finds that "a stress response occurred in all dolphins" 
sampled.513 Moreover, despite apparently considerable logistical challenges in conducting their 
study514, the authors conclude that:  
[C]hase and e ncirclement of dolphins by a tuna purse seiner results in a measurable 
stress response typical of odontocetes. The response is characterized by elevated 
blood catecholamine, cortisol, and ACTH levels, as well as a mild elevation of enzymes 
released from mu scle following exertion.515 
                                                
509 Albert C. Myrick and Peter C. Perkins, Adrenocortical Color Darkness and Correlates as Indicators of 
Continuous Acute Premortem S tress in Chased and Purse ‑Seine Captured Male Dolphins, 2 Pathophysiology 
191 (1995) , (Exhibit USA -46), p. 201.  
510 Albert C. Myrick and Peter C. Perkins, Adrenocortical Color Darkness and Correlates as Indicators of 
Continuous Acute Premortem Stress in Chas ed and Purse ‑Seine Captured Male Dolphins, 2 Pathophysiology 
191 (1995) , (Exhibit USA -46), p. 202.  
511 Mexico's first written submission, para. 62.  
512 David St. Aubin, et al., Hematological, serum, and plasma chemical constituents in pantropical 
spotted dolph ins (Stenella attenuata) following chase, encirclement, and tagging, Marine Mammal Science, 
29(1) , (Exhibit MEX -14), p. 29.  
513 David St. Aubin, et al., Hematological, serum, and plasma chemical constituents in pantropical 
spotted dolphins (Stenella attenuat a) following chase, encirclement, and tagging, Marine Mammal Science, 
29(1) , (Exhibit MEX -14), p. 15.  
514 David St. Aubin, et al., Hematological, serum, and plasma chemical constituents in pantropical 
spotted dolphins (Stenella attenuata) following chase, en circlement, and tagging, Marine Mammal Science, 
29(1) , (Exhibit MEX -14), pp. 28 -29. 
515 David St. Aubin, et al., Hematological, serum, and plasma chemical constituents in pantropical 
spotted dolphins (Stenella attenuata) following chase, encirclement, and ta gging, Marine Mammal Science, 
29(1) , (Exhibit MEX -14), p. 32. We note Mexico's argument that Exhibit MEX -14 itself states that, with respect 
to the apparent persistence of elevated levels of one of the hormones associated with stress that were 
measured in the study in this Exhibit, "more likely, chasing by swimmers,handling, and sampling for this study 
caused restimulation of the hypothalamic pituitary axis for these dolphins". Mexico's first written submission, 
para. 62. We observe, however, that this stat ement relates to the possible reason for the persistence  of one of 
the hormones associated with stress in dolphins. Moreover, the authors of the study in this Exhibit, even after 
acknowledging that the persistence of this hormone was likely caused by swimm ers handling and sampling 
dolphins for the study, nevertheless clearly conclude at page 32 that the " chase and encirclement of dolphins 
by a tuna purse seiner results in a measurable stress response typical of odontocetes ". Accordingly, the point 
identifie d by Mexico was apparently not considered by the authors of the study to undermine their  conclusion 
that setting on dolp hins causes measurable stress effects on dolphins.  Mexico has not identified or established 
any methodological flaw or shortcoming in t his study that would undermine its evidentiary value. In this 
connection, we note that the Exhibit in question is a scientific study published in a journal called Marine 
Mammal Science. The fact of its publication in such a journal suggests to us that the methodology used was 
objective and accepted in the relevant scientific community. Mexico has not suggested otherwise, and we have 
no basis to question the scientific or methodological legitimacy or objectivity of the study.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.301.   A number of other studies submitted by the United States also indicate that dolphins suffer 
stress as a result of the chase and encirclement process. These studies are not tied to the growth 
rate of dolphin populations. For exampl e, the report contained in Exhibit USA -47 indicates that 
there is "some evidence" for "potential stress -related injury or unobserved mortality of dolphins 
involved in purse seine fishing operations", including "(a) moderately elevated stress hormones 
and e nzymes indicative of muscle damage observed in live dol phins examined in the nets; 
(b) evidence of past (healed) muscle and heart damage in dolphins killed during fishing 
operations; and (c) fatal heart damage in virtually all fishery -killed dolphins, whic h most likely was 
related to elevated catecholomines".516 These findings are not connected to or underpinned by any 
assumption about the recovery of dolphin stocks.517 
7.302.   Similarly, the article submitted in Exhibit USA -48 and entitled "Depletion of spotted and 
spinner d olphins in  the Eastern Tropical Pacific: modeling  hypothesis for their lack of r ecovery " 
that was published in 2007 in the Marine Ecology Progress Series, observes that:  
Chase and encirclement by purse -seine vessels and their speedboats may (1) caus e 
changes in tissue chemistry that are associated with stress, (2) elevate body 
temperature and physically damage organ systems, (3) increase bioenergetics 
demands, and (4) influence swimming and schooling dynamics and behavior.518 
7.303.   The article then states th at "[w]hile these physiological and behavioral changes may affect 
some individuals, they have not been shown to be common enough to have population -level 
consequences"519, thus confirming that such effects exist regardless of whether they affect the 
populati on level.  
7.304.   Additionally, the United States submitted two new exhibits that, in its view, confirm the 
findings of the previous panels and Appellate Body on the existence of unobserved harms. Exhibit 
USA-140 contains a 2007 article entitled "Fishery Effects o n Dolphins Targeted by Tuna Purse -
seiners in the Eastern Tropical Pacific Ocean" and written by Elizabeth F. Edwards. It reviews the 
existing literature and finds that:  
[S]tudies of fishery effects on ETP dolphin physiology, behavior, and population 
dynami cs indicate that adult dolphins chased, encircled, and released during tuna 
purse -seine sets experience acute, intense stress during the event but most appear to 
                                                
516 Stephen B. Reilly et al., Repo rt of the Scientific Research Program Under the International Dolphin 
Conservation Program Act (2005) , (Exhibit USA -47), p. 25. The report notes that while all sampled live 
dolphins were  "well within those ranges from which dolphins are expected to recover  fully", there is 
nevertheless a risk of more serious stress effects that could lead to mortality "within hours or days of being 
released".  
517 We note Mexico's argument that the Exhibit states that no live dolphins evidencing such a strong 
stress reaction f rom the capture procedure has ever been identified or sampled. Mexico's second written 
submission, fn. 14. However, a plain reading of the Exhibit and the passage in question makes clear that this 
statement relates to what the authors of the research call "stronger" stress reactions, i.e. stress reactions that 
are stronger than ordinarily observed and they may be caused by "'catastrophic'  aspects of fishery operations 
when  dolphins may become trapped under a canopy in the net ". The authors contrast such "st ronger" stress 
reactions with "[t] he responses observed in the sampled live animals  [which]  were well within those  ranges 
from which dolphins are expected to recover fully ". We note, however, that the fact that dolphins are expected 
to recover from observe d stress does not undermine or contradict the proposition that setting on dolphins does 
cause stress to dolphins. To the contrary, it confirms  that setting on dolphins causes stress to dolphins, even 
though most dolphins are expected to recover. Thus, the fact that most dolphins are expected to recover from 
this stress is, in our view, beside the point. Moreover, we note that the mere fact that no live dolphin exhibiting 
"stronger" stress reactions has been identified or sampled is not of itself sufficient to undermine the authors' 
conclusions. Mexico has not alleged or explained why such lack of live testing would undermine the objectivity 
or scientific credibility of the authors' conclusions. We note that this Exhibit contains research conducted under 
a scientific research program under the auspices of the US International Dolphin Conservation Program Act. 
The scientific nature of the research suggests to us that the methodology used was objective and accepted in 
the relevant scientific community. Mexico ha s not suggested otherwise, and we have no basis to question the 
scientific or methodological legitimacy or objectivity of the study.  
518 Paul R. Wade et al., Depletion of Spotted and Spinner Dolphins in the Eastern Tropical Pacific: 
Modeling Hypothesis for t heir Lack of Recovery,  343 Marine Ecology Progress Series 1 (2007) , (Exhibit USA -
48), p. 11 (internal citations omitted).  
519 Paul R. Wade et al., Depletion of Spotted and Spinner Dolphins in the Eastern Tropical Pacific: 
Modeling Hypothesis for their Lack o f Recovery, 343 Marine Ecology Progress Series 1 (2007) , (Exhibit USA -
48), p. 11.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
- 99 - 
 
  recover from this experience, though some may develop long -term sequelae such as 
vascular and muscle lesions, reproductive failure, or reduced survival.520 
7.305.   It also makes clear that while "it is possible that fishery effects on adults remain an 
important factor in the observed lack of population recovery"521, the existence of these effects is 
not tied t o the recovery rate of the dolphin stocks, though they may have an effect on it.522 
7.306.   Exhibit USA -206 also contains an article, this one entitled "Estimation of relative exposure 
of dolphins to fishery activity" and published in 2010. This article notes that s etting on dolphins 
has a negative effect on dolphin reproduction.523 
7.307.   Finally, we observe that, in addition to the scientific studies discussed above, some 
environmental NGOs have also expressed concern about possible unobservable effects of setting 
on dolphi ns in the ETP . For example, according to the World Wildlife Fund, unobservable harms 
"are more detrimental than even an observed mortality of 15,000 dolphins per year".524 
7.308.   In our view, this evidence, much of which has been considered in previous stages of th is 
dispute, indeed establishes that setting on dolphins causes unobservable harms . We do not agree 
with Mexico that this evidence is "speculative". Neither do we agree with Mexico that the studies 
are based on the assumption that dolphin stocks in the ETP are not recovering at the expected 
rate. While some of the studies suggest that unobservable effects may have an impact on 
population recovery, the existence of those effects is not tied to the rate at which ETP dolphin 
stocks are recovering. Moreover, whi le some of the studies express uncertainty about the precise 
scope, extent, and impact of unobservable harms, none appears to doubt that unobserved harms 
exist and affect dolphins. The studies are also uniform in suggesting that these harms are caused 
by the chase itself.  
7.309.   Accordingly, we find no basis in the record to depart from the findings made in previous 
stages of this dispute that setting on dolphins causes unobservable harms including " cow-calf 
separation; potential muscle injury resulting from the c hase; immune and reproductive systems 
failures; and other adverse health consequences for dolphins, such as continuous acute stress".525 
Further, as explained above, new evidence placed on the record of these proceedings also confirm s 
these findings.  
7.310.   Because  of the qualitative nature of the evidence on the record, we are not in a position to 
estimate, with any accuracy, the number  of dolphins affected by unobservable harms. However, 
given that the evidence supports the existing finding that these harms are ca used by the chase 
itself, and given that some six million dolphins are chased per year in the ETP large purse seine 
fishery, it seems reasonable to think that each of those dolphins is at risk  of suffering 
unobservable harms, even though the evidence does not indicate that every dolphin chased will in 
fact suffer such harms. Indeed, as noted above, some of the evidence on the record suggests that 
                                                
520 Elizabeth Edwards, Fishery Effects on Dolphins Targeted by Tuna Purse -Seiners in the Eastern 
Tropical Pacific Ocean, 20 Int 'l J. Comp. Psychology 217 (2007), (Exhibit USA -140), p. 224.  
521 Elizabeth Edwards, Fishery Effects on Dolphins Targeted by Tuna Purse -Seiners in the Eastern 
Tropical Pacific Ocean, 20 Int 'l J. Comp. Psychology 217 (2007), (Exhibit USA -140), p. 224.  
522 Mexico argues that this Exhibit is a review of prior p ublications and does not contain any new 
research. Mexico's response to Panels' question No. 61, para. 18. We agree, as we acknowledge in the text of 
paragraph 7.304 However, Mexico has not argued that this fact undermines the c redibility or objectivity of the 
conclusions drawn in the Exhibit. Neither do we consider that the conclusions drawn in this Exhibit are invalid 
simply because they are based on a review of existing studies rather than original research. Mexico has not 
pointed to any methodological flaw or shortcoming in the Exhibit, and accordingly the mere fact that its 
conclusions are not based on original research does not consistute a reason for ignoring or according less 
weight to this Exhibit.  
523 Frederick I. Archer e t al., Estimation of Relative Exposure of Dolphins to Fishery Activity, 410 Marine 
Ecology Progress Series 245 (2010) , (Exhibit USA -206), p. 253.  
524 Letter from Annika Machensen, WWF, to Sian Morgan , WWF input: Northeastern Tropical Purse Seine 
YFT and SKJ Fishery (Jan uary 16, 2015) , (Exhibit USA -142), p. 6.  We note Mexico's argument that this letter 
provides no citation or other source for the figure of 15,000 and is therefore not probative evidence. Mexico's 
comments on the United States' response to Panel s' question No. 8, para. 20. We observe, however, that the 
letter does in fact indicate on page 5 that the figure is based on "expert opinion from scientists and 
veterinarians who study and work with dolphins".  
525 Appellate Body Report, US – Tuna II (Mexico ), para. 330, fn. 663.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  these effects are not so widespread as to have population -level effects.526 Thus, in our view, the 
evidence indica tes that all dolphins chased and encircled in the ETP are at risk of suffering 
unobservable harms, even though the evidence does not suggest that all or even the majority 
actually suffer such harms in the event. To us, this suggests that, because chasing a nd 
encirclement are essential elements of the process of setting on dolphins, setting on dolphins 
cannot be used without putting dolphins at risk, even though that risk may not eventuate in every 
set.527 
7.311.   Before concluding, we note Mexico's view that "[t] he only estimate of the magnitude of 
unobserved adverse effects on dolphins in the ETP is provided by a paper that theorizes that the 
unobserved impact is approximately 14 percent of the level of observed mortalities ".528 Mexico 
bases this argument on Exhibit US A-44, which contains a scientific article entitled "Annual 
estimates of u nobse rved incidental kill of pantropical spotted d olphin  calves in the tuna purse seine 
fishery of the eastern tropical Pacific". In our view, however, this article does not support M exico's 
contention. Rather, the article finds that the impact of cow -calf separation  due to the death of the 
mother in a purse seine net  can be estimated as being an additional 14 % of observed 
mortalities.529 Thus, the figure of 14 % represents an estimate of  the impact of one type  of 
unobservable harms.530 The article does not purport to estimate the equivalent in mortality of all 
unobservable effects. Indeed, as the evidence analysed above shows, not all unobservable harms 
in fact lead to mortality. Accordingl y, we do not consider it appropriate to describe the impact of 
unobservable harms in terms of equivalent mortalities.  
7.7.2.2   Purse seine fishing without setting on dolphins  
7.7.2.2.1   Introduction  
7.312.   We now turn to review the evidence concerning the risks to dolphins caused by  purse seine 
fishing without setting on dolphins , in different parts of the ocean.  
7.313.   We note that while the basic operation of purse seining is the same, depending on the way 
in which tuna is detected and encircled, this method is classified into variations,  including purse 
seine using dolphin sets or other types of sets. As explained by the FAO, tuna may be detected 
because of certain behaviours of a tuna school that makes them visible, or because of an 
association of a tuna school with objects or with other  species (seabirds, dolphins, whales, whale 
sharks, etc.).531 In this connection, we observe that the FAO mentions four types of sets a purse 
seine may make: (i) school sets, (ii) dolphin sets, (iii) sets on seamounts and (iv) f loating object 
sets.532 In these  Reports, when we refer to p urse seine fishing without  setting on dolphins , our 
reference includes all types of purse seine fishing other than setting on dolphins.  
7.314.   Regarding school sets, the FAO explains that "[i]n these sets, the tuna school is detected 
because of its activity at or near the surface of the water. Typically, a disturbance on the ocean 
surface is detected from the vessel. A tuna school in a feeding frenzy or other type of very active 
behaviour close to the surface has caused the disturbance.  Fishers recognize and identify, with 
different names, a variety of school sets".533 
                                                
526 Paul R. Wade et al., Depletion of Spotted and Spinner Dolphins in the Eastern Tropical Pacific: 
Modeling Hypothesis for their Lack of Recovery, 343 Marine Ecology Progress Series 1 (2007) , (Exhibit USA -
48), p. 11.  
527 We note that, b ecause of the nature of unobservable harms, it would not be possible to determine 
with certainty whether one or more dolphins did suffer unobservable harms as a result of any set.  
528 Mexico's first written submission, para. 64.  
529 Frederick Archer et al., An nual Estimates of the Unobserved Incidental Kill of Pantropical Spotted 
Dolphin (Stenella Attenuata Attenuata) Calves in the Tuna Purse -Seine Fishery of the Eastern Tropical Pacific, 
102 Fishery Bulletin 233 (2004) , (Exhibit USA -44), pp. 242 -244. 
530 This wa s understood by the original panel, which found that " dolphin mortality is at least 14% 
greater than observed dolphin mortality due to dependent calves that are separated from their mothers ". Panel 
Report, US – Tuna II (Mexico) , para. 4.356 (emphasis added ). 
531 Bycatch and non -tuna catch in the tropical tuna purse seine fisheries of the world, FAO Fisheries and 
Aquaculture Technical Paper 568, (Exhibit USA -60), p. 17.  
532 Bycatch and non -tuna catch in the tropical tuna purse seine fisheries of the world, FAO F isheries and 
Aquaculture Technical Paper 568, (Exhibit USA -60), pp. 17 -24. 
533 Bycatch and non -tuna catch in the tropical tuna purse seine fisheries of the world, FAO Fisheries and 
Aquaculture Technical Paper 568, (Exhibit USA -60), p.17. We note the followin g statements regarding the WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.315.   Regarding sets on seamounts, a category of oceanic ridges, the FAO explains that "[i]n 
many regions, tuna schools are found associated with seamounts … and the category is u sed to 
classify sets" .534 
7.316.   Regarding floating objects sets, the FAO explains that "[m]any species are found growing 
on or under floating objects … A list of more than 300 fish species associated with floating objects 
has been compiled … Several tuna species o f commercial and recreational value are included 
among them. Fishers discovered the association of tuna schools with floating objects early on, and 
took advantage of the opportunity offered by a behaviour that made the detection and the capture 
easier than  for unassociated schools, because of the strength of the association that kept the 
school relatively fixed in space, drifting with the object. The fishery on floating objects started as 
an opportunistic operation, whenever an object was encountered".535 
7.7.2.2.2   Findings made in the previous proceedings  
7.317.   Purse seine fishing without  setting on dolphins  has been discussed and analysed in the 
previous stages of this dispute. In this connection, we recall the Appellate Body 's statement that  
"doubts could arise about the o bjective nature of an Article  21.5 panel's assessment" if, on a 
specific issue, that panel were to "deviate from the reasoning" in the original report "in the 
absence of any change in the underlying evidence in the record".536 Thus, in our factual 
assessment  of purse seine fishing without setting on dolphins , we will take due account of the 
findings made by the panels and the Appellate Body in the original and first compliance 
proceedings regarding this particular method.  
7.318.   We recall that the original panel  referred  to "unassociated purse seine sets (sets on 
floating objects such as F ADs and free swimming schools)"537, without distinguishing between the 
three types of such unassociated sets.  With regard  to observed harms, the original panel found  
that "[…] use of unassociated purse -seine sets or FADs to catch tuna may result, in certain cases, 
in substantial dolphin bycatch" .538 Similarly, the Appellate Body in the original proceedings found 
that "it has been established that dolphin mortalities occur in relation to all the  major commercial 
tuna-fishing methods, including fish aggregating devices ('FAD') sets, unassociated sets".539 The 
first compliance panel also noted that "[t] he risks to dolphins from other fishing techniques are 
[not] insignificant"540, although it di d not refer in detail to purse seine fishing without setting on 
dolphins. On appeal in the first compliance proceedings, the Appellate Body observed that  "the 
Panel explicitly acknowledged that Mexico submitted evidence concerning the extent of mortality 
and serious injury caused by tuna fishing methods including FAD fishing […], but again opined that 
                                                                                                                                                  
notion of "unassociated sets": "Two names, school sets and unassociated sets, have been used for the same 
type of set. In recent years, part of the literature has replaced school sets with unassociated sets. School set 
seems to i mply that this is the only type of set where a school is captured. "Unassociated set" is a definition by 
a negative, and the tuna schools are frequently associated with other schools of different species, and also with 
seabirds, that facilitate the detecti on. Both terms can be used, but school set is preferred because the fishers 
use and understand this one to describe these sets. This is one case where researchers try to impose a 
definition that is meaningful to them, replacing one that is meaningful to th e fishers. As one of the objectives 
of tuna researchers should be to communicate with fishers, it makes sense that they follow the language of 
those that spend their time fishing, and understand their logic. When a vessel makes a set, it is made on a log, 
on a FAD, on dolphins, or on a school of tunas. The description is correct and accurate, and the logic is 
obvious".  
534 Bycatch and non -tuna catch in the tropical tuna purse seine fisheries of the world, FAO Fisheries and 
Aquaculture Technical Paper 568, (Ex hibit USA -60), p.  19. 
535 Bycatch and non -tuna catch in the tropical tuna purse seine fisheries of the world, FAO Fisheries and 
Aquaculture Technical Paper 568, (Exhibit USA -60), p. 20.  
536 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 5.9 (referring to 
Appellate Body Report, US – Softwood Lumber VI (Article  21.5 – Canada) , para.  103; US – Upland Cotton 
(Article  21.5 – Brazil) , para.  386).  
537 Panel Report, US – Tuna II (Mexico) , para. 7.534. We note that Mexico itself seems to have this 
same understanding: "Purse seine nets can be set on logs or fishing aggregating devices (FADs), which 
capitalize on the fact that sea life is attracted to the shadows that are cast by floating objects. This method 
attracts and kills immature as well a s mature tuna, as well as a wide variety of other bycatch, including sea 
turtles, sharks, and other species. Purse seine nets can also be set on 'free -swimming' schools of tuna (i.e. 
"unassociated sets"), which are not associated with logs or FADs but whic h also result in significant levels of 
bycatch". Mexico's first written submission, para. 34 (footnotes omitted ). 
538 Panel Report, US – Tuna II (Mexico) , para. 7.521. 
539 Appellate Body  Report, US – Tuna II (Mexico) , para s. 60, 289.  
540 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.124 , Appellate Body Report, US 
– Tuna II (Mexico) , para. 289.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
- 102 - 
 
  none of this eviden ce suggested that such fishing methods inflict the same kinds of unobserved 
effects as setting on dolphins ".541 
7.319.   We note, however, that the pr evious findings on purse seine fishing without setting on 
dolphins did not go into detail regarding the nature and scope of the observable harms posed by 
this fishing method. This contrasts with the detailed findings made regarding purse seine fishing by 
setting on dolphins.  
7.7.2.2.3   Panels' assessment in the present proceedings  
7.320.   Having recalled the  previous findings concerning purse seine fishing without setting on 
dolphins , we now turn to the assess ment of  parties' arguments  and evidence regarding the risk 
profile of this fishing method, starting with observable harms and moving on to unobservable 
harms.  
7.321.   We note at the outset that the United States contends that, in contrast to the ETP large 
purse seine fishery, in purse seine fisheries outside the ETP , there is no evidence that vessels 
routinely intentionally set on dolphins.  Rather, according to the United States, the available 
evidence describes only isolated, accidental or opportunistic incidents of sets on marine mammals 
that are in the vicinity of the tuna at a  particular time. In this regard, the United States maintains 
that less than 1% of the sets in purse seine fisheries outside the ETP involve any interaction at all 
with a dolphin, much less a mortality or serious injury.542 To support its contention about th e 
extent of dolphin interactions outside the ETP, the United States submits the following table543, 
later revised in Exhibit USA -179 Rev.:  
United States' Summary of the Evidence  
Fishery  Year  Sets with 
Dolphin 
Interactions  Dolphins Chased  Dolphin 
Interaction s % Sets with 
Dolphin 
Interactions  
WCPFC Purse 
Seine544 2007-2009 134 no evidence of any  798 0.70%  
2010 37 no evidence of any  144545 0.18%  
Eastern Tropical 
Atlantic Purse 
Seine546 2003-2009 0 0 0 0% 
Indian Ocean 
Tropical Purse 
Seine547 2003-2009 fewer than 31  no evidence of any  unknown  less than 1% 
for all marine 
mammals  
 
7.322.   The United States also points out that the first compliance panel found that most of the 
interactions that do occur outside the ETP are accidental548, and accepted that there is no evidence 
that vessels routinely chase dolphins outside the ETP.549 The United States further submits that, 
                                                
541 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico),  para. 7.246.  
542 United States' first written submission, para. 51. 
543 United Sta tes' first written submission, para. 51. 
544 Summary Information on Whale Shark and Cetacean Interactions in the Tropical WCPFC Purse Seine 
Fishery, Paper prepared by SPC -OFP, 8th Reg ular Session, Koror, Palau (November  2011) , (Exhibit USA -17), 
Table 2a, 2b ; WCPFC Scientific Committee, Fifth  Regular Session Summary Report  (2009) , (Exhibit USA -18), p. 
15. 
545 We note that the original number contained in the United States' first written submission was "397", 
but it was subsequently revised to "144" through Exhib it USA -179 Rev.  
546 Monin J. Amande et al., Bycatch of the European Purse Seine Tuna Fishery in the Atlantic Ocean for 
the 2003 -2007 Perio d, 23 Aquat. Living Resour. 353  (2010) , (Exhibit USA -19), pp. 355 -358; Monin J. Amande 
et al., Bycatch and Discards of t he European Purse Seine Tuna Fishery in the Atlantic Ocean: Estimation and 
Characteristics for 2008 and 2009, 66 ICCAT Collect. Vol. Sci. Papers 2113, (2011) , (Exhibit USA -20), pp. 
2114-2118.  
547 Monin J. Amande et al., Precision in Bycatch Estimates: The Ca se of Tuna Purse Seine Fisheries in 
the Indian Ocean, ICES J. Mar. Sci. (2012) , (Exhibit  USA-21), pp. 2 -3, and 6 . 
548 United States' first written submission, para. 52 (referring to Panel report, US – Tuna II  (Mexico)  
(Article 21.5 – Mexico) , para. 7.242 and  Summary Information on Whale Shark and Cetacean Interactions in 
the Tropical WCPFC Purse Seine Fishery, Paper prepared by SPC -OFP, 8th Reg ular Session, Koror, Palau 
(November  2011) , (Exhibit USA -17)). 
549 United States' first written submission, para. 52.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  where an accidental capture of dolphins does occur, only a handful of dolphins are likely be 
captured, as opposed to the ETP large purse seine fishery, where on a verage 300 -400 dolphins are 
captured per dolphin set.550 
7.323.   Regarding observable harms, Mexico argues that dolphin mortalities from purse seine 
fishing without setting on dolphin must be estimated to be at least 2,000 per year in the 
Philippines and at least 1, 200 to 1,900 per year in the Western and Central Pacific Ocean. In 
Mexico's view, these levels of mortality are comparable  to the equivalent of observed mortalities in 
the ETP. Mexico also submits that it is reasonable to assume that the same fishing metho d has 
similar adverse effects in other ocean areas.551 Mexico argues that vessels fishing not in 
association with dolphins in the WCPO killed as many as 180, 45, 21 and 10 dolphins in individual 
sets.552 
7.324.   Regarding unobservable harms, Mexico contends that if th e Panels accept that AIDCP -
compliant dolphin encirclement has unobserved adverse effects on dolphins, they must also accept 
that purse seine fishing without dolphin encirclement similarly entails unobserved adverse effects 
as some of the dolphins killed by  this fishing method will inevitably be dolphin cows and, thus  the 
fishing method  will effectively result in cow -calf separation effects. Mexico further  submits that this 
level of adverse effects exceeds the adverse effects of AIDCP -compliant dolphin encir clement in 
the ETP.553 
7.325.   Mexico also contends that the first compliance panel found that purse seine fishing in 
general may result in substantial dolphin bycatch, even in circumstances not involving 
encirclement of dolphins.554 Mexico notes that while the United  States refers to annual reports 
submitted to the Western and Central Pacific Fisheries Commission (WCPFC) that purport to report 
on interactions with cetaceans555, it leaves out the report on Papua New Guinea, which according 
to Mexico is the only country t hat sought to report comprehensive information from its own 
independent observer program. According to Mexico, Papua New Guinea reported that purse seine 
nets interacted with 292 dolphins in 2014 in its waters, of which all but 18 were reported to have 
been killed.556 Mexico contends that, based on the fact that the catch of tuna with purse seine nets 
in Papua New Guinea's waters is approximately 14.5% of the catch in the Western and Central 
Pacific Convention area (296,000 out of a total of 2.037 million ton nes in 2014)557, it is reasonable 
to assume that at least 1,890 dolphins were directly killed by purse seine nets in the WCPFC tuna 
fishery area in 2014.  
7.326.   The Panels begin by noting that the evidence on the record shows that purse seine fishing 
by setting on dolphins is mainly practiced in a widespread and systematic manner in the ETP.558 
However, it also shows that purse seine fishing without setting on dolphins is practiced in several 
areas of the ocean, including parts of the ETP, the Western and Central Paci fic Ocean (WCPO), the 
Indian Ocean and the Eastern Tropical Atlantic Ocean. Therefore, in the present proceedings, the 
parties have presented evidence regarding the risks posed to dolphins by this fishing method in 
the mentioned areas of the ocean. Consequ ently, we find it appropriate to assess the parties' 
arguments and evidence regarding harms caused to dolphins by purse seining without setting on 
dolphins on an area by area basis.  
7.327.   Before proceeding to our analysis, we recall that as discussed in section 7.7.1.2  above , in 
our assessment of the overall relative levels of risks, we will use the per set data on the record. 
More specifically, we will make use of the data presented in Exhibit USA -179 Rev.  
                                                
550 United States' first written submission, para. 52 (referring to Tables Summarizing Fishery -by-Fishery 
Evidence on the Record , (Exhibit USA -13)). 
551 Mexico's first written submission, para. 88.  
552 Mexico's responses to the Panels' questions, para. 181.  
553 Mexico's first written submission, paras. 88 -89. 
554 Mexico's first written submission, para. 75 (referring to Panel Report, US – Tuna II (Mexico) (Article 
21.5 – Mexico) , para. 7.132; and Panel Report, US – Tuna II (Mexico) , para. 7.521).  
555 Mexico's first writ ten submission, para. 76 (referring to Tables Summarizing Fishery -by-Fishery 
Evidence on the Record , (Exhibit USA -13)). 
556 Mexico's first written submission, para. 76 (referring to Papua New Guinea, Annual Report to the 
Commission, WCPFC -SC11 -AR/CCM -19 (Aug ust 2015) , (Exhibit MEX -23)). 
557 Mexico's first written submission, para. 78 (referring to Papua New Guinea, Annual Report to the 
Commission, WCPFC -SC11 -AR/CCM -19 (Aug ust 2015) , (Exhibit MEX -23) and Western and Central Pacific 
Fisheries Commission (WCPFC), Yearbook 2014 (15 Oct ober 2015) , (MEX -24)). 
558 See Section 7.7.2.1 . WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.328.   We first co nsider the evidence concerning purse seine fishing without setting on dolphins in 
the ETP.  
7.329.   We begin by noting that, regarding observable harms, the United States summarizes, on a 
per set basis, the evidence on observed mortalities and serious injuries for the ETP  large purse 
seine fishery without setting on dolphins in the following table:559 
United States' Summary of the Evidence  
Year  Observed 
Sets Observed 
Mortality  Observed Serious 
Injury, Injury, or 
Released Alive  Mortality per 1,000 Sets  
2009  11,186  2 0 injuries  0.18 
2010  10,285  1 0 injuries  0.10 
2011  12,103  10 0 injuries  0.83 
2012  12,979  0 0 injuries  0.00 
2013  12,194  1 0 injuries  0.08 
2014 12,146  0 No data  0.00 
Total 70,893  14 0 injured/released 
alive 0.20 
 
7.330.   Mexico has not commented on the figure s presented in th is table560, nor has it  introduce d 
any evidence on the harms caused by purse seine fishing without setting on dolphins in the ETP.561 
7.331.   We note that the data presented in the above table is sourced from the IATTC, in 
particular, from (i) a repor t dated July 2014 that provides a summary of the fishery for tunas in 
the Eastern Pacific Ocean (EPO), an assessment of the major stocks of tunas and billfishes that are 
exploited in the fishery, and an evaluation of the pelagic ecosystem in the EPO562, and (ii) a 
dataset of the EPO in the period 2009 -2013 also prepared by the IATTC.563 As the I ATTC is an 
RFMO, and given that RFMOs are experts in the field of fisheries management , as discussed 
previously,  we find it appropriate to rely on the data presented in the above -mentioned table in 
making our findings regarding the observable harms caused to dolphins by purse seining without 
setting on dolphins in the ETP.  
7.332.   On the basis of the data in the above table, we find that dolphin mortalities for the purse 
seine fi shing without setting on dolphins in the ETP was on average below 0. 2 per 1,000 s ets in the 
2009-2014 period, excluding a peak in 2011 where 10 mortalities were reported in 12,103  sets 
(corresponding to 0.83 mortality per 1,000 sets). We also find that, as  shown in the same table, 
the number of serious injuries caused by purse seine fishing without setting on dolphins in the ETP 
has been zero in the 2009 -2014 period.  
7.333.   We note that neither party has introduced any direct evidence on the extent of unobserved 
harms arising from ETP  large purse seine fishing without setting on dolphins. In this regard, we 
recall the United States' contention that the frequency of dolphin interactions and the number of 
dolphins generally involved in the fishing method may constitu te a good proxy for unobserved 
harms, as these figures would give a picture of how frequently dolphins might be endangered by a 
particular method, and represents the maximum possible number of mortalities and injuries. 
                                                
559 Tables Summarizing Fishery -by-Fishery Evidence on the Record , (Exhibit USA -179 Rev.). The 
evidence supporting the figures in this table is IATTC, Tuna, Bil lfishes and Other Pelagic Species in the Eastern 
Pacific Ocean in 2014, Doc. IATTC -89-04a, IATTC 89th Meeting (June 29 -July 3, 2015) , (Exhibit USA-14), 
Table A -7, for set numbers; and IATTC, EPO Dataset 2009 -2013, ( Exhibit USA-16), for the number of dolphi ns 
killed and injured in non -dolphin sets . 
560 Mexico's response to Panels' question No. 57.  
561 Table summarizing the data available regarding the relative overall risks of adverse effects on 
dolphins caused by different fishing methods in different ocean are as, (Exhibit MEX -95). 
562 IATTC, Tuna, Billfishes and Other Pelagic Species in the Eastern Pacific Ocean in 2014, Doc. IATTC -
89-04a, IATTC 89th Meeting (June 29 -July 3, 2015) , (Exhibit USA -14). 
563 IATTC, EPO Dataset 2009 -2013, (Exhibit USA -16). WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  However, the parties have not provide d any specific evidence on the extent of dolphin interaction 
associated with this fishing method in this area of the ocean. Given the nature of this fishing 
method, where no interaction with dolphins is required in order to spot the tuna, coupled with the 
data presented in the table above that shows that, on average, mortalities occurred in less than 
0.02% of the sets, we can reasonably conclude that purse seine vessels not setting on dolphins 
rarely interact with dolphins, if at all. We are mindful that, d ue to the significant and regular 
association between tuna and dolphins in the ETP, even purse seine fishing without setting on 
dolphins might end up, inadvertently, interacting with dolphins, perhaps even at a higher rate than 
purse seine fishing by setting on dolphins or other fishing methods in other areas of the ocean.564 
Nevertheless, none of the evidence on the record suggests that these interactions would rise to the 
level of those observed in purse seine fishing by setting on dolphins.  
7.334.   Accordingly, we  consider that the extent of unobserved harms caused by purse seining 
without setting on dolphins in the ETP may be low, although , without direct evidence on the record  
on this particular matter , we are unable to base this finding on a precise quantificati on. 
7.335.   Finally, we note that neither party has argued or submitted evidence showing that purse 
seining without setting on dolphins in the ETP causes the kind of unobservable harms caused by 
setting on dolphins. In this connection, however, we note that the ev idence does show that ETP  
large purse  seine fishing without setting on dolphins does not involve  the same level of interaction  
with dolphins as does large purse seine fishing by setting on dolphins . Indeed, as the sets in purse 
seine fishing without settin g on dolphins do not require interaction with dolphins , we do not see 
how this fishing method could pose the same kinds of risks of unobservable harms to dolphins.  
7.336.   We now turn to assess the risk profile of purse seining without setting on dolphins in the 
Western and Central Pacific Ocean (WCPO).  
7.337.    The United States argues that, in 2010, observers reported 55 dolphin mortalities in 
20,853 observed sets, that is, 2.64 dolphin mortalities per 1,000 sets. The United States contends 
that, on this basis, the WCPFC  estimated that there were a total of 110 dolphin mortalities in the 
fishery as a whole  in 2010. In 2014 and 2015, observers documented very low levels of dolphin 
mortalities, approximately 1.2 mortalities per 1,000 observed sets in 2014 and 2.2 dolphin 
mortalities per 1,000 observed sets in 2015. The United States also submits that 2007 -2009 was 
the only period in which observers documented a mortality rate distinctly higher than that 
documented in the Atlantic and Indian Ocean purse seine fisheries and th at in subsequent years, 
observers reported much lower levels.565 
7.338.   The United States also claims that in the WCPO purse seine fishery566 between 2007 and 
2009, observers reported that a dolphin interaction occurred in only 134 of the nearly 20,000 
observed sets,  that is, in only 0.7% of the sets observed. In 2010, only 37 of the 20,853 observed 
sets, or 0.18% of the sets observed, interacted with a dolphin.567 The United States also asserts 
that, in 2008, observers on New Zealand purse seine vessels in the Western and Central Pacific 
Convention area observed 28% of all sets and reported no marine mammal interactions.568 
7.339.   In support of its arguments, the United States submits, in Exhibit USA -179 Rev., the 
following table, which summarizes, on a per set basis, the data p resented in various pieces of 
evidence presented by the United States in the current proceedings regarding observable harms 
caused by purse seine fishing without setting on dolphins in the WCPO:569 
                                                
564 In this resp ect, we note that large purse seine vessels in the ETP, including those that do not set on 
dolphins, at least in every set or voyage, are subject to the heightened certification and tracking and 
verification requirements discussed in Sections 7.8.3and 7.8.4above.  
565 United States' response to Panels' question No. 16.  
566 We note that in this regard, in its submissions, the United States refers to the "WCPFC purse seine 
fishery", and uses data from the W estern and Central Pacific Fisheries Commission (WCPFC) to support its 
arguments on the risk profile of the WCPO.  
567 United States' first written submission, para. 55 (referring to Summary Information on Whale Shark 
and Cetacean Interactions in the Tropical  WCPFC Purse Seine Fishery, Paper prepared by SPC -OFP, 8th Reg ular 
Session, Koror, Palau (November  2011) , (Exhibit USA -17)). 
568 United States' first written submission, para. 55 (referring to  WCPFC Scientific Committee, Fifth  
Regular Session Summary Report  (2009) , (Exhibit USA -18)). 
569 Although we refer to the WCPO, we are mindful that the data for this area of the ocean relates to the 
Western and Central Pacific Convention area, and is collected and processed by the WCPFC . We note that WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  United States'  Summary of the Evidence  
Year  Observed 
Sets Dolphin 
Mortalities  Observed Serious 
Injury, Injury, or 
Released Alive  Mortality per 
1,000 Sets  Source of Data  
2007-2009570 19,136 519 279 released alive  27.12  
Observer Reports (15% 
coverage)  
2010 20,853 55 89 released alive  2.64 Observer Reports (est. 
40% coverage)  
 
 
2013  
Australia:571 0 dolphin mortalities; 0 dolphin injuries   
Logbook Reports (100% 
coverage)  
 
Micronesia :572 0 dolphin mortalities; 0 dolphin injuries  Observer Reports  
(100% coverage)  
Japan :573 0 dolphin mortalities; 5 cetacean interactions w here the cetacean 
was released alive   
Logbooks Reports (100% 
coverage)  
 
 
 
 
 
 
 
 
 
 
 
 2014   
Overall 
574 25,760 (est.)  31 1 serious injury  1.2 Observer Reports (46% 
coverage)  
Country  
 
Reports  China :575  9 dolphin mortalities; 5 dolphins caught and released ali ve  
Observer Reports 
(100% coverage)  Micronesia :576 0 dolphin mortalities; 0 dolphin injuries  Observer Reports (100% 
coverage)  
Japan :577 0 dolphin mortalities; 5 cetacean interactions where the cetacean 
was released alive  Vessel     Reports 
(100% coverage ; 
observer  onboard)  
Kirbat i:578  0 dolphin mortalities; 0 dolphin injuries  Observer Reports 
(100% coverage)  
                                                                                                                                                  
according to Article 3  of the Western and Central Pacific Convention, the area of competence of the WCPFC 
comprises "all waters of the Pacific Ocean bounded to the south and to the east by the following line: From the 
south coast of Australia due south along the 141° meridian o f east longitude to its intersection with the 55° 
parallel of south latitude; thence due east along the 55° parallel of south latitude to its intersection with the 
150° meridian of east longitude; thence due south along the 150° meridian of east longitude to its intersection 
with the 60° parallel of south latitude; thence due east along the 60° parallel of south latitude to its 
intersection with the 130° meridian of west longitude; thence due north along the 130° meridian of west 
longitude to its intersecti on with the 4° parallel of south latitude; thence due west along the 4° parallel of 
south latitude to its intersection with the 150° meridian of west longitude; thence due north along the 150° 
meridian of west longitude". We understand that the Western and  Central Pacific Convention area is a part of 
the WCPO.  
570 Summary Information on Whale Shark and Cetacean Interactions in the Tropical WCPFC Purse Seine 
Fishery, Paper prepared by SPC -OFP, 8th Reg ular Session, Koror, Palau (November  2011) , (Exhibit USA-17), 
Table s 2a, 2b . We note that the United States' original reference  was to Exhibit USA-58. However,  this seems 
to have been a typo as this Exhibit does not refer to the cited information) ; Peter Williams & Peter Terawasi, 
WCPFC, Overview of Tuna Fisheries in the Western and Central Pacific Ocean, Inclu ding Economic Conditions – 
2015 (August  30, 2016) , (Exhibit USA-108), pp. 2, 55, total set figures for 2007 -2009 and 2010.  
571 Australia, Annual Report to the Commission, WCPFC -SC10 -AR/CMM -01 (July 2014) (Exhibit USA-33), 
pp. 12-13. 
572 Federated States of Micronesia, Annual Report to the Commission, WCPFC -SC10 -AR/CCM -06 (Aug ust 
2014) , (Exhibit USA-34), p. 4. 
573 Japan, Annual Report to the Commission, WCPFC -SC10/AR/CCM -10 (July 2014) , (Exhibit USA-35) 
p.5. 
574 WCPFC, 7th Annual Report for the Regional Observer Programme (Sept ember  3, 2015) , (Exhibit 
USA-109), pp. 4-5, (dolphin mortalities and observer coverage); Peter Williams and  Peter Terawasi, WCPFC, 
Overview of Tuna Fisheries in the Western and Central Pacific Ocea n, Including E conomic Conditions – 2015, 
(August  30, 2016) , (Exhibit USA-108), pp. 2, 55 (total set figures for 2014).  
575 China, Annual Report to the Commission, WCPFC -SC11/AR/CMM -03 (August 2015) , (Exhibit USA-
184), p. 1 (coverage), p. 4 (catch), p. 15 (ce tacean interactions) . 
576 Federated States of Micronesia, Annual Report to the Commission, WCPFC -SC11 -AR/CCM -06 (July 
27, 2015) , (Exhibit USA-27), p.4, 11, Annex I .  
577 Japan, Annual Report to the Commission, WCPFC -SC11/AR/CCM -10 (July 31, 2015), (Exhibit USA-
29), pp. 5-7, 11, 13, 16 .  
578 Kirbati, Annual Report to the Commission, WCPFC -SC11/AR/CCM -11(July 20, 2015), (Exhibit USA -
36), pp. 3, 11 (observer coverage), p.16 (interactions).  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  United States'  Summary of the Evidence  
Year  Observed 
Sets Dolphin 
Mortalities  Observed Serious 
Injury, Injury, or 
Released Alive  Mortality per 
1,000 Sets  Source of Data  
Korea :579 0 dolphin mortalities; 0 dolphin injuries  Vessel     Reports 
(100% coverage; 
observer  onboard)  
 
Marshall Islands :580 17 dolphin mortalit ies; 0 injuries; 18 status unknown  Observer Reports 
(100% coverage)  
Papua New Guinea :581 255 dolphin mortalities; 0 injuries documented; 8 
status unknown  Observer Reports 
(100% coverage)  
Philippines :582  0 dolphin mortalities; 18 dolphin serious injuries  Observer Reports 
(100% coverage of 
HSP1) 
Solomon Islands :583 0 dolphin mortalities; 0 dolphin injuries  Observer Reports 
(100% coverage)  
Chinese Taipei :584 23 dolphin mortalities; 1 dolphin released alive  Vessel     Reports 
(100% coverage; 
observer  onboar d) United States :585 13 cetacean interactions  Vessel     Reports 
(100% coverage; 
observer  onboard)   
 
 
2015 Overall
586 30,240 (est.)  66 84 released alive  2.2 Observer Reports (63% 
coverage)  
Country  
Reports  China :587 22 dolphin mortalities; 12 dolphins caught  and released alive  Observer Reports 
(100% coverage)  
Micronesia :588 0 dolphin mortalities; 0 dolphin injuries  Observer Reports (100% 
coverage)  
Japan :589 1 dolphin mortality; 7 interactions where cetaceans were released 
alive Vessel     Reports 
(100% cover age; 
observer  onboard)  
Kirbat i:590 0 dolphin mortalities; 0 dolphin injuries  Observer Reports 
(100% coverage)  
Korea :591 0 dolphin mortalities; 0 dolphin injuries  Vessel     Reports 
(100% coverage; 
observer  onboard)  
Marshall Islands :592 16 dolphin mortali ties; 4 dolphins released alive  Observer Reports 
(100% coverage)  
                                                
579 Korea, Annual Report to the Commission, WCPFC -SC11 -AR/CCM -12 (August 30, 2 015), (Exhibit USA -
30), pp. 5, 10, 18 -19. 
580 Marshall Islands, Annual Report to the Commission, WCPFC -SC11 -AR/CCM -13 (August 2015),  
(Exhibit USA -185), pp. 1, 18.  
581 Papua New Guinea, Annual Report to the Commission, WCPFC -SC11 -AR/CCM -19 (August  2015) , 
(Exhib it MEX -23), pp. 5, 7.  
582 Philippines, Annual Report to the Commission, WCPFC -SC11/AR/CCM -20, (Exhibit USA -38) p. 10 
(observer coverage), p.18 (interactions) (September 28, 2015).  
583 Solomon Islands, Annual Report to the Commission, WCPFC -SC11 -AR/CCM -22(Augus t 2015), 
(Exhibit USA -186), pp. 13, 27.  
584 Chinese Taipei, Annual Report to the Commission, WCPFC -SC11 -AR/CCM -23 (November 3, 2015), 
(Exhibit USA -31), p. 15 (observer coverage), pp. 18 -19 (interactions).  
585 United States, Annual Report to the Commission, WCP FC-SC11/AR/CCM -20 (July 31, 2015), (Exhibit 
USA-187), p. 3 (catch), p. 25 (observer), p. 26 (cetaceans).  
586 WCPFC, 8th Annual Report for the Regional Observer Programme, (Exhibit USA -110), pp. 2, 5 -6 
(September 14, 2016); Peter Willia ms and  Peter Terawasi, WCPFC, Overview of Tuna Fisheries in the Western 
and Central Pacific Ocean, Including Economic Conditions – 2015 (August  30, 2016) , (Exhibit USA -108), pp. 2, 
55 (total set figures for 2014).  
587 China, Annual Report to the Commission, WCPFC -SC12 -AR/CMM -03 (A ugust 2016) , (Exhibit USA -
150), (catch) pp. 5, 15.  
588 Federated States of Micronesia, Annual Report to the Commission, WCPFC -SC11 -AR/CCM -06 
(September 21, 2016), (Exhibit USA -151), pp. 11, 16.  
589 Japan, Annual Report to the Commission, WCPFC -SC11/AR/CCM -10 (July 5, 2016), (Exhibit USA -
152), p. 5.  
590 Kirbati, Annual Report to the Commission, WCPFC -SC11/AR/CCM -11 (September 23, 2016), (Exhibit 
USA-153), pp. 10, 15.  
591 Korea, Annual Report to the Commission (August. 29, 2016), (Exhibit USA -13), pp.3, 8 -9. 
592 Marsha ll Islands, Annual Report to the Commission (August. 2016), (Exhibit USA -154), p. 15.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
- 108 - 
 
  United States'  Summary of the Evidence  
Year  Observed 
Sets Dolphin 
Mortalities  Observed Serious 
Injury, Injury, or 
Released Alive  Mortality per 
1,000 Sets  Source of Data  
Papua New Guinea :593 55 dolphin mortalities; 4 dolphins with fate unknown  Observer Reports 
(100% coverage)  
Philippines :594 0 dolphin mortalities, 7 dolphin serious injuries  Observer Reports  
(100% coverage of 
HSP1) Solomon Islands :595 0 dolphin mortalities; 0 dolphin injuries  ObserverReports 
(100%coverage)  
Chinese Taipei :596 10 dolphin mortalities; 9 dolphins encircled and released 
alive Vessel     Reports 
(100% coverage; 
observer  onboard)  
United States :597 8 cetacean interactions  Vessel     Reports 
(100% coverage; 
observer  onboard)  
 
7.340.   Mexico argues that the available data from the WCPO purse seine fishery indicates that 
dolphins are at significant risk, and that there is no reasonable basis t o presume that they are not. 
Mexico contends that the United State s cites the observer data from the WCPFC as  if it were 
complete and relevant to assessing the risk profiles for purposes of the Tuna M easure . However, 
Mexico contends that the primary respon sibility of observers in the WCPFC is to monit or the fish 
being harvested,  not to watch  for interactions with marine mammals598, and that the observers do 
not report to the WCPFC, but to the individual island nations'  program auth orities.  In Mexico's 
view, the United States has made no effort to adjust the data it submitted to take into account  
these types of factors .599 Mexico argues that according to the US Department  of Commerce : 
A common concern raised in the bycatch summary reports [from the WCOP fishery] is 
that the purpose of the observer program is to document operational compliance and 
record tuna catch composition data. Information on protected species interactions, 
such as turtle and whale species listed under the US ESA [Endangered Species Act] 
have been collected ancillary to other objectives of the program. In recent years, 
increasing emphasis has been placed on documenting interactions with marine 
mammals, turtles and sharks, however, the reliability and accuracy of the data have 
not been assessed.600  
7.341.   Mexico argues that the fact that WCPFC data is incomplete is confirmed  by Exhibit MEX -
116, a WCP FC report that shows that there is a significant time lag in providing data, and very 
uneven performance by nations in providing information.601 
7.342.   Mexico also no tes that there is an inconsistency between the data reported in the 2014 
and 2015 WCPFC reports and the individual country reports listed in the United States' chart 
because Exhibit US A-179 lists 31 mortalities in the WCPFC purse seine fishery in 2014, but  the 
                                                
593 Papua New Guinea, Annual Report to the Commission, WCPFC -SC12/AR/CMM -19 (Aug ust 2016) , 
(Exhibit USA -107), p. 20.  
594 Philippines, Annual Report to the Commission, WCPFC -SC11/AR/CCM -20 (July 2016), (Exhibit USA -
105) pp. 9 -10. 
595 Solomon Islands, Annual Report to the Commission (September 24, 2016), (Exhibits USA -155), p.26.  
596 Chinese Taipei, Annual Report to the Commission, WCPFC -SC11 -AR/CCM -23 (Aug ust. 2016) , 
(Exhibits USA-156) pp.11, 18-19. 
597 United States, Annual Report to the Commission, WCPFC -SC11/AR/CCM -20 (Aug ust. 2016) , (Exhibits 
USA-157), p. 26. 
598 Mexico's comments on the United States' response to Panels' questions 16; second written 
submission, para. 81.  
599 Mexico 's comments on the United States' response to Panels' questions 16.  
600 Mexico's comments on the United States' response to Panels' questions 16 (referring to National 
Marine Fisheries Service, Biological Opinion on the U S WCPO Purse Seine Fishery (November 1, 2006 ), (Exhibit 
MEX-124), p. 124) . 
601 Mexico's comments on the United States' response to Panels' questions 16 (referring to WCPFC, 
Status of ROP Data Management, WCPFC -TCC11 -2015-IP05_rev1 (10 September 2015), (Exhibit MEX -116), 
p.7). WT/DS381/RW/USA • WT/DS381/RW 2 
 
- 109 - 
 
  individual country reports to the WCPFC for 2014 that the United States shows in a separate part 
of the table total to 317 mortalities.602  
7.343.   In support of its position, Mexico submitted, through Exhibit MEX -95, the following table 
purporting to summarize  its evidence on observable mortalities and serious injury in this fishery , 
although not on a per set basis:  
Mexico's Evidence  
 
 
Fishery   
Year (as 
reported 
in cited 
documen
ts) Mortalities
/ Serious 
Injuries 
(MSI) as  
reported in 
cited 
documents)   
 
In relati on to 
PBR  
 
Observer Coverage  
WCPFC Purse Seine 
(excluding 
Philippines and 
Indonesian domestic 
fleets)603 2009  1,195 
(estimated 
by  
WCPFC)  Unknown  16% of fishing days  
PNG Purse Seine604 2014  280 Unknown  100% (not trained to observe 
dolphin interactions)  
Philippines (Sulu 
Sea), 5 purse seine 
vessels605 1994  1,500 to 2,250  Unknown  0% 
 
7.344.   The Panels begin their assessment by  noting that, regarding the observable harms caused 
by purse seine fishery without setting on dolphins in the WCPO , the United States submitted  
evidence on a per set basis for the following periods: 2007 -2009, 2010 , 2014 and 2015 . The data  
indicates that  the initial level of dolphin mortalities between 2007 and 2009, which was 27.12 per 
1,000 sets , dropped to 2.64 mortalities in 2010 and did not go up again afterwards . In 2015, the 
level of mortalities in this particular region was recorded as 2.2 per 1,000  sets. Regarding 
observed serious injury, we note that the period 2007-2009 presented a peak of 279 possible  
serious injuries to dolphins in 19 ,136 observed sets , followed by  a possible  89 serious injuries  in 
20,853 observed sets in 2010, 1  observed serious injury  in approximately 25,760 observed sets in  
2014, and 84 serious injuries in 30,240 observed sets in 2015.  
7.345.   Mexico, for its part, has subm itted evidence only for 2009, indicating an absolute number 
of 1,195  dolphin mortalities or serious injuries in the WCPO, without applying a per set 
methodology. Mexico has also presented data for the Papua New Guinea and the Philippines 
fisheries for 2014 . We note that the United States also took into account these areas of the ocean 
in presenting its per set figures.  
7.346.   The evidence submitted by the parties in respect of purse seining without setting on 
dolphins in the WCPO is voluminous and complex. The dis agreement between the parties on the 
interpretation of that evidence , however, seems to be focused on certain exhibits and issues.606 In 
what follows, we will address each of these in turn.  
7.347.   First, the parties disagree about Exhibit USA -17. Mexico  argues that  the report  contained  
in this exhibit supports the argument that dolphins are killed by purse seine nets in the WCPO, 
                                                
602 Mexico's comment s on the United States' response to Panels' questions 16.  
603 Summary Information on Whale Shark and Cetacean Interactions in the Tropical WCPFC Purse Seine 
Fishery, Paper prepared by SPC -OFP, 8th Regular Session, Koror, Palau (Nov ember  2011) , (Exhibit US A-17), p. 
3.  
604 Papua New Guinea, Annual Report to the Commission, WCPFC -SC11 -AR/CCM -19 (August  2015) , 
(Exhibit MEX -23), p. 29. 
605 L. Dolar, Incidental Takes of Small Cetaceans in Fisheries in Palawan, Central Visayas and Northern 
Mindanao in the Philippines, in Report of International Whaling Commission (Special Issue 15) (1994), (Exhibit 
MEX-117), p. 358.  
606 We recall that as discussed in Section 7.7.1.2.1.6 , we have already addressed some of Mexico's 
concerns regarding the data  and evidence submitted by the United States on the WCPO.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
- 110 - 
 
  with a very high rate (6 5%) when there is an interaction.607 In Mexico's view , this high percentage 
demonstrates that purse seine  vessels do  not proactively seek to protect dolphins, do not have 
nets with dolphin safety design elements, and do not have or utilize the dolphin safety gear, 
procedures or specialized training for the captains or crews, which are mandatory in the ETP. 
Mexico also n otes that the study itself states that no dat a from the domestic fisheries of  Indonesia 
and the Philippines was included, and that the study only covers the area between 20º south and 
20º north.608 According to  Mexico, this study shows that the fishery betwe en 20º south and 20º 
north had 41,871 purse seine sets in 2010, that is, less than one half of the 90,000 to 100,000 
purse seine sets per year undertaken in the entirety of the WCPO region.609 Mexico thus submits 
that a projection for the fishery limited to the area between 20º south and 20º north significantly 
underestimates the real level of dolphin mortalities and serious injuries.  
7.348.   Mexico also contends that the United States seeks to focus on the lower mortality reported 
for 2010, but does not explain why the higher numbers for the 2007 to 2009 period should be 
disregarded, and in particular why it ignored the report's own estimated dolphin mortality figure of 
1,195 for 2009.610 
7.349.   We note that, Exhibit USA -17 contains a summary of information on whale shark and  
cetacean interactions in the tropi cal WCP O purse seine fishery, prepared by the Secretariat of the 
Pacific Community -Oceanic Fisheries Programme of the WCPFC, in November 2011. We note that 
the paper defines its geographic coverage as follows:  
The data us ed in this paper comprise operational -level logsheet and observer data for 
the period 2007 -2010  for purse seiners operating in the tropical (20 ⁰N-20⁰S) purse 
seine fishery. The domestic fisheries of Indonesia and the Philippines are excluded as 
key data ar e not available. It is assumed in the analyses that the currently processed 
observer data, representing 16% coverage of fishing days over the 2007 -2009 period, 
and 45% coverage of fishing days in 2010, are representative of overall purse seine 
fishing oper ations during these periods.611 (footnotes omitted)  
7.350.    Regarding the interaction with, and mortalities of, toothed cetaceans, the Exhibit states 
that: 
Interactions occurred across all of the common purse seine set types (Table 3a, b), 
but were more common in t he associated set types (drifting and anchored FADs and 
logs). False killer whale (Figure 3a, b) and dolphin (Figure 4a, b) interactions have 
been observed widely throughout the WCPFC tropical purse seine fishery …  Mortality 
rates were generally high (65% of interactions), with some reports indicating that 
they were not detected in the net early enough for release to be effected and had 
drowned. These interaction and mortality rates infer a total mortality of toothed 
cetaceans in the purse seine fishery in 2009 of 1,195 animals (Table 2a). In 2010, 
both the encounter and mortality rates were substantially lower than observed in the 
previous 3 years, leading to a much lower estimate of total mortality of toothed 
cetaceans of 110 (Table 2b).612 
7.351.   We thus note that , as argued by Mexico, the study has a limited geographic coverage and 
it reports the total number of mortalities of toothed cetaceans in the purse seine fishery in 2009 as 
1,195.  
7.352.   That said, we are not persuaded by either of Mexico's arguments. Regarding t he fact that  
the study shows that the fishery between 20º south and 20º north had 41,871 purse seine sets in 
                                                
607 Mexico's first written submission, (referring to Summary Information on Whale Shark and Cetacean 
Interactions in the Tropical WCPFC Purse Seine Fishery, Paper prepared by SPC -OFP, 8th Regular Sess ion, 
Koror, Palau (Nov ember  2011) , (Exhibit USA -17), para. 80).  
608 Mexico's first written submission, para. 80.  
609 Mexico's first written submission, para. 80.  
610 Mexico's first written submission, para. 81. 
611 Summary Information on Whale Shark and Cetacean Interactions in the Tropical WCPFC Purse Seine 
Fishery, Paper prepared by SPC -OFP, 8th Reg ular Session, Koror, Palau (November  2011) , (Exhibit USA -17), p. 
1. 
612 Summary Information on Whale Shark and Cetacean Interactions in the Tropical WCPFC Purse Seine 
Fishery, Paper prepared by SPC -OFP, 8th Regular Session, Koror, Palau (Nov ember  2011) , (Exhibit USA -17), 
pp. 2-3. WT/DS381/RW/USA • WT/DS381/RW 2 
 
- 111 - 
 
  2010, that is , less than one half of the 90,000 to 100,000 purse seine sets per year made in the 
entirety of the WCPO region , we note that the stud y clearly states the processed observer data are 
representative of overall purse seine fishing operations during these periods.  There is otherwise no 
indication that such an extrapolation would be unreasonable or statistically flawed. In addition, we 
obser ve that the United States does not rely solely on this Exhibit in presenting its arguments 
regarding the WCPO. Exhibit USA-17 forms only part of the evidentiary basis for the United States' 
arguments concerning this particular fishery. Indeed, and as evide nced in the table above, the 
United States has presented data for more than 10 different sub -regions of the WCPO, and Exhibit 
USA-17 is but one of the pieces of evidence on which the table is based.  
7.353.   Similarly, the table presents data for a time period lon ger than just the 2007 -2009 period , 
and it does not disregard Exhibit USA -17's own estimated dolphin mortality figure of 1,195 for 
2009.  In this connection , we note that although the study  contained in Exhibit USA -17 mentions 
that it " infer[s] a total mort ality of toothed cetaceans in the purse seine fishery in 2009 of 1,195 
animals (Table 2a)"613, these are absolute dolphin mortalities extrapolated from the per set 
numbers contained in Table 2a. In fact, when reviewing this table, it is clear that the data 
presented therein corresponds to the same per set data in the United States' table, that is, 27.12 
mortalities per 1,000 sets.614 We therefore reject both of Mexico' s contentions regarding 
Exhibit  USA-17. 
7.354.   Second, the parties disagree regarding Exhibit MEX -21. Mexico introduces this report 
because it contains the following statements referring to harms posed to dolphins:  
Spinner and Fraser 's dolphins experience substantial bycatch in Philippine  fisheries . In 
the Philippines, scientists estimated that about 2,00 0 dolphins —primarily spinner, 
pan-tropical spotted, and Fraser 's—were being killed each year, probably at 
unsustainable levels, by a fleet of five tuna purse -seiners using fish -aggregating 
devices.615 
7.355.   In response, the United States argues that this study, wh ich underlies the statistics 
presented by Mexico, is over two decades old and that it is refuted by more recent reports.616 The 
United States also submits that Mexico's more recent Exhibit MEX -22, seems to revise down the 
old (1992) estimate of mortality to 500 dolphins per year and, with respect to the current fishery, 
it states only that sets "still have bycatch", with no suggestion that the level is comparable to what 
it was in the past.617 The United States also refutes the data presented in Exhibit MEX-21 by 
arguing that recent data from the WCPFC confirms that the level of dolphin mortality in the WCPO 
purse seine f ishery is much lower than in ETP dolphin sets (55 dolphin mortalities in 20,853 
observed sets in the tropical purse seine  fishery in 2010, comp ared to 1,169 observed mortalities 
in 11,645 observed dolphin sets in the ETP in the same year618, and 765 mortalities in 11,010 
observed dolphin sets in 2015).619 The United States also contends that recent reports from the 
Philippines purse seine fishery in particular found, based on 100% observer coverage of the high 
seas fishery, that only 18 dolphins were killed in 2014620 and 7 dolphins were killed in 2015.621 
7.356.   Exhibit MEX -21 contains a report on Worldwide Bycatch of Cetaceans, prepared  by the US 
Department of  Commerce in July 2007 . We note that the t he complete reference cited by Mexico 
reads as follows:  
                                                
613 Summary Information on Whale Shark and Cetacean Interactions in the Tropical WCPFC Purse Seine 
Fishery, Paper prepared by SPC -OFP, 8th Regula r Session, Koror, Palau (Nov ember  2011) , (Exhibit USA -17), 
pp. 2-3. 
614 Summary Information on Whale Shark and Cetacean Interactions in the Tropical WCPFC Purse Seine 
Fishery, Paper prepared by SPC -OFP, 8th Regular Session, Koror, Palau (Nov ember  2011) , (Exhibit USA -17), 
615 Mexico's first written submission, para. 74.  
616 United States' second written submission, para. 84.  
617 United States'  second written submission, para. 84.  
618 United States' second written submission, para. 84.  
619 United States' second written s ubmission, para. 84 (referring to IATTC, Fishery Status Report No. 14 
(2016) , (Exhibit MEX -06)). 
620 United States' second written submission, paras. 86 -87 (referring to Philippines, Annual Report to the 
Commission, WCPFC -SC11/AR/CCM -20 (Sept ember  28, 2015) , (Exhibit USA -38)). 
621 United States' second written submission, paras. 86 -87 (referring to Philippines, Annual Report to the 
Commission, WCPFC SC12 -AR/CCM -20 (June 2016) , (Exhibit USA -105)).  WT/DS381/RW/USA • WT/DS381/RW 2 
 
- 112 - 
 
  Roughly 1,700 bottlenose dolphins and 1,000 spinner dolphins are incidentally caught 
at unsustainable levels in gillnet, driftnet, and purse -seine fisheries i n the western 
central Pacific off the coast of Australia. Perhaps 5 to 50 pe rcent of the population of 
Indo-Pacific humpback dolphins are incidentally captured in offshore driftnets and in 
inshore gillnets set to protect bathers from sharks north of Brisba ne Australian and 
along the central section of the Great Barrier Reef. However, because poor population 
and bycatch estimates these percentages are suspect.  
Spinner and Fraser 's dolphins experience substantial bycatch in Philippine fisheries. In 
the Philip pines, scientists estimated that about 2,000 dolphins —primarily spinner, 
pan-tropical  spotted, and Fraser 's—were being killed each year, probably at 
unsustainable levels, by a fleet of five tuna purse -seiners using fish -aggregating 
devices. Scientists esti mate that even more cetaceans may be caught in round -haul 
nets; one estimate for the eastern Sulu Sea was 2,000 –3,000 per year. Directed 
fisheries for small cetaceans were also reported, with as many as 200 –300 dolphins 
caught annually in San Francisco and  smaller numbers caught for bait in shark and 
chambered nautilus (Nautilus pompilius) fisheries in Palawan. Currently there are no 
total bycatch estimates for the Philippines, but preliminary analyses of cetacean 
abundance surveys indicate that current byc atch is not sustainable.622 (footnotes 
omitted.)  
7.357.   We note that although the report is from July 2007, the source of the underlying dataset is 
a report from 1994. To us, this suggests that these conclusions need to be contrasted with more 
recent data, if avail able, to confirm whether the situation in 1994 still exists. In this connection, 
we note that the United States  has presented reports for the Philippines from 2014 and 2015, as 
summarized in the table presented by the United States. That table seems to sho w a different 
picture of the risks posed to dolphins, in particular, that dolphin mortality caused by purse seine 
fishing without setting on dolphins has decreased significantly in this area of the ocean. We 
therefore find no merit in Mexico's arguments re garding Exhibit MEX -21. 
7.358.   Third, the parties disagree about Exhibit MEX -22. Mexico contends that this recent report 
states that in a Philippines fishery, purse seine nets are deployed at night with lights to attract 
tuna, and this results in substantial dolp hin bycatch. In the United States' view, Mexico argues that 
the Panels should rely on anecdotal reports from the early 1990s .623 
7.359.   We note that Exhibit MEX -22 contains a report of the Third Southeast Asian Marine 
Mammal Symposium, CMS Technical Series No. 32 ( 2015) Convention on Migratory Species. It 
contains the following exchange:  
Peter Thomas: About purse seines at night, what evidence exists as to entanglement 
and capture?  
Response (Louella Dolar): … For tuna boats with lights, based on interviews in 1992, it 
was estimated that 500 dolphins were killed/year based on 2 months of observation. 
In 2012, 4 purse seines that use intense light still have bycatch.624 
7.360.   In our view, Exhibit MEX -22 suffers from the same flaws present in Exhibit MEX -21, 
namely, that the so urces of the underlying data are interviews from 1992. Thus, this conclusion 
needs to be compared with the more recent data presented by the United States. Also, the fact 
that in 2012 four purse seines that use intense light still have bycatch does not con flict with the 
                                                
622 Young and Iudicello, Worldwide Bycatch of Cetaceans, US  Depart ment of Commerce, NOAA Tech. 
Memo. NMFS -OPR-36 (July 2007) , (Exhibit MEX -21), pp. 112 -113. 
623 L. Dolar, Incidental Takes of Small Cetaceans i n Fisheries in Palawan, Central Visayas and Northern 
Mindanao in the Philippines, in Report of International  Whaling  Commission (Special Issue 15) (1994) , (Exhibit 
MEX-117), p. 355  (explaining that information was conducted "opportunistically" from "fishermen and other 
knowledgeable local people"). According to the United States' comments on Mexico's resp onse to Panels'  
question No. 57, it is also notable that the author clarified that the vessels in the paper were not producing for 
the global tuna product market but "for local markets". See p. 357 (referring to Convention on Migratory 
Species, Report of the Third Southe ast Asian Marine Mammal Symposium  (2015), (Exhibit MEX -22), p. 83 
(quoting the author of the 1994 paper referring to "interviews in 1992" and seeming to revise the earlier 
estimate from 2,000 to 500 dolphin mortalities per year); US Second Written Submissi on, para. 84.  
624 Convention on Migratory Species, Report of the Third Southeast Asian Marine Mammal Symposium, 
CMS Technical Series No. 32 (2015), (Exhibit MEX -22), p. 83.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
- 113 - 
 
  more recent data in the Philippines Annual Report to the Commission, presented in Exhibit USA -
105, as the former statements in Exhibit MEX -22 do not quantify the amount of the bycatch in this 
area of the ocean; they only introduce a qualitat ive indicator of bycatch for these four purse seine 
vessels.  We therefore disagree with Mexico's arguments regarding Exhibit MEX -22. 
7.361.   Finally , we turn to  Mexico's arguments regarding the reliability of observers' reports in this 
region , explained in para. 7.340  above . We recall that Mexico  contends  that the United States cites 
the observer data from the WCPFC as if it were complete and relevant to assessing the risk profiles 
for purposes of the Tuna M easure . 
7.362.   We note that Mexico  itself has not suggested any particular methodology according to  
which the United States should have adjusted the data it submitted to take account  of these  
sampling issues . To the extent that Mexico argues that WCPFC reports are inherently unreliable , at 
least for purposes of these proceedings, we disagree.  
7.363.   Regarding  Mexico's contention regarding the primary responsibility of observers in the 
WCPFC625, we are of the view that, e ven if the primary responsibility of observers in the WCPFC is 
to monitor the har vesting of fish and not  to report on interactions with marine mammals,  this does 
not necessarily render their reports unreliable or irrelevant to our assessment of marine mammal  
bycatch or harms posed to dolphins  by purse seine fishing without setting on d olphins in the 
WCPO . Indeed, the fact that observers do make reports concerning bycatch indicates that their 
task involves monitoring bycatch, even if they are also charged with other responsibilities.  Our 
view in this regard is supported by the fact that such information is routinely used by the WCPFC 
in its assessment of the situation in the fisheries under its purview. Additionally, and as we have 
previously stated, RMFOs, like the WCPFC, are experts in the field of marine resources 
conservation. It may be that the information from these observers is not always perfect in all 
regards. However, in our view this is the best available scientific evidence provided by the parties, 
and we see no reason to disregard it for the reasons identified by Mexico.  
7.364.   For the foregoing reasons , we reject Mexico's contention regarding observers, and find 
that, given that the source of the data in the table presented by the United States  is mainly from 
an RFMO, namely , the WCPFC , and  given  that in our view RFMOs are experts in  this field, we 
consider it appropriate to rely on this data in making our findings on observable harms  caused by 
purse seine fishing without setting on dolphins in the WCPO.  
7.365.   Consequently, with regard to observable harms, we find that the  data show s that t he per 
set mortalities of dolphins as a consequence of purse seine fishing without setting on dolphins in 
the WCPO was 2.64, 1.2 and 2.2 per 1,000 sets in 2010, 2014 and 2015, respectively. We also 
find that in the period 2007 -2009,  the data show s that the average per set mortalities of dolphins 
were significantly higher, namely, 27.12 mortalities per 1,000 sets. We also find that there were 
279 dolphins were released alive in the period 2007 -2009, 89 in 2010 and 84 in 2015; and that in 
2014 one dolphin was  seriously injured.  
7.366.   Regarding observable but unobserv ed harms,  we begin by noting that neither party has 
submitted evidence on the extent of unobserved harms arising from purse seine fishing without 
setting on dolphins in the WCPO.  We recall, as stated ab ove, that the frequency of dolphin 
interactions might serve as a proxy for assessing unobserved harms, since the extent of dolphin 
interactions represents the maximum possible number of mortalities and serious injuries. The 
United States has submitted, thr ough Exhibit USA -179 Rev., the following information, on a per 
set basis, on the extent of dolphin interactions associated with purse seine fishing without setting 
on dolphins in the WCPO:  
                                                
625 Mexico's comments on the United States' response to Panels' question No. 16; second  written 
submission, para. 81.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
- 114 - 
 
  United States'  Summary of the Evidence  
Year  Observ
ed Sets  Positive  
Sets % 
Positive 
Sets Dolphins 
Chased  Dolphins 
Encircled  Dolphin 
Mortalities  Interactions 
Per 1,000 
Sets Mortalities 
Per 1,000 
Sets 
 
2007-
2009  
19,136   
134  
0.70%  no 
evidence of 
any 798 
(interactions)   
519  
41.70   
27.23  
 
2010  
20,853   
37  
0.18%  no 
eviden ce of 
any 144 
(interactions)   
55  
6.91  
2.64 
 
2014  
25,760 
(est.)  309 
(maximu
m 
possible)   
1.51%  no 
evidence of 
any 350 
(interactions)   
31  
13.59   
1.2 
 
7.367.   The data in the table shows that in all of the three different time periods covered by the 
table, the p ercentage of sets where any interaction with dolphins was registered is below 2%, 
being as low as 0.18% in 2010. In per set terms, we note that the level of dolphin interactions per 
1,000 sets varied between 41.70  in the period 2007 -2009, 6.91 in 2010 and 13.59 in 2014.  To us, 
this indicates that the level of dolphin interaction is low in this area of the ocean and that therefore 
there is a very low likelihood of unobserved harm caused to dolphins.  
7.368.   Finally, we note that the neither party has presented evide nce that purse seining without 
setting on dolphins in the WCPO causes unobservable harms of the kind caused by setting on 
dolphins. In response to a question from the Panels, Mexico argued that  
In areas where FAD fishing interacts with dolphins with no sup ervision of dolphin 
safety precautions, such as in the Western and Central Pacific, it should be presumed 
that there are also unobservable harms, similar to those the United States presumes 
exist in the ETP. In particular, outside the ETP, there are no man datory procedures for 
protecting dolphins when they are being released from nets or hooks.  Under those 
circumstances the dolphins may suffer much greater stress and risk of physical harm 
than the United States claims they experience in the ETP.626 
7.369.   However, M exico has presented no evidence to support this proposition. Moreover, as we 
have explained, our conclusion concerning the existence of unobservable harms in the ETP large 
purse seine fishery is not based on an assumption, but rather on a close examination  of significant 
evidence collected over nearly two decades.  
7.370.   On this basis, we find that the record evidence does not show that purse seine fishing 
without setting on dolphins  in the WCPO  causes the kinds of unobservable harms caused by purse 
seine fishing  by setting on dolphins  in the ETP.  
7.371.   We now proceed to the assessment of the risk profile of purse seining without setting on 
dolphins in the Indian Ocean.  
7.372.    The United States claims that in the European purse seine fishery in the tropical Indian 
Ocean, less than 1% of the 3,052 sets observed involved any marine mammal interaction, and no 
marine mammals were encircled or caught.627 The United States also contends that an earlier 
study of tuna seiners in the Western Indian Ocean (WIO) supports the findings of thi s study, 
concluding that in "offshore regions of the WIO tuna -dolphin associations are rare, purse seining 
for them is not practiced, and there is no dolphin bycatch problem" .628 
7.373.   The United States submitted, through Exhibit USA -179 Rev., data on the European  purse 
seine fishery in the tropical Indian Ocean for the period 1995 - 2009, on a per -set basis, as 
reproduced below:  
                                                
626 Mexico's response to Panels' question No. 68, para. 45.  
627 United States' first written submission,  (referring to Monin J. Amande et al., Precision in Bycatch 
Estimates: The Case of Tuna Purse Seine Fisheries in the Indian O cean, ICES J. Mar. Sci. (2012) , (Exhibit USA -
21), para. 55).  
628 United States' first written submission, fn. 84  (referring to Evgeny V. Romanov, Bycatch in the Tuna 
Purse Seine Fisheries of the Western Indian Ocean, 100 Fisheries Bulletin 90 (2002) , (Exhibi t USA -9)).  WT/DS381/RW/USA • WT/DS381/RW 2 
 
- 115 - 
 
  United States' Summary of the Evidence  
Fishery  Year Observed Sets  Observed 
Mortality  Observed 
Serious Injury, 
Injury, or 
Released Alive  Mortality 
per 1,000 
Sets Source of Data  
 
EU 
Indian 
Ocean 
Tropical 
Purse 
Seine  1995-2011629 
 
 
 6,129  2 cetaceans 
(maximum 
possible)  37 cetaceans 
released alive  
 0.33 Observer Reports 
(7.8% of vessel 
activities)  
2003-2009630 3,052  0 None 
documented  0.00 Obser ver Reports 
(4.6% coverage)  
 
7.374.   The United States submits that according to one study, examining the period 1995 -2011, 
and which is reflected in the table above, the dolphin mortality rate as resulting from purse seine  
fishing  without setting on dolphins was  significantly low, namely, 0.33 per 1,000 sets in this 
particular period.  
7.375.   Mexico disagrees with the figures presented by the United States. It contends that one of 
the studies on which the above table relies was limited to a small sampling of French and S panish 
purse seine vessels.631 Regarding an earlier study mentioned by the United States, Mexico 
contends that such study was based on data collected by observers on several Soviet purse seine 
vessels during 1986 to 1992, involving only 492 sets.632 
7.376.   We note that Mexico itself has not introduce d any evidence regarding observable or 
unobservable harms to dolphins caused by purse seine fish ing without setting on dolphins in the 
Indian Ocean.  
7.377.   Regarding Mexico's arguments, we note that Exhibit USA -9 contains a study  of bycatch in 
the tuna purse seine fisheries of the Western Indian Ocean, from 2002, and that i t states that 
"Bycatch assessments were based on data collected by Yug -NIRO scientific observers aboard 
Soviet (since 1992 —Russian) tuna purse seiners in the WI O, during 1987, and 1990 –91. The 
vessels were the 'Rodina ' type. In addition, observer data collected in the same area aboard sister -
ships by AtlantNIRO and 'Zaprybpromrazvedka ' during 1986 –90 and data by TINRO and TURNIF 
during 1990 and 1992 were used. Th e fishing vessels all used purse seines of 1800 m in length, 
250–280 m in depth, and 90 –100 mm mesh size in the bunt" .633 We agree with Mexico that the 
data in Exhibit USA -9 seems to be outdated and therefore  the conclusions from this study should 
be checked  against more recent data, if available, to confirm whether the situation described in 
the study continues to exist . 
7.378.   However, w e note that  in the table above , the United States uses data from sources other 
than Exhibit USA -9. In fact, the table presents da ta from Exhibit USA -145, containing a 2015 study 
conducted by Lauriane Escalle et al., entitled "Cetaceans and Tuna Purse Seine Fisheries in the 
Atlantic and Indian Oceans: Interactions but Few Mortalities ", and from Exhibit USA -21, containing 
a 2012 study  by Monin J. Amande et al., entitled "Precision in Bycatch Estimates: The Case of 
Tuna Purse Seine Fisheries in the Indian Ocean ". Accordingly, as the United States has relied on 
other pieces of evidence apart from the study contained in Exhibit USA -9, we find Mexico's 
criticism to be inapposite.  
7.379.   Regarding Mexico's arguments on Exhibit USA -21, and in particular Mexico's contention 
that t he study on which the United States relies for its assertion that there are no dolphin 
mortalities in the Indian Ocean was  limited to a small sampling of French and Spanish purse seine 
vessels634, we note that the mentioned exhibit contains an " analysis focuse [d] on the European 
                                                
629 Lauriane Escalle et al., Cetaceans and Tuna Purse Seine Fisheries in the Atlantic and Indian Oceans: 
Interactions but Few Mortalities, 522 Mar. Ecol. Prog. Ser.  (2015), (Exhibit USA -145),  pp.255, 257, 260, 
showing that at least 37 of the 39 c etaceans encircled were released alive.  
630 Monin J. Amande et al., Precision in Bycatch Estimates: The Case of Tuna Purse Seine Fisheries in the 
Indian Ocean, ICES J. Mar. Sci.  (2012) , (Exhibit USA -21), pp. 2 -3, and 6.  
631 Mexico's first written submission, p ara. 82.                                                                                           
632 Mexico's first written submission, para. 83. 
633 Evgeny V. Romanov, Bycatch in the Tuna Purse Seine Fisheries of the Western Indian Ocean, 100 
Fisheries Bull etin 90 (2002) , (Exhibit USA -09), p. 91  (footnotes omitted) . 
634 Mexico's first written submission, para. 82.        WT/DS381/RW/USA • WT/DS381/RW 2 
 
- 116 - 
 
  purse -seine fishery in the Indian Ocean (IO) to address the majo r issue of estimating  fishery 
remova ls of non -target, associated, and dependent  species ".635 The exhibit contains data that was 
"collected during the European observer programme since 2003 " in order to : 
(i) estimate the annual bycatch for marine pelagic taxonomic groups and species of 
the Euro pean purse -seine fishery in the IO, based on simple raising procedures; (ii) 
analyse the relative error and bias of the bycatch estimates as a function of sampling 
coverage and of two indices describing the species bycatch statistical distribution and 
finally (iii) provide  guidelines into the levels of observer coverage required to 
accurately and precisely estimate species bycatch so as to reconcile current sampling 
strategies with the sustainable management and conservation objectives promoted by 
tuna RFMO s.636 
7.380.   We also note that, regarding the bycatch in the tuna purse -seine fishery, the Exhibit states  
that bycatch of "[m]arine mammals occurred in less than 1% of the observed sets and were 
always released alive without being brought on board the vessel, resul ting in no direct mortality 
due to the impact of the purse -seine operations. Turtles were also generally discarded alive, but 
no specific action was conducted to collect information on the survival rates of the released 
animals".637 
7.381.   In our view, the sampling  technique used in this study does not detract from the general 
conclusions that it reaches. We agree with the United States that national regulators, RFMOs, and 
scientists around the world use the methodology of extrapolating data from a subset of fishing  
operations in a fishery to give a n overall  picture of that fishery , and we note that n umerous 
exhibits on the record offer examples of studies using  this methodology.638 In this regard, we do 
not believe that using a sample consisting of only French and Spa nish purse seine vessels  to reach 
general conclusions  undermines the reliability of  the results reached in the studies.  Indeed, as 
noted by the United States639, the data on the Indian Ocean purse seine fishery  supporting this 
study was sufficient  for the au thors to generate an nual bycatch estimates, with 95% confidence 
intervals, for all the " major taxonomic groups and species" for which there was bycatch,640 as well 
                                                
635 Monin J. Amande et al., Precision in Bycatch Estimates: The Case of Tuna Purse Seine Fisheries in 
the Indian Ocean, ICES J. Mar. Sci.  (2012 ), (Exhibit USA -21), p. 2.  
636 Monin J. Amande et al., Precision in Bycatch Estimates: The Case of Tuna Purse Seine Fisheries in 
the Indian Ocean, ICES J. Mar. Sci.  (2012) , (Exhibit USA -21), p. 2.  
637 Monin J. Amande et al., Precision in Bycatch Estimates: The  Case of Tuna Purse Seine Fisheries in 
the Indian Ocean, ICES J. Mar. Sci.  (2012)  (Exhibit USA -21), p. 6.  
638 United States' response to Panels' question No. 95 (referring to William A. Karp, Lisa L. Desfosse, 
and Samantha G. Brooke (eds.), NMFS, US National  Bycatch Report, at 391, Table 4.6.C.1 and 394, Table 
4.6.D.1 (2011) , (Exhibit USA -61), pp. 391, Table 4.6.C.1 and  394, Table 4.6.D.1); US  National Bycat ch Report 
First Edition Update,  (Exhibit USA -62), Table 8.3 ; US National Bycat ch Report First Edition U pdate, (Exhibit 
USA-63), ; NMFS, False Killer Whale: Hawaiian Islands Stock Complex (January 8, 2013), (Exhibit  USA-113) p. 
267), Table 8.4;  NMFS, False Killer Whale: Hawaiian Islands Stock Complex  (December  31, 2015) , (Exhibit s 
USA-114, MEX -118), pp. 284 -285; Karin A. Forney, SFSC, Estimates of Cetacean Mortality and Injury in Two 
US Pacifi c Longline Fisheries, 1994 -2002 (2004) , (Exhibit USA -118), p. 14; AIDCP, Report on the International 
Dolphin Conservation Program, Document MOP -28-05 (October 18, 2013) , (Exhibit MEX -08), Table 3 ; 
Summary Information on Whale Shark and Cetacean Interactions in the Tropical WCPFC Purse Seine Fishery, 
Paper prepared by SPC -OFP, 8th Regular Session, Koror, Palau (Nov ember  2011) , (Exhibit USA -17), pp.5-6; 
Monin J. Amande et a l., Bycatch of the European Purse Seine Tuna Fishery in the Atlantic Ocean for the 2003 -
2007 Perio d, 23 Aquat. Living Resour. 353  (2010) , (Exh. USA -19), p. 358; Monin J. Amande et al., Bycatch 
and Discards of the European Purse Seine Tuna Fishery in the At lantic Ocean: Estimation and Characteristics 
for 2008 and 2009, 66 ICCAT  Collect. Vol. Sci. Papers 2113  (2011) , (Exhibit USA -20), p. 2120; Monin J. 
Amande et al., Precision in Bycatch Estimates: The Case of Tuna Purse Seine Fisheries in the Indian Ocean, 
ICES J. Mar. Sci.  (2012) , (Exh ibit USA-21), pp. 5 -6; Hernandez -Milian et al. , Results of a Short Study of 
Interactions of Cetaceans and Longline Fisheries in Atlanti c Waters, 612 Hydrobiologia 254  (2008), (Exhibit 
USA-40), p. 264 ; Hsiang -Wen Huang, Bycatch of High Sea Longline Fisheries and Measures Taken by Taiwan: 
Actions and Challenges, 35 Mar. Pol' y 712 (2011) , (Exhibit USA -127), p. 715; Japan, Annual Report to the 
Commission, WCPFC -SC12/AR/CMM -10 (July 5, 2016) , (Exhibit USA-152), p.38; Alison McCarthy et al., Pilot 
Observer Programme in Irish Pelagic Trawl and Gillnet Fisheries: Implementing Council Regulation (EC) No 
812/2004 (2011) , (Exhibit USA-163), pp.1 -2. 
639 United States' response to Panels' question No. 95.  
640 Monin J. Amande et al., Precision in Bycatch Estimates: The Case of Tuna Purse Seine Fisheries in 
the Indian Ocean, ICES J. Mar. Sci.  (2012) , (Exhibit USA-21), pp. 5-6. WT/DS381/RW/USA • WT/DS381/RW 2 
 
- 117 - 
 
  as to conclude that " the magnitude of bycatch in tropical tuna  purse seine fisheries is small ."641 We 
therefore disagree with Mexico's arguments in this respect.  
7.382.   Further, as noted above, and as underlined by the Appellate Body in the first compliance 
proceedings642, collection and assessment of data regar ding such harms is generally very difficult. 
In our view, a study does not necessarily need to meet a pre -established sampling threshold for it 
to be taken into account by a WTO panel. With respect to the Exhibits at issue here, we consider 
that the fact that these are scientific studies published in a peer reviewed journal suggests that 
their results may be deemed to provide an adequate assessment of the risks to dolphins. We also 
note that Mexico itself has not provided alternative evidence that we could have used in assessing 
the observable harms caus ed to dolphins by purse seine fishing without setting on dolphins in the 
Indian Ocean.  
7.383.   For the foregoing reasons , and given the scientific nature of the data in the table 
presented by the United States, we consider it appropriate to  rely on this data in assessing the 
extent of observable harms  to dolphins caused by purse seine fishing without setting on dolphins 
in the Indian Ocean. We thus find that dolphin mortalities caused by purse seine fishing without 
setting on dolphins in the Indian Ocean are very l ow, with a peak of 0.33 mortalities per 1,000 
sets, reported for the period 1995 -2011.  
7.384.   Regarding unobserv ed harms, we note that the parties have submitted no evidence for this 
type of harm in this particular area of the ocean for purse seine fishing withou t setting on dolphins. 
We recall nonetheless that the frequency of dolphin interactions might serve as a proxy to assess 
unobserved harms, since the extent of dolphin interactions represents the maximum possible 
number of mortalities and serious injuries. In this regard, we note that, through Exhibit USA -179 
Rev., the United States has submitted the following information, on a per set basis, on the extent 
of dolphin interactions in the Indian Ocean:  
United States' Summary of the Evidence  
Fishery  Year Obser ved 
Sets Positive 
Sets  Dolphins 
Chased  Dolphins 
Encircled  Dolphin 
Mortalities  Interactions 
Per 1,000 
Sets  Mortalities 
Per 1,000 
Sets  
 
 
Indian 
Ocean 
Tropica
l Purse 
Seine643  
2003
-
2009  
3,052 unknown 
(fewer  than 30)  no evidence 
of any  
unknown   
0  
fewer than 10  
0 
 
1995
-
2011  
6,129  
183 no evidence 
of any  
39 2 
(maximum 
possible)   
6.36  
0.00 
 
7.385.   The data presented by the United States shows that observed interactions were 6.36 per 
1000 sets  in the period 1995 - 2011, and fewer than 10  per 3,052 sets (3.28 per 1,000 sets)  in 
the period 2003-2009. This low level of dolphin interactions suggests that the extent of 
unobserved mortality and serious injury is likely to be low, if anything . 
7.386.   Finally, we note that neither party has argued or provided evidence that purse  seining 
without setting on dolphins in the Indian Ocean causes unobservable harms similar to those 
caused by setting on dolphins in the ETP.  
7.387.   We now turn to assess the evidence concerning purse seine fishing without setting on 
dolphins in the Eastern Tropi cal Atlantic Ocean (ETAO).  
7.388.   The United States argues that a study of vessels engaging in unassociated and floating 
object sets between 2003 and 2007 in the European purse seine fishery in the Atlantic Ocean 
                                                
641 Monin J. Amande et al., Precision in Bycatch Estimates: The Case of Tuna Purse Seine Fisheries in 
the Indian Ocean,  ICES J . Mar. Sci. (2012),  (Exhibit USA -21), p. 8.  
642 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.252.  
643 Monin J. Amande et al., Precision in Bycatch Estimates: The Case of Tuna Purse Seine Fisheries in the 
Indian Ocean,  ICES J. Mar. Sci.  (2012) , (Exhibit USA -21) pp. 2-3, 6; Lauriane Escalle et al.,  Cetaceans and 
Tuna Purse Seine Fisheries in the Atlantic and Indian Oceans: Interactions but Few Mortalities, 522 Mar. Ecol. 
Prog. Ser. , (Exhibit USA -145), pp. 255, 257, 260 . WT/DS381/RW/USA • WT/DS381/RW 2 
 
- 118 - 
 
  recorded only two "catch events" of marine mammals , both involving baleen whales644, and that 
the update for 2008 -2009 covered 27 trips (791 sets) and recorded no interactions at all with 
marine mammals, including dolphins.645 
7.389.   In addition, through Exhibit USA -179 Rev., the United States submitted evidence, on  a per 
set basis, of observable harms for the period between 1995 and 2009, as reproduced below:  
 
Fishery   
Year  
Observed 
Sets  
Observed 
Mortality   
Observed Serious 
Injury, Injury, or 
Released Alive  Mortality 
per 1,000 
Sets  
Source of Data  
 
 
Eastern 
Tropi cal 
Atlantic 
Purse  
Seine 
(EU) 1995-
2011646 9,969 13 cetaceans 
(maximum 
possible)  
142 cetaceans 
released alive  1.30 Observer Reports 
(9.2% of vessel 
activities)  
2013647 827 0 1 0.00 Observer    Reports 
(41% coverage of 
French  vessels)  
2003-
2007648 598 0 2 released alive  0.00 Observer Reports 
(2-6% coverage)  
2008-
2009649 791 0 0 0.00 Observer Reports 
(7-9% coverage)  
 
7.390.   We note that of the four periods covered in the table, three had zero mortality, and the 
period 1995 -2011 had only 1.30 mortalities per  1,000 set s. Similarly, the level of  potential  serious 
injuries reported is  also very low: 142 cetaceans released alive in the 1995 -2011 period, and 2 in 
the 2003 -2007 period.  
7.391.   We note that Mexico has not presented any evidence on the level of dolphin mortalities or 
serious injuries  resulting from purse seine fishery without setting on dolphins in the Eastern 
Tropical Atlantic  Ocean. Mexico, however, challenges the probative value of some of the evidence 
presented by the United States. In particular, Mexico argues tha t the study presented in Exhibit 
USA-19 is limited to a small sampling of French and Spanish vessels650 and that the update of this 
study, presented in Exhibit USA -20, was based on observer data "collected during 13 trips and 19 
trips in 2008 and 2009, respe ctively corresponding to 6.7% and 8.5% of total trips, 
respectively".651 Mexico contends that those are percentages for the French and Spanish fleets, not 
the other countries that fish in the Atlantic.652 For Mexico, these studies are based on a statistically 
invalid percentage of Spanish and French vessel fishing trips, and do not provide any information 
at all on the vessels of other countries.653 
7.392.   We note that Exhibit USA -19 contains a study titled "Bycatch of the European Purse Seine 
Tuna Fishery in the Atlant ic Ocean for the 2003 -2007 Period" from 2010. We recall that the United 
States argues that according to this exhibit, in the Eastern Tropical Atlantic purse seine fishery, 
observers on European vessels documented zero cetacean interactions in 1,389 observe d sets 
between 2003 and 2009.654 We also note that the data used in the study was collected by 
observers over the course of 27 trips, corresponding to 598 sets in the Atlantic Ocean (latitude 
                                                
644 United States' first written submission, para. 44.  
645 United States' first written submission, para. 44.  
646 Lauriane Escalle et al., Cetaceans and Tuna Purse Seine Fisheries in the Atlantic and Indian Oceans: 
Interactions but Few Mortalities, 522 Mar. Ecol. Prog. S er., (Exhibit  USA-145), pp. 255, 257, 260.  
647 Emmanuel Chassot et al., Statistics of the French Purse Seine Fishing Fleet Targeting Tropical Tunas 
in the Atlantic Ocean (1991 -2013), 71 ICCAT Collect. Vol. Sci. Papers (2015), (Exhibit USA -191), pp. 540, 542, 
Table 17.  
648 Monin J. Amande et al., Bycatch of the European Purse Seine Tuna Fishery in the Atlantic Ocean for 
the 2003 -2007 Perio d, 23 Aquat. Living Resour. 353  (2010) , (Exhibit USA -19), pp.  353, 355 -58. 
649 Monin J. Amande et al., Bycatch and Discards of the European Purse Seine Tuna Fishery in the 
Atlantic Ocean: Estimation and Characteristics for 2008 and 2009, 66 ICCAT Collect. Vol. Sci. Papers 2113, 
(2011) , (Exhibit USA -20), pp. 2113, 2114 -18. 
650 Mexico's first written submission, para. 84.  
651 Mexico's f irst written submission, para. 85.  
652 Mexico's first written submission, para. 85.  
653 Mexico's first written submission, para. 86.  
654 United States' first written submission, para. 55. WT/DS381/RW/USA • WT/DS381/RW 2 
 
- 119 - 
 
  between 10◦S and 15◦N and longitude from 35◦W to the African coast ) over the 2003 –2007 period. 
The overall coverage rate reached 2.9% of the total number of trips, and increased from 1.5% in 
2003 to 6.5% in 2007. The sample included observations made on 301 free school sets and 297 
log-school sets.655 
7.393.   The study reports onl y two events of catch of marine mammals, but none of those involve 
dolphins:  
Only two catch events of marine mammals were reported by observers. It occurred 
during the third quarter period (August and September) and involved free school sets. 
One event in volved a fin whale, Balaenoptera physalus , and the second event involved 
two humpback whales, Megaptera novaeangliae . All individuals were released alive 
without being brought on board the vessel. The rarity of these observations impeded 
any attempt to ext rapolate bycatch figures for marine mammals at the fishery level.656 
7.394.   Exhibit USA -20 contains a 2011 study titled "Bycatch and Discards of the European Purse 
Seine Tuna Fishery in the Atlantic Ocean: Estimation and Characteristics for 2008 and 2009". It 
provides an update of the study presented in Exhibit USA -19. We note that the data used in the 
study in Exhibit USA -20 was sampled from Spanish and French purse seine fishery data (i.e., 
logbook, well maps, and landing data), and that observers' data collected within the framework of 
the DCF programme for 2008 and 2009 were used to update the estimates of bycatch of the 
European tuna purse seine fishery in the Atlantic Ocean.657 
7.395.   Similar to our analysis of Exhibit USA -21, in paras. 7.379 -7.382  above, we are not 
persuaded by Mexico's argument that the fact that the studies presented in these exhibits are 
based on limited sampling of French and Spanish vessels658 or that the subsequent updated study 
was based on limited observer data659, undermines the importance of their conclusions. As noted 
above, we do not consider the fact that a study regarding bycatch from a particular tuna fishing 
method is based on a subset of the relevant area of the ocean, or of the fleet s fishing in that area, 
to undermine the probative value of the study for purposes of WTO dispute settlement 
proceedings. On the contrary, we note that the datasets in Exhibits USA -19 and USA -20 were  
sufficient for the reports  to generate scientifically si gnificant bycatch estimates, including 95% 
confidence intervals for those estimates , for all the species for which there was bycatch in the 
dataset.660 Indeed, Exhibit USA -19 confirms specifically that the data that it contains reflects 
"acceptable observati on levels".661 
7.396.   In these circumstances, we find it appropriate to base our finding on the studies presented 
in the exhibits that form the basis for the table presented by the United States. We thus find that, 
of the four periods covered in the table, three ha d zero mortality, and the period 1995 -2011 had 
only 1.30 mortalities per  1,000 sets. Similarly, the level of potential serious injuries reported is  
also very low: 142 cetaceans released alive in the 1995 -2011 period, and 2 in the 2003 -2007 
period.  
7.397.   Regardin g unobserved harms, we observe that none of the parties have submitted 
evidence regarding the possible extent of unobserved mortality and serious injury.  Nonetheless, as 
stated above, we consider that the frequency of dolphin interactions might serve as a proxy to 
assess unobservable harms , since the extent of dolphin interactions represents the maximum 
possible number of mortalities and serious injuries . We note the following evidence on the record , 
                                                
655 Monin J. Amande et al., Bycatch of the European Purse Seine Tuna Fishery  in the Atlantic Ocean for 
the 2003 -2007 Perio d, 23 Aquat. Living Resour. 353  (2010) , (Exhibit USA -19), p. 355.  
656 Monin J. Amande et al., Bycatch of the European Purse Seine Tuna Fishery in the Atlantic Ocean for 
the 2003 -2007 Perio d, 23 Aquat. Living Reso ur. 353  (2010) , (Exhibit USA -19), p. 358.  
657 See Monin J. Amande et al., Bycatch and Discards of the European Purse Seine Tuna Fishery in the 
Atlantic Ocean: Estimation and Characteristics for 2008 and 2009, 66 ICCAT Collect. Vol. Sci. Papers 2113, 
(2011), (Exhibit USA -20), pp. 2114 -18. 
658 Mexico's first written submission, para. 84.  
659 Mexico's first written submission, para. 85.  
660 Monin J. Amande et al., Bycatch of the European Purse Seine Tuna Fishery in the Atlantic Ocean for 
the 2003 -2007 Period, 23 Aquat . Living Resour. 353  (2010) , (Exhibit USA -19), pp. 358 -362; Monin J. Amande 
et al., Bycatch and Discards of the European Purse Seine Tuna Fishery in the Atlantic Ocean: Estimation and 
Characteristics for 2008 and 2009, 66 ICCAT  Collect. Vol. Sci. Papers 21 13 (2011)  (Exhibit USA -20), p. 2120.  
661 Monin J. Amande et al., Bycatch of the European Purse Seine Tuna Fishery in the Atlantic Ocean for 
the 2003 -2007 Perio d, 23 Aquat. Living Resour. 353  (2010) , (Exhibit USA -19), pp.  360-61. WT/DS381/RW/USA • WT/DS381/RW 2 
 
- 120 - 
 
  presented in Exhibit USA -179 Rev.,  with regard to dolphin  interactions in connection with purse 
seine fishing without setting on dolphins in the ETAO:  
United States' Summary of the Evidence  
Fishery  Year Observed 
Sets Positive Sets  % Positive 
Sets Injury, or 
Released Alive  Dolphins 
Chased  Dolphins 
Encircled  Dolphin 
Mortalities  Interactions 
Per 1,000 
Sets Mortalities 
Per 1,000 
Sets 
 
 
 
Eastern 
Tropical 
Atlantic 
Purse 
Seine662  
2003-
2007  
598  
0  
0%  
0  
0  
0  
0  
0 
 
2008-
2009  
791  
0  
0%  
0  
0  
0  
0  
0 
 
1995-
2011  
9,969  
363  
3.64% no 
eviden
ce of 
any  
155 13 
(maxi mum 
possible)  
15.55  
1.30 
 
7.398.   To us, this table shows that interactions with dolphins take place infrequently in the ETAO 
purse seine fishery. Accordingly, we consider that the risk of unobserved mortalities or serious 
injuries is likely to be low.  
7.399.   Finally,  we note that neither party has submitted evidence showing that purse seine fishing 
without setting on dolphins in the ETAO causes the kinds of unobservable harms caused by setting 
on dolphins in the ETP.  
7.7.2.2.4   Overall conclusion  
7.400.   On the basis of our analysis of the evidence on the record, we conclude that purse seine 
fishing without setting on dolphins has killed and seriously injured dolphins in the past and, 
consequently, has the potential of killing and seriously injuring dolphins. However, the evidence 
sugges ts that the risk profile of this fishing method is generally low, particularly as  this fishing 
method does not require interaction with dolphins in order to spot the tuna.  
7.401.   When assessing past mortalities and serious injuries on a per set basis, it appears to us 
that this fishing method has a relatively low risk profile in terms of both observed and unobserved 
mortality and serious injury. Additionally, we have found that no evidence on the record suggests 
that purse seine fishing without setting on dolphins  causes the kinds of unobservable harms 
caused by setting on dolphins.  
7.402.   Accordingly, we conclude that while purse seine fishing without setting on dolphins poses 
some risks to dolphins, the risk profile of this fishing method as used in different areas of t he 
ocean is relatively low.  
7.7.2.3   Gillnet fishing  
7.7.2.3.1   Introduction  
7.403.   We now turn to reviewing the evidence concerning the risks to dolphins caused by gillnet 
fishing. Once again, we begin by recalling the arguments of the parties concerning gillnet fishing. 
We next su mmarize the existing findings concerning the risks to dolphins posed by this fishing 
method, before moving on to examine the evidence submitted in the course of these proceedings. 
First, however, we describe the fishing method involving gillnets, the activ ities incurred in a gillnet 
set and how, if any, serious injury or death to dolphins can occur.  
                                                
662 Monin J. Amande et al., Byc atch of the European Purse Seine Tuna Fishery in the Atlantic Ocean for 
the 2003 -2007 Perio d, 23 Aquat. Living Resour. 353  (2010) , (Exhibit USA -19), pp. 353, 355 -58 (2010); Monin 
J. Amande et al., Bycatch and Discards of the European Purse Seine Tuna Fishe ry in the Atlantic Ocean: 
Estimation and Characteristics for 2008 and 2009, 66 ICCAT  Collect. Vol. Sci. Papers 2113  (2011) , (Exhibit 
USA-20), pp. 2113, 2114 -18 (2011), Lauriane Escalle et al., Cetaceans and Tuna Purse Seine Fisheries in the 
Atlantic and In dian Oceans: Interactions but Few Mortalities, 522 Mar. Ecol. Prog. Ser., (Exhibit USA -145), pp. 
255, 257, 260.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
- 121 - 
 
  7.404.   According to the FAO, gillnets "consist of a panel of fine, nearly invisible webbing 
suspended vertically in the water column by a series of floats along the to p of a series of weights 
along the bottom. The fish become entangled when they try to pass through the net".663 Gillnets 
come in varying mesh sizes depending on the target fish species.664 "The mesh spaces are large 
enough for a fish 's head to pass through, bu t not its body. As fish, such as sardines, salmon, or 
cod try to back out, their gills are entangled in the net or buoy lines".665 Gillnets also vary widely in 
length  and height, with longer nets "often exceeding 100 km" in length and tens of meters in 
heigh t.666 
7.405.   A gilln et can be set on the seafloor (set, bottom set or sink  gillnets) or floated vertically 
depending on the target species. When maintained closer to the surface by the use of buoys, they 
are called "driftnets" or "drift gillnets".667 A gillnet haul i nvolves the setting, fishing and hauling in 
of the net by "several fishermen" and will usually last a "whole night", during which patrolling may 
be done every "two or three hours " to determine if there is catch. 668 
7.406.   Gillnets are used to capture a variety of marine species, i ncluding tuna669, sharks670, 
groundfish671, swordfish672, and squids673, and can be operated from boats and canoes on inland 
waters and inshore, decked small vessels in coastal waters and from larger  sized vessels fishing 
offshore, including in the high seas.674 According to the FAO, "[o]nly a small percentage of the 
world catch of tunas is taken with gillnets", namely less than  6% of world tuna catch .675 
Accordingly, gillnets are not among the "primary commercial fish ing methods for catching 
tunas" ,676 but are "very popular among the small -scale fishermen" and "semi -industrial fisheries" 
given its simplicity and effectiveness i n catching tuna.677 
7.407.   In 1992, in reaction to the high rate of bycatch, that is, incidental capture of non -targeted 
fish species, marin e mammals, sea turtles and sea birds, a moratorium on the use of large scale 
drift gillnets in the high seas was called by the United Nations General Assembly and the method 
has since been prohibited by several Regional Fisheries Management Organizations a nd 
countries.678 However, the FAO indicates that "drifting gillnets are still widely used, and very 
                                                
663 James Joseph, FAO, Managing Fishing Capacity of the World Tuna Fleet, Chapter 4: The Tuna Fishing 
Vessels of the World,  (Exhibit USA-148), p. 2. 
664 Natural Resources Defense Council, Net Loss: The Killing of Marine Mammals in Foreign 
Fisheries ,(Exhibit MEX -18), p. 13.  
665 Government Accountability Office, National Marine Fisheries Service: Improvements are Needed in 
the Federal Process Used to Prot ect Marine Mammals from Commercial Fishing, GAO 09 -78, (Exhibit MEX -7), p. 
58. 
666 James Joseph, FAO, Managing Fishing Capacity of the World Tuna Fleet, Chapter 4: The Tuna Fishing 
Vessels of the World,  (Exhibit USA-148), p. 2. See also FAO, Tuna Driftnet Fi shing , (Exhibit MEX -15); NOAA 
Fisheries, CA Thresher Shark/Swordfish Drift Gillnet Fishery, (Exhibit MEX -122).  
667 Natural Resources Defense Council, Net Loss: The Killing of Marine Mammals in Foreign Fisheries,  
(Exhibit MEX -18), p. 13. See also FAO, Tuna Dr iftnet Fishing,  (Exhibit MEX -15). 
668 FAO, Tuna Driftnet Fishing,  (Exhibit MEX -15), pp. 3 -4. See also NOAA Fisheries, CA Thresher 
Shark/Swordfish Drift Gillnet Fishery, (Exhibit MEX -122), p. 2; US Department of Commerce, Differentiating 
Serious and Non -Serious Injury of Marine Mammals: Report of the Serious Injury Technical Workshop 10 -13 
September 2007, Seattle, Washington , (Exhibit MEX -102), p. 35.  
669 Shane Griffiths et al., Biology, Fisheries and Status of Longtail Tuna ( Thuunus tongol ), with Special 
Refere nce to Recreational Fisheries in Australian Waters (Exhibit USA-197), p. 29.  
670 NOAA Fisheries, 2015 Stock Assessment and Fishery Evaluation (SAFE) Report for Atlantic Highly 
Migratory Species (2015) , (Exhibit USA-39), p. 52.  
671 Natural Resources Defense Cou ncil, Net Loss: The Killing of Marine Mammals in Foreign Fisheries,  
(Exhibit MEX -18), p. 25.  
672 FAO, Tuna Driftnet Fishing,  (Exhibit MEX -15), p. 2.  
673 Natural Resources Defense Council, Net Loss: The Killing of Marine Mammals in Foreign Fisheries,  
(Exhibit M EX-18), p. 29.  
674 FAO, Tuna Driftnet Fishing,  (Exhibit MEX -15), p. 3.  
675 James Joseph, FAO,  Managing Fishing Capacity of the World Tuna Fleet, Chapter 4: The Tuna Fishing 
Vessels of the World,  (Exhibit USA-148), p p. 2 and 6.  
676 Eric L. Gilman and Carl Gustaf Lundin, IUCN Global Marine Programme,  Minimizing Bycatch of 
Sensitive Species Groups in Marine Capture Fisheries: Lessons from Tuna Fisheries , (Exhibit USA-53), p. 2.  
677 FAO, Tuna Driftnet Fishing , (Exhibit MEX -15), p. 3.  
678 United Nations General Assembly R es. 46/215, Large -Scale Pelagic Drift -net Fishing and Its Impact 
on the Living Marine Resources of the World's Oceans and Seas,  (Exhibit  USA-66); NMFS , 2012 Report of The 
Secretary Of Commerce to the Congress of the United States Concerning US Actions Take n On Foreign Large -
Scale High Seas Driftnet Fishing , (Exhibit USA -67). WT/DS381/RW/USA • WT/DS381/RW 2 
 
- 122 - 
 
  popular, in many coastal and small to medium -scale fisheries in developing countries, particularly 
in Southeast Asia".679 
7.408.   Apart from High Seas Large -scale Drift net fishing, which the United States notes is 
ineligible to receive the dolphin -safe label under the 2016 Tuna Measure680, the United States 
adopts a position regarding gillnet fisheries similar to other fisheries analysed in these 
proceedings, namely that, differently from setting on dolphins, gillnet fishing can produce dolphin -
safe tuna products for the US market.681 In support of this position, the United States first argues 
that gillnet fishing does not intentionally target dolphins, any interaction being accidental and 
"actively" avoided by fishermen.682 Second, the United States posits that gillnets are not capable 
of causing the unique, unobservable harms caused by dolphin sets that occur as a result of the 
"chase itself " even if no dolphins were directly observed to have been killed683. As a consequence, 
the United States argues that gillnet fishing produces tuna that could be " truthfully " and  accurately 
certified as safe for dolphins.684 Third, according to the United States, gillnet fishing  does not, 
necessa rily or as a general matter, cause direct dolphin mortalities at a rate on par with that 
caused by dolphin sets in the ETP .685 Additionally, the United States points to the fact that there 
are effective mechanisms and practices employed by gillnet fisheries to avoid or reduce dolphin 
interactions.686 
7.409.   Mexico adopts a different position . With respect to observable harms, Mexico points to a 
string of scientific reports that would establish gillnet fishing as "highly destructive to dolphins".687 
According to Mexico, the absolute numbers of observed mortalities in Pakistan688, Indian Coast689, 
Chinese Taipei690, and South -East Asia691 shown in these studies "exceed the combined observable 
and unobservable mortalities in the ETP by many multiples".692 Mexico argues, in sum, that the 
"destructive effect on dolphins simply on the basis of their absolute numbers" indicates that 
"gillnet fishing should be ineligible [for the dolphin -safe label], just as fishing with high seas 
driftnets is ineligible".693 According to Mexico, the fact th at some gillnet sets might be made 
without killing or injuring dolphins "does not ameliorate the massive dolphin mortalities caused by 
gillnet fishing".694 
                                                
679 FAO, Tuna Driftnet Fishing,  (Exhibit MEX -15), p. 4. The United Nations Food and Agriculture 
Organization  further in dicates that drift gillnetting is used, among other, by the followin g fishing fleets: Sri 
Lanka, Philippines, India, Indonesia, China, Honduras, Japan, Panama, Korea, Chinese Taipei , Maldives, Belize, 
France, Netherlands Antilles, Seychelles, Spain,  and Italy. "Drifting gillnets are used to catch different species 
of tunas  in the South east Asia, Western and Central Indian, Western Mediterranean (Tirrenian, Ligurian, St. 
Sicily)".  
680 United States' first written submission, para. 89. On this matter, the United States also posits that 
"Mexico did not dispute in the previous c ompliance proceeding that the eligibility criteria regarding large -scale 
driftnets or dolphin mortality or serious injury lacked even -handedness, and the DSB made no finding that this 
was the case " (United States' first written submission,  para. 90).  
681 United States' first written submission,  paras. 24, 38; second written submission, para. 105; third 
written submission, para. 93.  
682 United States'  response to Panel s' question No.  13, para. 69; second written submission, para. 105. 
683 United States'  response to Panels' question  No.13, para. 70; second written submission, para. 106. 
684 United States' third written submission, paras. 94 and 96. See also United States' comments on 
Mexico's response to Panels' question No. 60, para. 36.  
685 United States'  response to  Panel s' question No. 13, para. 71 (arguing that "gillnet fishing does not, 
necessarily or as a general matter, cause direct dolphin mortalities at a rate on par with that caused by dolphin 
sets in the ETP "); third written submission, para. 96 (arguing that  "[gillnet] vessels may operate with low 
bycatch even in f isheries where the average is high" since  "[i]ndividual vessel operators can make different 
choices about how and when to fish and, in particular, how much time and effort to invest in avoiding dolp hin 
interactions") . 
686 United States' third written submission, para. 95.  
687 Mexico's  first written submission, paras. 69 -71. 
688 World Wildlife Fund Pakistan and Australian Marine Mammal Centre, An Assessment of Cetacean 
Mortality in the Tuna Fisheries of Pak istan (Exhibit MEX -16). 
689 K.S.S.M. Yousuf, et al., Observations On Incidental Catch Of Cetaceans In Three Landing Centres 
Along The Indian Coast, (Exhibit MEX -17). 
690 Natural Resources Defense Council, Net Loss: The Killing of Marine Mammals in F oreign Fish eries 
(Exhibit MEX -18). 
691 Convention on Migratory Species, Report of the Second Workshop on The Biology and Conservation 
of Small Cetaceans and Dugongs of South -East Asia,  (Exhibit MEX -19). 
692 Mexico's  first written submission, para. 71.  
693 Mexico's closing statement at the Panels' meeting with the parties, para. 5.  
694 Mexico's closing statement at the Panels' meeting with the parties, para. 5. WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.410.   Mexico also points to evidence of indirect harms caused to dolphins and other marine 
mammals by  intera ction with gillnets. In particular, Mexico adduces evidence showing that 
although "s mall marine mammals, such as harbor porpoise and bottlenose dolphins, that contact 
and become entangled in gillnets seldom survive  …[g]illnet interactions are often identif ied as the 
cause of death of stranded harbor porpoise in the mid -Atlantic ".695 Additionally, Mexico argues that 
gillnet fishing (along with other fishing techniques) is the source of a considerable amount of 
derelict fishing gear that continue to "fish" and have a harmful impact on marine mammals, 
including dolphins (so -called "ghost fishing"). In effect, Mexico points both to evidence presented 
in the previous proceedings, regarding d olphins that choke on pieces of the net , and to new 
evidence on ghost fishi ng to argue that, even when dolphins  escape gillnets  or do not interact with 
them during a fishing set, dolphins may suffer indirect harm from gillnet fishing.696 On this same 
note, Mexico argues that d olphin interactions  that do occur  with gillnet (and long line) fishing gear 
may happen  at a distance from the fishing vessel  or after dark, which would prevent them from 
being observed, and that dolphins may later die from injuries or complications arising from these 
interactions.697 
7.411.   With respect to unobservable h arms, Mexico argues that there is sufficient evidence 
pointing to the potential stress effects on marine mammals, including cetaceans, of being 
entangled in gillnet gear to "raise a presumption that  genuine concerns exist " that gillnet fishing 
(and fishing  methods)  cause unobservable adverse effects on dolphins . However, according to 
Mexico, none of such unobservable adverse effects are addressed by the 2016 Tuna Measure, and 
are rather simply presumed as being de minimis .698 
7.412.   Moreover, in Mexico's view, the l ack of knowledge or oversight of such harmful 
consequences as they relate to gillnet fishing renders the technique more harmful to dolphins than 
certified setting on dolphins in the ETP, whose high degree of oversight ensures that any harm to 
dolphins is c orrectly identified.699 Mexico argues that an indication of the harmful consequences to 
dolphins of gillnet fishing is the fact that no gillnet fishery for tuna "has ever been certified, or 
recommended for certification, by the Marine Stewardship Council (MS C)", "a well -regarded eco -
labelling organization".700 
7.413.   The United States contests Mexico's evidence concerning indirect harms caused by gillnet 
fishing. The United States contends that the first compliance panel  used the term "unobservable 
harms " to mean harm s that arise as a result of the "chase itself " in dolphin sets, independent ly of 
whether a dolphin is directly killed or seriously injured by the fishing gear .701 The United States 
thus argues that none of the evidence presented by Mexico suggests that the h armful interactions 
caused by gillnet fisheries mentioned in the evidence were not, in fact, observed or accounted for 
in per set dolphin interaction rates .702 First, the United States notes that the evidence regarding 
"gillnet parts 'protruding from the mou th' of dolphins " had already been considered by the first 
compliance panel, which found them " to be the kind of serious injury that is observable and that 
must, under the amended tuna measure, be certified ". Second, the United States argues that 
Mexico' s assertions concerning "ghost fishing " do not relate to fishing, in the sense of catching 
fish, but to potential harms distinct from fishing operations (akin to waste from a fish processing 
plant). In this sense, such evidence would lack any connection to th e Tuna Measure, which relates 
to enabling consumers to know whether the tuna they purchase was caught by harming dolphins . 
According to the United States, the evidence does not suggest any "nexus" between ghost fishing 
and tuna fisheries either. Third, the  United States notes that any calf-cow separation caused by 
                                                
695 Mexico's response to Panels' question  No. 68, para. 46. 
696 Mexico's response to Panels' question  No. 68, para. 44.  
697 Mexico's response to Panels' question No. 60, para. 17. See also Mexico's comments on United 
States' response to Panels' question No. 4, para. 7, fn. 5  (where Mexico posits that "[i]t  is unclear how an 
observer could monitor interactions between dolphins and the gillnet that take place underwater and at night.  
Presumably the observer can only monitor animals that are pulled up with the net".)  
698 Mexico's response to Panels' question No. 68,  paras. 47-49. See also Mexico's response to Panels' 
question  No. 92, para s. 161-162. 
699 Mexico' s first written submission, paras . 21 and 230 . 
700 Mexico's second written submission, paras. 12 -13. 
701 United States' comments on Mexico's response to Panels' question No. 68, para. 61.  
702 United States' comments on Mexico's respon se to Panels' question No. 68, para. 62. See also United 
States' comments on Mexico's response to Panels' question No. 60, para. 36.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
- 124 - 
 
  the death of the mother  in a gillnet fishery would "flow from an observable mortality that renders 
the set non -dolphin safe".703 
7.414.   Finally, regarding evidence on potential stress to dolphins from the interaction with 
gillnets, the United States contends that the evidence doe s not suggest that any harms not 
associated with direct, observable mortalities and serious injuries are caused by any fishing 
methods other than setting on dolphins. In effect, t he United States agrees  that any capture in 
fishing  gear is stressful for dolphins, alluding to the fact that one of the key features that 
distinguishe s dolphin sets from other fishing methods is the necessity of capturing (on average) 
hundreds of dolphins e very time the fishing method is used. In this regard, the United States 
argues that setting on dolphins is at a different order of magnitude than any fishery on the record 
in terms of the number of dolphins that are chased and captured in purse seine nets in every set 
and in every year .704 In sum, we understand the United States' central argument to be that any 
mortalities or serious injuries to dolphins caused by gillnet fishing contained in the evidence 
presented by Mexico would be observable (or flow from observable harms or deaths) and would 
thus render ineligible for the dolphin -safe label  any tuna captured during the set or gear 
deployment where such mortalities or serious injuries occurred . 
7.415.   Additionally, the United States contends that Mexico' s evidence  does not contradict the 
conclusion that certification conditions for gillnet  (or longli ne) fishing are far easier than setting on 
dolphins in the ETP.  According to the United States, the evidence presented by Mexico r ather 
suggests that the nature of the injuries may be difficult to see , given that "[h]ooked cetaceans are 
often very active, complicating an assessment of where and how the animals are hooked" and that 
animals may "break the line and swim away … before they are close enough for the observer t o 
see details " or to "identify species and observe details  of the interaction events" .705 In this sense, 
certification conditions would be significantly more difficult  in the ETP large purse seine fishery  
"where there are hundreds of dolphin interactions (on  average) in each set, with many of them 
taking place far from the vessel ".706 
7.416.   The United States also rejects Mexico's allegations on observable harms caused by gillnet 
fishing. As a general point, the United States asserts that the absolute dolphin mortalit ies caused 
by gillnet fisheries presented by Mexico (under the "overall absolute levels of adverse effects" 
metric) do not address the "relative harms to dolphins " of different fishing methods , but r ather 
represent an incorrect compari son between  the dolph in mortalities caused by "80-90 vessels 
setting on dolphins in the ETP with the dolphin mortalities allegedly caused by thousands of (…) 
gillnet vessels in different fisheries around the world ".707 In this sense, the evidence would not 
allow for a comparison  on an "apples -to-apples" basis. The United States also argues that given 
the uneven distribution of marine mammals in different ocean areas, "there are [gillnet] fisheries, 
including tuna [gillnet] fisheries, that pose no known risk to any dolphin species ".708 Such fisheries 
would include gillnet fisheries in US waters which have been determined by the NMFS in 2016 to 
pose " a remote likelihood of or no known incidental mortality and serious injury of marine 
mammals ".709 On this particular point, as it applies to gillnet fisheries in US waters, Mexico 
disagrees, arguing that the fisheries identified " are not tuna fisheries, and in any event the same 
document identifies a total of 26 gillnet fisheries that are designated as posing risks to marine 
mammals ".710 
7.417.   Regar ding the specific evidence provided by Mexico, the United States first argues that the 
evidence regarding Chinese Taipei's  fisheries  does not address dolphin mortalities in "currently 
existing tuna fisheries".711 The United States also raises concerns regard ing the scientific basis of 
the evidence presented by Mexico, arguing that the report on Chinese Taipei's  near-shore fisheries  
is "not based on a scientific study, is out of date, and may not relate to tuna fisheries at all ", while 
                                                
703 United States' comments on Mexico's response to Panels' question No. 68, para. 62.  
704 United States' comments on Mexico's response to Panels' question No. 68, para. 62.  
705 United States' comments on Mexico's response to Panels' question No. 60, para. 36.  
706 United States' comments on Mexico's response to Panels' question No. 60, para. 36.  
707 United States' second written submiss ion, para. 128.  
708 United States' second written submission, para. 57. See also United States' third written submission, 
para. 59.  
709 NMFS, Proposed Rule: List of Fisheries for 2017, (Exhibit USA -101). 
710 Mexico's second written submission, para. 69.  
711 United  States' second written submission, para. 107 (arguing that one of the Chinese Taipei fisheries 
mentioned in the evidence provided by Mexico had been shut down in 1986, while there was no evidence that 
the others targeted tuna).  WT/DS381/RW/USA • WT/DS381/RW 2 
 
- 125 - 
 
  the dolphin mortalities reported on Indian fisheries could not all be attributed to tuna fishing given 
that only a limited part of the fisheries covered by the study targeted tuna.712 According to the 
United States, the evidence from Pakistani and Indian gillnet fisheries "at most"  suggests that 
gillnet fishing "in particular fisheries may be putting dolphins in significant danger " and that such 
situation i s appropriately addressed under "other  provisions of the US dolphin safe labelling 
measure" .713 On this point, the United States s ubmits that certain gillnet fisheries in the Indian 
Ocean region did meet the regular and significant mortality and serious injury standard under the 
determination provisions .714 The United States explains that, based on evidence regarding absolute 
levels of  harms to dolphins presented by Mexico in the first compliance proceedings715, there was 
evidence on Pakistani gillnet fisheries in the Indian Ocean, as well as in neighbouring fisheries , 
suggest ing that "alarming" levels of mortality were occurring such tha t, "if per set data were 
available, the per set mortality rate likely would meet or exceed the "regular and significant " 
standard ".716 Based on the available dolphin bycatch data, NOAA thus determined these Indian 
Ocean gillnet fisheries to exhibit  bycatch r ates (i.e. number of dolphins killed per ton of tuna 
landed ) significantly higher than that caused by dolphin sets in the ETP (the " ETP benchmark "), 
thus justifying a "regular and significant " mortality determination" .717 Accordingly, o n this basis, 
and in t he absence of contradictory information submitted by the countries, NOAA designated such 
fisherie s.718 
7.418.   In sum, with respect to the determination of these Indian Ocean gillnet fisheries, the 
United States argues that where gillnet fishing causes a high level of direct dolphin mortality in 
particular fisheries, such harm can be addressed through the enhanced requirements applied 
under the determination provisions.719 The United States further argues that the determination 
made for the Indian Ocean addresses only how gillnet fishing is conducted in that particular area, 
and not in general.720 In the view of the United States, there is no evidence on the record showing 
high levels of dolphin mortality in any currently operating gillnet fishery for tuna other than the 
Indian Ocean fisheries designated under the determination provision s.721 
7.419.   Additionally, in response to a question by the Panels, the United States provided a table 
summarizing the "available information regarding tuna gillnet fisheries" on a per set basis (se e the 
table below).722 According to the United States, the available data on the table and other evidence 
on the record suggest that, with the exception of Indian Ocean gillnet fisheries, levels of direct 
dolphin mortality are s ignificantly below those cause d by dolphin sets in the ETP.723 
Table  – Available Per Set Tuna Gillnet Fisheries Data724 
Fishery  Year Observed Sets  Observed 
Mortalities  Mortality Per 
1,000 Sets  Source of Data  
Northern 
Australia Gillnet 
Fishery725 2000-2003 105 (exp.)  2 19.0 Observer 
reports  
160 (control)  3 18.9 
California Drift 2014 113 4 35.4 Observer 
                                                
712 United States' second wri tten submission, para. 107.  
713 United States' second written submission, para. 108 ( emphasis from original).  
714 United States' second written submission, para. 157.  
715 R.C. Anderson, Cetaceans and Tuna Fisheries in the Western and Central Indian Ocean , (Exhib it 
MEX-42). 
716 United States' second written submission, para. 169.  
717 United States' second written submission, para. 172.  
718 United States' second written submission, para. 175.  
719 United States' third written submission, para. 99.  
720 United States'  response  to Panels' question No. 1 3, para.  72. 
721 United States' third written submission, para. 115.  
722 United States'  response to Panels' question  No. 4, para.  16. 
723 United States'  response to Panels' question  No. 4, para. 17. 
724 Reproduced as presented by the Unit ed States in its response to Panels' question  No. 4, para.  16. 
725 Geoffrey R. McPherson et al., Acoustic Alarms to Reduce Marine Mammal Bycatch from Gillnets in 
Queensland Waters: Optimising the Alarm Type and Spacing, (Exhibit USA -196); Shane Griffiths et al., Biology, 
Fisheries and Status of Longtail Tuna ( Thuunus tongol ), with Special Reference to Recreational Fisheries in 
Australian Waters, (Exhibit. USA -197).  WT/DS381/RW/USA • WT/DS381/RW 2 
 
- 126 - 
 
  Fishery  Year Observed Sets  Observed 
Mortalities  Mortality Per 
1,000 Sets  Source of Data  
Gillnet 
Fishery726 2015 41 1 24.4 reports (30% 
and 11% 
coverage)  
California Set 
Gillnet 
Fishery727 2010 216 1 4.6 Observer 
reports (13% 
and 8% 
coverage)  2011 171 0 0.0 
Indian Ocean 
Mixed-Target 
Gillnet Fisheries  According to the United States:"[n]o per set data is available for this fishery. However, as 
the United States has explained, the available information suggests that, if per set data 
were available, it would be above the level o f observed dolphin mortality caused by dolphin 
sets in the ETP, on average over the past 20 years, i.e. [126.5]  dolphin mortalities per 
1,000 sets" . 
 
7.420.   In response, Mexico observes that the California Drift -Gillnet Fishery  included in the table 
and consider ed by the United States to be a "dolphin -safe fishery", is rated as a Category I fishery 
by the US Department  of Commerce due to its impact on sperm whales. 728 Mexico further 
observes that the gear and method used by the fishery are very similar to the larg e-scale driftnet 
method that is ineligible for the dolphin -safe label when use d in the high seas , "the main 
differences being that (i) the nets in the California fishery are just under 2 kilometr es compared to 
the 2.5 kilometr e length with which "large sca le" driftnets are defined and (ii) the fishery is in US 
territorial waters rather than the high seas ".729 Mexico also points to the fact that, in 2014, 
members of the California st ate legislature  urged the US Department of Commerce to require the 
phasing out  of this fishery considering the amount of bycatch of " endangered and protected 
species that are of great significance to the people of California and are an important part of the 
ocean ecosystem " by the "large -mesh drift gill nets".730 Finally, Mexico posit s that,"[e] ven 
accepting the United States'  data about this fishery at face value, the United States has failed to 
explain why a mortality rate of 35.4 per 10 0[0] sets should be considered not harmful to 
dolphins ".731 
7.7.2.3.2   Findings made in the previous proceeding s 
7.421.   The Panels now turn to the findings made by the panels and the Appellate Body in previous 
stages of this dispute  regarding the risk profile of gillnet fishing.  
7.422.   At the outset, we note that, as it is also the case in the present proceedings, the harms to 
dolphins caused by gillnet fishing was the object of extensive debates and considerable evidence 
adduced both in the original and the first compliance proceedings. A significant part of such 
evidence has been reintroduced by the parties and therefore the pr evious findings made regarding 
gillnet fishing are of particular relevance to the present proceedings.  
                                                
726 NMFS, California/Oregon Drift Gillnet Observer Program Observed Catch, (Exhibit USA -198).  
727 NMFS, California Set Gillnet Observer Program Observed Catch, (Exhibit USA -199);  NMFS, Proposed 
Rule: List of Fisheries for 2017, 81 Fed. Reg. 54,019 (Aug ust 15, 2016) , (Exhibit  USA-101).  
728 Mexico's comments on United States' response to Panels' question N o. 4, para. 7. The NMFS 
classifies fisheries under three different categories based on PBR levels of mortality and serious injury of 
marine mammals. NMFS, Proposed Rule: List of Fisheries for 2017 so describes the categories:  
Category I : Annual mortality a nd serious injury of a stock in a given fishery is greater than 
or equal to 50 percent of the PBR level (i.e. frequent incidental mortality and serious injury 
of marine mammals).  
Category II : Annual mortality and serious injury of a stock in a given fisher y is greater than 
1 percent and less than 50 percent of the PBR level (i.e. occasional incidental mortality and 
serious injury of marine mammals).  
Category III : Annual mortality and serious injury of a stock in a given fishery is less than or 
equal to 1 % of the PBR level (i.e. a remote likelihood of or no known incidental mortality 
and serious injury of marine mammals).  
NMFS, Proposed Rule: List of Fisheries for 2017, 81 Fed. Reg. 54,019 (Aug ust 15, 2016) , 
(Exhibit  USA-101), p. 2.  
729 Mexico's comments on Un ited States' response to Panels' question No. 4, para. 8.  
730 Mexico's comments on United States' response to Panels' question No. 4, para. 8.  
731 Mexico's comments on United States' response to Panels' question No. 4,  para. 9. WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.423.   In the original proceedings, a considerable amount of evidence was adduced regarding 
harms to dolphins caused by tuna driftnet fishing in coastal areas.732 The original panel found that 
"the use of driftnets to catch tuna in coastal areas within Exclusive Economic Zones (EEZs) is 
considered "a highly destructive practice" and one of "the greatest threats to populations of small 
cetaceans" in certain areas of  the world ".733 In reaching such finding, the original panel  quoted 
evidence submitted by Mexico , noting  that: 
The case of pelagic driftnets used in tuna and swordfish fisheries is an example of a 
highly destructive practice that has now been addressed by th e EU in the form of the 
driftnet ban that came into effect in January 2002. However, there is ample evidence 
of problems in other fisheries that have yet to be addressed. Moreover, many fisheries 
in the EU that present a threat to cetaceans are not yet bei ng monitored for their By-
Catch  [sic]. Therefore, the data that are available represent only a minimum estimate 
of the scale of the problem.734 
7.424.   The original panel further indicated that evidence had been adduced reporting dolphin 
bycatch and mortalities resu lting from tuna fishing operations in European, Asian and African 
fisheries.735 Among the European tuna fisheries, the original panel quoted particular evidence on 
estimates of bycatch from the French driftnet fishery for tuna736 and from the UK737 and Irish738 
driftnet fisheries for albacore.  Among the Asian tuna fisheries, the original panel quoted evidence 
on estimates of bycatch from:  "gillnet,  driftnet, and purse -seine fisheries in the western central 
Pacific "739; a driftnet fishery operating off Tristan da Cunh a740; a formerly  operating Chinese Taipei  
shark and tuna gillnet fishery off Northern Australia741; tuna driftnet fisheries on the West coast of 
India742, in particular, Sri Lankan coastal tuna gillnet and driftnet fisheries743; and a tuna driftnet in 
                                                
732 Panel Report, US – Tuna II (Me xico),  paras. 7.521 -564. 
733 Panel Report, US – Tuna II (Mexico),  para. 7.521.  
734 Panel Report, US – Tuna II (Mexico), fn. 735 (quoting o riginal Panel Exhibit MEX -99 p. Ev 26).  In the 
same footnote, the original panel observed, in relation to tuna driftnets , that even though the US dolphin -safe 
provisions prohibit the use of the dolphin -safe label for tuna caught "on the high seas by a vessel engaged in 
driftnet fishing ", they do not impose the same restriction in relation to driftnet fishing for tuna within t he 
exclusive economic zones . 
735 Panel Report, US – Tuna II (Mexico),  para. 7.522.  
736 Panel Report, US – Tuna II (Mexico),  fn. 737, indicating bycatch estimates of "1,722 (1365 -2079) 
common, striped and bottlenose dolphins, and long -finned pilot whales in 199 2; and 1,654 (1115 -2393) 
common, striped and bottlenose dolphins, and long -finned pilot whales in 1993" (quoting o riginal Panel  Exhibit  
MEX-5, p. XX-16, fn. 89). 
737 Panel Report, US – Tuna II (Mexico),  fn. 737, indicating the bycatch estimates in 1995 of " 104 
striped dolphins (38 – 169)" (quoting o riginal Panel Exhibit MEX-5, p. AA -16). 
738 Panel Report, US – Tuna II (Mexico),  fn. 737, indicating bycatch estimates in 1996 and 1998 
respectively of " 136 and 964 striped dolphins"  (quoting o riginal Panel Exhibit M EX-5, p. AA -16). 
739 Panel Report, US – Tuna II (Mexico),  fn. 738, indicating bycatch estimates of "[r]oughly 1,700 
bottlenose dolphins and 1,000 spinner dolphins  … Also at risk are Irrawaddy dolphins. This  region's fisheries 
are diverse and poorly documente d. Nevertheless, coastal gillnets, especially driftnets for tunas  and mackerels, 
are widely used . After a closure in Australian waters , the [Chinese Taipei]  driftnet fishery relocated  and 
continued fishing in Indonesian waters in the Arafura Sea. With no r eduction in effort, high cetacean bycatch 
rates are probable " (emphasis from original) (quoting o riginal Panel  Exhibit  MEX-5, p. 26 ).  
740 Panel Report, US – Tuna II (Mexico) , fn. 738, noting "[t]he rec ent revelation that a driftnet  fishery 
has been operatin g off Tristan da Cunha for tuna , with concomitant incidental mortality of small whales and 
dolphins, suggests that there may also be considerable mortality to some as yet unidentified species. 
Incidental mortality to Heaviside's dolphin, which is restricte d to the coastal zone of South Africa and Namibia, 
may also be an important interaction , but recent data on bycatch and population size are lacking" (emphasis 
from original) (quoting o riginal Panel  Exhibit  MEX-5, p. 18). 
741 Panel Report, US – Tuna II (Mexic o), fn. 738, noting  "[a] now-terminated  [Chinese Taipei]  shark and 
tuna gillnet fishery  operated off Northern Australia  and caught bottlenose dolphins, spinner dolphins, spotted 
dolphins, humpback dolphins and false killer whales , a proportion of which are  in this area. The fishery was 
mainly located in Area 71 and is discussed under that section. Given the amount of gillnetting likely to occur in 
this region, accidental catches may adversely affect small coastal species such as the finless porpoise and 
Irrawaddy dolphin to some extent . The driftnet fisheries operating farther offshore —in the Bay of Bengal , for 
example —might be expected to catch spinner and spotted dolphins, at least, and perhaps other species . 
Driftnet fisheries in the southern Indian Ocean  may catch a variety of species such as the spectacled porpoise, 
the southern right whale dolphin, and common dolphin. All of these fisheries require more detailed information 
on non -target catches" (emphasis from original) , (quoting o riginal Panel  Exhibit  MEX-5, p. 23). 
742 Panel Report, US – Tuna II (Mexico),  fn. 738, noting  "[c]atches in India are reported quite 
frequently, and formed 33% of the total catch of cetaceans recorded in the gillnet fishery at Calicut. Bottlenose 
dolphins are one of the commonly  caught dolphins in seerfish and tuna driftnet fisheries  on the west coast of 
India, and in coastal gillnet fisheries for pomfrets and other species too. In Sri Lanka, this species was found to WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  Negros Orien tal744. Finally, among the African tuna fisheries, the original panel quoted evidence on 
estimates of bycatch from Eastern Central Atlantic large -meshed drift gillnets745, in particular small 
scale coastal drift gillnet fisheries in Ghana.746 In this conn ection,  we note in particular the finding 
by the original panel that Mexico had  "sufficiently demonstrated that tuna caught during a trip 
where dolphins were killed or seriously injured using a method of fishing other than setting on 
dolphins outside the ETP may be contained in the tuna products sold in the US market under the 
dolphin -safe label ".747 We also note that the original panel based its decision on the fact that the 
"vast majority of tuna products containing tuna caught in the western Pacific Ocean " using,  inter 
alia, gillnets was eligible to be labelled dolphin -safe.748 
7.425.   We finally note the original panel's statement, when discussing whether the use of AIDCP 
labelling requirements would "discourage" the unobserved effects of setting on dolphins and their 
potential consequences on dolphin populations, that:  
[T]he evidence before the Panel suggests that significant dolphin mortality also arises 
outside the ETP from the use of other techniques than setting on dolphins, and that 
some of the affected dolphin popula tions may be at risk as a result. The Panel notes in 
this respect the example of a Japanese driftnet fishery  for albacore that was observed 
to have a dolphin mortality rate of three animals per net . In contrast, as previously 
mentioned, the vast majority o f the dolphin sets in the ETP are zero -kills. 749 
7.426.   The Appellate Body also made findings regarding the harms to dolphins caused by drift 
gillnets during the original proceeding. We first note the United States' allegation on appeal that 
the original panel had  erroneously relied on evidence of harm to dolphins from driftnet fishing 
given that the US measure disallowed labelling tuna products as "dolphin -safe", when the tuna was 
caught using this fishing method on the high seas.750 The Appellate Body disagreed, no ting that 
while the US measure  stipulate d that tuna caught using driftnets on the high seas was not eligible 
                                                                                                                                                  
consist of between 5 and 25% of the total cetacean catch  in four different surveys amounting to 1,250 to 
10,000 animals " (emphasis from original) , (quoting o riginal Panel  Exhibit  MEX-5, p. AA-40). 
743 Panel Report, US – Tuna II (Mexico),  fn. 738, noting  "[s]pinner dolphins are caught in Sri Lankan 
coastal gillnet and d riftnet fisheries . This species is caught in Pakistani offshore deepwater gillnet fisheries and 
is commonly entangled in coastal driftnet fisheries  for seerfish and tunas  on the west coast of India, and is also 
entangled in other gillnet fisheries for shar ks, pomfrets and other species" (emphasis from original) , (quoting 
original Panel  Exhibit  MEX-5, p. AA-41). Also that "[s]  pinner dolphins are the most frequently caught species 
in the Sri Lankan fishery, where they formed between 33 and 47% of the total c etacean catch in for different 
surveys, or roughly 7,050 -11,750 dolphins per year " (emphasis from original) , (quoting o riginal Panel  Exhibit  
MEX-5, p. AA-41). Finally, "[f]inless porpoise  are entangled in Sri Lankan coastal gillnet and driftnet fisheries, 
shark nets in Australian, and Indian ocean coastal gillnets. This species is commonly caught in seerfish and 
tuna driftnet fisheries  throughout the west coast of India. Finless porpoises have been caught in a shrimp trawl 
in Pakistan in 1989, entangled in beach seines and stake nets for shrimp, and entangled in small and medium 
mesh finfish gillnets in shallow inshore waters of Pakistan (emphasis from original) , (quoting o riginal Panel  
Exhibit  MEX-5, p. AA-43). 
744 Panel Report, US – Tuna II (Mexico),  fn. 738, indicating annual bycatch estimates of small cetaceans 
"in a single tuna driftnet fishery in Negros Oriental" of "about 400"  (quoting o riginal Panel  Exhibit  MEX-5, pp. 
26,27, 131 ) 
745 Panel Report, US – Tuna II (Mexico),  fn. 739, noting "[i]n the Eastern C entral Atlantic, the clymene 
dolphin  (Ghanaians call it the "common dolphin "), bottlenose, pantropical spotted, Risso's, long -beaked 
common, and rough -toothed dolphins; short -finned pilot whale , melon -headed whale, dwarf sperm, and 
Cuvier's beaked whale ma y all be caught in large-meshed drift gillnets targeting tuna , sharks, billfish, manta 
rays, and dolphins" (emphasis from original) , (quoting o riginal Panel  Exhibit  MEX-5, p. 102). 
746 Panel Report, US – Tuna II (Mexico),  fn. 739, noting  "[i]n 1997, the IWC Scientific Committee 
concluded that information on small cetaceans in Africa (outside southern Africa) is very sparse and that issues 
of cetacean fishery bycatch must be addressed. Projects that have sampled landing sites of small scale coastal 
fisheries i n Ghana since 1998 show that bycatch and directed harvests of small cetaceans are commonplace 
and possibly increasing . The largest catches, by far, are the result of deployment of large meshed drift gillnets 
targeting tuna, sharks billfish, manta rays, and  dolphins. The species most frequently caught are clymene 
(Ghanaians call it the " common dolphin "), bottlenose, pantropical spotted, Risso's, long -beaked common, and 
rough -toothed dolphin s, together with short -finned pilot and melon -headed whales"noting (e mphasis from 
original) , (quoting o riginal Panel  Exhibit  MEX-5, p. 9). 
747 Panel Report, US – Tuna II (Mexico),  para. 7.534. 
748 Panel Report, US – Tuna II (Mexico),  para. 7.534. 
749 Panel Report, US – Tuna II (Mexico),  para. 7.613 (emphasis added) (internal cita tions omitted) 
(quoting original Panel  Exhibit MEX-2, p.101). The Panels note that the study presented in original Panel 
Exhibit MEX -2 dates from 1992, being thus based on data prior to the adoption of the UN moratorium on high -
seas driftnets which  signifi cantly reduced mortalities  in covered fisheries. See Exhibit MEX -18, p. 29.  
750 Appellate Body Report, US – Tuna II (Mexico) , para. 26.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  for a "dolphin -safe" label, it grant ed access to the label to tuna products containing  tuna caught 
with driftnets in exclusive economic zones. The Appellate Body thus found that "insofar as such 
tuna products are eligible for a "dolphin -safe" label, the Panel's reliance on sources relating to 
driftnet fishing was not "mistaken"".751 We note, as we explained above,752 that the eligibility 
criteria have no t been modified since the original proceedings and thus we understand that this 
finding by the Appellate Body is relevant to the 2016 Tuna Measure. Consequently, in the present 
proceedings, we will also rely on sources relating to driftnet fishing, in part icular in domestic 
waters, to ascertain the harms to dolphins caused by gillnet fisheries in different parts of the 
ocean.  
7.427.   Turning now to the findings made in the first compliance proceedings, we first note that 
the first compliance panel found that Mexico  had submitted substantial evidence showing that 
gillnets kill and seriously injure dolphins.753 The first compliance panel further considered that 
Mexico had summarized a substantial number of reports and studies testifying to the "deleterious 
effects " that tuna fishing methods other than setting on dolphins may have on dolphins , include 
gillnet fishing .754 This evidence , according to the first compliance panel,  present ed "a compelling 
case" that these methods were " negatively impacting the health and well -being of dolphin 
populations ".755 Thus, the first compliance panel confirmed the original panel's finding regarding 
the existence of "substantial evidence" on observable harms caused to dolphins by gillnet fisheries.  
7.428.   However, the first compliance panel found th at none of the evidence showing that gillnets 
kill and seriously injure dolphins suggested that gillnets have "the same kind of unobservable 
effects as setting on dolphins". The panel found:  
With respect to gillnet fishing, Mexico has submitted substantial  evidence showing that 
gillnets kill and seriously injure dolphins. None of this evidence, however, suggests 
that gillnets have the same kind of unobservable effects as setting on dolphins. The 
closest that the evidence comes to making such an allegation i s the finding by 
Gomercic et al that "[e]ven when dolphins do not immediately drown in a gillnet, 
interactions with the net causes dolphins to die later". Specifically, the report suggests 
that gillnets may cause eventual strangulation even of dolphins tha t manage to break 
free from the net. Accompanying this statement is a photograph of a dolphin with a 
"gillnet part…protruding from [its] mouth". While it may be that dolphins injured in 
gillnets die at some later time, injuries such as those leading to gil lnet parts 
"protruding from the mouth" of dolphins would seem clearly to be the kind of "serious 
injury" that is observable and that must, under the amended tuna measure, be 
certified. Accordingly, while the evidence presented by Mexico suggests that gilln ets 
caused delayed death or serious injury, it does not suggest that such nets cause the 
same kind of unobservable harms as are caused by setting on dolphins.756 
7.429.   The first compliance panel further noted that Mexico's evidence concerned the extent of 
mortalit y and serious injury caused by tuna fishing methods, including gillnet fishing, that were 
"precisely the kind of interactions that can and, under the amended tuna measure, must be 
certified, and whose occurrence renders ineligible for the dolphin -safe labe l any tuna caught in the 
set in which the harmful interaction (i.e. the death or serious injury) occurred ".757 Thus, for the 
first compliance panel, while gillnets did cause serious injury and death, these harms were 
observable and did not amount to the same  kind of unobservable harms as those found to be 
caused by setting on dolphins.  
7.430.   On appeal, Mexico challenged this finding by the first compliance panel under Article 11 of 
the DSU. A ccording to Mexico, the panel had erred in finding that all of the effects  on dolphins 
caused by fishing methods other than setting on dolphins would be "observable" if a trained 
                                                
751 Appellate Body Report, US – Tuna II (Mexico) , para. 270. 
752 See Section 7.4 above.  
753 Panel Report, US – Tuna II  (Mexico)  (Article 21.5 - Mexico) , para. 7.130.  
754 Panel Report, US – Tuna II  (Mexico)  (Article 21.5 - Mexico) , para. 7.132 (quoting, with reference to 
gillnets, original compliance Panel Exhibit MEX-39, and with reference  to driftnets original compliance Panel 
Exhibit MEX-103).  
755 Panel Report, US – Tuna II  (Mexico)  (Article 21.5 - Mexico) , para. 7.132.  
756 Panel Report, US – Tuna II  (Mexico)  (Article 21.5 - Mexico) , para. 7.130 (internal citations omitted) 
(quoting original compliance Panel Exhibit MEX-52). 
757 Panel Report, US – Tuna II  (Mexico)  (Article 21.5 - Mexico) , para. 7.132 (internal citations omitted).  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  person were watching for them .758 The Appellate Body disagreed, noting that the panel had not 
found that all the effects on dolphins of other fishing met hods would be "observable", but rather 
that none of the evidence presented by Mexico regarding the adverse effects on dolphins caused 
by other fishing methods suggested that fishing methods other than setting on dolphins inflict the 
same kinds of unobserva ble harms  that are caused by setting on dolphins as a result of the chase 
itself.759 The Appellate Body further found, contrary to Mexico's argument, that the first 
compliance panel did examine the available evidence regarding gillnet fishing as it relates t o 
unobservable harms and that by raising the claim under Article 11 of the DSU, Mexico seemed to 
be "rearguing the case " and asking the Appellate Body  to "attribute to its evidence greater 
significance than did the Panel ". According to the Appellate Body, such a request was not  
compatible with the scope of appellate review .760 
7.7.2.3.3   Panels' assessment in the present proceedings  
7.431.   We now turn to our own assessment of the evidence presented by the parties in these 
proceedings. At the outset, we note that the relevant e vidence put forward by both parties in these 
proceedings with respect to observable and unobservable harms caused by gillnet fishing is 
particularly contested and considerably limited in scope. As we have already explained, the limited 
nature of the data b efore us is a common feature of a significant part of the evidence on dolphin 
mortalities in non -ETP fisheries.761 We note that this issue is of particular relevance to the 
determination of the risk profile of gillnet fishing.  
7.432.   First, we note, as pointed out above762, that even though there is evidence indicating the 
existence of several gillnet (and driftnet) fisheries that fish for tuna, these tend to be small and 
medium coastal m ixed-target fisheries that are not major suppliers of tuna to international 
marke ts.763 This seems to be one of the reasons explaining the limitedness of scientific studies 
with comprehensive observer coverage regarding gillnet fisheries (apart from large scale driftnet 
gillnets in the high seas).764 At the same time, we note that even if gillnet fishing is not among the 
"primary commercial fishing methods for catching tunas"765, it is "very popular among the small -
scale fishermen" and "semi -industrial fisheries" given its simplicity and effectiveness in catching 
tuna.766 We also note that Mexi co has adduced evidence that gillnet fishing represents a large 
share of tuna produced in some regions.767 
7.433.   The Panels further note that both parties presented  evidence regarding gillnet fisheries  
which included non -tuna gillnet fisheries or gillnet fisheries  that did not fish exclusively or even 
primarily for tuna.768 In this case, we find particular merit in the argument presented by the United 
States regarding the "relevance" of some exhibits on the record concern ing dolphin mortalities in 
                                                
758 Appellate Body Report, US – Tuna II  (Mexico)  (Article 21.5 – Mexico) , para. 7.198.  
759 Appellate Body Report, US – Tuna II (Mexico)  (Article 21.5 – Mexico) , para. 7.200.  
760 Appellate Body Report, US – Tuna II  (Mexico)  (Article 21.5 – Mexico) , para. 7.201.  
761 See Section 7.7.1.2.3 . 
762 See para . 7.406  
763 See James Joseph, FAO, Managing Fishing Capacity of the World Tuna Fleet, Chapter 4: The Tuna 
Fishing Vessels of the World,  (Exhibit USA-148), p.2 (stating, in particular, that "[o]nly a small percentage of 
the world catch of tunas is taken with gillne ts"). 
764 In this respect, we find the considerations by the NRDC on " challenges and limitations " concerning 
data on mortalities of marine mammals in connection with "gillnet interactions" illustrative. We note, in 
particular, NRDC's reference to a 2013 stud y on marine mammal bycatch in gillnet and other entangling net 
fisheries  which reviewed "20 years' worth of literature" and identified important " data gaps " concerning species 
"at greatest risk from gillnet interactions ".  Natural Resources Defense Council , Net Loss: The Killing of Marine 
Mammals in Foreign Fisheries, (Exhibit MEX-18), p.24. We note that these issues are not particular to tuna 
gillnet fisheries, but as far as they help illustrate the challenges in data collection for gillnet fisheries in general 
we find the evidence to be of relevance. See also Alison McCarthy et al., Pilot Observer Programme in Irish 
Pelagic Trawl and Gillnet Fisheries: Implementing Council Regulation (EC) No 812/2004 , (Exhibit US A-163), p. 
23; and L. Mannocci et al., Asses sing the Impact of Bycatch on Dolphin Populations: the Case of the Common 
Dolphin in the Eastern North Atlantic,  (Exhibit MEX -120), p. 8. 
765 Eric L. Gilman and Carl Gustaf Lundin, IUCN Global Marine Programme,  Minimizing Bycatch of 
Sensitive Species Groups in Marine Capture Fisheries: Lessons from Tuna Fisheries , (Exhibit USA-53), p. 2.  
766 FAO, Tuna Driftnet Fishing,  (Exhibit MEX -15), p. 3.  
767 See Mexico's opening statement, para. 60. See also International Seafood Sustainability Foundation, 
Fishing Methods, (Exhibit MEX -82), p. 2 (mentioning IOTC data indicating that between 30% and 40% of catch 
in the Indian Ocean is attributed to gillnets).  
768 See, e.g., K.S.S.M. Yousuf, et al., Observations On Incidental Catch Of Cetaceans In Three Landing 
Centres Along The  Indian Coast , (Exhibit MEX -17); and NMFS, Proposed Rule: List of Fisheries for 2017, 81 
Fed. Reg. 54,019 (Aug ust 15, 2016) , (Exhibit USA-101). WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  non-tuna gillnet fisheries . According to the United States, given that information about gillnet 
fishing generally does not relate to tuna fisheries, "more general information could be useful in 
providing an accurate picture of the fishing method".769 Finally, we also note tha t in the "summary 
tables" presented by each party summarizing the evidence on the record regarding the overall 
relative risk profiles of different fishing methods in different areas of the ocean, very few data 
were available on the risks to dolphins relate d to gillnet fishing.770 In particular, we note that the 
table provided by Mexico only indicated evidence on harms to dolphins in one group of fisheries, 
namely the Indian Ocean Gillnet fisheries (indicating a total absolute mortality of 60,115  dolphins 
in 2009).771 Conversely, the table presented by the United States, which contains data on dolphin 
mortality and interaction on a per set basis, makes no reference to gillnet fisheries. In response to 
a request by the Panels, the United States provided a table on  the available per set data for tuna 
gillnet fisheries.772 The table presents information on one Australian (the " Northern Australia 
Gillnet Fishery ") and two US tuna gillnet fisheries (the California Drift and Set Gillnet Fisheries). 
Additionally, the table  includes estimates of per set mortalities for the gillnet fisheries in the Indian 
Ocean that were object of the determination procedure by NOAA.  
7.434.   As explained in Section 7.7.1.2.1.2  above, we will use per set data in determinin g risk 
profiles of different fishing methods. However, as we have just noted, the data on the record 
regarding gillnet fishing is partial in scope, and is not generally provided on a per set basis, except 
for limited the information provided by the United States, as indicated above. We therefore find it 
appropriate to base our assessment of gillnets risk profile on "more general information" on the 
record, in terms of measurement (per set or absolute) and the target species of the fisheries for 
which data o n gillnet is available (exclusively tuna fisheries or not).  
7.435.   We finally note that a considerable part  of the evidence adduced by the parties in the 
present proceedings regarding the risk profile of gillnet fishing has already been assessed by 
panels and the  Appellate Body in the previous segments of this dispute.773 In our assessment of 
the observable harms caused by gillnet fishing, therefore, we will first note the findings made in 
those previous proceedings. We will then assess the evidence submitted in the se proceedings to 
determine whether that evidence requires us to modify any of those previous findings.  
7.436.   With regard to observable harms , we recall that the extensive evidence on absolute levels 
of death to dolphins presented in the original proceedings774 led the original panel to consider that 
Mexico had sufficiently demonstrated that gillnet fisheries around the world were capable of 
harming dolphins, while remaining eligible to be labelled dolphin -safe.775 We further note that none 
of the evidence adduced du ring the first compliance proceedings changed that finding, and the first 
compliance panel thus also considered that Mexico had submitted "substantial evidence" showing 
that gillnets kill and seriously injure dolphins.776 
7.437.   On this, we note  that there seems to  be no contention among the parties that tuna gillnet 
fishing can and indeed does cause observable harms to dolphins. What the parties disagree on is 
the extent , frequency  and nature  of such harms.  
                                                
769 United States'  response to Panels' question  No. 94, para. 311 (internal citations omitted).  
770 See Table summar izing the data available regarding the relative overall risks of adverse effects on 
dolphins caused by different fishing methods in different ocean areas, (Exhibit MEX -95) ; and United States, 
Tables Summarizing Fishery -by-Fishery Evidence on the Record , (Exhibit USA -179 Rev.).  
771 Table summarizing the data available regarding the relative overall risks of adverse effects on 
dolphins caused by different fishing methods in different ocean areas, (Exhibit MEX -95), p. 2. We note that a 
second fishery seemed to include gillnets, namely the " Eastern North  Atlantic Trawl and  Gillnet ". However, 
upon analysis of the related evidence and considering the arguments presented by Mexico based on this 
Exhibit, it seems that the data in the report as it relates to dolphin b ycatch rates refer primarily to trawl 
fisheries. See Mexico's response to Panels' question  No. 65, para. 33 ; L. Mannocci et al., Assessing the Impact 
of Bycatch on Dolphin Populations: the Case of the Common Dolphin in the Eastern North Atlantic,  (Exhibit  
MEX-120), p. 2 (noting that "[i] n the eastern North  Atlantic, at least 1000 common dolphins (Delphinus 
delphis) are bycaught each year, particularly in pelagic pair -trawls "). 
772 See para. 7.419  above.  
773 See para s. 7.421 -7.430  above.  
774 Mostly reflected in Panel Report, US – Tuna II (Mexico),  para. 7.522 , fn. 737-739. See also para.  
7.425  above.  
775 Panel Report, US – Tuna II (Mex ico), para. 7.534.  
776 Panel Report, US – Tuna II  (Mexico)  (Article 21.5 - Mexico) , para. 7.130.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.438.   In the present proceedings, Mexico again has presented evi dence to demonstrate absolute 
levels of death to dolphins caused by gillnet fishing in different areas of the ocean.777 We note, in 
particular, several studies presented by Mexico, pointing to considerable risks to dolphins (and 
other marine mammals) of bein g bycaught and killed in gillnets, particularly by coastal driftnets, 
given that this technique indiscriminately affects marine life.778 Indeed, the evidence on the record 
suggests that gillnet fishing in several ocean areas has killed cetaceans arising to t he tens of 
thousands annually, potentially posing a risk to the sustainability of many cetacean stocks.779 We 
                                                
777 See Mexico's first written submission, paras. 69 -71. See also Mexico's closing statement, para. 5.  
778 See Kobe II Bycatch Workshop Background Paper , (Exhibit ME X-113), p. 2 ("It is generally accepted 
that, wherever gillnets are deployed, there is likely some degree of marine mammal bycatch… "). 
 See also World Wildlife Fund Pakistan and Australian Marine Mammal Centre, An Assessment of 
Cetacean Mortality in the Tu na Fisheries of Pakistan,  (Exhibit MEX -16), p. 10 ("It is an established fact that 
cetaceans are highly prone to the gillnet operation and die due to entanglement and suffocation. High mortality 
was reported by tuna gillnet operation but there [sic] freque ncy and quantification were not well known") .  
 See also L. Mannocci et al., Assessing the Impact of Bycatch on Dolphin Populations: the Case of the 
Common Dolphin in the Eastern North Atlantic,  (Exhibit MEX -120), p. 2 ("In the eastern North Atlantic (ENA) , 
short-beaked common dolphin (Delphinus delphis) has been reported as bycatch in several fisheries, including 
tuna driftnet fishery [2], pelagic pair -trawl fishery [3,4], gillnet fishery [5] and set gillnet fishery [6]") . 
 See also Young and Iudicello, Wo rldwide Bycatch of Cetaceans, US  Department of Commerce, NOAA 
Tech. Memo. NMFS -OPR-36 (July 2007) , (Exhibit MEX -21), p. 12 ("Fishing gear, especially gillnets, 
indiscriminately catches an undetermined number of marine species, including dolphins and porpoi ses"); p. 15 
("In the Atlantic Ocean, the major bycaught species and gear types in which this bycatch occurs are … 
humpback dolphins in West Africa, coastal gillnets; sperm whales, striped dolphins, and short -beaked common 
dolphins in the Mediterranean, pe lagic driftnets and gillnets; harbor porpoises in Black Sea, coastal gillnets; … 
dusky and Commerson 's dolphins in Argentina, coastal gillnets and midwater trawls and franciscanas in coastal 
gillnets"); p. 16 ("In the Pacific Ocean, the major bycaught spec ies and gear types in which this bycatch occurs 
are Risso 's dolphins in Sri Lanka, drift and set gillnets in combination with direct harpooning; bottlenose 
dolphins … south coast of Zanzibar (Tanzania), drift and bottom -set gillnets; Indo -Pacific humpback dolphins … 
south coast of Zanzibar (Tanzania), drift and bottom -set gillnets, Madagascar and East Africa, coastal gillnets; 
… Irrawaddy dolphins in … Bay of Bengal, heavy -mesh drift gillnets for elasmobranches;… Spinner dolphins and 
Fraser 's dolphins in th e Philippines, driftnets for large pelagics and flying fish, purse seines for small pelagics; 
... Hector 's dolphins, North Island (New Zealand), coastal gillnets; Dusky dolphin, Peru, drift gillnets"); p. 194 
("The French driftnet fishery for albacore in t he northeast Atlantic in the early 1990s caught between 420 –460 
dolphins, apparently both whitesided and striped dolphins … Common dolphins are frequently caught in coastal 
Portuguese fisheries: 47% of those reported were from gillnet fisheries. In 1996 an d 1998 respectively, the 
Irish driftnet fishery for albacore caught 356 and 2,522 common dolphins"); p. 198 ("[stripped dolphin] 
bycatch has been reported in coastal gillnet fisheries in Brazil … Spotted dolphins are incidentally captured in 
gillnets throu ghout much of its range off Brazil, Venezuela and Colombia -- particularly high bycatch occurs in 
coastal gillnets in southern Brazil. Common dolphins may be regularly caught in northeastern Venezuela and in 
coastal gillnets and driftnets in southern and so utheastern Brazil"); pp. 206 -207 ("Italian, Greek and Moroccan 
pelagic drift fishing vessels have high levels of incidental [striped dolphins] mortality. … Moroccan driftnet 
vessels kill more than 3,600 dolphins (striped and common, combined) in the Alborá n Sea per year… In 2000, 
the French thonaille drift net fishery killed 326 (180 -472) striped dolphins"); p. 254 ("In conclusion, during the 
1990s, the IWC estimated that more than 1,800 dusky dolphins died each year in coastal Peruvian fisheries. … 
Capture  rates were lower in 1995 -1998 when fishers were using fixed bottom -setting gillnets") (internal 
quotations omitted).  
779 See Natural Resources Defense Council, Net Loss: The Killing of Marine Mammals in Foreign 
Fisheries,  (Exhibit MEX -18), p. 9 ("For instan ce, it is possible that the vaquita, a unique species of porpoise 
found in the northern Gulf of California, has been reduced to far fewer than 250 individuals in the past century 
largely due to bycatch in gillnets"); p. 20  ("False killer whales are bycaugh t in gillnet, purse seine, trawl, and 
longline fisheries in tropical and temperate waters worldwide. US assessments of interactions between false 
killer whales and fisheries in Hawaiian waters show bycatch levels that consistently exceed the potential 
biological removal level for many of the region 's populations"); p.20 ("The problem of spinner dolphin 
interactions with Sri Lankan driftnets and set gillnets was identified as a priority in a 2005 paper authored by 
some of the world 's foremost cetacean expert s …Spinner dolphins often get entangled in seer fish and tuna 
driftnets off the west coast of India"); p. 22 ("Even after the hunt ended, the Black Sea [harbour porpoise] 
population continued to decline due to interactions with bottom -set gillnets, with in cidental mortality possibly in 
the thousands per year "); p. 29 ("In the 1980s, the estimated total bycatch for the squid driftnet fisheries of 
Japan, [Chinese Taipei] , and South Korea was estimated at 15,000 to 24,000 cetaceans per year… Sightings, 
boardin gs, and fishing vessel seizures indicate that driftnets are still a threat, although driftnet fishers have 
recently shifted from targeting salmon to mostly squid, tuna, and sharks"); p. 30 (" Japan' s inland gillnet 
fishery, along with the [Chinese Taipei] offshore and distant -water driftnet fisheries, have been implicated as 
problem fisheries for marine mammal bycatch  … Data on Chinese fisheries and bycatch are not publicly 
available, but China' s offshore and distant -water fisheries use gear known to interac t with cetaceans, mainly 
gillnets and trawls "); p. 32 ( "Bycatch from Sri Lankan and Indian tuna gillnet fisheries has been implicated as a 
critical threat to marine mammals. During a two -year period in the mid -1980s, Sri Lankan gillnet fisheries 
caught at least 8,000 cetaceans. An IWC workshop held in 1990 estimated that more than 40,000 marine 
mammals were killed annually in Sri Lankan artisanal gillnet fisheries … In India, as in many other regions of 
the world, gillnets are believed to present the most s ignificant bycatch threats for marine mammals. It is WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  further note that some of the evidence presented by the United States confirms that tuna gillnets 
and driftnets pose considerable risks to dolphins in different areas of the ocean.780 
7.439.   In particular, we note that despite the UN moratorium on large scale  high-seas driftnets 
that took effect in 1992781, the evidence on the record strongly suggests that driftnets continue to 
pose considerable risks to dolphin s and other cetaceans, mainly in inland and coastal waters, but 
also by means of IUU driftnet fishing.782 We note that several countries have reacted to the 
harmful consequences of driftnet fishing to marine life, including dolphins, by banning or 
restrictin g driftnet fishing, including in their domestic waters.783 Additionally, as pointed out by the 
                                                                                                                                                  
estimated that India' s coastal gillnet fisheries catch approximately 9,000 to 10,000 marine mammals each 
year"); p. 34 ("The Atlantic humpback dolphin (Sousa teuszii) is a species of particular concern. Endemic to the 
West African coast, the population is experiencing marked declines in abundance and is currently listed as 
Vulnerable by the IUCN. Bycatch from local small -scale gillnets represents the primary threat…"); p. 35 ("The 
Franciscana dolphin is c onsidered particularly vulnerable to coastal, mainly artisanal, gillnet fisheries operating 
out of Argentina, Brazil, and Uruguay … Reeves et al. estimated that around 2,900 individuals could be caught 
in coastal fisheries each year, while a 2009 study est imated bycatch mortality to range from 1,200 to 1,800 
per year. While the species ' abundance is unknown, researchers believe gillnet mortality is not sustainable in 
most areas") (internal citations omitted) . 
780 See Eric L. Gilman and Carl Gustaf Lundin, IUC N Global Marine Programme, Minimizing Bycatch of 
Sensitive Species Groups in Marine Capture Fisheries: Lessons from Tuna Fisheries , (Exhibit USA- 53), p. 3 
(noting on tuna fisheries that "[p]rominent bycatch issues include dolphins and porpoises in purse s eine 
fisheries and driftnets; fish discards in shrimp trawl fisheries; and seabird, sea turtle, marine mammal, and 
shark bycatch in longline, purse seine, gillnet and trawl fisheries") . 
  See also Al Kingston and Simon Northridge, Extension Trial of an Aco ustic Deterrent System to 
Minimise Dolphin and Porpoise Bycatch in Gill and Tangle Net Fisheries , (Exhibit USA-160), p. 3 ("It should be 
noted that when Council Regulation 812/2004 was drafted it was not clear that common dolphins were also 
bycaught in gil lnets to the extent to which we now know they are and it is not known whether the pingers 
described in the regulation are effective in minimising dolphin bycatch") . 
  See also Alison McCarthy et al., Pilot Observer Programme in Irish Pelagic Trawl and Gill net Fisheries: 
Implementing Council Regulation (EC) No 812/2004 , (Exhibit USA-163), p. 23 ("…10 harbour porpoises 
(Phocoena phocoena) and three common dolphins were observed bycaught in gillnet and tangle net fisheries in 
the UK in 2009, raising the total bycatch to the UK fleet level to 791 (CV 0.31) and 237 (CV 0.58), 
respectively") (internal citations omitted) . 
781 See United Nations General Assembly Res. 46/215, Large -Scale Pelagic Drift -net Fishing and Its 
Impact on the Living Marine Resources of the Wor ld's Oceans and Seas,  (Exhibit USA-66). 
782 See, e.g., Natural Resources Defense Council, Net Loss: The Killing of Marine Mammals in Foreign 
Fisheries , (Exhibit MEX -18), p. 29 ("In the 1980s, the estimated total bycatch for the squid driftnet fisheries of 
Japan, [Chinese Taipei] , and South Korea was estimated at 15,000 to 24,000 cetaceans per year. … The U.N. 
moratorium on high -seas driftnets that took effect in 1992 significantly reduced mortalities … And yet illegal 
drift-netting still occurs in the Norther n Pacific. Sightings, boardings, and fishing vessel seizures indicate that 
driftnets are still a threat, although driftnet fishers have recently shifted from targeting salmon to mostly squid, 
tuna, and sharks"); p. 22 ("Unlike in the Mediterranean, where I UU driftnetting is being slowly tackled to 
reduce marine mammal bycatch, illegal drift -netting continues unabated in the Black Sea "); p. 31 ("A large 
number of Dall 's porpoises were killed in the 1990s and 2000s in the exclusive economic zones of Russia an d 
Japan, despite the driftnet moratorium. Japanese salmon driftnet fisheries that operated in Russia' s exclusive  
economic zone had an estimated bycatch of more than 20,000 Dall 's porpoises from 1992 to 2008. Bycatch of 
the species continues in Russia, wher e several fisheries still use gillnets")  (internal citations omitted) .  
783 See Panel Report, US – Tuna II (Mexico), fn. 735 (quoting o riginal Panel Exhibit MEX -99, p. Ev 26) 
("The case of pelagic driftnets used in tuna and swordfish fisheries is an example of a highly destructive 
practice that has now been addressed by the EU in the form of the driftnet ban that came into effect in January 
2002") . 
 See also  Young and Iudicello, Worldwide Bycatch of Cetaceans, US  Department of Commerce, NOAA 
Tech. Memo. NMFS -OPR-36 (July 2007) , (Exhibit MEX -21), p. 207 (" The Italian drift net (spadare) fishery is 
estimated to have killed thousands of striped dolphins per year through the early 1990s … The Italian driftnet 
fishery in the Ligurian Sea has been banned since 1992, but illegal fishing may still contribute to striped 
dolphin fishery mortality in Italian waters") . 
 See also,  Natural Resources Defense Council, Net Loss: The Killing of Marine Mammals in Foreign 
Fisheries,  (Exhibit MEX -18), p. 19 ("In June 2013, the gover nment took another important step toward saving 
the vaquita by adopting modifications to shrimp fishing standards, calling for a three -year phaseout of drift 
gillnet shrimp gear, to be replaced by more selective equipment that would reduce the likelihood o f vaquita 
bycatch "). 
See also World Wildlife Fund Pakistan and Australian Marine Mammal Centre, An Assessment of 
Cetacean Mortality in the Tuna Fisheries of Pakistan,  (Exhibit MEX -16), p. 4 ("It is estimated that about 12,000 
dolphins are killed every year  in tuna gillnet operation. … Marked seasonality was observed in the enmeshment 
of dolphin with maximum mortality in November ... Considering exceptionally highly mortality of dolphins it is 
recommended to take appropriate management measures including ban  on new entry in tuna gillnet fishing, 
compliance to UNGA Resolutions restricting gillnet length to 2.5 Km, conversion of gillnetting fleet to longlining, 
declaration of marine protected areas (MPAs), establishment of a regular data base of turtle and ceta cean WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  United States784, several other measures were put in place in different fisheries to reduce the 
negative effects of gillnet and driftnet fishing on marine mammals, i ncluding dolphins.785 On this 
point, we note that the Appellate Body confirmed the original panel's finding that  while large scale 
drift gillnet fishing in the high seas was disallowed by the US measure, other types of driftnet 
fishing were not, notably, for  instance, driftnet fishing in domestic waters.786  
7.440.   Our assessment of the evidence submitted in the present proceedings does not, in our 
view, change the previous factual findings that gillnet fishing  causes considerable observable 
harms to dolphins in diffe rent areas of the ocean.787 In this regard, we note in particular the 
finding made by the original panel that some tuna gillnet fisheries, particularly driftnets used in 
coastal areas, are "highly destructive" and represent one of "the greatest threats to po pulations of 
small cetaceans" in certain areas of the world ".788 
7.441.   We also recall the high numbers of dolphin mortalities (rising to the tens of thousands) 
caused by large scale drift nets in the high seas during the 1980s and early 1990s that led to the 
1992 UN moratorium on the practice.789 Additionally, we note the significant numbers of dolphins 
mortalities in the Indian Ocean Mixed -Target Gillnet Fisheries  which led NOAA to determine that 
the mortalities in such fisheries would surpass, many times over, the ETP "regular and significant 
dolphin mortality or serious injury of dolphins"  standard.790 We find that this evidence 
demonstrates that gillnet fisheries, and driftnet fisheries in particular, have caused, in some 
circumstances and in certain regions, levels  of observable harms  greater than those caused by 
setting on dolphins in the ETP.  
                                                                                                                                                  
enmeshment and adherence to management measures suggested by tRFMO  (IOTC ) ... it may be kept in mind 
that a few tuna gillnet vessels sometime transship their catch to vessels from neighbouring country as well as 
retain themselves for later auction or dispose off their catch to other types of local vessels") . 
784 See United States' third written submission, para. 95.  
785 See e.g. Natural Resources Defense Council, Net Loss: The Killing of Marine Mammals in Foreign 
Fisheries,  (Exhibit MEX -18), p. 12 ("Take R eduction Plan requires the use of acoustic net alarms, called 
"pingers, " which are attached to gillnets in certain fisheries along the Atlantic Coast to reduce the incidence of 
harbour porpoise bycatch"); p. 22 ( "While mild acoustic deterrents called "pingers" have proved effective at 
reducing harbor porpoise bycatch, they are required in the Baltic Sea only on gillnet vessels more than 12 
meters long"); p. 26 ("Harbor Porpoise Take Reduction Plan. The plan applies to most sink gillnet fisheries from 
North  Carolina to Maine and includes both time and area closures where bycatch rates are high, as well as a 
mandate for the use of pingers on gillnets in certain areas. Following implementation of the plan, bycatch 
levels dropped in the Northeast sink gillnet f ishery and the mid -Atlantic gillnet fishery…  Since full 
implementation of the Take Reduction Plan, harbor porpoise bycatch has been below PRB in several years, with 
numbers as low as 73 porpoises by -caught per year. The Canadian government does not impose  any 
requirements to protect harbor porpoises") (internal citations omitted) . 
See also Alison McCarthy et al., Pilot Observer Programme in Irish Pelagic Trawl and Gillnet Fisheries: 
Implementing Council Regulation (EC) No 812/2004 , (Exhibit USA- 163), p. 4 6 ("NMFS scientists analyzed data 
from previous incidental take in the gillnet fisheries of concern for bottlenose dolphins and found that incidental 
take had occurred at a higher rate on the vessels that used nets with larger mesh openings. Because this t ype 
of gear would be restricted under the proposed regulations, NMFS had reason to believe that these gear 
restrictions would result in reduced incidental take of bottlenose dolphins") . 
 See also Young and Iudicello, Worldwide Bycatch of Cetaceans, US  Department of Commerce, NOAA 
Tech. Memo. NMFS -OPR-36 (July 2007) , (Exhibit MEX -21), p. 14 ("Solutions to the problem of cetacean 
entanglement have been sought in several parts of the world with a variety of techniques. No universal solution 
to the problem has been found, but in one or two cases some reduction in the numbers of cetaceans caught in 
gillnets has been accomplished through gear modifications (e.g., rigging driftnets to fish a few meters below 
the surface or increasing twine size) or technological ai ds (e.g., pingers). Because banning the use of gillnets 
worldwide is not an option and site -specific gear prohibitions are not always effective, approaches will have to 
be found on a fishery -by-fishery basis, and such solutions should consider socio -econom ic alternatives (e.g., 
eco-tourism opportunities)"); p. 252 ("Set net fishing poses a major threat to Maui 's dolphins. A significant 
number of Maui's dolphins have been caught and killed in gill nets since 1987 when the New Zealand 
Department of Conservati on began investigating dolphin deaths. In the early 2000s over a 20 month period, 
six Maui 's dolphins showed signs of having been entangled in nets. [Estimated Annual Mortality] No estimates 
of mortality are available, but New Zealand has banned set nettin g along part of the North Island west coast 
and the Manukau Harbor entrance").  
786 Appellate Body Report, US – Tuna II (Mexico) , para. 270. See also para. 7.426  above.  
787 Panel Report, US – Tuna II (Mexico),  para. 7.534.  
788 Panel R eport, US – Tuna II (Mexico),  para. 7.521.  
789 See United Nations General Assembly Res. 46/215, Large -Scale Pelagic Drift -net Fishing and Its 
Impact on the Living Marine Resources of the World's Oceans and Seas, (Exhibit USA -66). 
790 United States' second writ ten submission, paras. 169 -172. See also United States, Dolphin Bycatch 
Rate Due to Dolphin Sets in the ETP and Fisheries Where Per Set Data Are Unavailable , (Exhibit USA-133). WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.442.   That said, we also note the evidence provided by the United States indicating that there 
are gillnet fisheries in which dolphin interactions are rare791, and some in which no d olphin 
interactions are known to happen at all.792 We agree with the United States' argument that this 
evidence demonstrates that although tuna gillnet fishing can be highly destructive to dolphins in 
certain areas of the world, there are other areas where t his particular method does not cause such 
harms. This shows that, while gillnet fishing may be harmful to dolphins, it does not necessarily  
cause such harms in every area of the ocean.  
7.443.   We also note that the per set data on gillnet fishing, presented by the  United States in the 
current proceedings, indicates, per 1,000 sets, mortalities of around 19 in the Northern Australia 
Gillnet Fishery  (2000 -2003); 35.4 (2014) and 24.4 (2015) in the California Drift Gillnet Fishery ; 
and 4.6 (2010) and 0 (2011) in the California Set Gillnet Fishery .793 In our view, this data confirms 
our finding that gillnet fisheries can be particularly harmful to dolphins, but they are not 
necessarily so in all areas of the ocean. In this regard, we also note the examples of bycatch take 
reduction plans and technologies used in some gillnet fisheries.794 At a minimum, they confirm that 
gillnet fishing does not necessarily  cause high levels of observable harms to dolphins and that the 
observable harms that it causes could be reduced.  
7.444.   In sum, we conclude that gillnet fishing poses high levels of observable harms to dolphins 
in certain areas of the ocean, but does not pose the same harms in other areas.  
7.445.   With respect to unobservable harms , we start our assessment by noting that the evidence 
on th e nature of unobservable harms caused to dolphins by gillnet fishing was discussed 
extensively by the first compliance panel. In this regard, we find it important to note the first 
compliance panel's finding that none of the evidence showing that gillnets kill and seriously injure 
dolphins suggested that gillnets have "the same kind of unobservable effects as setting on 
dolphins".795 That panel also found that even if the evidence showed that gillnets may cause 
eventual strangulation of dolphins that manage t o break free from the net, such harms would 
seem clearly to be the kind of "serious injury" that is observable and that must, under the 
amended tuna measure, be certified.796 We also note that the first compliance panel's assessment 
of the evidence pertainin g to unobservable harms from gillnet fishing was upheld by the Appellate 
Body.797 
7.446.   With these previous findings in mind, we now turn to the evidence presented in the 
present proceedings regarding unobservable harms caused by gillnet fishing. In this regard, w e 
note that Mexico has presented two new arguments and certain new evidence pertaining to 
indirect harms to dolphins caused by gillnet fishing, namely, "ghost fishing" and stress stemming 
from dolphin interaction with the net.798 
7.447.   In support of its argument r egarding "ghost fishing", Mexico cites a 2015 report by NOAA, 
which reads in relevant parts:  
"Ghost fishing " is a part of the global marine debris issue that impacts marine 
organisms and the environment. Lost or discarded fishing gear that is no longer und er 
a fisherman 's control becomes known as derelict fishing gear (DFG), and it can 
continue to trap and kill fish, crustaceans, marine mammals, sea turtles, and seabirds. 
                                                
791 United States' second written submission, para. 57. See also United States' t hird written submission, 
para. 59.  
792 See e.g.  NMFS, Proposed Rule: List of Fisheries for 2017, 81 Fed. Reg. 54,019 (Aug ust 15, 2016) , 
(Exhibit USA -101). See also Alison McCarthy et al., Pilot Observer Programme in Irish Pelagic Trawl and Gillnet 
Fisheries:  Implementing Council Regulation (EC) No 812/2004 , (Exhibit USA - 163), p. 7 ("There was no 
cetacean incidental take observed during the programme. In addition, there were no cases of cetacean 
'dropout' from the nets. The chance of observers noticing cetace an bycatch was extremely high as observers 
were on deck at all times before, during and after hauling, with full view of the nets").  
793 United States'  response to Panels' question No. 4, para. 17. See also para. 7.419 above.  
794 See para. 7.439  above.  
795 Panel Report, US – Tuna II  (Mexico)  (Article 21.5 - Mexico) , para. 7.130. See also para. 7.428  
above.  
796 Panel Report, US – Tuna II  (Mexico)  (Article 21.5 - Mexico) , para. 7.130.  
797 Appellate Body Report, US – Tuna II  (Mexico)  (Article 21.5 – Mexico) , para. 7.200.  
798 Mexico's response to Panels' question No. 68,  paras. 47-49. See also Mexico's response to Panels' 
question No. 92, paras. 161-162. WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  The most common types of DFG to ghost fish are gillnets and crab pots/traps, with 
longlines and trawls less likely to do so.799 
7.448.   Having defined "ghost fishing" in this way, with respect to the harmful effects of ghost 
fishing linked to gillnet fishing, the report states that "ghost fishing by gillnets has an impact on a 
wide variety of marine life—from fish to sea birds and mammals to benthic organisms —with some 
of the greatest impacts on turtles".800 Regarding the specific harms to dolphins and other marine 
mammals, the report indicates that derelict gillnets can represent an important share of "reported 
entanglements" in some areas, but the absolute numbers of marine mammals involved are 
relatively small.801 These parts of the report thus suggest that ghost fishing linked to gillnets poses 
some risks to dolphins, although its extent is unclear.  
7.449.   The United States contends that " ghost fishing " does not relate to fishing  in its intrinsic 
sense (i.e. deliberate action of catching fish ), but rather to potential harms more akin to waste 
from a fish processing plant.802 To the extent that this argument mean s that the evidence 
presented by Mexico on "ghost fishing" is not relevant to our analysis, we disagree. As the 
evidence presented by Mexico shows, "gear loss" is part of fishing operations and is duly taken 
into account by fishermen, especially considerin g its economic impact.803 We are therefore of the 
view that the harms posed to dolphins by "ghost fishing" are relevant to our assessment of the risk 
profile of gillnet fishing.  
7.450.   However, we do not consider such harms to be "unobservable" given that they resu lt from 
interaction with the fishing gear. In this regard , the harms  caused by "ghost fishing"  are of the 
same nature as those  that flow from interactions with gillnets . These harms are  thus akin to the 
indirect harms to dolphins caused by gillnets assesse d by the panel during the first compliance 
proceedings (i.e. evidence of strangulation with parts of gillnets "even of dolphins that manage to 
break free from the net").804 We note, in particular, that the harms from "ghost fishing" might  
typically  not be observed given that the "interaction" with the gillnet will happen  because of the 
gear parts which break free and move away from the fishing vessel .805 This, however, does not 
change the observable nature of such harms.  Such harms are not the kind of unobserva ble harms 
caused by setting on dolphins and that "may be inflicted even in cases where no dolphin is caught 
in the net, or where any caught dolphin is released without apparent injury"806. 
7.451.    We now turn to the assessment of the evidence provided by Mexico per taining to alleged 
stress to dolphins caused by gillnet fishing. Mexico considers that there is sufficient evidence on 
the record pertaining to the s tress effects on marine mammals, including cetaceans, from being 
entangled in fishing nets to "raise a pres umption that  genuine concerns exist " that gillnet fishing 
                                                
799 U US National Oceanic and Atmospheric Administration, Impact of Ghost Fishing via Derelict Fishing 
Gear (March 2015) , (Exhibit MEX -104), p. 6.  
800 US National Oceanic and Atmospheric Administration, Impact of Ghost Fishing via Derelict Fishing 
Gear (March 20 15), (Exhibit MEX -104), p. 13.  
801 US National Oceanic and Atmospheric Administration, Impact of Ghost Fishing via Derelict Fishing 
Gear (March 2015) , (Exhibit MEX -104), p. 13 (noting that "approximately 25% of reported cetacean 
entanglements in Australia oc curred in derelict fishing nets. … Two Indo -Pacific humpback dolphins and three 
Australian snubfin dolphins, both "near threatened " species, were reported to have drowned in nets in the 
Australian Shark Control Program between 2008 and 2011. … There are st ill very few controlled experiments 
that focus specifically on determining gillnet ghost fishing mortalities and how long they can effectively still 
capture organisms once they become DFG. … In another DFG "hot spot " in Puget Sound, WA, a comprehensive 
analysis quantified the mortality of all marine organisms recovered from 870 derelict gillnets found and 
included (Good et al., 2010): 960 marine fishes (22 species); 509 marine birds (15 species); 23 marine 
mammals (4 species); 65 species of marine invertebr ates"). 
802 United States' comments on Mexico's response to Panels' question No. 68, para. 62.  
803 US National Oceanic and Atmospheric Administration, Impact of Ghost Fishing via Derelict Fishing 
Gear (March 2015) , (Exhibit MEX -104), p. 12 (summarizing gillnet  loss rates for several fisheries, varying from 
as low as 0.02% in the North Sea and North East Atlantic  to as high as 79% in the Caribbean).  
804 Panel Report, US – Tuna II  (Mexico)  (Article 21.5 - Mexico) , para. 7.130.  
805 We take note of the challenges that such harms to dolphins might pose for certification under the 
2016 Tuna Measure.  See Natural  Resources Defense Council, Net Loss: The Killing of Marine Mammals in 
Foreign Fisheries, (Exhibit MEX-18), p.24 ("To make matters worse, a great deal of bycatch is  simply never 
detected. For example, entanglements in nets that are not actively being used (known as "ghost nets ") are 
nearly impossible to evaluate, as is "cryptic " bycatch, which occurs when animals manage to escape 
entanglement from active or ghost net s but then die as a result of their injuries"). We note, however, that such 
challenges are not particular to any specific fishing gear and would also seem  to be relevant for other fishing 
methods, such as purse seine nets in the ETP.  
806 Panel Report, US – Tuna II  (Mexico)  (Article 21.5 - Mexico) , para.  7.134.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
- 137 - 
 
  (and other fishing methods)  cause unobservable adverse effects on dolphins .807 In support of its 
argument, Mexico presents a NOAA technical memorandum reporting on a "Serious Injury 
Workshop" held in 1997.808 Mexico's arguments on the stress effects on dolphins from being 
entangled in fishing nets are based on the report s of two distinct expert presentations made during 
the workshop. The first presentation covers the "immediate or short term consequences  of 
entanglement and release from entanglement" on marine mammals809, while the second one 
focuses on  the "chronic effects of entanglement and other stressors on cetaceans".810 
7.452.   The Panels first note that Mexico's arguments allege that entanglement causes stres s 
effects. We observe that the exhibit relied upon by Mexico is over twenty years old and, as noted 
above, is not a fully -researched and cited scientific study but the report of presentations given at a 
conference. This does not render this evidence irrele vant for our inquiry, but raises doubts about 
its probative value. We note, however, that our findings regarding the unobservable harms caused 
by setting on dolphins are supported by a series of scientific studies conducted and corroborated 
over two decade s. In respect of entanglement, however, the exhibit relied upon by Mexico is not 
corroborated by other, more recent studies, which may suggest that the concerns raised by the 
two presentations were either not pursued further or else were not ultimately con sidered to pose a 
real risk to dolphins.  
7.453.   Moreover, we are not convinced that the conference report establishes with any degree of 
certainty that entanglement can lead to unobservable stress effects. As a general matter, the 
information regarding stress eff ects on dolphins in Mexico's exhibit is general in nature and do es 
not allow us to identify the relative unobservable effects caused by  different fishing gears. 
Moreover, it is not clear whether the fisheries discussed in the reports were tuna fisheries. W e 
accept that  report s do suggest  that, in general , dolphins and other marine mammals may suffer 
from stress effects when entangled in fishing nets, including gillnets, that could lead to 
mortality.811 However, such effects are physically noticeable in some c ircumstances.812 Indeed, the 
evidence appears to suggest that in most and perhaps all cases, the stress suffered by dolphins led 
or contributed to observable mortality.813 
7.454.   Additionally, the report s suggest  that the particular species of dolphins studied may ha ve 
been "predisposed" to stress effects, which raises questions as to both the causal link between 
entanglement and stress effects, on the one hand, and the generalizability of this study to other 
dolphin species, on the other hand. We also note that the r eport indicates that dolphins may suffer 
after "exposure to chronic stress" and "long -term exposure  … to high levels of adrenaline".814 We 
understand this to mean that, even if entanglement is a stress factor for dolphins, dolphins do not 
suffer any harm as a result of being entangled once or even a few times. Rather, any serious 
                                                
807 Mexico's response to Panels' question  No. 68,  paras. 47-49. 
808 US Department of Commerce, Differentiating Serious and Non -Serious Injury of Marine Mammals 
Taken Incidental to Commercial Fishing Operati ons: Report of the Serious Injury Workshop 1 -2 April 1997,  
(Exhibit MEX -105). We note that the objective of the Workshop was to explore a "broad range of guidelines 
that could be used to determine which marine mammals entangled in fishing gear or injured i ncidental to 
fishing operations should be considered seriously injured as a result of the encounter". The  results of the 
workshop would be used by NMFS when developing proposed guidelines for what constitutes serious injury. 
See pp. 7 and 13.  
809 US Departme nt of Commerce, Differentiating Serious and Non -Serious Injury of Marine Mammals 
Taken Incidental to Commercial Fishing Operations: Report of the Serious Injury Workshop 1 -2 April 1997,  
(Exhibit MEX -105), pp. 20 -24. 
810 US Department of Commerce, Differentia ting Serious and Non -Serious Injury of Marine Mammals 
Taken Incidental to Commercial Fishing Operations: Report of the Serious Injury Workshop 1 -2 April 1997,  
(Exhibit MEX -105), pp. 26 -28. 
811 US Department of Commerce, Differentiating Serious and Non -Seriou s Injury of Marine Mammals 
Taken Incidental to Commercial Fishing Operations: Report of the Serious Injury Workshop 1 -2 April 1997,  
(Exhibit MEX -105), p. 10 ("Marine mammals may die from physiological responses to stressful events such as 
live strandings, chase, capture, or interaction with fishing gear"); p. 27 ("stress has been reported to be a 
factor leading to mortality in several species of cetacean caught in nets").  
812 US Department of Commerce, Differentiating Serious and Non -Serious Injury of Marine Mammals 
Taken Incidental to Commercial Fishing Operations: Report of the Serious Injury Workshop 1 -2 April 1997, 
(Exhibit MEX -105), p. 26 ("An early sign of eschemic injury is heart muscle fibers that appear wavy").  
813 US Department of Commerce, Differentia ting Serious and Non -Serious Injury of Marine Mammals 
Taken Incidental to Commercial Fishing Operations: Report of the Serious Injury Workshop, 1 -2 April 1997, 
Silver Spring, Maryland (January 1998) , (Exhibit MEX -105), p. 22.  
814 US Department of Commerce, D ifferentiating Serious and Non -Serious Injury of Marine Mammals 
Taken Incidental to Commercial Fishing Operations: Report of the Serious Injury Workshop, 1 -2 April 1997, 
Silver Spring, Maryland (January 1998), (Exhibit MEX -105), p. 26.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
- 138 - 
 
  stress effects arise as a result of "chronic" stress. We do not, however, have any evidence 
suggesting that dolphins are repeatedly entangled. This contrasts with the evidence on the  record 
that dolphins in the ETP are subject to numerous chases and encirclement every year.815 
7.455.   Finally, we note that the report repeatedly mentions that the severity of the stress effect 
varies from species to species of marine mammals (and even between dol phin species)816 and 
depends on the "age and general health/condition of the marine mammal and the type and 
duration of the stressors".817 We are thus not convinced that the evidence presented by Mexico 
suggests that such stress effects would occur in every in stance of interaction.  
7.456.   In sum, we find that the evidence submitted by Mexico is not sufficient to "raise a 
presumption"818 that gillnets (and other fishing gears) would cause the kinds of unobservable  
harms that ar e caused by setting on dolphins. In particul ar, we do not consider that the report 
submitted by Mexico, at least without further corroboration, is sufficient to raise a presumption 
that entanglement causes acute unobservable stress effects similar to those caused by setting on 
dolphins.  
7.457.   Accordingly,  on the basis of the evidence before us, we conclude that gillnet fishing can 
pose particularly high levels of observable harms to dolphins in certain areas of the ocean. We 
have also found , however,  that in some gillnet fisheries dolphin interactions are rare, while in 
others dolphin interactions  are not  known to happen at all.  In our view, the available per set data 
on the record confirms our finding that gillnet fisheries can be particularly harmful to dolphins, but 
are not necessarily so in all areas o f the ocean. Additionally, we have found that the evidence on 
the record pertaining to "ghost fishing " and stress stemming from dolphin interaction s with fishing 
nets does not support a finding that gillnet fishing causes the kinds of unobservable harms ca used 
by setting on dolphins.  
7.7.2.4   Longline fishing  
7.7.2.4.1   Introduction  
7.458.   We now turn to consider the evidence relating to longline fishing. The FA O explains that:  
Tuna longlining is a passive type of fishing technique making use of lines with baited 
hooks as fishing gea r. Midwater longlining allow catches of fish in midwater and near 
surface (while casting and retrieving). Midwater longlining for tuna … is now a widely 
used method for catching tunas in the depth range from the subsurface up to 300m … 
A typical set consis ts of 200 or more units or "baskets" connected together, with a 
buoy at each connection, and a total of about 3000 hooks. … [The hooks are] set over 
a total distance of about 100 km.819 
7.459.   According to Mexico, the association between dolphins and longline fishi ng is well -
established. Mexico argues that dolphins are attracted to fish on longlines820, and it is widely 
recognized that dolphins are severely harmed by this interaction (called "depredation") with 
longline hooks.821 In Mexico's view, longline fishing kills  tens of thousands of dolphins per year822 
and these mortalities are threatening the viability of dolphin stocks in some fisheries .823 
                                                
815 See Stephen B. Rei lly et al., Report of the Scientific Research Program Under the International 
Dolphin Conservation Program Act (2005) (Exh ibit USA-47), p . 26; Elizabeth Edwards, Fishery Effects on 
Dolphins Targeted by Tuna Purse -Seiners in the Eastern Tropical Pacific Oce an, 20 Int’l J. Comp. Psychology 
(2007) (Exh ibit USA-140), p. 218 . 
816 US Department of Commerce, Differentiating Serious and Non -Serious Injury of Marine Mammals 
Taken Incidental to Commercial Fishing Operations: Report of the Serious Injury Workshop 1 -2 April 1997,  
(Exhibit MEX -105), pp. 21 -24 and 27 -28. 
817 US Department of Commerce, Differentiating Serious and Non -Serious Injury of Marine Mammals 
Taken Incidental to Commercial Fishing Operations: Report of the Serious Injury Workshop 1 -2 April 1997,  
(Exhibi t MEX -105), pp. 10 -11.  
818 Panel Report, US – Tuna II (Mexico) , para. 7.737.  
819 FAO, Industrial Tuna Longlining , (Exhibit MEX -26), pp. 2 -3. 
820 Mexico's response to Panels' question No. 90, para. 159.  
821 Mexico's second written submission, para. 92.  
822 Mexico's  first written submission, para. 105.  
823 Mexico's second written submission, para. 71.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.460.   Mexico also argues that dolphins suffer serious injury as a result of interactions with 
longliners. According to Mexico, even  when dolphins do not immediately die from an interaction 
with a longline, they are at risk of becoming hooked on longlines824 and maiming their mouths, 
dorsal fins, and other body parts, as well as from eventual drowning when they cannot free 
themselves fro m the hooked lines.825 Moreover, Mexico maintains that longlining may cause 
unobservable harms because harms to dolphins from longlines can occur deep underwater or miles 
away from the vessel, where they cannot be seen even by an observer.826 Additionally, Mex ico 
argues that longlining, together with gillnets, is a source of "ghost fishing", where lost equipment 
adrift in the ocean can continue to kill dolphins and other sea life on their own827, as well as of 
stress caused by interactions with the net.828 
7.461.   Finally,  Mexico also notes that there are no comprehensive programs to monitor the harms 
caused to dolphins by longline fishing, and argues that data collection is further complicated by the 
fact that lines can be as long as 90 miles in length, which may impair th e ability of observers to 
see deaths and injuries as they are occurring.829 
7.462.   In the United States' view, longlining is significantly less dangerous to dolphins than 
setting on dolphins.830 The United States argues that the vast majority of longlining occurs wit hout 
any dolphin interaction, and thus puts no dolphins at risk of harm.831 Indeed, according to the 
United States, depredation is contrary to the economic interests of longline fishers because it 
removes or damages commercially valuable catch, and according ly longline fisherman actively 
avoid dolphin interaction.832 At any rate, in the United States' view, only a small fraction of 
depredation events result in the death of the depredating dolphin.833 Moreover, the United States 
argues that marine mammals are not dispersed uniformly and therefore do not interact with 
longline gear consistently across the ocean.834 
7.463.   With respect to observed mortalities, the United States considers that, on a per set basis, 
dolphin mortality levels in longline fisheries are small fracti ons of dolphin mortality due to dolphin 
sets in the ETP.835 The United States also argues that Mexico's evidence about the PBR levels of 
different fisheries are inapposite, because the number of dolphins killed or seriously injured by 
longlining is, on an an nual basis, a fraction of the number of dolphins killed in dolphin sets in the 
ETP.836 
7.464.   With respect to unobserved harms, the United States argues that there is no evidence in 
support of Mexico's view that injuries in longline fisheries can occur out of sight  of the observer.837 
According to the United States, a dolphin becoming hooked on a longline is exactly the type of 
direct, observable mortality that would render a set not dolphin safe.838 
7.465.   Finally, the United States argues that the first compliance panel alre ady found, and the 
Appellate Body accepted, that longlining does not cause the kinds of unobservable harms caused 
by setting on dolphins.839  
7.7.2.4.2   Panels' assessment in the present proceedings  
7.466.   The Panels  now turn to our assessment of the risk profile of longline fishing. We start by 
recalling the first compliance panel's finding that in those proceedings Mexico had presented 
"convincing evidence" that "longline fishing operations kill and maim dolphins". The first 
                                                
824 Mexico's response to Panels' question No. 116, para. 236.  
825 Mexico's first written submission, para. 103.  
826 Mexico's response to Panels' question No. 68, para. 43.  
827 Mexico's response to Panels' question No. 68, para. 44.  
828 Mexico's response to Panels' question No. 92, para. 162 . 
829 Mexico's first written submission, para. 95.  
830 United States' first written submission, para. 95.  
831 United States' second written submission,  para. 94.  
832 United States' second written submission, para. 96.  
833 United States' third written submission, para. 89.  
834 United States' second written submission, para. 99.  
835 United States' second written submission, para. 95.  
836 United States' second writte n submission, para. 98.  
837 United States' comments on Mexico's response to Panels' question No. 68, para. 62.  
838 United States' comments on Mexico's response to Panels' question No. 68, para. 62.  
839 United States' second written submission, para. 94.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  compliance panel further found that the evidence p resented by Mexico suggested that, at least in 
some fisheries, longlining was having a negative effect on the sustainability of dolphin 
populations.840 
7.467.   In the present proceedings, Mexico has once again presented a series of reports 
concerning the negative ef fects that longline fishing is causing to dolphins in different areas of the 
ocean.841 Among such reports, we note, in particular, a report published by the Sea Turtle 
Restoration Project on longline fishing estimating that over 18,000 dolphins are killed an nually by 
longline fishing in the Pacific Ocean.842 The report estimates the value of absolute annual mortality 
in the region by extrapolating bycatch information from the Hawaii longline fishery from 1994 to 
2002.  
7.468.   The United States does not seem to contest the fact that longline fishing is capable of 
causing such observable harms. However, the United States disputes that the evidence available 
on the record demonstrates that longline fishing causes observable harms at the same level as is 
caused by setting o n dolphins.843 According to the United States, the manner in which Mexico 
presented its evidence does not allow for an "apples -to-apples" comparison, given that it compares 
many different longline fisheries involving about 4,800 -6,300 active vessels to 80 -90 large purse 
seine vessels authorized to set on dolphins in the ETP.844 We find such argument compelling, 
particularly for the reasons we have already explained above.845 When the available bycatch data 
on the Hawaii longline fishery is assessed under the per set methodology, for instance, it reveals a 
relatively low rate of dolphin interactions (2.63 per 1000 sets from 2004 to 2015).846 
7.469.   In this regard , we note that the data in Exhibit US A-179 Rev. concerning dolphin mortalities 
in longline fisheries, which we re produce below, is as follows:847 
Fishery  YEAR  OBSERVE
D SETS  OBSERVED 
MORTALITY  OBSERVED 
INJURY/ 
RELEASED 
ALIVE  MORTALITY 
PER 1000 
SETS  MORTALITY OR 
INJURY/ 
RELEASED ALIVE 
PER 1000 
SETS848 
Hawaii 
Deep-set 
Longline  2009 3,520  1 13 0.28 3.98 
2010 3,580  0 9 0 2.51 
2011 3,540  1 5 0.28 1.69 
2012 3,659  0 5 0 1.37 
2013 3,830  4 7 1.04 2.87 
2014 3,831  0 13 0 3.39 
2015 3,728  2 8 0.54 2.68 
2016 (3 
quarters)  2,801  0 6 0 2.14 
Total 28,489  8 66 0.28 2.60 
American 
Samoa 
Longline  2009 306 0 0 0 0.00 
2010 798 0 0 0 0.00 
2011 1,257  0 10 0 7.96 
2012 662 0 0 0 0.00 
2013 585 1 1 1.71 3.42 
2014 565 0 1 0 1.77 
2015 504 1 1 1.98 3.97 
2016 (3 
quarters)  230 2 1 8.7 13.04  
Total 4,907  4 14 0.82 3.67 
 
                                                
840 Panel Report, US – Tuna II  (Mexico)  (Article 21.5 - Mexico) , para. 7.131.  
841 Mexico's first written submission, paras. 90 -105. 
842 Sea Turtle Restoration Project, Pillaging the Pacific, (Exhibit MEX -34). We note that the same report 
was presented and assessed by th e panel during the first compliance proceedings (Panel Report, US – Tuna II  
(Mexico)  (Article 21.5 - Mexico) , para. 7.132).  
843 United States' second written submission, para. 101.  
844 United States' second written submission, para. 99.  
845 See Section 7.7.1.2  above.  
846 Exhibit USA-179.Rev., p. 6.  
847 Exhibit USA-179.Rev. (with additional corrections and calculations by the Panels).  
848 We arrive at this figure by adding the number of "observed mortalities" and of "observed injuries / 
released alive", multiplying the sum by 1000 and dividing it by the total number of "observed sets".  WT/DS381/RW/USA • WT/DS381/RW 2 
 
- 141 - 
 
  Fishery  YEAR  OBSERV -
ED SETS  OBSERVED 
MORTALITY  OBSERVED 
INJURY/ 
RELEASED 
ALIVE  MORTALITY 
PER 1000 
SETS  MORTALITY OR 
INJURY/ 
RELEASED ALIVE 
PER 1000 
SETS849 
Atlantic 
HMS 
Pelagic 
Longline  2009 1,376  1 19 0.73 14.53  
2010 725 2 19 2.76 28.97  
2011 864 1 34 1.16 40.51  
2012 945 1 29 1.06 31.75  
2013 1,474  0 38 0.00 25.78  
2014 1,247  0 29 0.00 23.26  
Total 6,631  5 168 0.75 26.09  
Uruguay 
Atlantic 
Longline  2004 1,348  0 1 0 0.74 
2005 1,470  0 2 0 1.36 
2006 933 0 0 0 0 
2007 586 0 0 0 0 
Total 4,337  0 3 0 0.69 
Mediterra
nean 
Pelagic 
Longline  2000-
2009 2,587  8 49 (36 release 
alive, 13 
unknown 
status)  3.09 22.03  
Chinese 
Taipei  
Longline  2004-
2008 4,409  0 0 0 0 
EU 
Atlantic 
Longline  2006-
2007 635 2 3.15 - 
Chinese 
Taipei  
Atlantic 
Longline  2007 2,117 
(est.)  1 0.47 - 
 
Fishery  YEAR  OBSERVED SETS  OBSERVED 
CAPTURES  POSSIBLE MORTALITY PER 
1000 SETS  
Australia 
Eastern Tuna & 
Billfish Longline  2010 196 (est.)  3 15.31 (est.)  
2011 289 (est.)  2 6.92 (est.)  
2012 274 (est.)  0 0 (est.)  
2013 288 (est.)  2 6.94 (est.)  
2014 134 (est.)  1 7.46 (est.)  
2015 333 (est.)  0 0 (est.) 
Total 1,514 (est.)  8 5.28 (est.)  
Japan Longline  2014 1,369  6 (marine mammals)  4.38 
2015 1,740  11 (marine 
mammals)  6.32 
 
7.470.   From the available data on the record, it appears that the dolphin mortality rate per 1000 
sets in longline fisheries is consi stently low, with many years in different fisheries registering no 
known mortality or captures.850 Indeed, the highest available rate of possible dolphin mortalities 
associated with longline fisheries is 15.31 dolphins per 1000 sets in the Australia Eastern Tuna and 
Billfish Longline in 2010.  
7.471.   We also note that even when considering the total rate of interactions per 1000 sets, 
longline fishing does not appear to cause particularly high levels of observable harms to dolphins. 
Accordingly, when adding the data  available on the record for "observed injuries" to dolphins and 
"dolphins released alive" (non -deadly interactions) to the observed dolphin mortalities, the 
                                                
849 We arrive at this figure by adding the number of "observed mortalities" and of "observed injuries / 
released alive", multiplying the sum by 1000 and dividing  it by the total number of "observed sets".  
850 We further note that additional observer evidence on a non -per set basis available on the record 
demonstrates that dolphin bycatch in several longline fisheries is rare. The fisheries covered include: Tongan 
EEZ Longline in 2008 (no observed incidents); Western Tropical Pacific shallow -set and dee -set longline 
fisheries and the Western South Pacific Albacore fishery in 2010 (marine mammal interactions were "very 
low"); WCPFC Chinese Taipei longline from 2004 -2013 (observed cetacean mortality was from 0 to 2 animals 
per year) and in 2014 and 2015 (2 and 1 cetaceans caught, respectively); WCPFC longline fisheries of Korea in 
2014 and 2015 (0 dolphin mortality or injury), Australia in 2015 (1 dolphin mortality and 6  interactions) and 
Solomon Islands in 2015 (0 dolphin mortality or injury). See Exhibit USA-179.Rev.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
- 142 - 
 
  resulting rate of interaction per 1000 sets is in the majority of cases a fraction of the dolphin 
mortalities in the ETP. The highest rates are found in the US Atlantic HMS Pelagic Longline, where 
the rate of non -deadly interactions is substantially higher than the mortality rate. However, even 
in this case, the highest rates of interaction are 40.51 i n 2011 and 52.29 in 2005, figures 
significantly below the lowest mortality rates on the record for setting on dolphins in the ETP.851 
7.472.   Mexico argues that, in addition to this data, the Panels must take account of the fact that 
there is a "strong possibility t hat false killer whales, and possibly also other small cetacean 
species, are being shot by tuna longline fishermen within the Indian Ocean".852 Such reports are 
concerning, but Mexico has provided no evidence regarding  the extent  of such incidents. Moreover,  
given the generally low levels of dolphin interaction with longliners, we consider that, at least 
without more detailed evidence, we cannot conclude that shooting represents a very serious threat 
to dolphins in some or all longline fisheries.  
7.473.   Before concl uding our review of the observable harms caused by longlining in different 
areas of the ocean, we note that much of Mexico's argument regarding the observable harms to 
dolphins caused by longline fishing relates to its effects on the sustainability of some  dolphin 
stocks. In particular, Mexico presents data summarized in Exhibit MEX -95 pointing to three 
longline fisheries whose PBR for some dolphin species are close to their limits (Main Hawaii Island 
Insular Stock Longline fishery853 and West North Atlantic Longline854) or over the limits (Pelagic 
Hawaii Longline fishery855). We note that the low PBR values for these dolphin stocks are a result 
of the limited number of dolphins in the stocks affected by these longline fisheries. Consequently, 
even a few mortaliti es per year might affect their sustainability. However, worrisome though these 
low PBR levels may be for the population -level conservation of particular stocks, they are not in 
our view necessarily apposite for the purposes of determining the risk profiles  under the Tuna 
Measure, which, as already described, is mainly concerned with the risks facing dolphins at an 
individual  level, rather than at a population level. As we have explained above, the PBR level of a 
particular dolphin stock is not necessarily i ndicative of the number of dolphins killed by a particular 
fishing method in a particular area of the ocean. This is because, depending on the size of a 
particular dolphin stock, a stock may be sustainable even if a large number of individual dolphins 
are killed each year. Conversely, the sustainability of a small stock may be threatened if even a 
single dolphin is killed. The Tuna Measure, however, is concerned with the relative mortality and 
serious injury caused to individual dolphins by different fishin g methods in different areas of the 
ocean, concerning which PBR levels are not necessarily probative.  
7.474.   We also note that, as pointed out by Mexico, the United States is implementing other 
measures to protect these dolphins stocks.856 We do not consider that these additional measures, 
which are not part of the measure at issue in these proceedings, undermine our assessment that 
longlining causes relatively low levels of observable harms to dolphins. In our view, it would not be 
inherently inconsistent for the U nited States (or any other Member) to pursue a certain dolphin -
related policy through a given measure (e.g. discouraging fishing methods that cause dolphin 
mortality or serious injury by denying tuna caught in sets that harm dolphins access to a dolphin -
safe label), and to pursue another, complementary dolphin -related policy through another 
measure (e.g. a measure aimed at preserving dolphin stocks at a population level, without regard 
to mortality or serious injury of individual dolphins). Accordingly, we do not agree with Mexico that 
the United States' adoption of different measures concerned with dolphin populations  shows that 
                                                
851 See Exhibit USA-179.Rev., p. 6.  
852 Mexico's second written submission, para. 72.  
853 For which the average annual rate of mortalities and serious injuries t o false killer whales from 2009 
to 2013 is 83% of the PBR. See  Table summarizing the data available regarding the relative overall risks of 
adverse effects on dolphins caused by different fishing methods in different ocean areas , (Exhibit MEX -95), p. 
2. 
854 For which the average annual rate of mortalities and serious injuries to short finned pilot whales from 
2009 to 2013 is 93% of the PBR. See  Table summarizing the data available regarding the relative overall risks 
of adverse effects on dolphins caused by d ifferent fishing methods in different ocean areas , (Exhibit MEX -95), 
p. 3. 
855 For which the average annual rate of mortalities and serious injuries to false killer whales from 2009 
to 2013 is above the PBR. See  Table summarizing the data available regarding  the relative overall risks of 
adverse effects on dolphins caused by different fishing methods in different ocean areas , (Exhibit MEX -95), p. 
3. 
856 Mexico's second written submission, paras. 96 -98. See also Me xico's response to Panel s' question 
No. 67, para . 41. WT/DS381/RW/USA • WT/DS381/RW 2 
 
- 143 - 
 
  longlining must be considered highly dangerous under the scheme established by the Tuna 
Measure.  
7.475.   In sum, for the reasons given abo ve, we see no reason to deviate from the first 
compliance panel's finding that some longline fisheries are likely having a negative effect on the 
sustainability of some dolphin populations. Moreover, we accept the evidence that dolphins may 
suffer some obs ervable mortality and serious injury as a result of longlining in some fisheries. 
However, we note that some longline fisheries present no known risks of observable harms to 
dolphins,857 while in the ones that do present  some level of risk , such levels are, in general, 
relatively low. We also find that, on a per set basis, longline fishing presents a relatively low level 
of observable harms to dolphins.  
7.476.   We next turn to Mexico's arguments regarding the unobservable effects to dolphins arising 
from longline fis hing in different parts of the ocean. First, in Mexico's view, longlining may cause 
unobservable harms, because, harms to dolphins from longlines can occur deep underwater or 
miles away from the vessel, where they cannot be seen even by an observer.858 
7.477.   We no te that this argument by Mexico is not different in nature to its argument presented 
during the first compliance proceedings. During those proceedings, Mexico argued that even when 
dolphins do not "immediately die from an interaction with a longline", they  are at risk to suffer 
from other harms and eventual drowning when they "cannot free themselves from the lines".859 
The first compliance panel found that such harms flow from interactions that are themselves 
"observable" and are not the kind of unobservable harm that occurs as a result of setting on 
dolphins, and which cannot be certified because it leaves no observable evidence.860 
7.478.   We see nothing in the evidence presented by Mexico in the course of the present 
proceedings to deviate from this finding by the fi rst compliance panel. Accordingly, even if part of 
the harms to dolphins caused by longline fishing might not be observed  because the harm occurs 
"away from the vessel", these are nevertheless not the kind of unobservable harms caused by 
setting on dolphin s and that "may be inflicted even in cases where no dolphin is caught in the net, 
or where any caught dolphin is released without apparent injury". Rather, as the first compliance 
panel found, they are the kind of harms that "flow from mortalities or injur ies that are themselves 
observable, and whose occurrence renders non -dolphin -safe all tuna caught in the set or gear 
deployment in which the injury or mortality was sustained".861 
7.479.   Moreover, even accepting that dolphins may suffer unobserved harms as a result  of 
interactions away from the vessel, the evidence suggests to us that the risk of such harms is 
relatively small. This is because, based on the data on the record concerning observed 
interactions, dolphin interactions with longlines appear to be relative ly low, and thus the chance of 
unobserved harms is also likely to be relatively small. In this connection, we note that dolphin 
interactions may undermine the commercial viability of longlining, and thus longliners have 
developed techniques to avoid  such i nteractions.862 This, in our view, likely reduces the extent of 
dolphin interaction, and thus the risk of unobserved mortality or serious injury. Indeed, based on 
the number of observed interactions, it seems to us that even if a significant percent of inter acting 
dolphins suffered unobserved mortality or serious injury as a result of their interaction with 
longlines (and the evidence on the record does not suggest that that is the case), the low levels of 
recorded interaction indicates that the number of dol phins that may suffer unobserved mortality or 
serious injury would still be relatively low. Accordingly, we consider that the possibility of 
unobserved mortality or serious injury is real but likely to be relatively low.  
7.480.   We also note the arguments presente d by Mexico regarding unobservable harms caused by 
longline fishing in res pect of derelict fishing gear (ghost fishing ) and the stress of interaction with 
                                                
857 NMFS, Proposed Rule: List of Fisheries for 2017, 81 Fed. Reg. 54,019 (August 15, 2016), (Exhibit 
USA-101). 
858 Mexico's response to Panels' question No. 68, para. 43.  
859 Panel Report, US – Tuna II  (Mexico)  (Article 21.5 - Mexico) , paras. 7.131 -7.132.  
860 Panel Report, US – Tuna II  (Mexico) (Article 21.5 - Mexico) , para. 7.132.  
861 Panel Report, US – Tuna II  (Mexico)  (Article 21.5 - Mexico) , para. 7.134.  
862 Megan J. Peterson et al., Killer Whale (Orcinus orca) Depredation Effects on Catch Rates of Six 
Ground fish Species: Implications for Commercial Longline Fisheries in Alaska, 70 ICES J. of Marine Science 
1220 (2013) , (Exhibit USA -68), p. 1228.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  the net or hook.863 We note that the same arguments were raised by Mexico in respect of the 
"unobservab le" harms caused to dolphins by gillnet "ghost fishing" and by the interaction with 
gillnet fishing gear. We finally note that the evidence presented by Mexico to substantiate both 
arguments does not differentiate these harmful effects to dolphins arising from gillnet or longline 
fishing gears.864 Insofar as the nature of such effects is not different when caused by gillnet or 
longline fishing gears, we see no reason to modify our assessment of the evidence as it relates to 
longline fishing. In our view , therefore,  as was the case for gillnet fishing, the evidence on the 
record does not suggest that longline "ghost fishing" causes the kind of unobservable harms 
caused by setting on dolphins and that may be inflicted even in cases where no dolphin is caught 
in the net, or where any caught dolphin is released without apparent injury. Similarly, we do not 
consider the evidence on the record to be sufficient to raise a presumption that i nteraction with 
longline gear (depredation ) causes acute unobservable stress ef fects similar to those caused by 
setting on dolphins.  
7.481.   Accordingly, we find that while longlining does cause mortality and serious injury to 
dolphins, its risk profile in terms of observable harms is low. Additionally, we consider that the 
evidence does not  support a finding that longlining is capable of causing the kinds of unobservable 
harms caused by setting on dolphins.  
7.7.2.5   Trawl fishing  
7.7.2.5.1   Introduction  
7.482.   The Panels now turn to consider the risk profile associated with trawl fishing. According to 
the FAO:  
Trawlin g is the operation of towing a net to catch fish and/or shellfish. The trawls are 
towed either with bottom contact or in midwater. Different devices provid[e] the 
forces to keep the trawls open horizontally … The catch principle is filtering the water. 
The towing speed varies, according to the type of trawl and trawling, to the target 
species, etc., from  1 to 7 knots, the most common being 3 to 5.865 
7.483.   Mexico argues that trawl fishing is a highly destructive fishing method that kills dolphins in 
many types of f isheries.866 According to Mexico, trawl fishing has a very high risk profile, which is 
greater than that of setting on dolphins practiced under the regulations of the AIDCP.867 Moreover, 
Mexico recalls that the panels in both the original and the first complia nce proceedings found that 
dolphins are killed in trawl nets.868 
7.484.   The United States argues that trawling is less dangerous to dolphins than other fishing 
methods used to catch tuna.869 Further, according to the United States, the evidence establishes 
that trawl  fishing does not intentionally target dolphins, and there is no evidence suggesting that 
trawling is capable of causing the type of unobservable effects caused by dolphin sets that can 
occur in the absence of direct dolphin mortalities. The United States therefore contends that trawl 
fishing for tuna has a lower risk profile for dolphins than setting on dolphins in the ETP large purse 
seine fishery.870 
7.485.   We begin our analysis by recalling that the first compliance panel found that trawl fishing 
may cause morta lity and serious injury to dolphins. The panel did not, however, make specific 
findings about the extent of harms suffered by dolphins as a result of trawling. Moreover, the first 
compliance panel explicitly found that the evidence did not support a findin g that trawling causes 
                                                
863 Mexico's response to Panels' question No. 68, paras. 44 and 47. See also Mexico's response to 
Panels' question No . 92, para. 162.  
864 US National Oceanic and Atmospheric Administration, Impact of Ghost Fishing via Derelict Fishing 
Gear (March 2015) , (Exhibit MEX -104); US Department of Commerce, Differentiating Serious and Non -Serious 
Injury of Marine Mammals Taken Inci dental to Commercial Fishing Operations: Report of the Serious Injury 
Workshop 1 -2 April 1997 , (Exhibit MEX -105).  
865 FAO, Trawl Nets , (Exhibit MEX -37). 
866 Mexico's second written submission, para. 75.  
867 Mexico's response to Panels' question No. 65, para. 34.   
868 Mexico's first written submission, para. 107.  
869 United States' second written submission, para. 109.  
870 United States' third written submission, para. 103. WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  the kind of unobservable harms caused by setting on dolphins in the ETP.871 Additionally, we note 
that the original panel found that "[t] rawl fishing is another method that may be employed to 
harvest tuna, and that may also produce dol phin bycatch ".872 Like the first compliance panel, 
however, the original panel did not describe in detail the extent of dolphin bycatch caused by 
trawling. Additionally, the original panel did not find that trawling causes the kind of unobservable 
harms caus ed by setting on dolphins in the ETP.  
7.7.2.5.2   Panels' assessment in the present proceedings  
7.486.   We note that both parties recognize that trawling may harm dolphins. In the absence of 
detailed findings by the previous panels, however, it is necessary for us to review t he evidence to 
determine more precisely the risk profile of trawling.  
7.487.   We note that trawl fishing is used in a number of different oceans, and is often used in 
non-tuna fisheries. Indeed, evidence on the record suggests that due to its slow speed, trawling is 
not well -suited to catching tuna, and that therefore "tuna is very rarely a target catch of trawl 
fishing".873 Nevertheless, because it can be, and sometimes  is, used to catch tuna, it is necessary 
for us to carefully examine the impact that trawling for tuna may have on dolphins.  
7.488.   We note that the evidence generally shows that trawling can result in dolphin mortalities. 
On the whole, however, the risks do not appear to be particularly high. The FAO, for example, has 
observed that " bycatch rates of other sp ecies [i.e. other than that target fish]  are low ", although in 
the same document it recognized that "[o]n [a] few fishing ground[s] the incidental catch of 
dolphins and marine mammals create some problems".874 Similarly, an article entitled 
"Observations on incidental catch of cetaceans in three landing centres along the Indian coast" by 
K.S.S.M. Yousuf and others indicates that although "[e]ntanglement of cetaceans in … fishing 
gears such as trawls … has also been reported"875, "trawlers cause less mortality o f marine 
mammals compared to gillnetters and purse -seiners". According  to the article, this "could be 
explained by the disturbance caused by the trawling action at the bottom and at midwater warning 
cetaceans before they can get caught".876 
7.489.   The other exhibit s submitted by the parties show a somewhat mixed picture, which may 
reflect the fact that, as one scientific study puts it, "dolphin bycatch in pair -trawl fisheries is a 
sporadic event".877 Thus, evidence on the record suggests that in the Pilbara Trawl Fish ery878 in 
North -Western Australia, 500 bottlenose dolphins were killed between 2003 and 2012, with 12.6 
dolphin mortalities per 1000 trawls based on observer information.879 Similarly, the evidence 
suggests that in the Eastern North Atlantic, between 2003 and 2009, a mean of 189 dolphins per 
year were bycaught in trawl tuna fisheries.880 This figure elides the apparent yearly fluctuation in 
dolphin mortalities. For example, in 2006 and 2008 no dolphin bycatch was observed, whereas in 
2009, 904 dolphins were kille d. It is not possible to determine a per set equivalent for this figure, 
as Exhibit MEX -120 does not indicate the total number of sets carried out. Moreover, we observe 
that this data is taken from European, French, and British vessels, and accordingly it appears that 
the figures cover more than one fishery.  
                                                
871 Panel Report, US – Tuna II (Mexico)  (Article 21.5 – Mexico) , para. 7.132.  
872 Panel Report, US – Tuna II (Mexico) , para. 7.521.  
873 William Jacobson Witness Statement (May 26, 2014), (Exhibit USA -52), p. 3.  
874 FAO, Tuna Midwater Pair Trawling,  (Exhibit USA -162), p. 2.  
875 K.S.S.M. Yousuf, et al., Observations On Incidental Catch Of Cetaceans In Three Landi ng Centres 
Along The Indian Coast, Marine Biodiversity Records, Vol. 2 (2009) , (Exhibit MEX -17), p. 1.  
876 K.S.S.M. Yousuf, et al., Observations On Incidental Catch Of Cetaceans In Three Landing Centres 
Along The Indian Coast, Marine Biodiversity Records, Vo l. 2 (2009) , (Exhibit MEX -17), p. 4.  
877 L. Mannocci et al., Assessing the Impact of Bycatch on Dolphin Populations: the Case of the Common 
Dolphin in the Eastern North Atlantic, Plos One 7(2) e32615 (February 2012) , (Exhibit MEX -120), p. 8.  
878 S. Allen et al ., Patterns of Dolphin Bycatch in a North -Western Australian Trawl Fishery, PLOS ONE, 
Vol. 9, Issue 4 (April 2014) , (Exhibit MEX -72) does not indicate whether tuna is caught in this fishery.  
879 K.S.S.M. Yousuf, et al., Observations On Incidental Catch Of Ce taceans In Three Landing Centres 
Along The Indian Coast, Marine Biodiversity Records, Vol. 2 (2009) , (Exhibit MEX -72), p. 4. Skipper logbooks 
recorded lower bycatch rate of 6.5 dolphin mortalities per 1000 trawls . 
880 L. Mannocci et al., Assessing the Impact  of Bycatch on Dolphin Populations: the Case of the Common 
Dolphin in the Eastern North Atlantic, Plos One 7(2) e32615 (February 2012) , (Exhibit MEX -120), p. 5 (based 
on the data in Table 1, column "Oceanic stock", which represents the dolphins bycaught in  fisheries whose 
target species was tuna).  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.490.   It is possible to calculate a per set equivalent on the basis of Exhibit MEX -71, which 
contains a Greenpeace article on trawl fishing in the North Atlantic. This article states that 
"[o]bservers of pair  trawling in 2001 saw 53 dolphins killed in 116 hauls of the net ; with two Irish 
boats in 1999, 145 dolphins were killed in 313 hauls".881 We note, however, that the article, which 
is popular rather than scientific, does not identify the source of its data, and neither does it 
indicate whether these dolphins were killed in tuna fisheries. Moreover, and in our view 
importantly, it does not account for the evident fluctuations in dolphin bycatch (as evidenced, for 
example, in Exhibit MEX -120). In our view, thes e fluctuations are very important to understanding 
the risks caused to dolphins by trawling in different areas of the ocean, because focusing on one 
particularly harmful year without noting the general trends in other years could give a biased 
overall view  of the fishery. Accordingly, we do not consider this article to be very probative. 
Nevertheless, we note that these figures, taken at face value, would suggest a per set equivalent 
of approximately 450 dolphins  killed  per 1000 trawls.  
7.491.   The most detailed ev idence we have relates to trawl fishing in and around Ireland. We note 
that the original panel accepted  evidence showing that "an experimental fishery involving pair 
trawling for tuna , which was conducted by the Republic of Ireland in 1998 and 1999, during  which 
period it  recorded a total catch of 180 cetaceans".882 We also note, however, that more recent 
data from the Irish pelagic trawl fishery dating from 2010 -2011 and 2011 -2012, based on at least 
10% observer coverage of the fishery in 2010 -2011883 and 100 % coverage in 2011 -2012884, found 
that no dolphins were killed as a result of trawling for albacore tuna.885 We also observe that the 
report from the 2011 -2012 fishery states that "[c]ommon dolphins were reported bow -riding 
fishing vessels but not interacting w ith the fishery"886 and "[b]ottlenose dolphins were sighted in 
transit from the fishing grounds"887, suggesting that although there are dolphins in the vicinity of 
the fishery, they do not commonly interact with the fishing vessels. Indeed, the report itself 
concludes that " during the albacore tuna fishery … [cetacean] interactions  with fishing operations 
were negligible"888, and notes that "[c]onfirmed incidences of interactions with fishing vessels were 
restricted to either bow -riding or competing with the vess els for fish … however none of these 
interactions led to bycatch".889 
7.492.   Having said that, we also note that the report from the 2011 -2012 fishery states that the 
"[f]ailure to record cetacean bycatch during this study does not imply that it does not occur in 
these fisheries but may indicate that it is a catastrophic rather routine occurrence".890 Moreover, it 
                                                
881 Greenpeace International, Dolphins die in trawler nets, (Exhibit MEX -71). 
882 UK House of Commons Environment, Food and Rural Affairs Committee, Caught in the net: bycatch 
of dolphins and porpoises off the UK Coas t (21 January 2004) , (Exhibit MEX -121), p. 32; see also Panel Report, 
US – Tuna II (Mexico) , para. 7.521, fn. 734.  
883 Alison McCarthy et al., Pilot Observer Programme in Irish Pelagic Trawl and Gillnet Fisheries: 
Implementing Council Regulation (EC) No 812/ 2004 (2011) , (Exhibit USA -163), p. 1.  
884John Boyd et al., Report on the Pilot Observer Programme in Irish Pelagic Trawl Fisheries: 
Implementing Council Regulation (EC) No 812/2004 (2012) , (Exhibit USA -164), p. 7.  
885 Alison McCarthy et al., Pilot Observer Pro gramme in Irish Pelagic Trawl and Gillnet Fisheries: 
Implementing Council Regulation (EC) No 812/2004 (2011) , (Exhibits USA -163), pp. 8 -10 and John Boyd et 
al., "Report on the Pilot Observer Programme in Irish Pelagic Trawl Fisheries: Implementing Council Regulation 
(EC) No 812/2004 " (2012) , (USA-164), pp. 8 -9. 
886 Alison McCarthy et al., Pilot Observer Programme in Irish Pelagic Trawl and Gillnet Fisheries: 
Implementing Council Regulation (EC) No 812/2004 (2011) , (Exhibits USA -163), pp. 8 -10 and John Boyd et  
al., "Report on the Pilot Observer Programme in Irish Pelagic Trawl Fisheries: Implementing Council Regulation 
(EC) No 812/2004 " (2012) , (Exhibit USA -164), p. 16.  
887 Alison McCarthy et al., Pilot Observer Programme in Irish Pelagic Trawl and Gillnet Fisher ies: 
Implementing Council Regulation (EC) No 812/2004 (2011) , (Exhibits USA -163), pp. 8 -10 and John Boyd et 
al., "Report on the Pilot Observer Programme in Irish Pelagic Trawl Fisheries: Implementing Council Regulation 
(EC) No 812/2004 " (2012) , (Exhibit US A-164), p. 17.  
888 Alison McCarthy et al., Pilot Observer Programme in Irish Pelagic Trawl and Gillnet Fisheries: 
Implementing Council Regulation (EC) No 812/2004 (2011) , (Exhibits USA -163), pp. 8 -10 and John Boyd et 
al., "Report on the Pilot Observer Progra mme in Irish Pelagic Trawl Fisheries: Implementing Council Regulation 
(EC) No 812/2004 " (2012) , (Exhibit USA -164), p. 34.  
889 Alison McCarthy et al., Pilot Observer Programme in Irish Pelagic Trawl and Gillnet Fisheries: 
Implementing Council Regulation (EC) No 812/2004 (2011) , (Exhibits USA -163), pp. 8 -10 and John Boyd et 
al., Report on the Pilot Observer Programme in Irish Pelagic Trawl Fisheries: Implementing Council Regulation 
(EC) No 812/2004 " (2012) , (Exhibit USA -164), p. 34.  
890 Alison McCarthy et al., P ilot Observer Programme in Irish Pelagic Trawl and Gillnet Fisheries: 
Implementing Council Regulation (EC) No 812/2004 (2011) , (Exhibits USA -163), pp. 8 -10 and John Boyd et 
al., Report on the Pilot Observer Programme in Irish Pelagic Trawl Fisheries: Imple menting Council Regulation 
(EC) No 812/2004 (2012) , (Exhibit USA -164), p. 34.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  notes that "[t]he limited number of cetacean observations recorded on other fishing grounds may 
be in part be due to shorter day length and less favourable winter sea conditions".891 Also of note 
is the report's observation that there was an increase in cetacean stranding reports during 
January -March 2011 and January -March 2013, with 47% of dolphins reported stranded in 2011 
and 27% of dolphins reported strande d in 2013 showing "lesions consistent with fisheries 
bycatch".892 Nevertheless, the report ultimately considers that bycatch in this fishery seems to be 
"infrequent ".893 
7.493.   On the basis of the evidence before us, it appears that trawling has the potential to harm  
dolphins. Although much of the evidence on the record relates to non -tuna fisheries, we consider 
that this evidence, together with the evidence that does relate to tuna fisheries, show that 
dolphins may be killed as a result of tuna trawling. In our view,  the evidence suggests that 
observed mortalities are very low in some fisheries and moderate in others. It also suggests that 
there may be some unobserved mortality and serious injury resulting from trawling for tuna. 
However, given that the evidence sugge sts that interaction with dolphins is generally low, we do 
not consider that the extent of unobserved mortality or serious injury is likely to be very high.  
7.494.   In our view, the evidence establishes that trawling may pose some risk to dolphins. 
However, it app ears from the evidence to be a low -to-moderate risk fishing practice. First, the 
evidence makes clear that trawling can be, and in many instances actually is, carried on without 
interacting with dolphins. Dolphins are not an essential or an inherent part o f this fishing method. 
Second, the evidence relating to observed mortalities shows that, with some exceptions, mortality 
caused by trawling is generally low, especially when considered on a per set basis. The only exhibit 
suggesting a high per set mortalit y rate is the article by Greenpeace submitted by Mexico. 
However, as we explained above, we do not consider that exhibit to be very probative. Third, there 
is no evidence on the record of observed serious injury caused by trawling. Although the evidence 
suggests that trawling may cause some unobserved mortality and serious injury, we consider that 
this risk is probably not very  substantial , since tuna do not appear to routinely associate with 
dolphins. Finally, we note that none of the evidence suggests tha t trawling causes the kinds of 
unobservable harms caused by setting on dolphins.  
7.7.2.6   Tuna handlining  
7.7.2.6.1   Introduction  
7.495.   We now turn to the evidence concerning tuna handlining. The FAO defines this fishing 
method as follows:  
Tuna handline is a fishing gear composed o f a single vertical line with one barbed 
hook at the distal point. If several barbed hooks are used, branchlines are connected 
along the mainline at regular intervals. Specification of the gear varies according to 
the ideas and traditions of fishermen in d ifferent areas of the world. Most fishermen 
use nylon (polyamide) for their handlines. Line must be strong enough to hold the fish 
and withstand the combined force of its weight, swimming power and determination to 
escape. Handlines can be set and hauled e ither manually or by mechanized reel. It is 
operated by simply dropping the baited hook into the level of the sea where tuna are 
found abundant. Handliners generally use natural baits such as squid, chopped pieces 
of scad mackerel, hairtail and tuna .894 
                                                
891 Alison McCarthy et al., Pilot Observer Programme in Irish Pelagic Trawl and Gillnet Fisheries: 
Implementing Council Regulation (EC) No 812/2004 (2011) , (Exhibits USA -163), pp. 8-10 and John Boyd et 
al., Report on the Pilot Observer Programme in Irish Pelagic Trawl Fisheries: Implementing Council Regulation 
(EC) No 812/2004 (2012) , (Exhibit USA -164), p. 34.  
892 Alison McCarthy et al., Pilot Observer Programme in Irish Pelagic Trawl  and Gillnet Fisheries: 
Implementing Council Regulation (EC) No 812/2004 (2011) , (Exhibits USA -163), pp. 8 -10 and John Boyd et 
al., "Report on the Pilot Observer Programme in Irish Pelagic Trawl Fisheries: Implementing Council Regulation 
(EC) No 812/2004 " (2012) , (Exhibit USA -164), pp. 34 -35. 
893 Alison McCarthy et al., Pilot Observer Programme in Irish Pelagic Trawl and Gillnet Fisheries: 
Implementing Council Regulation (EC) No 812/2004 (2011) , (Exhibits USA -163), pp. 8 -10 and John Boyd et 
al., Report on the  Pilot Observer Programme in Irish Pelagic Trawl Fisheries: Implementing Council Regulation 
(EC) No 812/2004 (2012) , (Exhibit USA -164), p. 34.  
894 FAO, Tuna handlining , (Exhibit MEX -38). WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.7.2.6.2   Pane ls' assessment in the present proceedings  
7.496.   We observe that neither the original nor the first compliance panel made factual findings 
about the risk profile of handline fishing. Accordingly, we review the relevant evidence for the first 
time. 
7.497.   According to Me xico, tuna associate with dolphins in some areas of the Indian Ocean, and 
handline fishers target895 and "chase herds of dolphins to locate tuna".896 In Mexico's view, if the 
Panels were to accept that setting on dolphins is harmful because chasing dolphins in  and of itself 
causes dolphins to suffer unobservable harms, then handline fishing in association with dolphins 
must be "assumed" to have the same effects.897 
7.498.   The United States rejects Mexico's argument, and notes that Mexico does not assert that 
handline fi shing has a higher risk profile for dolphins than dolphin s ets, including under the AIDCP.  
The United States observes that  Mexico does not suggest that handlining cannot be carried out in 
a manner that is not dangerous to dolphins or that it causes levels of dolphin mortality comparable 
to that cau sed by dolphin sets in the ETP.  It also argues that  none of the exhibits submitted by 
Mexico suggest that tuna handlining is associated with dolphin b ycatch at all,  and that several of 
the exhibits suggest that it  is not .898 Accordingly, the United States asserts that Mexico's argument 
that handline fishing in the Indian Ocean is capable of causing the type of unobservable effects 
caused by dolphin sets in the ETP, due to a tuna -dolphin association similar to that in  the ETP that 
handline vessels exploit by chasing dolphins to catch tuna is "incorrect" and "unsupported".899 
7.499.   The Panels begin their assessment by noting that very little evidence concerning the extent 
of observable mortalities or serious injuries caused by handlining has been submitted by the 
parties. One report states that "[r]eports from Maldives and Sri Lanka have indicated that no 
dolphins are caught during [sic] this fishery",  although it also notes " two instances of dolphins 
taking baited hooks ", which  dolphins were, however, released alive. The same report concludes 
that "[t]he scale of this issue [i.e. dolphins taking baited hooks], and of possible post -release 
mortality or sublethal effects are unknown, but deserve study".900 On the basis of this limit ed 
evidence, it appears that dolphins are not known to suffer significant mortality or serious injury as 
a result of handline fishing. However, it appears that dolphins may occasionally hook themselves 
onto the baited hooks, and that the effects of handlin ing on dolphins may be worthy of further 
study. Nevertheless, the risk profile of handlining in terms of mortality and serious injury appears 
to be very low.  
7.500.   With respect to Mexico's argument that handlining should be "assumed"901 to cause 
unobservable harms  to dolphins because handliners target and chase dolphins, we first observe 
that the finding, made in previous stages of this dispute and reaffirmed above, that setting on 
dolphins is harmful to dolphins, was and is not based on an abstract assumption  about the effect 
of chasing dolphins, as Mexico seems to suggest.902 Rather, that finding is based on the evidence 
on the record showing that the particular nature of the chase and encirclement process inherent in 
the method of setting on dolphins has negative u nobservable effects on dolphins. Put another way, 
the finding in respect of setting on dolphins is based not merely on the fact that setting on 
dolphins involves chasing dolphins, but rather on the fact that studies have shown that the specific 
chase and e ncirclement process involved in setting on dolphins actually causes harmful 
unobservable effects. Thus, even if Mexico were correct that handliners chase dolphins, that fact 
on its own would not, in our view, be a sufficient basis for concluding that handl ining causes 
unobservable effects, in the absence of scientific or other studies showing that the chase engaged 
in by handliners actually does cause unobservable effects similar to those caused by setting on 
dolphins in the ETP large purse seine fishery.  
                                                
895 Mexico's second written submission, para. 78.  
896 Mexico's first writte n submission, para. 110.  
897 Mexico's first written submission, para. 111; second written submission, para. 78.  
898 United States' second written submission, para. 110.  
899 United States' second written submission, para. 111.  
900 R.C. Anderson , Cetaceans and Tuna Fisheries in the Western and Central Indian Ocean, IPNLF 
Technical Report 2, International Pole and Line Foundation (2014) , (Exhibit MEX -42), p. 70.  
901 Mexico's first written submission, para. 111.  
902 Mexico's second written submission, para. 78.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.501.   At any rate, in our view, the evidence does not establish that handliners do target and 
chase dolphins in a systematic way. Indeed, the definition of handlining cited above does not 
mention dolphins, indicating that there is no necessary or inherent relatio nship between the 
method of handlining and dolphins. It thus appears that, unlike setting on dolphins, handlining can 
be carried out without interacting with dolphins in any way.  
7.502.   For example, Exhibit MEX -39, which contains a report from 2009, entitled " Handline Large 
Yellowfin Tuna Fishery of the Maldives", observes that "[l]arge yellowfin schools are sighted by 
presence [of] dolphins and livebait is thrown to attract and maintain the school within reach of the 
boat. More than 90% of the schools are reporte d to be sighted by dolphins".903 However, the 
report does not suggest that the fishing boats "chase" the dolphins. To the contrary, the report 
indicates that once the tuna schools have been sighted, the handlines are baited and then " the line 
is paid out whi le the vessel steams slowly forward ".904 As we read it, this means that although the 
presence of dolphins alerts handliners to the presence of tuna schools, dolphins are not involved in 
or affected by the fishing effort itself, which relies on baited lines t o attract the tuna. Indeed, 
nothing in the report suggests that dolphins are themselves chased, encircled, or subject to any 
kind of interaction with the fishing vessels. The report itself makes no mention of dolphin mortality 
or serious injury, nor does i t mention the existence or risk of bycatch of any kind.  
7.503.   Similarly, Exhibit MEX -40, which contains another report on the Maldives yellowfin tuna 
fishery from 2013, notes that "[f] ishers look for dolphins and large yellowfin tuna asso ciated with 
the dolphin schools" in the Maldives905, but does not suggest that those dolphins are chased, 
encircled, or subject to any kind of interaction. Rather, it seems that dolphins are looked for as a 
marker of the presence of tuna schools, but that the fishing effort itself involves using "larger size 
bait" to lure " surface -dwelling larger individuals ".906 
7.504.   Exhibit MEX -41 contains an article by R.C. Anderson and A. Shann entitled "Association of 
Yellowfin Tuna and Dolphins in Maldivian Waters", published in IOTC Proceedings in 1 998. The 
article notes that association is "widespread" in Maldivian fisheries. However, it contains a number 
of statements that clearly demonstrate the difference between the tuna -dolphin association in the 
ETP and that in Maldivian waters. Thus, the repo rt observes that: "[m]ost Maldivian fishermen 
report that when schools of yellowfin and dolphins are associated, the dolphins follow the 
yellowfin, and not vice versa. Indeed, they refer to dolphin -associated yellowfin schools as koamas 
kuri ainu , i.e. sch ools in front of the dolphins", and notes that this is the opposite of the pattern 
observed in the ETP.907 The article notes that tuna -dolphin association in other fisheries has been 
reported but is rarer908, and concludes that "the association of dolphins and  yellowfin tuna appears 
to be more widespread and frequent in the Indian Ocean than was previously realised, although it 
appears to be less common than in the eastern tropical Pacific".909 
7.505.   Most importantly, the article nowhere suggests that dolphins are chas ed, encircled, or 
subject to any other kind of interaction with fishing vessels. To the contrary, it observes that 
"[d]olphins are not caught by Maldivian tuna fishermen ".910 As with the exhibits reviewed in the 
                                                
903 Marine Re search Center, Ministry of Fisheries and Agriculture, Republic of Maldives, Handline Large 
Yellowfin Tuna Fishery of the Maldives, IOTC -2009-WPTT -15 (Oct ober 2009) , (Exhibit MEX -39), p. 5.  
904 Marine Research Center, Ministry of Fisheries and Agriculture, Re public of Maldives, Handline Large 
Yellowfin Tuna Fishery of the Maldives, IOTC -2009-WPTT -15 (Oct ober 2009) , (Exhibit MEX -39), p. 5.  
905 Adam, Jauharee and Miller, Review of Yellowfin Tuna Fisheries in the Maldives, IOTC –2015–WPTT17 –
17 (8 Oct ober. 2015) , (Exhibit MEX -40), p. 6.  
906 Adam, Jauharee and Miller, Review of Yellowfin Tuna Fisheries in the Maldives, IOTC –2015–WPTT17 –
17 (8 Oct ober. 2015) , (Exhibit MEX -40), p. 2.  
907 Marine Research Center, Ministry of Fisheries and Agriculture, Republic of Maldives, Ass ociation of 
Yellowfin Tuna And Dolphins In Maldivian Waters, IOTC 1998 -ECT-22 (1998) , (Exhibit MEX -41), p. 157. See 
also R.C. Anderson, Cetaceans and Tuna Fisheries in the Western and Central Indian Ocean, IPNLF Technical 
Report 2, International Pole and L ine Foundation (2014) , (Exhibit USA -42), p. 70 (contrasting the behavior of 
tuna and dolphins in the Maldives with that in ETP). The video submitted by Mexico (and discussed in more 
detail below) also appears at one point to show dolphins swimming behind  a small fishing vessel.  
908 Marine Research Center, Ministry of Fisheries and Agriculture, Republic of Maldives, Association of 
Yellowfin Tuna And Dolphins In Maldivian Waters, IOTC 1998 -ECT-22 (1998) , (Exhibit MEX -41), p. 158. The 
article reports that some a ssociati on has been reported in the Savu  Sea in Indonesia and in the Western Indian 
Ocean.  
909 Marine Research Center, Ministry of Fisheries and Agriculture, Republic of Maldives, Association of 
Yellowfin Tuna And Dolphins In Maldivian Waters, IOTC 1998 -ECT-22 (1998) , (Exhibit MEX -41), p. 158.  
910 Marine Research Center, Ministry of Fisheries and Agriculture, Republic of Maldives, Association of 
Yellowfin Tuna And Dolphins In Maldivian Waters, IOTC 1998 -ECT-22 (1998) , (Exhibit MEX -41), p. 157.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  preceding paragraphs, the article in Exhibit M EX-41 suggests that " fishermen use the presence of 
dolphins to locate large  yellowfin schools", but it does not state that the fishing effort affects 
dolphins in any way. It seems that dolphins are used to help locate the fish, which are then caught 
using hooks with live bait.911 
7.506.   The same is true of the report Cetaceans and Tuna Fisheries in the Western and Central 
Indian Ocean by Dr Charles Anderson, contained in Exhibit MEX -42. It notes that handliners in the 
Maldives, Yemen, Sri Lanka and Oman "typically l ocate the large yellowfin tuna by the presence of 
the dolphins (and often seabirds too). The schools are typically fast moving, and the fishermen 
move ahead of the dolphin school to deploy their lines".912 Although this report notes two 
instances of dolphins  taking baited hooks, thus indicating the possibility of interaction, it does not 
suggest that dolphins are chased or encircled. Moreover, the fact that there are only two reported 
instances of dolphin interaction seems to confirm that, although handliners  may sight dolphins to 
help locate tuna schools, dolphins are not usually subject to any interaction with the fishing vessel 
during the fishing effort.  
7.507.   Finally, in support of its claim that handline fishing vessels chase dolphins, Mexico has 
submitted as e vidence a video, posted on the Internet by one Feriansyah Putra , that according to 
Mexico shows handline vessels chasing dolphins.913 The video is in a foreign language, and it is not 
clear exactly what the images are showing. They appear to show a small, tr aditional boat cruising 
at moderate speed. At one point, dolphins are seen in the middle distance swimming quickly and 
jumping out of the water. Subsequently, dolphins are seen in the near distance moving slowly. At 
another point, the video shows a traditi onal boat moving at moderate speed, with a dolphin 
swimming and jumping behind it. The video also shows the fishing effort itself, which appears to 
take place once the boat has stopped by baiting thin wire and pulling up tuna that bite. During the 
fishing effort, dolphins appear at rest in the middle -distance.  
7.508.   It is difficult for us to know precisely what the video is showing. We note that there is 
some text situated beneath the embedded video, but this does not appear to be a translation of 
the spoken narr ation. Of note, however, is the statement in the text that "[t]he position of best 
fishing is in front of [a] group of dolphins", again suggesting that dolphins are neither targeted nor 
chased.  
7.509.   Nevertheless, the content of the video appears to be consisten t with what the other 
exhibits on the record show, namely that in some fisheries, and particularly in the Maldives, the 
presence of dolphins indicates the presence of tuna schools. Thus, there may be dolphins nearby 
when handline fishing takes place. Howev er, as with the other evidence on the record, the video 
does not show dolphins being chased or otherwise interacted with. The dolphins in the video do 
not appear to come close to the fishing vessels, and neither do the vessels themselves seem to be 
moving in the direction of the dolphins. Rather, the video seems to show dolphins swimming some 
way away on the side of the vessel.  
7.510.   Moreover, even if the vessels in the video were chasing dolphins, the video shows that 
handlining takes place using very small, tr aditionally -shaped boats. There are no speed boats or 
helicopters. It is accordingly clear that the method of handlining is very different from the method 
of setting on dolphins.  
7.511.   Accordingly, we do not find support in the evidence for the suggestion that h andliners 
chase dolphins, and certainly not in a way that is similar to the chase and encirclement in the ETP. 
To the contrary, we find that dolphins do not appear to be an essential component of handlining, 
and that although handliners may sight dolphins to locate tuna populations, the dolphins 
themselves are not chased, encircled, or otherwise interfered with. None of the evidence supports 
the claim that handlining causes unobservable harms to dolphins. In conclusion, we find that there 
is no evidence of handlining causing observable mortalities to dolphins. There is some indication in 
the evidence that dolphins may occasionally become hooked on baited handlines, although this 
seems to be very uncommon. We have also found no support in the evidence for the  proposition 
                                                
911 Marine Research  Center, Ministry of Fisheries and Agriculture, Republic of Maldives, Association of 
Yellowfin Tuna And Dolphins In Maldivian Waters, IOTC 1998 -ECT-22 (1998) , (Exhibit MEX -41), p. 157.  
912 R.C. Anderson, Cetaceans and Tuna Fisheries in the Western and Centra l Indian Ocean, IPNLF 
Technical Report 2, International Pole and Line Foundation (2014) , (Exhibit USA -42), p. 70 . 
913 Mexico's second written submission, para. 76.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  that handlining causes unobservable harms similar to those caused by setting on dolphins. 
Therefore, in our view, the risk profile of handlining fishing is low.  
7.7.2.7   Pole and line fishing  
7.7.2.7.1   Introduction  
7.512.   We now consider the risk profile of pole and li ne fishing. The FAO defines pole and line 
fishing as follows:  
Fish are attracted by the bait. In small -scale professional or sport fisheries the pole is 
swung so to reach the line, a moulinet has to be used when the line is much longer than 
the pole; the s mall fish is, then, taken from the hook by hand. On board tuna pole and 
lines vessels, the hooked fish tuna are swung on board, by hands (by two to three 
fishermen if the tuna is very big) or with an automatic swinging system; the tuna 
normally release the mselves from the barbless hook when they touch the deck of the 
vessel.914 
7.513.   We observe that, in the first compliance proceedings, both parties accepted that pole -and-
line fishing causes no risks to dolphins.915 Moreover, in these proceedings, the safety of pole -and-
line fishing has not been contested by either party. According to the United States, pole and line 
fishing is not associated with harm to dolphins, either observable or unobservable, and poses a 
much lower level or risk to dolphins than dolphin sets.916 Mexico also accepts that pole and line 
fishing is "relatively safe for dolphins".917 
7.7.2.7.2   Panels' assessment in the present proceedings  
7.514.   There is little evidence on the record concerning pole and line fishing, and it confirms that 
pole and line fishing has a very low risk profile. Thus, a report by  Eric L. Gilman and 
Carl Gustaf  Lundin entitled " Minimizing Bycatch of Sensitive Species  Groups in Marine Capture 
Fisheries: Lessons from Tuna Fisheries " finds that "[t] here are  extremely low bycatch levels in 
pole-and-line fisheries", and what bycatch there is, is composed of non -target fish rather than 
dolphins. Similarly, Exhibit MEX -42, which we discussed above in the context of handline fishing, 
states that "[p] ole-and-line fishing is not known to have any direct impa ct on cetaceans. Tuna are  
caught individually, one by one, and fishermen can clearly see what they are catching ".918 The 
same report notes that while dolphins sometimes approach pole -and-line vessels at night, this is in 
order to feed, and has no negative im pact on the dolphins themselves.919 
7.515.   It is clear from the evidence that pole and line vessels do not intentionally interact with 
dolphins, and that pole and line fishing can be carried out without any dolphins in the vicinity. Pole 
and line fishing appears ha rdly to interact with dolphins, except when the dolphins themselves 
approach vessels at night searching for food. There is no report of any dolphins being killed or 
seriously injured as a result of pole and line fishing. There is naturally also no evidence  about any 
unobservable harm that this method causes to dolphins.  
7.516.   Accordingly, on the basis of the evidence before us, we find that pole and line fishing poses 
no risk of observable or unobservable harms to dolphins. The risk profile of the fishery is 
accordingly very low.  
                                                
914 FAO, Pole and Line , (Exhibit MEX -111).  
915 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.185, fn. 366 (noting that "[b]oth 
parties accept that dolphins are at some risk from all tuna fishing methods  and in all fisheries " "[e]xcept for 
pole-and-line fishing" (emphasis in original).  
916 United States' second written submission, p ara. 104.  
917 Mexico's response to Panels' question No. 89, para. 155. We note that in other parts of its 
submission, Mexico seems to accept that pole and line fishing is safe for dolphins, without qualification. See 
e.g. Mexico's response to Panels' questio ns Nos. 111, para. 222 and 116, para. 234.  
918 R.C. Anderson, Cetaceans and Tuna Fisheries in the Western and Central Indian Ocean, IPNLF 
Technical Report 2, International Pole and Line Foundation (2014) , (Exhibit MEX -42), p. 71.  
919 R.C. Anderson, Cetaceans a nd Tuna Fisheries in the Western and Central Indian Ocean, IPNLF 
Technical Report 2, International Pole and Line Foundation (2014) , (Exhibit MEX -42), p. 71.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.7.2.8   Overall relative assessment of the method -specific findings  
7.517.   Above, we have made findings about the risk profiles of individual fishing methods as used 
in different areas of the ocean. Specifically, we have considered the evidence on the r ecord in 
respect of setting on dolphins, purse seine fishing without setting on dolphins, gillnet fishing, trawl, 
longline fishing, pole and line, and handline fishing. In assessing the risk profiles, we have taken 
into account both observable and unobserv able harms caused by each of these fishing methods in 
different parts of the ocean. In this last section of our factual findings, we provide a comparative 
assessment of method -specific findings. We recall that the issue before us is whether the 2016 
Tuna M easure, under which tuna products obtained from tuna caught by setting on dolphins are  
ineligible for the dolphin -safe label whereas tuna products obtained from tuna caught by the other 
six methods cited above are conditionally eligible for that label, is calibrated to different levels of 
risks posed to dolphins by different fishing methods in different areas of the ocean. Therefore, in 
providing a comparative assessment of the risk profiles of the seven methods analysed in these 
Reports, we will compare th e method of setting on dolphins to each of the other six methods.  
7.518.   In the preceding sections of these Reports, we have found that setting on dolphins causes 
both observable and unobservable harms to dolphins. The unobservable harms are caused by the 
chase a nd encirclement process itself, and include cow-calf separation; potential muscle injury 
resulting from the chase; immune and reproductive systems failures; and other adverse health 
consequences for dolphins, such as continuous acute stress.  We have also f ound that none of the 
other fishing methods causes to dolphins the kind of unobservable harms that setting on dolphins 
causes. Thus, as far as unobservable harms are concerned, setting on dolphins stands out in that 
it is the only method that causes such h arms.  
7.519.   With regard to observable harms, we have found that setting on dolphins in the ETP has 
caused on average 91.15 dolphin mortalities between 2009 and 2015. This method also causes 
serious injuries to dolphins, albeit to a lesser extent compared to mort alities. The record evidence 
shows that setting on dolphins in the ETP has caused serious injuries to 72 dolphins in 2009, 57 in 
2010, 36 in 2011, 13 in 2012, and 27 in 2013. The evidence before us also suggests that it is 
likely that the number of dolphin s killed or seriously injured by setting on dolphins in the ETP is 
higher than the mentioned figures.  
7.520.   We have found that gillnet fishing poses high levels of observable harms to dolphins in 
certain areas of the ocean, but does not pose the same harms in ot her areas. Specifically, we have 
found that driftnets killed tens of thousands of dolphins on the high seas during the 1980s and 
1990s that led to the 1992 UN moratorium on this particular method  in the high seas . We have 
also found, however, that per set figures on dolphin mortalities caused in other gillnet fisheries 
have been 19 in the Northern Australia Gillnet Fishery  (2000 -2003); 35.4 (2014) and 24.4 (2015) 
in the California Drift Gillnet Fishery ; and 4.6 (2010) and 0 (2011) in the California Set Gill net 
Fishery . We therefore note that, while significant, the observable harms caused by gillnet fishing 
remained clearly below those caused by setting on dolphins in the ETP.  
7.521.   With regard to trawl fishing, we have found that, as far as observable harms to do lphins 
are concerned, this is a low -to-moderate risk fishing method because it entails very little, if any, 
interaction with dolphins, and therefore causes a low level of dolphin bycatch. Specifically, the 
evidence on the record shows, for instance, that i n North -Western Australia, on average 12.6 
dolphins per 1000 sets were killed by trawlers. We have also found that the risk of unobserved 
mortality or serious injury is likely to be very low. Thus, it is clear that trawling poses a much 
smaller level of ri sk of observable harms to dolphins, compared to setting on dolphins in the ETP.  
7.522.   Regarding purse seine fishing without setting on dolphins, we have found that dolphin 
mortalities caused by purse seine fishing without setting on dolphins in the ETP was on av erage 
below 0. 2 per 1,000 s ets in the 2009 -2014 period, excluding a peak in 2011 where 10 mortalities 
were reported in 12,103  sets (corresponding to 0.83 mortality per 1,000 sets). We have also found 
that the number of serious injuries caused by purse sein e fishing without setting on dolphins in the 
ETP has been zero in the 2009 -2014 period. In the WCPO, the per set mortalities of dolphins as a 
consequence of purse seine fishing without setting on dolphins was 2.64, 1.2 and 2.2 per 1,000 
sets in 2010, 2014 and 2015, respectively. In the period 2007 -2009, the average level was 27.12 
mortalities per 1,000 sets. In the Indian Ocean, one study shows an average of 0.33 dolphin 
mortality per 1,000 sets as well as a total of 37 dolphins released alive in the 1995 -2011 period, 
whereas another study shows no dolphin mortality in the 2003 -2009 period. In the Eastern WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  Tropical Atlantic Ocean, the average level of mortalities has been close to zero, and that of serious 
injuries has been similarly very low. Additionally, w e have found that the risk of unobserved 
mortality or serious injury is likely to be low. Thus, it is clear that the level of observed harms 
caused by purse seine fishing without setting on dolphins is very low compared to setting on 
dolphins in the ETP.  
7.523.   Regarding longline fishing, we have found that the rate of dolphin mortalities caused by 
this method has been consistently low, with many years in different fisheries registering no known 
mortality or captures of dolphins. The highest available rate of possible dolphin mortalities 
associated with longline fisheries has been 15.31 dolphins per 1000 sets in the Australia Eastern 
Tuna and Billfish Longline in 2010. Moreover, we have found that the risk of unobserved mortality 
or serious injury is likely to be l ow. Therefore, this method causes much less observable harm to 
dolphins, compared to setting on dolphins in the ETP.  
7.524.   Regarding handlining and pole and line fishing, we have found that the limited amount of 
evidence on the record shows that these two method s generally do not interact with dolphins, and 
therefore do not cause significant, if any, observable harms to dolphins. They therefore cause 
much less observable harm to dolphins, compared to setting on dolphins in the ETP.  
7.525.   In sum, given that none of the six methods we have assessed causes the kinds of 
unobservable harms to dolphins that setting on dolphins causes, and considering the important 
differences between setting on dolphins and each of the other six methods with respect to 
observable harms to dol phins, we conclude that, overall, the risk profile of setting on dolphins is 
much higher than that of each of the other six fishing methods used to catch tuna.  
7.8  Whether the 2016 Tuna Measure is consistent with Article 2.1 of the TBT Agreement  
7.8.1   Introduction  
7.526.   In the preceding sections of these Reports, we (a) described the 2016 Tuna Measure; (b) 
set out our understanding of the applicable legal standard; (c) found that (i) the 2016 Tuna 
Measure is a technical regulation within the meaning of Annex 1.1 to the TBT  Agreement, (ii) 
Mexican tuna products and tuna products from the United States and other countries are "like", 
and (iii) the 2016 Tuna Measure has a detrimental impact on Mexican tuna products vis-à-vis tuna 
products from the United States and other count ries; and (d) conducted an assessment of the 
relative risks posed to dolphins by the use of different fishing methods in different areas of the 
ocean.920 In this section, we assess whether the 2016 Tuna Measure brings the United States into 
compliance with t he WTO Agreement. In particular, we assess whether the 2016 Tuna Measure is 
"calibrated" to the risks to dolphins arising from the use of different fishing methods in different 
areas of the ocean, such that the detrimental impact caused by the 2016 Tuna Me asure can be 
said to stem exclusively from a legitimate regulatory distinction and therefore not to accord 
treatment less favourable within the meaning of Article 2.1 of the TBT Agreement.  
7.527.   We recall that in the first compliance proceedings, the Appellate B ody criticized the 
compliance panel for conducting a "segmented" analysis of the different elements of the measure 
by making "discrete findings" on each element without reaching "a finding of consistency or 
inconsistency of the … measure more broadly, or a s a whole".921 The Appellate Body emphasized 
that analysing a measure in a segmented manner may raise concerns when the constituent parts 
of the measure are interrelated and operate in an integrated way922, because in that context a 
segmented approach may resu lt in panel failing  "to make an overall assessment that synthesizes 
its reasoning or intermediate conclusions concerning related elements of a measure at issue so as 
to reach a proper finding of consistency or inconsistency in respect of that measure ".923 In the 
specific context of the 2013 Tuna Measure, the Appellate Body explained that "there are various 
'connections' between the different elements of" the Tuna Measure924, and emphasized that the 
substantive conditions for gaining access to the dolphin -safe l abel can not be properly understood 
                                                
920 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.155.  
921 Appellate Bo dy Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.12. 
922 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.13. 
923 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.15. 
924 Appellate Body R eport, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.14. WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  without reference to the certification and tracking and verification requirements that define, and 
demonstrate compliance with, those very conditions .925 The Appellate Body also stated that:  
[T]he d etrimental impact resulti ng from the amended tuna measure cannot properly 
be examined through isolated analyses of the detrimental impact associated with 
discrete sets of requirements under that measure. Since all of the conditions for 
access to the dolphin -safe label may bear on such detrimental impact926, a proper 
assessment of the detrimental impact of the amended tuna measure on Mexican tuna 
products calls for an examination of the manner in which the different labelling 
conditions under the measure operate together in a way that  affects the conditions of 
competition for Mexican tuna products in the US market.927 
7.528.   In the light of these considerations, the Appellate Body found that the compliance panel 
had committed legal error928 by conducting:  
[A] segmented analysis that isolated cons ideration of each element of the measure 
without accounting for the manner in which the elements are interrelated, and without 
aggregating or synthesizing its analyses or findings relating to those elements before 
reaching its ultimate conclusions as to th e consistency or inconsistency of the 
amended tuna measure .929 
7.529.   However, the Appellate Body also recognized that it is not necessarily inappropriate for a 
panel, in analysing the conformity of a measure with obligations under the WTO covered 
agreements, to pr oceed by assessing different elements of the measure in a sequential manner. 
Indeed,  according to the Appellate Body,  such an approach may, depending on the nature of the 
measure at issue, be useful, or in some instances critical, to understanding how that  measure is 
designed and applied .930 In our view, the question whether the detrimental impact caused by the 
2016 Tuna Measure stems exclusively from a legitimate regulatory distinction can be answered by 
looking first at whether each of the elements of the m easure is calibrated to the risks to dolphins 
arising from the use of different fishing methods in different areas of the ocean, and then 
synthesizing our intermediate analyses to reach an overall, holistic conclusion about the WTO -
consistency of the Measu re. We note that this is also how the parties themselves have presented 
their arguments.931  
7.530.   Accordingly, in the remainder of this section, we will examine whether (a) the eligibility 
criteria, (b) the certification requirements, (c) the tracking and verific ation requirements, and (d) 
the determination provisions are calibrated to the difference in the overall risks to dolphins arising 
from the use of different fishing methods in different areas of the ocean. In considering whether 
each of these elements is c alibrated, we will not undertake an "isolated consideration of each 
element".932 Rather, where appropriate, we will pay close attention to the ways in which each of 
these elements "interrelate with each other".933 In particular, as we explain in detail below, we 
consider that the determination provisions work together with and reinforce  the certification and 
tracking and verification requirements, and our consideration of the certification and tracking and 
verification requirements necessarily includes consider ation of the determination provisions. After 
concluding these intermediate analyses, we will proceed to consider how they relate to one 
another.934 Finally, we will synthesize our analysis in order to reach an ultimate conclusion as to 
the consistency of the  2016 Tuna Measure with the WTO Agreement.935 
                                                
925 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.17. 
926 As the panel itself recognized, the US dolphin -safe labelling regime necessarily includes not only the 
"substantive … requirement[s]", but also the various certification and tracking and verification requirements 
constituting the mechanisms by which compliance with those substantive requirements is "monitored and 
demonstrated". (Panel Report, fn . 125 to para . 7.37)  
927 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.63. 
928 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.76. 
929 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.21. 
930 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.14. 
931 See e.g. United States' first written submission, paras. 71 -186; Mexico's first written submission, 
paras. 226-301. 
932 Appellate Body Report, US – Tuna II (Mexico) (Ar ticle 21.5 – Mexico) , para. 7.21. 
933 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.19. 
934 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.20. 
935 Appellate Body Report, US – Tuna II (Mexico) (Articl e 21.5 – Mexico) , para. 7.21. WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.531.   Before proceeding to our calibration analysis, however, we find it important to underline 
that the question of how the risk profiles of different fishing methods should be assessed and 
compared is explained in ea rlier parts in these Reports. Accordingly, in this section, we do not 
repeat the parties' arguments or our analysis concerning issues such as whether it is appropriate 
to use a per set, a PBR, or an overall adverse effects methodology. Additionally, in thi s section, we 
do not repeat in detail our findings concerning the overall relative risk profiles of different fishing 
methods. Rather, we assess whether the 2016 Tuna Measure is calibrated based on the parties' 
arguments and the findings we have made above  concerning the relative risks to dolphins arising 
from the use of different fishing methods in different areas of the ocean. In particular, we will 
assess whether the 2016 Tuna Measure is "appropriately tailored to", "commensurate with", or 
"explained by"  the differences in the risk profiles we have already analysed.  
7.8.2   Eligibility criteria  
7.532.   As we have explained above, the eligibility criteria are the criteria pursuant to which tuna 
products made from tuna caught by (a) setting on dolphins and (b) driftnets in  the high seas936 
are disqualified from accessing a dolphin -safe label, while tuna products made from tuna caught by 
other fishing methods are provisionally eligible. In the first compliance proceedings, the Appellate 
Body referred to the eligibility criteri a as the "substantive conditions for access to [a] dolphin -safe 
label".937 
7.533.   According to the United States, the eligibility criteria are even -handed because they 
address the risks of both setting on dolphins and other fishing methods, commensurately with the 
risks the different methods pose to dolphins.938 In the United States' view, setting on dolphins is 
unique because it is the only fishing method in which vessels intentionally target marine mammals 
in order to catch commercially valuable fish. The United Sta tes recalls that every dolphin set 
involves the chasing and encircling of numerous dolphins, sometimes for hours at a time, and 
emphasises that therefore every dolphin set necessarily poses a risk of both observable and 
unobservable harms. Thus, in the Uni ted States' view, setting on dolphins cannot be carried out in 
a way that does not endanger dolphins, and accordingly is inherently unsafe.939 Moreover, the 
United States argues that setting on dolphins remains uniquely dangerous in terms of the numbers 
of dolphins killed and seriously injured as a result of the fishing method940, when assessed on a 
per set basis.941 
7.534.   The United States contrasts the fishing method of setting on dolphins with other fishing 
methods, which, according to the United States, are not inh erently unsafe to dolphins.942 The 
United States explains that fishing methods other than setting on dolphins do not target dolphins, 
and in fact often actively strive to avoid them. For these fishing methods, dolphins are not an 
essential part of the fishin g method, and they can therefore be carried out in ways that do not 
endanger dolphins.943 Indeed, according to the United States, dolphin mortalities caused by fishing 
methods other than setting on dolphins are a small fraction of those caused by setting on 
dolphins.944 
7.535.   The United States also notes that setting on dolphins causes unobservable harms as a 
result of the chase itself, whereas no evidence on the record suggests that other fishing methods 
cause similar kinds of harms.945 
7.536.   In the light of these differenc es between setting on dolphins, on the one hand, and other 
fishing methods on the other hand, the United States argues that the eligibility criteria are 
calibrated because they distinguish between the only fishing method that intentionally targets 
dolphins  and those fishing methods that do not.946 Thus, according to the United States, the 
                                                
936 We note that the parties have not submitted arguments concerning the disqualification of tuna 
caught by driftnet on the high seas.  
937 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.19. 
938 United States' first written submission, para. 91.  
939 United States' first written submission, para. 96.  
940 United States' first written submission, para. 102.  
941 United States' second written submission, para. 136.  
942 United States' first written submission, para. 1 05. 
943 United States' first written submission, para. 97.  
944 United States' first written submission, para. 105.  
945 United States' first written submission, para. 100.  
946 United States' first written submission, para. 104.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  eligibility criteria distinguish between a fishing method that is inherently unsafe for dolphins 
(setting on dolphins) and other fishing methods that may be, and in fact usu ally are, safe for 
dolphins.947 
7.537.   Mexico disagrees with the United States on this issue. According to Mexico, the difference 
in treatment between ineligible and eligible fishing methods is not even -handed.948 In Mexico's 
view, the question of whether the eligibi lity criteria are calibrated must be answered through an 
assessment of whether there are observed and/or unobserved dolphin mortalities and serious 
injury associated with a fishing method and fishing area and the magnitude of those adverse 
effects.949 Howeve r, according to Mexico, when a consistent method of comparison, such as PBR, 
is applied across fishing methods and ocean areas, it is clear that the eligibility criteria are not 
calibrated to the overall levels of risk, taking account of the objectives of the 2016 Tuna 
Measure950, because AIDCP -compliant setting on dolphins has a lower risk profile than other tuna 
fishing methods.951 
7.538.   Moreover, Mexico argues that the Panels must not focus their assessment of whether the 
eligibility criteria are calibrated on the  unique activities comprising each fishing method.952 
According to Mexico, what is relevant to the calibration analysis is the adverse effects that a 
particular fishing method has on dolphins, not the activities making up that fishing method.953 
Thus, Mexico c autions the Panels from basing their conclusions "simply on the nature of the 
activities" making up a particular fishing method. Rather, in Mexico's view, "the assessment must 
be undertaken based on the absolute levels of adverse effects or on an objective  measure like 
PBR".954 We understand this argument to mean that in our assessment of the risk profile of setting 
on dolphins, we should focus on the harms caused to dolphins by this fishing method, and not on 
the fact that it always requires interaction with  dolphins.  
7.539.   We recall our earlier finding that setting on dolphins is significantly more dangerous to 
dolphins than are other fishing methods. In reaching this conclusion, we considered the evidence 
on the record concerning the existence and extent of obser vable harms, unobservable harms, and 
interaction with dolphins. We explained that dolphin sets necessarily interact with dolphins, and 
that therefore dolphins are an essential element of the method of setting on dolphins. We also 
explained that, because ev ery dolphin set chases and encircles dolphins, every dolphin is at risk of 
both observable harms and unobservable harms, which, because of their nature, cannot be 
certified. This contrasts with other fishing methods, which do not routinely and systematical ly 
interact with dolphins, which cause observable harms at a much smaller magnitude compared to 
setting on dolphins, and which do not cause the same kinds of unobservable harms as are caused 
by setting on dolphins.  
7.540.   Taking into account the relative risk pro files of setting on dolphins, on the one hand, and 
other fishing methods on the other hand, we consider that the eligibility criteria are appropriately 
calibrated to the risks to dolphins arising from the use of different fishing methods in different 
areas  of the ocean. A number of considerations lead us to this conclusion.  
7.541.   First, based on the data on the record, we have concluded that setting on dolphins poses a 
much higher risk of observed dolphin mortality and serious injury, on a per set basis, than oth er 
fishing methods. We have found that, on a per set basis, setting of dolphins is more likely to kill or 
seriously injure a dolphin than any other fishing method. For instance, in the period 2009 -2015, 
there were 91.15 dolphin mortalities per 1,000 sets i n the ETP large purse seine fishery by setting 
on dolphins, compared to 0.20 dolphin mortalities per 1,000 sets in the ETP large purse seine 
fishery without setting on dolphins in the period 2009 -2014, and an annual average of 2.01 
dolphin mortalities per  1,000  sets in the WCPO purse seine fishery without setting on dolphins in 
the years 2010, 2014 and 2015. In fact, even the highest observed mortalities per set in other 
fisheries are almost three times smaller than those occurring in the ETP large purse se ine fishery 
by setting on dol phins. This is the case of the WCPO purse seine fishery without setting on 
                                                
947 United States' first written submis sion, para. 105.  
948 Mexico's second written submission, para. 53.  
949 Mexico's second written submission, para. 62.  
950 Mexico's first written submission, para. 239.  
951 Mexico's first written submission, para. 253.  
952 Mexico's second written submission, para. 62.  
953 Mexico's first written submission, para. 258.  
954 Mexico's first written submission, para. 259. WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  dolphins in the period 2007 -2009, which registered a mortality of 27.12 dolphins  per 1,000 sets . 
We also recall that gillnet fishing caused, per 1,000 s ets, 19 mortalities in the Northern Australia 
Gillnet Fishery (2000 -2003); 35.4 (2014) and 24.4 (2015) mortalities in the California Drift Gillnet 
Fishery; and 4.6 (2010) and 0 mortality (2011) in the California Set Gillnet Fishery, which are also 
consider ably lower compared to the ETP large purse seine fishing by setting on dolphins.  
7.542.    Moreover, in terms of the magnitude of observed harms, the difference between setting 
on dolphins, on the one hand, and other fishing methods on the other hand is, in our vie w, 
significant. The greater risks caused by setting on dolphins appear to us to justify the finding of 
the original and first compliance panel s that setting on dolphins is "particularly harmful " to 
dolphins.955 
7.543.   Second, we have also concluded that the method of setting on dolphins is more likely than 
other fishing methods to cause unobserved mortality and serious injury. This is because, as we 
have explained above, setting on dolphins routinely and systematically interacts with dolphins, 
meaning that there is a higher likelihood than in respect of other fishing methods that dolphins will 
be killed or seriously injured, even if such mortality or injury is not in fact observed. As we noted 
above, fishing methods other than setting on dolphins can be, and often ar e, carried out without 
any dolphin interactions, and thus do not pose any risks to dolphins. Moreover, although some 
fishing methods do interact with dolphins, the extent of the interaction, on a per set basis, is 
significantly smaller than it is in respec t of setting on dolphins.  
7.544.   Finally, we have accepted, based on our assessment of the evidence on the record that 
setting on dolphins causes a unique kind of unobservable harm that by its nature cannot be 
certified. Therefore, setting on dolphins poses a ris k of harms whose realization cannot be 
definitively established. This means that, even where no dolphins have been killed or seriously 
injured, there remains a risk that dolphins subject to chase and encirclement may have suffered 
from unobservable harms, such as continuous acute stress.956 As such, a certification, even by an 
independent observer, that no dolphins were killed or seriously injured in a set on dolphins could 
not indicate, with any degree of certainty, that the tuna caught in that set was dolph in-safe, since 
dolphins may well have suffered unobservable harms as a result of the chase itself. In this sense, 
we agree with the United States that allowing tuna caught by setting on dolphins, in a set in which 
no dolphins were killed or seriously injur ed, to access a dolphin -safe label may mislead US 
consumers957, since it could not control for the unobservable harms that may have been caused as 
a result of the chase and encirclement process.  
7.545.   To be clear, we are not suggesting that every dolphin chased an d encircled in a dolphin set 
actually does suffer unobservable harms. As we explained above, the evidence would not support 
such a finding. However, the evidence does indicate that every dolphin chased and encircled is at 
risk of suffering unobservable har ms, and because these harms cannot be certified, there is no 
way in which tuna caught in a set in which dolphins suffered unobservable harms could be 
distinguished from tuna caught in a set in which dolphins did not suffer unobservable harms.  
7.546.   This contrast s with other fishing methods, which, as we have concluded on the basis of the 
evidence before us, do not cause the same kinds of unobservable harms as setting on dolphins. 
Accordingly, these other fishing methods do not cause the same sort of harms whose o ccurrence 
cannot, by definition, be certified. In this sense, in respect of tuna caught other than by setting on 
dolphins, it is generally possible to distinguish between tuna caught in a set in which dolphins were 
harmed, and tuna caught in a set in which  dolphins were not harmed.  
7.547.   Taking all of these factors into account, we consider that the eligibility criteria embodied in 
the 2016 Tuna Measure are calibrated to the risks to dolphins arising from the use of different 
fishing methods in different areas of  the ocean.  
7.8.3   The certification requirements  
7.548.   We now turn to consider whether the certification requirements  are calibrated to the risks 
to dolphins arising from the use of different fishing methods in different areas of the ocean.  
                                                
955 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.120.  
956 See also Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.122 . 
957 United States' first written submission, para. 5. WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.549.   As we have explained above,  the certification requirements provide that certain 
documentation must accompany tuna intended to be labelled as dolphin -safe in the US market. 
The required certifications differ depending on whether the tuna product is produced from the ETP 
large purse s eine fishery or from another fishery. Thus, tuna caught in the ETP large purse seine 
fishery must be accompanied by a certification from the vessel captain and an independent 
observer that (a) no dolphins were killed or seriously injured during the sets in  which the tuna was 
caught, and (b) none of the tuna was caught on a trip using a purse seine net intentionally 
deployed on, or used to encircle, dolphins. For tuna caught outside the ETP large purse seine 
fishery, a certification from the vessel captain t hat "[n]o purse seine net or other fishing gear was 
intentionally deployed on or used to encircle dolphins during the fishing trip in which the tuna were 
caught, and that no dolphins were killed or seriously injured in the sets or other gear deployments 
in which the tuna were caught" is required. An independent observer certification may also be 
required for tuna caught outside the ETP large purse seine fishery if the tuna was caught in a 
fishery that has been designated, under the "determination provisions ", as having either a regular 
and significant association between dolphins and tuna (similar to the association between dolphins 
and tuna in the ETP) or a regular and significant mortality or serious injury of dolphins is occurring.  
7.550.   In the first compliance  proceedings, the panel engaged in a detailed analysis of the 
certification requirements. On appeal, the Appellate Body reversed the first compliance panel's 
conclusions on the basis that the panel had made an improperly segmented analysis and had failed 
to properly  consider whether the certification requirements were calibrated to the risks to dolphins 
arising from the use of different fishing methods in different areas of the ocean.958 However, the 
Appellate Body did not find that the substance of the compl iance panel's analysis was itself 
incorrect. Rather, it noted that "while the concept of different risks to dolphins in relevant fisheries 
seems to have played some part in" the compliance panel's analysis, that analysis nevertheless 
failed to "encompass[]  a clear identification of the respective risks or an assessment of whether 
such risks were addressed in an even -handed manner by the different certification 
requirements".959 Moreover, the Appellate Body rejected a claim by Mexico that the first 
compliance panel had violated Article 11 of the DSU in making certain factual findings related to 
the certification requirements.960 Accordingly, we consider that some of the factual and legal 
findings of the first compliance panel and the Appellate Body in respect of the certification 
requirements are relevant to our analysis in these proceedings. We will set out what we see as the 
most relevant findings from the first compliance proceedings, before proceeding to summarize the 
arguments of the parties in these proceedi ngs and conduct our own assessment of whether the 
certification requirements are calibrated to the risks to dolphins arising from the use of different 
fishing methods in different areas of the ocean.  
7.551.   We begin by observing that, in considering the certifica tion requirements, the first 
compliance panel accepted the United States' argument that the 100% observer requirement in 
the ETP is intrinsically tied to the "special risk profile"961 in the ETP large purse seine fishery.962 In 
this respect, the first complian ce panel accepted that although dolphins may occasionally and 
incidentally be set on outside the ETP, it is only inside the ETP that setting on dolphins is practiced  
consistently or systematically .963 On appeal, the Appellate Body rejected Mexico's claim tha t this 
finding was made in violation of Article 11 of the DSU.964 The Appellate Body explained that the 
evidence presented by Mexico did "not suggest widespread tuna -dolphin association or widespread 
use of the fishing technique of setting on dolphins outsid e the ETP".965 
7.552.   Having accepted that the different certification requirements were tied to the special risk 
profile of the ETP large purse seine fishery, the first compliance panel went on to accept that the 
United States had raised a prima facie  presumption that the different certification requirements 
stemmed exclusively from a legitimate regulatory distinction.966 Specifically, the panel accepted 
the United States' argument that:  
                                                
958 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para s. 7.159 and 7.165.   
959 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para . 7.165.  
960 Appellate Body Rep ort, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para s. 7.215 – 7.226.  
961 Panel Report, US – Tuna II (Mexico) Article 21.5 – Mexico) , para.  7.398.   
962 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.238.  
963 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.242.  
964 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para s. 7.220 and 7.227.  
965 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para . 7.226.  
966 Panel Report, US – Tuna II  (Mexico) (Article 21.5 – Mexico) , paras. 7.242 and 7.245.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  A large ETP purse seine vessel carries a crew of approximately 20 persons on any  
particular trip. The primary job of the crew is to harvest tuna. However, given the 
intensity and length of the interactions in a dolphin set between the dolphins, on the 
one hand, and the vessel, speed boats, helicopter, and purse seine net on the other,  
the AIDCP parties concluded that it was appropriate to require a vessel capable and 
permitted to engage in such a dangerous activity to carry a single person to observe 
the impact of the vessel on the dolphins that it was chasing and capturing.967 
7.553.   Thus, the  first compliance  panel  appeared to accept that:  
[O]bservers are necessary on ETP large purse seiners but may not be necessary on 
other vessels in other fisheries not because the risk of dolphin mortality or serious 
injury is somehow less important in othe r fisheries, but rather because the nature of 
the fishing technique used by ETP large purse seiners, which essentially involves the 
chasing and encirclement of many dolphins over an extended period of time, means 
that it is necessary to have one single per son on board with the responsibility of 
keeping track of those dolphins caught up in the chase and/or the purse seine nets 
set. Other fishing methods in other oceans may – and, as the United  States 
recognizes, do – cause dolphin mortality and serious injur y, but because the nature 
and degree of the interaction is different in quantitative and qualitative terms (since 
dolphins are not set on intentionally, and interaction is only accidental), there is no 
need to have a single person on board whose sole task is to monitor the safety of 
dolphins during the set or other gear deployment.968 
7.554.   Moreover, the first compliance panel rejected an argument by Mexico that "captains' 
certifications are unreliable because captains have a financial incentive not to report accur ately on 
the dolphin -safe status of tuna caught in a given set or other gear deployment".969 The panel 
explained that the fact that domestic, regional, and international regimes have continued to rely 
on captains' certifications and logbooks even though inst ances of non -compliance have been 
reported suggests that such instances of non -compliance should not be considered as seriously 
undermining the general reliability of captains' certifications.970 On appeal, the Appellate Body 
rejected Mexico's claim that the  compliance panel had violated Article 11 of the DSU in arriving at 
this conclusion.971 
7.555.   However, the compliance panel did accept Mexico's argument that "captains may not 
necessarily and always have the technical skills required to certify that no dolphins we re killed or 
seriously injured in a set or other gear deployment, and this may result in inaccurate information 
being passed to consumers, in contradiction with the objectives of the amended tuna measure".972 
According to the first compliance panel, certifyi ng whether a set or other gear deployment is 
dolphin -safe can be a "highly complex" activity "for which training and education are required".973 
The compliance panel found, however, that the United States had "not explained sufficiently why it 
assume[d] that  captains are capable of carrying out [that] activity".974 
7.556.   We note, however, that although the first compliance panel concluded that the certification 
requirements did not stem exclusively from a legitimate regulatory distinction, it also stated that:  
[W]e a re not finding that the only way for the United  States to make its measure 
even-handed is to require observer coverage. To the contrary, as we found above, 
captains' certifications are relied upon by domestic, regional, and international 
regimes for a wide  variety of purposes, and we see no reason why captains could not, 
                                                
967 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.239.  
968 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.240 (internal citations omitted). 
In fact, the first compliance panel was in this paragraph setting out  its understanding of the United States' 
argument. However, the panel then went on to find the United States' argument "compelling", and to accept 
that it "would be sufficient to raise a presumption" tha t the different certification requirements stemmed 
exclusively from a legitimate regulatory distinction. Panel Report, US – Tuna II (Mexico) (Article 21.5 – 
Mexico) , para. 7.242.  
969 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.211.  
970 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.209. 
971 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para s. 7.215 – 7.219.  
972 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.233. 
973 Panel Rep ort, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.246. 
974 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.246. WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  in principle and as a general matter, accurately certify the dolphin -safe status of a 
tuna catch. As we see it, the key problem with the amended tuna measure as 
currently designed is that t he United  States has not explained why its measure 
assumes that captains have at their disposal the skills necessary to ensure accurate 
certification.975  
7.557.   Having set out what we consider to be the most important findings from the first 
compliance proceedings , we now proceed to summarize the parties' submissions in these 
proceedings.  
7.558.   The United States argues that the differences in the certification requirements are 
commensurate with the different risk profiles of the ETP large purse seine fishery, on the one 
hand, and other fisheries on the other hand.976 The United States explains that the ETP has a 
"special risk profile" because it is the only ocean that exhibits an association between tuna and 
dolphins so frequent that it is exploited systematically by a comm ercial fishery.977 Indeed, the 
United States argues that the ETP is the only ocean where large purse seiners are both capable of 
and permitted to set on dolphins.978 The United States contrasts the situation in the ETP large 
purse seine fishery with the situat ion in other fisheries where, according to the United States, 
there is no evidence that vessels set on dolphins or are even capable of doing so. The United 
States also submits that in fisheries other than the ETP large purse seine fishery, less than 1% of 
sets involve any interaction with dolphins.979 On the basis of these differences, the United States 
argues that the frequency and intensity of interactions between dolphins and fishing vessels in the 
ETP large purse seine fishery is "unparalleled".980 
7.559.   Having a rgued that the ETP large purse seine fishery has a special risk profile, the United 
States proceeds to argue that the difference in the certification requirements is commensurate 
with, or calibrated to, the difference between the risk profile of the ETP la rge purse seine fishery 
on the one hand, the risk profiles of other fisheries on the other hand.981 The United States 
submits that this is so for two reasons.  
7.560.   First, the United States argues that the difference in the certification requirements is 
commensura te with the differences in risk because the task of verifying that tuna meets the 
eligibility criteria is so much more difficult in the ETP large purse seine fishery than it is in other 
fisheries, due to both the large numbers of dolphin that interact with  purse seine vessels setting 
on dolphins982 and to the nature of the interaction between dolphins and purse seine vessels 
setting on dolphins, which includes chasing and encirclement.983 The United States explains that, 
in its view, it is appropriate to requir e two certifiers984 (one of whom has to meet certain minimum 
education standards and has undergone some training) where the conditions facing the certifier 
are very difficult, and to require only one certifier (who need not meet minimum education 
standards b ut is required to have taken a training course) where the conditions are less difficult.985 
7.561.   The United States also notes that in order to assist captains outside the ETP large purse 
seine fishery to accurately certify whether a particular set or other gear d eployment was dolphin -
safe, the NOAA has developed a new training course that covers key aspects of the eligibility 
criteria and the requirement to segregate dolphin -safe from non -dolphin -safe tuna following 
catch.986 
7.562.   Second, relying on the separate opinion of one panelist in the first compliance proceedings, 
the United States argues that the different certification requirements are calibrated because any 
difference in the accuracy of certifications made in the ETP large purse seine fishery on one hand 
                                                
975 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.224 (ifootnotes omitted).  
976 United States' f irst written submission, para. 123.  
977 United States' first written submission, para. 124.  
978 United States' first written submission, para. 125.  
979 United States' first written submission, para. 126.  
980 United States' first written submission, para. 127.  
981 United States' first written submission, para. 132.  
982 United States' first written submission, para. 134.  
983 United States' first written submission, para. 135.  
984 By "certifier" we mean a person who observes the fishing effort and certifies whether the effort  was 
dolphin -safe, depending on compliance with established requirements.  
985 United States' first written submission, para. 133.  
986 United States' first written submission, para. 138.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  and in  other fisheries on the other hand has a rational connection to the differences in risk. The 
United States explains that even if the conditions facing the certifiers in the ETP large purse seine 
fishery and other fisheries were the same (which they are not ), and a captain working outside the 
ETP large purse seine fishery were, therefore, a less sensitive mechanism than an AIDCP observer, 
the regulatory distinction would nevertheless be calibrated in tolerating a higher 'margin of error' 
for the certifier wh ere the risks to dolphins are lower and tolerating a lower 'margin of error' where 
the risks to dolphins are higher.987 
7.563.   Mexico disagrees with the United States. According to Mexico, the certification 
requirements are being applied in a manner that is not eve n-handed.988 Mexico advances four 
main reasons in support of its position.  
7.564.   First, Mexico argues that the findings made by the first compliance panel concerning the 
general reliability of captain certification "pertained to captain certifications generally". However, in 
Mexico's view, many fisheries outside the ETP have substantial deficiencies in regulatory 
compliance and reporting. Therefore, according to Mexico, although captain certifications may be 
reliable in some fisheries, they cannot be reasonably rel ied upon in fisheries where there are 
widespread regulatory compliance and reporting issues.989 
7.565.   Second, Mexico argues that the new training course developed by the United States 
contains "clear substantive gaps".990 Moreover, noting that the training requireme nt relies on 
captains to self -certify that they have completed the training course, Mexico submits that a system 
should be created to keep track of persons who accessed the training materials, or at least require 
persons to register online and certify that  they have reviewed the training information, or even to 
take an examination. According to Mexico, in the absence of such a system, a captain can easily 
certify that he or she has taken the training course without actually reviewing the material.991 In 
suppo rt of this argument, Mexico submits statements made by Bumblebee Seafoods concerning 
the difficulty of fully implementing the new training requirements.992 Mexico concludes that the 
training requirement does not equip vessel captains with the technical skill s required to certify that 
no dolphins were killed or seriously injured in a set or other gear deployment.993 
7.566.   Third, Mexico notes that the 2016 Tuna Measure requires captains of non -purse seine 
vessels to certify that they did not intentionally deploy gear s uch as longlines and gillnets on 
dolphins.994 According to Mexico, however, the explanation of the concept of "intentional" in the 
Federal Register notice accompanying the publication of the 2016 Tuna Measure is vague, leaves 
considerable discretion to the c aptain, and appears designed to encourage evasion. Moreover, 
Mexico submits that there is no incentive for captains to report honestly in this regard, and, 
without observers, there is no mechanism to ensure accuracy of certifications.995 
7.567.   Finally, Mexico argu es that the United States' arguments concerning the existence of an 
acceptable margin of error is not a reasonable approach where the very objective of the Measure is 
to provide accurate information to consumers regarding the dolphin -safe status of the tun a in the 
products that they choose to purchase.996 According to Mexico, it is essential that a dolphin -safe 
certification be accurate, and to ensure accuracy, trained observers should be present in all 
fisheries where the risk profiles are comparable to thos e of the ETP. In Mexico's view, if this is not 
the case, the certification requirements cannot be considered to be even -handed. Moreover, 
Mexico argues that even if the Panels were to accept that the margin of error may be calibrated to 
the different risk profiles of different fisheries, the 2016 Tuna Measure is not properly calibrated in 
this respect, because the risk profiles of all fisheries other than the ETP large purse seine fishery 
are not so minor in relation to the ETP large purse seine  fishery as to make it even -handed to 
allow untrained captains to make inaccurate certifications for tuna caught in those fisheries.997 
                                                
987 United States' first written submission, para. 140.  
988 Mexico's second wr itten submission, para. 94.  
989 Mexico's first written submission, para. 265.  
990 Mexico's first written submission, para. 270.  
991 Mexico's first written submission, para. 271.  
992 Mexico's first written submission, para. 272.  
993 Mexico's first written submission,  para. 275.  
994 Mexico's first written submission, para. 276.  
995 Mexico's first written submission, para. 278.  
996 Mexico's first written submission, para. 280.  
997 Mexico's first written submission, para. 283.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.568.   The Panels begin their analysis by noting that, unlike the eligibility requirements, the 
certification requirements (and the tracking and verification requirements, which we consider later 
in these Reports) draw distinctions on the basis of different fisheries, rather than different fishing 
methods. Thus, the certification requirements that apply in the ETP large purse seine fishery appl y 
to all large purse seine vessels fishing in the ETP, regardless of whether those vessels actually set 
on dolphins. The question before us, therefore, is whether the distinction  that the 2016 Tuna 
Measure makes between the ETP large purse seine fishery, o n the one hand, and all other 
fisheries, on the other hand, is calibrated.  
7.569.   In this connection, we recall the finding of the original panel that:  
[T]he association between schools of tunas and dolphins does not occur outside the 
ETP as frequently  as it does  within the ETP. This evidence further suggests that 
although there are indications that intentional setting on dolphins occurs outside the 
ETP, there are "no records of consistent or widespread fishing effort on tuna -dolphin 
associations anywhere other th an in the ETP.998 
7.570.   The first compliance panel also confirmed that setting on dolphins is not practiced 
consistently or systematically outside the ETP large purse seine fishery.999 And on appeal, the 
Appellate Body found no error in this finding, and reiterated that the evidence submitted by Mexico 
did not demonstrate the existence of widespread tuna -dolphin association or widespread use of the 
fishing method of setting on dolphins outside of that fishery.1000 In the present proceedings too, no 
evidence has been sub mitted suggesting setting on dolphins occurs systematically outside the ETP. 
Accordingly, we consider  that the existing finding that setting on dolphins is only practised 
routinely and systematically in the ETP continues to be relevant to the present proce edings.  
7.571.   We also recall that, on the basis of our analysis of the evidence on the record, we have 
concluded that setting on dolphins is a particularly dangerous fishing method that is liable to cause 
observable and unobservable harms to dolphins at rates si gnificantly in excess of those caused by 
other fishing methods.  
7.572.   We are aware that not all large purse seine vessels in the ETP actually do set on dolphins, 
at least in every set or on every voyage. According to the evidence on the record, dolphin sets 
make  up somewhere near half of all sets by large purse seine vessels in the ETP.1001 In our view, 
however, the crucial point is that in the ETP, unlike in other areas of the ocean, large purse seine 
vessels are permitted  to and actually can  set on dolphins in a c onsistent and systematic manner. 
One of the purposes of the certification requirement in the ETP is precisely to certify that dolphins 
were not set on, even though the fishing vessels could, both technically and legally, have set on 
dolphins. Thus, it is n ot simply the fact that dolphins are set on in the ETP large purse seine fishery 
that gives it its "special risk profile"1002, but the fact that only in the ETP are large purse vessels 
actually able and permitted to set on dolphins. Thus, in our view, it is b oth the technical and legal 
possibility of setting on dolphins and the fact that dolphin sets occur in a consistent and systematic 
manner in the ETP large purse seine fishery that gives this fishery its special risk profile.  
7.573.   Having made these observations,  we now turn to consider whether the different 
certification requirements are appropriately calibrated. As noted above, in the first compliance 
proceedings, the panel accepted that, because "the nature and degree of the interaction [with 
dolphins] is diffe rent in quantitative and qualitative terms"1003 in the ETP than in other fisheries, it 
may be necessary to have one single person on board a large purse seine vessel in the ETP with 
the responsibility of keeping track of those dolphins caught up in the chase and/or the purse seine 
nets set, whereas there may be no need in other fisheries to have a single person on board a 
fishing vessel whose sole task is to monitor the safety of dolphins during the set or other gear 
deployment.1004 
                                                
998 See Panel Report, US – Tuna II (Mexico) , para. 7.5 20 (internal  citations omitted, emphasis in 
original).  
999 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.240.  
1000 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.226.  
1001 See United States' first written submi ssion, para. 50, Table 2.  
1002 Panel Report, US – Tuna II (Mexico) Article 21.5 – Mexico) , para. 7.398.  
1003 Panel Report, US – Tuna II (Mexico) Article 21.5 – Mexico) , para.  7.240.  
1004 Panel Report, US – Tuna II (Mexico) Article 21.5 – Mexico) , para.  7.240.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.574.   In the present proceedings, ho wever, Mexico contests the proposition that the task of 
certifying is more difficult in the ETP than outside it. Indeed, according to Mexico, the opposite is 
true.1005 In Mexico's view, the certifier in the ETP large purse seine fishery is a highly -trained 
scientific observer whose sole function aboard a fishing vessel is specifically to observe all 
procedures relating to dolphins during fishing sets, to monitor compliance with all mandatory 
dolphin -protection procedures, and to provide written reports on any and all bycatch and 
interactions with marine mammals, including detecting and reporting on any mortalities or serious 
injuries caused to dolphins in the course of a fishing set. This is the observer 's sole priority.1006 
Mexico contrasts this situation with th e situation outside the ETP large purse seine fishery, where, 
it submits, the certifier is the captain of the fishing vessel. According to Mexico, the captain has a 
number of other important responsibilities that are given more priority, relating to the op eration of 
the vessel and fishery manoeuvres, than observing fishing sets or gear deployments to detect 
harms to dolphins. It is those other responsibilities that require the captain 's attention during a 
fishing set or gear deployment, rather than closely observing the fishing operation for signs of 
mortality or serious injury to dolphins.1007 
7.575.   Moreover, Mexico maintains that in the ETP, dolphin interactions are anticipated and 
carefully controlled or prevented during AIDCP -compliant dolphin encirclement manoeu vers. 
According to Mexico, any mortalities or serious injuries that might occur are evident because the 
affected animals will be either unable or less able to exit from the net as it is pursed closed and 
'rolled up'. Mexico further submits that harms to do lphins would also be noted by the crew rescue 
teams and divers inside the net area that patrol and observe the dolphins' behaviour inside the net 
and their release during the 'back down' procedure.1008 Mexico contrasts this situation with the 
situation in fis heries other than the ETP large purse seine fishery, where unanticipated and/or 
uncontrolled dolphin interactions may be more difficult to identify and observe, particularly by a 
vessel captain who has simultaneous roles and responsibilities other than obs ervation.1009 
7.576.   The United States does not agree with Mexico on this issue . Echoing its arguments in the 
first compliance proceedings (which, as we noted above, the first compliance panel accepted), the 
United States argues that certifying whether a set is dolp hin-safe is far more difficult in the ETP 
than in other fisheries because:  
Every ETP dolphin set involves sustained, intense interactions with, on average, 
hundreds of dolphins for a sustained period, as the speedboats and helicopter chase 
and herd the dol phins, the seiner deploys the net and encircles them, and the 
backdown procedure and manual release of dolphins are conducted. Many interactions 
are happening simultaneously in different places as the set proceeds. On average, ETP 
large purse seiners captu re and (attempt) to release about 350 dolphins every set.1010 
7.577.   The United States contrasts this with the situation in other fisheries, where any dolphin 
interaction is rare and involves, on average, only a few dolphins.1011 
7.578.   In our view, the finding of the first c ompliance panel1012 that it may be necessary to have 
one single person on board a large purse seine vessel in the ETP with the responsibility of keeping 
track of those dolphins caught up in the chase and/or the purse seine nets set, whereas there may 
be no ne ed in other fisheries to have a single person on board a fishing vessel whose sole task is 
to monitor the safety of dolphins during the set or other gear deployment, is, like other existing 
findings, a finding from which we should not depart in the absence  of new evidence requiring us to 
do so.1013 As we see it, Mexico's arguments on this point are not sufficient to require a revision of 
                                                
1005 Mexico's response to Panels' question No. 60, para. 12.  
1006 Mexico's response to Panels' question No. 60, para. 13.  
1007 Mexico's response to Panels' question No. 60, para. 14. 
1008 Back down is "a procedure for releasing dolphins over the net's corkline … A channel is formed at 
the far side of the net and the corkline is submerged so that the dolphins can exit. Speedboats may be used to 
pull the corkline, thus keeping the channel from collapsing. Crewmen may enter the water, when necessary, to 
pull dolphins over the corkline". Barbara E. Curry, Stress in Mammals: The Potential Influence of Fishery -
Induced Stress on Dolphins in the Eastern Tropical Pacific Ocean , NOAA NMFS Technical Memorandum (1999) , 
(Exhibit USA-42), p. 6.  
1009 Mexico's response to Panels' question No. 60, para. 16.  
1010 United States' comments on Mexico's response to Panels' question No. 60, para. 31.  
1011 United States' comments on Mexico's response to Panels' question No. 60, para. 32. 
1012 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , paras. 7. 240, 7.242 and 7.245.  
1013 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 5.9. WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  this existing finding. Most importantly, in our view, Mexico's argument confuses cause and effect. 
Mexico argues that it is easier to certify dolphin mortality and serious injury in the ETP large purse 
seine fishery because, inter alia , there are dedicated trained observers and there are established 
procedures governing interactions with dolphins. However, as we understand it, the reason why 
trained observers are required in the ETP and the reason why procedures are in place governing 
dolphin interactions is precisely because the parties to the AIDCP considered it necessary to 
implement such safeguards in the ETP large purse sei ne fishery due to that fishery's special risk 
profile. In other words, if it is easier to certify dolphin mortality or serious injury in the ETP large 
purse seine fishery, that is because  of the requirements that were adopted for that fishery due to 
its pa rticularly high risk profile, including the very requirement to have an independent observer 
on board.  
7.579.   Moreover, the fact that captains often have responsibilities other than certifying the 
dolphin -safe status of a set or other gear deployment does not, in  our view, mean that it is 
necessarily more difficult to certify the dolphin -safe status of a set or other gear deployment 
outside the ETP large purse seine fishery than inside it. In this connection, we find relevant the 
finding of the first compliance pa nel that RFMOs and other fisheries and environmental 
organizations, which are experts in their respective fields, routinely rely on captains' statements in 
a variety of fishing and environmental areas. For the first compliance panel, this indicated that, 
generally, such organizations consider captain certifications to be reliable.1014 This finding was not 
contested on appeal, and nothing in the evidence submitted in the present proceedings suggests 
to us that we should depart from or revise it. Moreover, for u s, the widespread reliance by RMFOs 
and other organizations on captain certifications indicates that the fact that captains may have a 
number of responsibilities is not considered by these fisheries management experts to undermine 
the ability of vessel cap tains to properly discharge their sometimes multiple functions.  
7.580.   Therefore, we see no reason to depart from the finding of the first compliance panel that 
requiring an independent observer in the ETP large purse seine fishery but not in other fisheries is 
prima facie  calibrated to the difference between the risk profile of the ETP large purse seine 
fishery, on the one hand, and other fisheries on the other hand. However, we recall that the first 
compliance panel ultimately found that the calibration of the c ertification requirements was 
undermined by the fact that captains, although not inherently unable to provide accurate 
certifications, may not necessarily and always have the specific technical skills required to certify 
that no dolphins were killed or ser iously injured in a set or other gear deployment. The first 
compliance panel found that this may result in inaccurate information being passed to consumers, 
contrary to the objectives of the Tuna Measure.1015 
7.581.   In this regard, we recall that, following the firs t compliance proceedings, the United States 
introduced a new requirement that captains of vessels operating outside the ETP large purse seine 
fishery certify completion of an "NMFS dolphin -safe captain's training course" (training course).1016 
According to th e United States, this training course includes information on (a) identifying dolphins 
of the taxonomic family Delphinidae ; (b) identifying intentional gear deployment on or 
encirclement of dolphins; (c) identifying dolphin mortality and serious injury; an d (d) physically 
separating dolphin -safe tuna from non -dolphin -safe tuna from the time of capture through 
unloading. According to the United States, the addition of this training requirement narrows the 
differences between the different certification requi rements.1017 
7.582.   As we noted above, Mexico does not agree that the new training course remedies the 
problem identified by the first compliance panel. As noted above, Mexico argues that the training 
course is flawed both because it contains substantive gaps and be cause it relies on self -
certification and cannot be easily implemented.  
7.583.   With respect to the substance of the training course, Mexico notes that the training course 
consists of 10 slides that can be read in a number of minutes. Moreover, Mexico draws the Pa nels' 
attention to one of the slides, which lists certain injuries that dolphins may suffer and states that 
"the following injuries, on a case -by-case basis, may or may not indicate a serious injury. 
However, the presence of multiple injuries may be a seri ous injury, but again, that depends on the 
                                                
1014 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , paras. 7.208 -7.209.  
1015 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para.  7.233.  
1016 United States' first written submission, para. 121.  
1017 United States' first written submission, para. 121.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  severity of each injury on a case -by-case basis".1018 According to Mexico, the use of language such 
as "may or may not" implies that captains always have the discretion to decide that there was not 
a serious injury. Similarly, Mexico contends that terms like "that depends" or "likely" invite 
interpretation, but that the training course provides no further guidance to captains on how to 
decide these discretionary issues.1019 Moreover, Mexico argues that the United States'  arguments 
fail to mention the intensive training undergone by observers in the ETP, who have primary 
responsibility for certifications under the AIDCP system.1020 
7.584.   The United States responds to Mexico's argument by stating that the training course is 
much mor e detailed and clear with respect to the dolphin -safe certifications than the analogous 
trainings for the ETP large purse seine fishery.1021 The United States points out that, for example, 
whereas Mexico claims that it is ambiguous how the word "intentional" should be interpreted, the 
training in fact states that if deploying the net or gear on or around dolphins was "intentional[]" 
(i.e. deliberate or on purpose) then the tuna is not dolphin -safe, whereas if the encirclement of a 
dolphin is "accidental" (in t he sense of the dolphin being seen only after the set was commenced), 
then there is no "i ntentional deployment".  According to the United States, this is significantly more 
guidance than is given to captains in the AIDCP training, and at least equal to the guidance given 
by the RFMOs that proscribe intentionally setting on cetaceans.1022 Moreover, the United States 
argues that the training course is also much more detailed concerning identifying mortalities and 
serious injuries than the AIDCP captain training a nd the AIDCP requirements for observers.1023 
7.585.   In our view, the training course appears to provide useful guidance to vessel captains. It 
contains relatively detailed information about dolphin anatomy and taxonomy1024, identifying an 
intentional dolphin set1025, iden tifying dolphin mortality and serious injury1026, and maintaining 
physical segregation between dolphin -safe and non -dolphin -safe tuna.1027 With respect in 
particular to identifying serious injury, the training course defines "serious injury" as meaning an 
injury  that is more likely than not to lead to the death of the dolphin.1028 It then contains a list of 
injures that indicate serious injury1029, followed by the list mentioned by Mexico in its arguments, 
i.e. a list of injuries that "may or may not" indicate serious injury.1030 
7.586.   We do not agree with Mexico that this second list is insufficiently detailed. In addition to 
the definition of serious injury, which would obviously guide a captain in deciding whether or not 
an injury constitutes serious injury, the training cour se provides some additional guidance by 
indicating that "the presence of multiple injuries may be a serious injury". Moreover, we do not 
consider that the terms "likely" or "severity" lack clarity. To the contrary, it seems to us that they 
are used in the training course in their plain sense, and there is no evidence on the record 
suggesting that captains would not be able to understand them. Additionally, we do not agree with 
Mexico that the language used in the second list "implies that captains always ha ve the discretion 
to decide that there was not a serious injury".1031 As we have explained, the training course 
contains two lists, one of which lists injuries that should be considered serious injuries. It does not 
appear that captains would have any discret ion not to certify the occurrence of such injuries. 
Neither do we consider that captains would have difficulty identifying the kinds of injuries 
enumerated in the two lists.1032 They appear to us to be described in plain language, and technical 
anatomical ter ms (such as "dorsal fin") are already clearly explained in a previous slide.  
                                                
1018 NOAA, Dolphin -Safe Captain 's Training Course  (March  23, 2016) , (Exhibits USA -10, MEX -56). 
1019 Mexico's first written submission, para. 270.  
1020 Mexico's response to Panels' question No. 103, para. 195.  
1021 United States' third written submission, para. 119.  
1022 United States' third written submission para. 119.  
1023 United States' third written submission para. 120.  
1024 NOAA, Dolphin -Safe Captain 's Train ing Course  (March  23, 2016) , (Exhibits USA -10, MEX -56), pp. 4 -
5. 
1025 NOAA, Dolphin -Safe Captain 's Training Course  (March  23, 2016) , (Exhibits USA -10, MEX -56), p. 6.  
1026 NOAA, Dolphin -Safe Captain 's Training Course  (March  23, 2016) , (Exhibits USA -10, MEX -56), p p. 7-
9. 
1027 NOAA, Dolphin -Safe Captain 's Training Course  (March  23, 2016) , (Exhibits USA -10, MEX -56), pp. 
10-11. 
1028 NOAA, Dolphin -Safe Captain 's Training Course  (March  23, 2016) , (Exhibits USA -10, MEX -56), p. 7.  
1029 NOAA, Dolphin -Safe Captain 's Training Course  (March  23, 2016) , (Exhibits USA -10, MEX -56), p. 8.  
1030 NOAA, Dolphin -Safe Captain 's Training Course  (March  23, 2016) , (Exhibits USA -10, MEX -56), p. 9.  
1031 Mexico's first written submission, para. 270.  
1032 See Mexico's second written submission, para. 89.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.587.   We also note Mexico's argument that the official guidelines published by the US   
Department of  Commerce for its scientists on determining serious injury prove that the United 
States considers certifying serious injury to be a complex task, and show that the NOAA training 
course is "insufficient to provide the training that the  US Department of  Commerce itself believes 
is necessary to recognize and appropriately record serious injur ies".1033 
7.588.   In our view, the guidelines published by the US Department  of Commerce  do not 
necessarily provide a model against which other training courses must be measured. The fact that 
the US  Department of  Commerce has prepared detailed guidelines – which, we  note, are designed 
for scientists rather than vessel captains – does not necessarily indicate that the United States 
considers this to represent a "minimum standard" of training. At any rate, we do not consider that 
there is, in fact, a very significant d ifference between the US Department of Commerce guidelines 
and the NOAA training course. Both the guidelines and the NOAA course identify many of the same 
injuries. Moreover, the guidelines, like the NOAA course, indicate that some injuries should always 
be classified as serious, whereas others may or not be, depending on the severity.1034 And like 
NOAA course, the guidelines provide, in respect of injuries that may or may not be serious, 
additional indications that may counsel towards a determination of serio us injury. The two 
documents thus seem to us to be quite similar.  
7.589.   Based on the foregoing, we do not consider that the training course has significant 
substantive gaps. Rather, we consider that it contains meaningful information concerning key 
aspects of th e certification process that would assist captains to understand and properly carry out 
their responsibility to certify the dolphin -safe status of a set or other gear deployment.  
7.590.   With respect to the fact that the training course is self -certifying and may be difficult to 
implement, we begin by noting that, had the United States established an online register or 
examination as Mexico suggests, such a register may have contributed to or facilitated the 
enforceability of the training course. We do not consider , however, that without such a register the 
training course is "meaningless", as Mexico suggests.1035 
7.591.   While it is true that the training course is self -certifying, we note that, under the 
architecture of the 2016 Tuna Measure, the private tuna companies that supply the US tuna 
market are subject to the requirements of the 2016 Tuna Measure, and it is they that must ensure 
that the products they sell meet the conditions of US law, including that the captain certifications 
are accurate. Indeed, as the first comp liance panel recognized, there are a range of legal 
consequences for submitting false certifications to the NMFS.1036 It seems to us that a number of 
                                                
1033 Mexic o's response to Panels' question No. 103, paras. 198 and 199.  
1034 In this connection, we note that the guidelines use some of the same terms, such "severity", as are 
used in the NOAA course, and in respect of which Mexico has complained about ambiguity.  
1035 Mexico's second written submission, para. 88.  
1036 The United States notes the following , which seem to us to be particularly relevant : 
 
Criminal Penalties for Fraudulently Importing or Bringing in Merchandise.  18 USC  Section  545 
establishes crimina l liability for any person who " knowingly and willfully, with intent to defrau d 
the United States"  brings or attempts to bring into the United States  "any merchandise which 
should have been invoiced, or makes out or passes . . . through the customhouse any false, 
forged, or fraudulent invoi ce, or other document or paper".  According to the United States, 
penalties include fines of up to $250,000 and up to 5 years imprisonment, and merchandise 
entered in violation of this law may be forfeited. Depending on the facts of t he particular case, 
tuna product companies, as well as US  and foreign captains, could be held liable under this 
provision for false dolphin safe certifications.  United States' third written submission, para. 
123. 
Criminal Penalties for Making a False State ment or Writing.  18 USC  Section  1001 establishes 
criminal liability for any person who "knowingly and wilfully"  "makes a materially false, 
fictitious, or fraudulent statement or represent ation"  or "makes or uses any false writing or 
documents knowing the s ame to contain any materially false, fictitious, o r fraudulent 
statement or entry"  to the US government in any matter within its jurisdiction. Violation of this 
provision may be punished by a fine of up to $250,000 and/or up to 5 years imprisonment. 
Sectio n 1001 could potentially cover false statements on a Form 370 or a dolphin safe 
certification, if the captain or observer intentionally  lied. Both US  and foreign captains could 
potentially be liable under Section  1001 for making a false certification.  United States' third 
written submission, para. 123.  
Administrative Penalties for Violating the Dolphin Safe Regulations.  16 USC  Section  1375 
provides for a civil administrative penalty for" any person who violates any provision of this 
subchapter or of any perm it or regulation issued thereunder".  The penalty may be up to WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  these penalties may be applicable in cases where a tuna is imported with a Form 370 containing a 
false self -certification in respect of the training course. In our view, these sanctions provide 
important support to the new training requirement, and would create powerful incentives for tuna 
companies to ensure that the captains who pilot the vessels from which the y purchase tuna 
truthfully certify their completion of the training course.  
7.592.   Indeed, in our view, the statements submitted by Mexico from Bumblebee Tuna and 
TriMarine appear to support the view that US tuna companies have incentive to, and actually do, 
take the training requirement seriously. Thus, in its letter to the NMFS, BumbleBee states that " we 
find this component of the rule extremely challenging, if not virtually impossible, to fully 
implement".1037 Similarly, in its letter TriMarine observes that the n ew training course "places a 
significant and undue administrative burden on US tuna businesses and international supply 
chains ", and observes that even though many vessel captains "may not have access to computers, 
nor even be fully literate", "it is now the responsibility of the buyers of their fish to ensure that 
they" have completed the training course.1038 These statements express concern about the 
additional administrative burden that is placed by the new training requirement on US tuna 
companies , as well  as about the sanctions that may apply to such companies if they fail to 
properly implement the requirement. This indicates that these companies see the requirement as 
meaningful and enforceable, albeit difficult for them  to implement.  
7.593.   In this connection,  we recall the observation of the first compliance panel (made in the 
context of the different tracking and verification requirements) that "there is nothing inherently 
problematic, from the perspective of WTO law, about governments delegating functions to  private 
entities, including industry".1039 We maintain  this view, and see no problem with the 2016 Tuna 
Measure imposing responsibility to US importers of tuna to ensure that vessel captains undertake 
the necessary training, at least where, as we believe is the case, the training requirement is 
embedded within a sufficiently enforceable regulatory framework. The fact that tuna companies 
may have difficulty implementing the requirement is not, in our view, directly relevant to the 
question of whether the diffe rent certification requirements are calibrated to the different risks to 
dolphins arising from the use of different fishing methods in different areas of the ocean. Private 
enterprises often have to respond to regulatory interventions, but this fact does n ot, in our view, 
render the regulatory intervention meaningless or unenforceable.  
7.594.   Moreover, it appears that some of the concerns expressed by BumbleBee and TriMarine 
concerning the practicability of enforcing the training requirement have been addressed by  the 
United States. For example, BumbleBee expresses concern that the course "will not reach 
thousands of small scale tuna boat operators in developing nations", including because, at the time 
of writing, the course was only available in English.1040 However,  the course is in fact available in 
Mandarin Chinese, Indonesian, Japanese, Korean, Spanish, Tagalog, Thai, and Vietnamese, as well 
as English, and data from the NOAA Form 370 database for 2005 -2013 shows that 90% of records 
associated with the importation  of frozen and/or processed tuna came from vessels flying the flags 
of countries or territories that have at least one of the nine languages in which the course is 
available as an official language.1041 Similarly, we note that the United States has sent a dém arche 
to embassies of all countries that supply tuna product to the United States notifying these 
countries of the TTVP training course, and has mailed over 2,100 hard copies of the Training 
Course to fishermen, importers, and processors.1042 In our view, the se actions suggest that the 
                                                                                                                                                  
$27,500 per violation and up to $100,000 and/or up to a year 's imprisonment per knowing 
violation. The dolphin safe regulations fall with in the scope of this provision.  Thus making a 
false state ment or certification about the dolphin safe status of tuna on an FCO would violate 
50 CFR Sections  216.24(f)(2)  and (4), which require that a " properly co mpleted" and 
"accurate"  Form 370 accompany all imported tuna product.1036 This provision covers those wh o 
produce, import, distribute, or sell tuna product.  United States' third written submission, para. 
123. 
1037 Bumblebee Seafoods, Comments on Enhanced Document Requirements and Captain Training 
Requirements to Support Use of Dolphin Safe Label on Tuna Product s (April 15, 2016) , (Exhibit MEX -57) 
(emphasis added).  
1038 Tri Marine, Enhanced Document Requirements and Captain Training Requirements to Support Use of 
Dolphin Safe Label on Tuna Products, p. 1 (April 22, 2016) , (Exhibit MEX -58) (emphasis added).  
1039 Panel R eport, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.368.  
1040 Bumblebee Seafoods, Comments on Enhanced Document Requirements and Captain Training 
Requirements to Support Use of Dolphin Safe Label on Tuna Products (April 15, 2016) , (Exhibit MEX -57). 
1041 William Jacobson Second Witness Statement (July 21, 2014) , (Exhibit USA-11), Appendix 1.  
1042 United States' first written submission, para. 27, fn. 43.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  United States is aware of the potential difficulties tuna companies may face in implementing the 
training requirements, and is taking steps to facilitate the dissemination of the training course.  
7.595.   Taking these considerations into  account, we are of the view that the new training 
requirements do indeed narrow the difference between the certification requirements that apply in  
the ETP large purse seine fishery and other fisheries, as the United States argues. Unlike the 
situation un der the 2013 Tuna Measure, we consider that the training course incorporated in the 
2016 Tuna Measure contains meaningful information concerning key aspects of the certification 
process that would assist captains to understand and properly carry out their responsibility to 
certify the dolphin -safe status of a set or other gear deployment. We also consider that the 
training requirement is embedded within a sufficiently enforceable regulatory framework, and are 
therefore not meaningless or unenforceable, as M exico contends. We also note that the training 
course is being actively disseminated by the United States itself, in order to facilitate the effective 
implementation of the training requirement.  
7.596.   Having said all of the above, we nevertheless recognize that the new training course is not 
the same as the training that AIDCP observers receive. For example, although we have found 
above that the NOAA training course contains meaningful information concerning key aspects of 
the certification process that would ass ist captains to understand and properly carry out their 
responsibility to certify the dolphin -safe status of a set or other gear deployment, we also 
recognize that a 10 -slide training course is not equivalent to a degree in biology or a related 
subject (zo ology, ecology, etc.), which AIDCP observers are required to have. Moreover, AIDCP 
observers apparently receive extensive training. For example, Mexico has submitted a sample 
program of an observer training course that lasts 16 days, which covers a range o f topics related 
to dolphins.1043  
7.597.   Similarly, although we have found that many fisheries management experts rely on 
captain certifications, and therefore that such certifications are not inherently unreliable, we 
acknowledge, as did the first compliance panel , that observer certification could strengthen the 
certification system, and may "heighten[] or increase[] the accuracy and reliability of the 
label" .1044 
7.598.   Finally, we accept some of the concerns raised by BumbleBee and TriMarine, in particular 
relating to the  possible lack of Internet access and illiteracy among some tuna vessel captains, 
suggest that there may be some captains who are unable or unwilling to complete the training 
course. Additionally, there may be captains who do not understand any of the lang uages in which 
the course is available, and who consequently will not be able to complete the training.  
7.599.   The above factors indicate that, although the 2016 Tuna Measure has narrowed the 
difference between the certification requirements that apply in  the ETP  large purse seine fishery 
and other fisheries, differences remain. It also appears to us that, as the first compliance panel 
found, these differences may make it easier or more likely for dolphin -safe certifications made only 
by captains to be inaccurate than it is for dolphin certifications made by captains and 
observers.1045 
7.600.   However, we do not consider that this deprives the certification requirements of 
calibration. Rather, we believe that the differences that still exist between the certification 
requirem ents in the ETP large purse seine fishery and those that exist in other fisheries are 
calibrated to the different risk profiles associated with those fisheries.  
7.601.   In arriving at this conclusion, we draw on the reasoning provided by the panelist who 
wrote a separate opinion in the first compliance proceedings , which we find particularly compelling 
in the light of the Appellate Body's emphasis in the first compliance proceedings on the importance 
of conducting a calibration analysis . The separate opinion conta ined the following passages:  
[N]either captain nor observer certification is capable of detecting every  instance of 
dolphin mortality or serious injury . The language of the certification notwithstanding, 
all that can really be certified, by either a captai n or an observer, is that no dolphin 
                                                
1043 Agenda de trabajo para el curso de observadores a bordo de barcos atuneros de la Comisión 
Interamerica na del Atún Tropical, Manta - Ecuador, mayo 23 al 9 de junio de 2016 , (Exhibit MEX -86). 
1044 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.168.  
1045 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.168.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  mortality or serious injury was detected  – that is, observed - in a set or other gear 
deployment. The capacity for human error being what it is, it is simply impossible for 
even the most highly qualified observer to say  with certainty that no dolphin was 
killed or seriously injured during a fishing operation. Both the observers' and captains' 
certificate should be seen as reliable indication of whether dolphin mortality or injury 
was detected or not. However, it is obvio us that when there is no independent 
observer on board, the probability that dolphin mortality or serious injury is detected 
is less likely than in situations where a specially trained independent observer is on 
board.  
The consequence of this is that, in r espect of both captain and observer certification, a 
certain degree or margin of error is necessarily tolerated. The margin of error may be 
smaller in the case of observer certification than in the case of captain certification; 
but in both cases there is always some chance that a dolphin death or serious injury 
will go unobserved. Accordingly, we can talk of the difference between captain and 
observer certification not only in terms of how accurate or sensitive  each one is, but 
also in terms of how large a  margin of error  each one allows.  
Now, accepting that certification, whether by captain or observer, always allows a 
certain margin of error, the question is whether it is acceptable, under Article  2.1 of 
the TBT  Agreement, for the United  States to tolerat e a greater margin of error in the 
mechanisms in place outside the ETP large purse seine fishery than inside it. In my 
view, it is. Put simply, my opinion is that where the probability of dolphin mortality or 
serious injury is smaller – because, for instan ce, the degree of tuna -dolphin 
association is less likely - the United  States may accept a proportionately larger 
margin of error. Conversely, where the risks are higher, it may be appropriate to 
tolerate only a smaller margin of error. Provided that the t olerated margin of error is, 
to use a term from the original proceedings, "calibrated" to the risks faced by dolphins 
in a particular fishery, the mere fact that the detection mechanisms inside the ETP 
large purse seine fishery and outside of it are not th e same does not deprive the 
amended tuna measure of even -handedness. Indeed, understood in this sense, 
"calibration" of the acceptable margin of error to the degree of risk in a particular 
fishery seems to me to be at the very heart of the even -handedness analysis in this 
case.  
A hypothetical may help to clarify my view. Say a city imposes a speed limit of 80 
km/h on all roads. Say also that to detect violations of this speed limit, the city has 
developed a system of police observation. Now, assume that su burb A has a higher 
incidence of speeding than does suburb B. As a result, the city requires police 
observation every day on major roads in suburb A with highly sensitive detectors, but 
only four days a week in suburb B with less sensitive machines. Could such a set -up 
be described as lacking even -handedness? In my view, it could not. As I see it, it is 
entirely reasonable for governments, in the course of enforcing regulations, to vary 
the intensity of their detection mechanisms in accordance with the hist orical incidence 
of and future potential for violations. Provided that there is a rational connection 
between the variation in intensity and the difference in risk, I would not find that the 
implementation of different detection mechanisms lacks even -hande dness or is 
otherwise discriminatory.1046 
7.602.   As we have stated above, in the light of the Appellate Body's emphasis on calibration in 
these proceedings, we consider that analysing the relationship between any margin of error 
existing under the 2016 Tuna Measure and the degree of risk in a particular fishery may be an 
important consideration in our calibration assessment. In the context of the certification 
requirements, our view is that it is calibrated for the United States to tolerate a higher margin of 
error i n respect of fisheries other than the ETP large purse seine fishery and to tolerate a lower 
margin of error inside the ETP large purse seine fishery. This is so because, as we have explained, 
the ETP large purse seine fishery has a special risk profile.  
7.603.   Specifically, as we have explained, the association between dolphins and tuna and the 
interaction between fishing vessels and dolphins are particularly intense in the ETP. The ETP is the 
                                                
1046 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , paras. 7.274 -7.277 (emphasis in 
original).  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  only area of the ocean where setting on dolphins can technically and le gally be carried out in a 
consistent and systematic manner.1047 In our view, the unique intensity of the association and 
interaction explains why the parties of the AIDCP considered it necessary to place observers on -
board large purse seine vessels in the ETP  large purse seine fishery whose sole task it is to monitor 
dolphin interactions and certify the dolphin -safe status of a set. Conversely, the relatively low risk 
profiles o f other fisheries, which result  from both the absence of a tuna -dolphin association  similar 
to that in the ETP and the fact that other fishing methods pose relatively fewer risks to dolphins, 
and in many cases do not interact with dolphins at all, explain why the 2016 Tuna Measure does 
not generally require observer certification in thos e fisheries. To use the language of the separate 
panelist in the first compliance proceedings, the significantly higher risk profile of the ETP large 
purse seine fishery vis-à-vis other fisher ies explains the use in the former  of more sensitive 
detection m echanisms.  
7.604.   Mexico argues  that the use of a less sensitive mechanism outside the ETP  large purse seine 
fishery cannot be even -handed if it would result in the label becoming less accurate.1048 According 
to Mexico, any possibility of label inaccuracy would be inconsistent with the objectives of the 2016 
Tuna Measure, because "[i]f the dolphin -safe information regarding the tuna in products is 
inaccurate, then consumers cannot make a properly informed or meaningful decision".1049 
According to Mexico, "[a]ccuracy ca nnot be calibrated".1050 
7.605.   Mexico's argument appears to us to be premised on the notion that certification can 
guarantee accurate labelling in every case. However, as the separate panelist explained in the first 
compliance proceedings (and as the United States recognizes in these proceedings1051), 
certification, whether by captain or captain and observer, is unlikely to be able to detect every  
instance of dolphin mortality or serious injury in every case. In our view, it is unlikely that any 
system could be complet ely error -proof. Neither, in our view, must the United States' dolphin -safe 
labelling regime be completely error -proof in order to be calibrated. Rather, as we see it, the more 
pertinent question is whether the possibility of error is tailored to, or comme nsurate with, the 
different risks to dolphins arising from the use of different fishing methods in diffe rent areas of the 
ocean.  
7.606.   In our view, a measure that tolerates a larger margin of error where a risk is low, but 
tolerates a lower margin of error where  the risk is high, may very well be calibrated. Thus, insofar 
as the different certification requirements tolerate a higher margin of error in respect of fisheries 
where the risk to dolphins is relatively low, but tolerate a lower margin of error in fisher ies where 
the risk to dolphins is relatively high, we consider that they could be tailored to or commensurate 
with the relevant relative risks. As we have established above, the ETP large purse seine fishery 
has a special risk profile that sets it apart fr om other fisheries. This is due both the intense tuna -
dolphin association and the fact that only in the ETP is setting on dolphins, which is particularly 
harmful to dolphins, possible and permitted on a consistent and systematic manner. In the light of 
the ETP's special risk profile, we consider that it is calibrated for the United States to require a 
more sensitive mechanism in the ETP large purse seine fishery, while tolerating a less sensitive 
mechanism in other fisheries, which have relatively lower ris k profiles. In our view, this distinction 
addresses the relative risks posed to dolphins in the ETP large purse seine fishery on the one hand 
and other fisheries on the other hand in a way that is calibrated to, tailored to, and commensurate 
with the risk profiles of those fisheries.1052 
7.607.   We also do not believe that, by tolerating a higher or lower margin of error, the 
certification requirements conflict with the objectives of the 2016 Tuna Measure. This is because, 
in our view, the risk of inaccurate certifica tion is not a constant that remains unchanged in all 
fisheries. Rather, the risk of inaccurate certification seems to us to be closely tied to the level of 
risk posed to dolphins by the use of a particular fishing method in a particular area of the ocean. 
That is, in our view the risk of inaccurate labelling is a function,  inter alia , of the risk profile of a 
fishery. In a fishery where there is no dolphin interaction, the risk that a certifier (whether captain 
or observer) may make an incorrect dolphin -safe certification will surely be very low, if not zero. 
                                                
1047 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.226.  
1048 Mexico's response to Panels' question No. 86, para. 147. 
1049 Mexico's comments on  the United States' response to Panels' question No. 40, para. 94.  
1050 Mexico's response to Panels' question No. 86, para. 147.  
1051 United States'  comments on Mexico's  response to Panels' question No. 76, paras. 91-92. 
1052 See Appellate Body Report s, US – Tuna I I (Mexico) (Article 21.5 – Mexico) , para.  7.122; US – Tuna 
II (Mexico) , para. 292.   WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  On the other hand, where there is significant dolphin interaction, or where there is evidence that a 
fishing method has a history of causing harms to dolphins, the chance of inaccurate labelling may 
be higher (since there is more risk that a dolphin will be killed or seriously injured). In this sense, 
the possibility of inaccurate certification seems to us to be tied not only to the presence or absence 
of an observer, but also to the relative risk profil es in different fisheries. These two factors work 
together, such that where the risk profile is higher, an independent observer may be needed to 
counterbalance the heightened risk. Conversely, in fisheries with relatively low risk profiles, 
captain certifi cation may be sufficient.  
7.608.   Thus, in our view, the mere fact that a vessel has an observer on -board does not 
necessarily, or in isolation, mean that that vessel less likely to produce an inaccurate certification. 
As the first compliance panel recognized1053, accuracy is a function of potentially many variables. 
Thus, while an observer may strengthen the certification, such additional strength may not always 
be needed, as in fisheries where the risk profile is relatively low.   
7.609.   Finally, we note that the certifica tion requirements are complemented by the 
determination provisions. We will discuss the determination provisions in detail later in these 
Reports. For present purposes, it suffices to  note that the 2016 Tuna Measure fills the gap in the 
determination provi sions identified by the panel and the Appellate Body in the first compliance 
proceedings.  In the first compliance proceedings, the panel found that the determination 
provisions "open[ed] up a gap in the certification procedures applied outside the ETP larg e purse 
seine fishery" because a determination of regular and significant mortality could not be made in 
respect of purse seine fisheries outside the ETP, and a determination of regular and significant 
tuna-dolphin association could not be made in respect of a non -purse seine fishery.1054 On appeal, 
the Appellate Body confirmed that "the determination provisions do not provide for the substantive 
conditions of access to the dolphin -safe label to be reinforced by observer certification in all 
circumstances of c omparably high risk".1055 
7.610.   In response to these findings, the United States amended the determination provisions in 
the 2016 Tuna Measure . Under the 2016 Tuna Measure,  an observer certification may be required 
in addition to a captain certification where the A ssistant Administrator of NOAA has determined 
that the fishery in question has a regular and significant tuna -dolphin association (similar to that in 
the ETP), or has regular and significant dolphin mortality or serious injury.1056 This means that the 
2016 Tu na Measure contains sufficient flexibility to enable the United  States to impose the same 
requirements in fisheries where the same degree of risk prevails.1057 Thus, where the risks rise to 
a level where the requirement of an independent observer would be "co mmensurate", the 
determination provisions enable the United States to so require. The determination provisions help 
to ensure that the certification requirements are calibrated to, tailored to, and commensurate with 
the relevant relative risks, since they ensure that similar situations are treated similarly under the 
2016 Tuna Measure.1058 In our view, the revised determination provisions help to ensure that the 
2016 Tuna Measure addresses the risks posed to dolphins by tuna fishing outside of the ETP large 
purse seine fishery in a way that is "calibrated" to the risk profiles of those fisheries vis-à-vis the 
special risk profile of the ETP large purse seine fishery.  
7.611.   For all of these reasons, our opinion is  that the certification requirements in the 2016 Tuna 
Measure address the relative risks posed to dolphins in the ETP large purse seine fishery on the 
one hand and other fisheries on the other hand in a way that is calibrated to, tailored to, and 
commensurate with the risk profiles of those fisheries.  Accordin gly, we consider  that the different 
certification requirements are calibrated to the risks to dolphins arising from the use of different 
fishing methods in different areas of the ocean.  
                                                
1053 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.382.  
1054 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.263 . 
1055 Appellate Body Rep ort, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.266.  
1056 50 CFR Section  216.91(a)(3)(v) , (Exhibits USA-02, MEX -2). 
1057 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.280 . See also Appellate Body 
Report, para. 7.185.  
1058 Panel Re port, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.263.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.8.4   The tracking and verification requirements  
7.8.4.1   Introduction  
7.612.   We now turn to  consider whether the tracking and verification requirements are calibrated 
to the risks to dolphins arising from the use of different fishing methods in different areas of the 
ocean.  
7.613.   As we have explained in Section 7.4.2 above , tuna products are eligible to receive a 
dolphin -safe label only if they meet the tracking and verification requirements provided for in the 
2016 Tuna Measure. The 2016 Tuna Measure, like the original and the 2013 Tuna Measures, 
requires that dolphin -safe and non -dolphin -safe tuna, wherever and however caught, be 
segregated from the moment of catch through the entire processing chain.1059 However, the 
requirements pursuant to which tuna must be segregated, tracked, and verified differ between 
tuna caught in t he ETP large purse seine fishery, on the one hand, and other fisheries, on the 
other hand. This is because the tracking and verification of tuna caught in the ETP large purse 
seine fishery must be conducted consistently with the AIDCP Tracking and Verifica tion System.1060 
However, the tracking and verification of tuna caught in other fisheries must be conducted 
according to different regulations established under the 2016 Tuna Measure and contained 
principally in the implementing regulations . 
7.614.   We recall that in  the first compliance proceedings, the panel concluded that, with respect 
to the second tier of Article  2.1 of the TBT  Agreement, Mexico had shown that there was no 
rational connection between the differential burden created by the different tracking and 
verification requirements and the objectives of the 2013 Tuna Measure.1061 In reaching this 
conclusion, the first compliance panel stated that Mexico's evidence suggested that there were 
three crucial differences between the tracking and verification system th at applies to tuna caught 
by large purse seine vessels inside the ETP and that which applies to other tuna. These differences 
were (i) depth , (ii) accuracy , and (iii) degree of government oversight  of the tracking and 
verification systems.1062 
7.615.   Regarding the c oncept of depth , the first compliance panel explained that it understood 
this concept "to refer to the point to which tuna can be traced back".1063 It explained that Mexico 
had shown that tuna caught by large purse seine vessels in the ETP could, pursuant to the record -
keeping requirements embedded in the AIDCP and incorporated into the 2013 Tuna Measure, be 
tracked back all the way to the particular set in which the tuna was caught and the particular well 
in which it was stored1064, but that in contrast, it appe ared that outside the ETP, tuna could be 
traced back only to the vessel  and trip on which it was caught.1065 
7.616.   Regarding accuracy , the first compliance panel explained that by using this term it meant 
"the degree of confidence that a particular captain (or, whe re applicable, observer) statement 
properly describes the lot of tuna to which it is assigned".1066 The panel stated that while Mexico's 
evidence suggested that the tuna tracking forms required for tuna caught by large purse seine 
vessels in the ETP accompany  particular catches of tuna throughout the fishing and production 
process, from the point of catch right through to the point of retail1067, it was not clear how, under 
the NOAA regime, particular certificates were kept with particular lots of tuna up until t he tuna 
reached the canning plant.1068 The first compliance panel went on to say that the difficulty of 
ensuring that a particular certification matched an identified batch of tuna was compounded by the 
fact that in many cases tuna appears to pass through a n umber of parties before it reaches a 
US cannery.1069 The first compliance panel explained that it did not appear that there was any 
additional or explicit legal requirement in the 2013 Tuna Measure that US  canneries ensure or 
                                                
1059 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 6.12; 50 CFR Section 
216.9 3(c)(1) -(3), (Exhibit s USA-02, MEX -02). 
1060 Appellate Body Report, US – Tuna II (Mexico)  (Article 21.5 – Mexico) , para. 6.12. 
1061 Panel Report,  US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.392.  
1062 Panel Report,  US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.354.  
1063 Panel Report,  US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.355.  
1064 Panel Report,  US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.355 . 
1065 Panel Report,  US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.356.  
1066 Panel Report,  US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.360.  
1067 Panel Report,  US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.360.  
1068 Panel Report,  US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.361.  
1069 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.362.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  otherwise satisfy themselves, at the time they receive a batch of tuna, of either the validity of a 
dolphin -safe certificate or whether such certificate in fact described the batch of tuna with which it 
was associated.1070 Regarding this last point, the first compliance panel noted that unde r 50 CFR 
Section  216.93(g)(1), canneries were required to "maintain records", but there did not appear to 
be any legal requirement that the canneries verify the accuracy of the records, or that the records 
in fact correctly describe the particular batches of tuna to which they are assigned.1071 
7.617.   As to government oversight , the first compliance panel defined this as "the extent to which 
a national, regional, or international authority is involved in the tracking and verification 
process".1072 It explained that acco rding to Mexico's evidence, in respect of tuna caught by large 
purse seine vessels in the ETP, information concerning every stage of the tuna catch and canning 
process was made available to national and regional authorities, which had to be sent copies of 
tuna tracking forms and were thus able to verify at any stage of the catch and canning process 
whether a particular batch of tuna was dolphin -safe. The first compliance panel also noted that 
various national and regional authorities were also required to b e notified whenever ownership of 
tuna changed.1073 The first compliance panel then went on to contrast these requirements with 
those under the NOAA regime, and stated that US  authorities received information concerning the 
origin and history of tuna only from  US tuna canneries themselves, through the monthly reports 
that such canneries were required to submit, and when the authorities carried out an audit or spot 
check.1074 However, the panel noted that even then it seemed that, under the NOAA regime, the 
United States was only able to verify that proper tracking mechanisms were implemented from the 
time the cannery received the tuna.1075 
7.618.   For the first compliance panel, it appeared that the United  States had to rely on the 
canneries for information about the movement  of the tuna prior to arrival at the cannery, and the 
United States was not able to go "behind the documents", as it were, to verify that a particular 
dolphin -safe certification actually described the batch of tuna with which it was associated. This led 
the first compliance panel to conclude that the US  authorities were not able to ensure that they 
received information that would enable them to track the movement and dolphin -safe status of 
tuna from the time of catch up to the point of delivery to a US  cannery.1076 
7.619.   The first compliance panel concluded that these three differences showed that the different 
tracking and verification requirements modify the conditions of competition, in particular, because 
the system imposed outside the ETP large purse seine fishe ry was significantly less burdensome 
than the system imposed inside the ETP large purse seine fishery.1077 The panel also found that 
these differences were not even -handed because there was no rational connection between the 
differential burden created by the  different tracking and verification requirements and the 
objectives of the 2013 Tuna Measure.  
7.620.    As we have explained above, the Appellate Body found fault in the first compliance panel's 
analysis and concluded that it "erred in its discrete assessments of the even -handedness of the 
different certification requirements, and of the different tracking and verification requirements".1078 
With respect specifically to the tracking and verification requirements, the Appellate Body found 
that the first compliance pane l's analysis failed to encompass consideration of the relative risks to 
dolphins from different fishing methods  in different areas of the oceans, and of whether the 
distinctions that the 2013 T una Measure draws in terms of the different conditions of acces s to the 
dolphin -safe label were explained in the light of the relative risk profiles.1079 In this regard, the 
Appellate Body faulted the panel for failing to identify those risks in respect of tuna caught both 
inside and outside the ETP large purse -seine fis hery, and for failing to  compare the different 
tracking and verification requirements in the light of those risks and the 2013 Tuna Measure's 
objectives concerning the protection of dolphins and providing accurate consumer information.1080 
                                                
1070 Panel Report, US – Tuna II (Mexico) (Article  21.5 – Mexico) , para. 7.363.  
1071 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.363.  
1072 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.364.  
1073 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.364 . 
1074 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.364.  
1075 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.364 . 
1076 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.365 . 
1077 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.370.  
1078 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.169.  
1079 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.169.  
1080 Appellate Body Report, US – Tuna I I (Mexico) (Article 21.5 – Mexico) , para. 7.167.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.621.   The Appellate Body also found fault in the first compliance panel's "segmented approach" 
when analysing the different sets of certification and tracking and verification requirements, as it 
"did not properly apply the legal test that it had identified as relevant to an asses sment of 
even-handedness, namely, 'whether the detrimental treatment can be reconciled with, or is 
rationally related to, the policy pursued by the measure at issue.'"1081 According to the Appellate 
Body, the panel failed to take "full account … of the manner  in which similar circumstances 
pertaining to the original tuna measure had been assessed in the original proceedings ".1082 
7.622.   We note, however, that the Appellate Body did not find any fault with the first compliance 
panel's conceptual approach to assessing the  2013 Tuna Measure's tracking and verification 
requirements. In particular, the Appellate Body did not criticize the panel for analysing the 
differences between the different regimes from the points of view of depth , accuracy  and degree of 
government overs ight. Indeed, the parties during the course of the present proceedings have also 
presented their arguments from the same three points of view. For these reasons, and in 
particular, being mindful of the Appellate Body's criticism of the fact that first comp liance panel 
failed to take "full account … of the manner in which similar circumstances pertaining to the 
original tuna measure had been assessed in the original proceedings "1083, we find it appropriate to 
follow the conceptual framework devised by the first  compliance panel with respect to depth , 
accuracy  and degree of government oversight , in assessing the 2016  Tuna Measure . 
7.8.4.2   Arguments of the parties in the present proceedings  
7.623.   Having recalled  the findings made in the previous stages of this dispute, we now m ove to  
assess the parties' arguments  in the present proceedings . 
7.624.   The United States argues that the evidence confirms the first compliance panel's finding 
that the ETP large purse seine fishery has a "special risk profile" for dolphins distinct from the ris k 
profiles of other fisheries.1084 The United States contends that similar to the eligibility criteria and 
the certification requirements, the difference in the tracking and verification requirements for tuna 
product s produced from the ETP large purse seine f ishery and from other fisheries able to produce 
dolphin -safe tuna product is commensurate with the different risk profiles of these fisheries. For 
the United States, given the fact that the Appellate Body has observed that the assessment of the 
even-handed ness of the Tuna Measure "must take account of the fact" that these three aspects 
"are cumulative and highly interrelated"1085, it is consistent with both the law and the evidence 
that the legal conclusion regarding the tracking and verification requirements be consistent with 
the legal conclusions in respect of the other two aspects of the measure (i.e. the eligibility criteria 
and the certification requirements).1086 
7.625.   The United States contends that the tracking and verification requirements are calibrated, 
and thus even -handed, because it is appropriate to use a more "sensitive" mechanism where the 
risks of dolphin mortality and serious injury are high, and a less "sensitive" mechanism where the 
risks of dolphin mortality and serious injury are low. For the Unit ed States, the fact that the 
"mechanism" here occurs subsequent to the catch of the tuna does not mean that the calibration 
argument is rendered irrelevant to this stage of the analysis. Thus, according to the United States, 
the fact that the two regimes m ay tolerate different "margin[s] of error[s]" does not mean that the 
tracking and verification requirements lack even -handedness.1087 
7.626.   The United States argues that any difference in the "margin of error" caused by the 
different requirements is commensurate to  the difference in risk because there is a significant 
difference in the risk profile for dolphins of the ETP large purse seine fishery compared to other 
fisheries that can produce dolphin -safe tuna, including in terms of direct dolphin mortalities caused 
in the fisheries. For the United States, this indicates that there is a greater likelihood that a vessel 
                                                
1081 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.169 (referring to 
Panel Report,  US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.91 ). 
1082 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.169.  
1083 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.169.  
1084 United States first written submission, para.  171 (referring to Panel Report, US – Tuna II  (Mexico)  
(Article 21.5 – Mexico), para. 7.398).  
1085 United States first written submission, para.  172 (referring to Appellate Body Report, US – Tuna II  
(Mexico)  (Article 21.5 – Mexico) , para. 7.166).  
1086 United States first written submission, para.  172. 
1087 United States first written sub mission, para.  173. WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  in the ETP large purse seine fishery will produce both dolphin -safe and non -dolphin -safe tuna on 
any fishing trip and that the two groups of tuna will have to be segregated and tracked.1088 
7.627.   The United States further contends that any differences between the two "mechanisms" , 
i.e. the tracking and verification systems, are small, particularly in the light of the significant 
difference in risk between the ETP  large purse seine fishery and other fisheries.1089 Regarding 
depth , the United States contends that both the AIDCP and NOAA regimes require that tuna 
product that is dolphin -safe (for purposes of their respective regimes) be traceable back to the 
harvesting vessel and trip and to the group of wells that held dolphin -safe tuna. Regarding 
accuracy , the United States contends that both regimes require chain of custody recordkeeping 
sufficient to enable national authorities to trace a particular lot of tuna from harvesting through 
processing. Regarding government oversight , both regimes enable a government authority to 
obtain documentation "concerning every stage of the tuna catch and canning process" and thus 
both enable governmental authorities to "go behind" th e dolphin -safe certifications to the same 
extent.1090 
7.628.   The United States argues that it would not be consistent with a calibrated approach to 
rigidly impose  the same level of tracking and verification requirements for all fisheries where there 
is any risk of d olphin harm. The United States contends that the differences in the 2016 Tuna 
Measure's tracking and verification requirements conform to the recordkeeping requirements that 
participants in different fisheries have adopted, in particular, the IATTC, which manages all the 
tuna fisheries in the ETP, and does not require similar recordkeeping for longline or pole and line 
vessels.1091 
7.629.   Mexico contends that under the 2016 Tuna Measure, dramatic differences remain between 
the tracking and verification requirements f or tuna caught by large purse seine vessels in the ETP 
and tuna caught elsewhere.1092 Mexico argues that the 2016 Tuna Measure continues to require 
that tuna products caught by large purse seine vessels in the ETP be supported by the 
documentation requirement s of the AIDCP, and that  the AIDCP rules for tracking dolphin -safe tuna 
are very detailed and comprehensive, applying from the moment of capture of the tuna all the way 
through unloading of the tuna, and then to the processing and marketing of the tuna pro ducts 
containing that tuna.1093 Mexico further contends that the 2016 Tuna Measure purports to require 
US processors and importers to collect and retain for two years " information on each point in the 
chain of custody regarding the shipment of the tuna or tun a product to the point of entry into US 
commerce", but that this is merely a repetition of what the United States said was already the 
situation under the 2013 Tuna Measure, namely, that i t was completely dependent on importers 
and processors, with no gove rnment oversight of the catch and processing operations that take 
place outside the United States.1094 
7.630.   Regarding the applicable legal test to assess the tracking and verification requirements, 
Mexico contends that the United States' proposed standard, whereby  it is appropriate to use a 
more "sensitive" mechanism where the risks of dolphin mortality and serious injury are high, and a 
less "sensitive" mechanism where the risks of dolphin mortality and serious injury are low1095, is 
legally incorrect. Mexico refers to its general arguments on the calibration test and underscores 
that the regulatory differences that pertain to the accuracy of information provided to US 
consumers are an integral part of the calibration test . In Mexico's view, where there are 
deficienci es in control and monitoring, a more stringent or more "sensitive" mechanism should be 
used in order to ensure that the information is accurate, as otherwise, any difference in the 
relevant regulatory distinctions that result in the provision of inaccurate  information to consumers 
would be contrary to the 2016 Tuna Measure 's objectives.1096 
                                                
1088 United States first written submission, para. 174. 
1089 United States first written submission, para. 175. 
1090 United States first written submission, para. 175 (referring to Panel Report, US – Tuna II  (Mexico)  
(Article 21.5 – Mexico) , paras. 7.364 -7.365).  
1091 United States' first written submission, paras. 175-176. 
1092 Mexico's first written submission, para. 285.  
1093 Mexico's first written submission, para. 287.  
1094 Mexico's first written submission, paras. 289 -290. 
1095 Mexico's first written submi ssion, paras. 289 -290. 
1096 Mexico's firs t written submission, para. 291. WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.631.   Mexico points to the fact that during the first compliance proceedings, the panel 
determined that the evidence provided by the United States from two major tuna products 
companies did not demonstrate that those companies could track tuna back to the vessel from 
which it was caught. Mexico contends that the first compliance panel found that the captains’ 
certifications were associated with lots of tuna only after they arrived  at a processing plant.1097 In 
this connection, Mexico argues that a form letter dated 28 March 2016 from the  US Department of 
Commerce sent to importers uses similar language  to that used in the Federal Register notice that 
explains the type of documents tha t are required under the new record keeping provision ,1098 
although it adds that the type of documentation that may be used includes Form 370 and the 
captain 's statement.1099 Mexico claims that , the modifications introduced in the 2016 Tuna 
Measure therefore app ear to contemplate that producers and importers can satisfy the tracking 
requirements with documents they already have received in the normal course of business. 
However, according to Mexico, the first compliance panel already found that such documents, 
including documents obtained by the  US Department of Commerce during its verification visits to 
US producers were insufficient to demonstrate precise tracing back to the vessel that caught the 
fish.1100 
7.632.   Additionally, Mexico submit s that outside the ETP there ar e no requirements for, and no 
established practice of, segregating dolphin -safe tuna from non -dolphin -safe tuna in storage wells 
or during trans -shipment1101, and that, under the 2016 Tuna Measure, to avoid the burdens of 
segregation , captains will have an ev en stronger incentive than previously not to disclose dolphin 
mortalities and serious injuries.1102 
7.633.   Mexico also argues that the  US Department of Commerce lacks jurisdiction to audit foreign 
fishing vessels, carrier vessels, and foreign processors, and the new  regulations do not impose any 
obligation on US processors or importers to validate the documentation they receive.1103 Mexico 
claims that under some other US government regulatory compliance programs, unrelated to 
fishing, a US company would be expected to a udit its suppliers or customers, and to have records 
of such audits available for review by governmental authorities, but notes that there is no such 
obligation under the new regulations.1104 
7.634.   Mexico contends that in the first compliance proceedings, it submit ted extensive evidence 
regarding the complex supply chain for tuna, the widespread practice of trans -shipping, and the 
problem of IUU fishing, and that the first compliance p anel took note of the issue.1105 Mexico 
maintains that , unlike the Mexican industry, most major tuna products companies in other 
countries are not vertically integrated. According to Mexico, tuna companies in these countries 
purchase tuna from third party companies, and in many cases tuna passes through several parties 
before it is process ed.1106 
7.635.   In conclusion, Mexico contends that the changes introduced in the determination 
provisions do not alter the foregoing, and that a number of the countries that are the largest 
suppliers of tuna and tuna products, such as Thailand, the Philippines and Chinese Taipei , are 
significantly deficient in the control and monitoring of fishing activities, and have been identified as 
extremely vulnerable to IUU fishing.1107 In this regard, Mexico submitted reports of the European 
Commission that , according to Mexico,  identify  significant problems in Thailand, the Philippines and 
                                                
1097 Mexico's first written submission, para. 292 (referring to Panel Report, US – Tuna II (Mexico) 
(Article 21.5 – Mexico) , paras. 7.361 -7.363, 7.365; Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 
– Mexico) , para. 7.55).  
1098 Mexico's first written submission, para. 292 (referring to Enhanced Document Requirements and 
Captain Training Requirements To Support Use of the Dolphin Safe Label on Tuna Products, 81 Fed. Reg. 
15,444 (Mar ch 23, 2016) , p. 15447, (Exhibit USA -07)). 
1099 Mexico's first written submission, para. 293 (referring to Letter from US Department of Commerce 
to US tuna importer (March 28, 2016), (Exhibit MEX -60)). 
1100 Mexico's first written submission, para. 294 (referring  to Panel Report, US – Tuna II (Mexico) 
(Article 21.5 – Mexico) , paras. 7.356 -7.359 (BCI)  and 7.361) . 
1101 Mexico's first written submission, para. 295 (referring to Panel Report, US – Tuna II (Mexico) 
(Article 21.5 – Mexico) , paras. 7.361-7.363 (BCI) , 7.365,  7.368 -7.370, 7.378, 7.380) . 
1102 Mexico's first written submission, para. 295. 
1103 Mexico's first written submission, para. 297. 
1104 Mexico's first written submission, para. 297. 
1105 Mexico's second written submission, para. 96 (referring to Panel Report, US – Tuna II (Mexico) 
(Article 21.5 – Mexico) , para. 7.352).  
1106 Mexico's second written submission, para. 97.  
1107 Mexico's first written submission, para. 300. WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  Chinese Taipei with record -keeping and controls, including deficient use of logbooks, lack of 
traceabilty, and specifically problems with dolphin -safe certifications.1108 
7.8.4.3   Differences between the NOAA and the AIDCP regimes with respect to tracking 
and verification  
7.636.   The Panels  begin their analysis by noting that, as argued by Mexico, the 2016 Tuna 
Measure continues to impose different tracking and verification requirements on tuna products 
made from tuna caught in the ETP large purse seine fishery, on the one hand, and tuna products 
made from tuna caught in other fisheries, on the other hand. In particular, the tracking and 
verification for tuna from the ETP large purse seine fishery must be conducted  consistently with 
the AIDCP Tracking and Verification System1109, while tuna from other fisheries must be conducted 
according to different regulations established principally in the implementing regulations . 
7.637.   Although we have already described in detail the t racking and verification system of the 
2016 Tuna Measure in Section 7.4.2  above, we  find it essential for our task of assessing whether 
the tracking and verification  requirements are calibrated to differences in  the risk profiles of the 
different fisheries in different parts of the ocean to first pinpoint the relevant  regulatory 
distinctions that the 2016 Tuna Measure draws between tuna caught in the ETP large purse seine 
fishery, on the one hand, and tuna caught  in other fisheries, on the other.  
7.638.   In this connection, we note that the AIDCP Tracking and Verification System is based on 
the use of TTFs. Every TTF has a unique number. On every fishing trip, ETP large purse seine 
vessels must maintain two forms, one to record tuna harvested in dolphin -safe sets, and one to 
record tuna harvested in non -dolphin -safe sets.1110 The determination of the dolphin -safe status of 
tuna is made at the end of each set1111, and once the tuna harvested in a particular set is on -
board, it is  loaded into wells of the proper designation and recorded on the trip TTF.1112 
7.639.   Under the NOAA regime, all tuna product imported into the United States, regardless of 
where the tuna was caught and whether the dolphin -safe label is used, must be accompanied by a 
Form 370, which designates, inter alia , whether the tuna is dolphin -safe. Dolphin -safe and non -
dolphin -safe tuna products must have separate Form 370s. For tuna product designated dolphin -
safe, Form 370 contains the necessary certifications, and requires  identification of the harvesting 
vessel, the fishing gear used, and the trip on which the tuna was caught.1113 
7.640.   The NOAA regime requires US tuna processors to submit monthly reports to the US Tuna 
Tracking and Verification Program for all tuna received at the ir processing facilities. These reports 
contain the same information as is contained in the Form 370, as well as certain additional 
information, such as unloading dates and the condition of the tuna products. Additionally, NMFS is 
empowered to undertake ve rification activities, including dockside inspections of vessels, 
monitoring of Form 370s, monitoring of cannery reports, audits of US canneries, and retail market 
spot checks. Other US agencies may conduct on -board inspections on the high seas and in US 
waters.  
7.641.   We note that there are also differences be tween the two regimes regarding  certain other 
issues. Regarding the storage of tuna once it has been caught, we note that under the AIDCP 
regime , dolphin -safe and non -dolphin -safe tuna must be kept in separa te wells. Any tuna entered 
into a non -dolphin -safe well is considered to be non -dolphin -safe.1114 However, there is no 
requirement that tuna be segregated according to set. Thus, dolphin -safe tuna from different sets 
can be stored in the same well. In contras t, under the NOAA regime, dolphin -safe tuna must be 
stored physically separate from non -dolphin -safe tuna by the use of netting, other material, or 
                                                
1108 Mexico' s first  written submission, para. 115.  
1109 Appellate Body Report, US – Tuna II (Mexico) (Article 21. 5 – Mexico) , para. 6.12. As we noted 
above , the Appellate Body did not find any fault with this conceptual approach adopted by the first compliance 
panel in assessing the 2013 Tuna Measure's tracking and verification requirements . 
1110 International Dolphin C onservation Program, System for Tracking and Verifying Tuna, as amended 
(2015) , Section 3(2), (Exhibit USA -90); AIDCP TTF, (Exhibits USA -91, MEX -106).  
1111 International Dolphin Conservation Program, System for Tracking and Verifying Tuna, as amended 
(2015) , Section 4(1), (Exhibit USA -90). 
1112 See International Dolphin Conservation Program, System for Tracking and Verifying Tuna, as 
amended (2015) , Section  4(3), (Exhibit USA -90); AIDCP TTF, (Exhibits USA -91, MEX -106).  
1113 Appellate Body Report, US – Tuna II (Mexic o) (Article 21.5 – Mexico) , para. 6.25. 
1114 50 CFR Section  216.93(a). 50 CFR Section  216.93(c)(i) , (Exhibits USA -02, MEX -02). WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  separate storage areas from the time of capture through unloading.1115 Thus, under the NOAA 
regime, there is no  requirement to keep the dolphin -safe and non -dolphin -safe tuna in separate 
wells. In this regard, we note that the United States recognizes that segregation on -board a 
harvesting vessel outside the ETP large purse seine fishery could be achieved through t he 
designation of dolphin -safe and non -dolphin safe wells where a vessel has multiple wells, but could 
also be achieved through the use of netting or other materials.1116 
7.642.   Regarding the processing of tuna during the canning process, under the AIDCP regime, 
during storage and processing, dolphin -safe and non -dolphin -safe tuna cannot be processed on the 
same lines at the same time.1117 Additionally, dolphin -safe and non -dolphin -safe tuna must be 
unloaded from fishing or carrier vessels into separate bins and each bi n must be identified with 
corresponding TTF number, the dolphin -safe status of the tuna, and confirmed scale weight for the 
tuna in that bin.1118 Also, and at the time of unloading, the relevant TTF must be transmitted to 
the competent authority of an AIDCP p arty.1119 Similarly, under the NOAA regime, non -dolphin -
safe tuna may not be mixed in any manner or at any time during processing with any dolphin -safe 
tuna or tuna products and may not share the same storage  containers, cookers, conveyers, tables, 
or other c anning or labelling machines.1120 In regards to the unloading of tuna under the NOAA 
regime, tuna offloaded to trucks, storage facilities, or carrier vessels must be loaded or stored in 
such a way as to maintain and safeguard the identification of the dolphin -safe designation of the 
tuna as it left the fishing vessel.  However, under the NOAA regime, there are no similar 
requirements to that of the AIDCP regime regarding the transmission of the relevant TTF to the 
competent authority of an AIDCP party ; the NOAA  regime does not require that equivalent 
information be sent to US authorities at the same stages of tuna processing .  
7.643.   With respect to record keeping, under the AIDCP regime, processors must maintain 
records complete enough to allow the lot numbers of proc essed tuna to be traced back to the 
corresponding TTF number.1121 In addition, tuna exported as dolphin -safe must be accompanied by 
a certificate of its dolphin -safe status issued by a competent authority, which must include a 
reference to the relevant TTF nu mber.1122 National programs established by AIDCP parties should 
undertake periodic spot checks and audits for tuna products.1123 Under the NOAA regime, and in 
particular, under the amendments introduced under the 2016 Tuna Measure introduced in 50 CFR 
216.91(a)( 5), there are new chain of custody record -keeping requirements for tuna products 
produced from "other fisheries". Specifically, US processors and importers of tuna or tuna products 
from such "other fisheries" are now required to collect and retain, for two  years, information on 
each point in the chain of custody of the tuna or tuna product, including information on all storage 
facilities, trans -shippers, processors, and wholesalers/distributors. This information must be 
provided to the NMFS upon request and  must be sufficient for the NMFS to conduct a trace -back of 
any product marketed as dolphin -safe to verify that the tuna product in fact meets the dolphin -
safe labelling requirements. The information must also be sufficient for the NMFS to trace any non -
dolphin-safe tuna loaded onto the harvesting vessel back to one or more storage wells or other 
storage locations for a particular fishing trip to prove that such non -dolphin -safe tuna was kept 
physically separate from dolphin -safe tuna through unloading.1124 In addition, as was the case  
already  under the 2013 Tuna Measure, the NMFS may undertake verification activities such as 
dockside inspections of vessels, monitoring of Form 370 s, monitoring of monthly cannery or 
                                                
1115 50 CFR Section  216.91(a)(4) , (Exhibits USA -02, MEX -02). 
1116 United States' first written submission, fn. 303.  
1117 International Dolphi n Conservation Program, System for Tracking and Verifying Tuna, as amended 
(2015) , Section  6(b) – (c), (Exhibit USA -90) 
1118 International Dolphin Conservation Program, System for Tracking and Verifying Tuna, as amended 
(2015) , Section  5(6), (Exhibit USA -90). 
1119 International Dolphin Conservation Program, System for Tracking and Verifying Tuna, as amended 
(2015) , Section  5(2) – (5) (Exhibit USA -90). 
1120 50 CFR Section  216.93(d)(4), (Exhibits USA -02, MEX -02). 
1121 International Dolphin Conservation Program, System fo r Tracking and Verifying Tuna, as amended 
(2015) , Section  6(c), (Exhibits USA -90). 
1122 International Dolphin Conservation Program, System for Tracking and Verifying Tuna, as amended 
(2015) , Section  6(d), (Exhibit USA -90). 
1123 International Dolphin Conservation  Program, System for Tracking and Verifying Tuna, as amended 
(2015) , s 7, (Exhibit USA -90). 
1124 United States' first written submission, para. 28. WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  processor reports1125, audits of US canneries1126, retail market spot -checks, and on -board 
inspection in US waters and high seas.1127 
7.644.   We observe that additionally, under the NOAA regime, and only if the fishery is designated 
under the determination provisions, in addition to the above requirements, valid docum entation 
signed by a representative of the vessel flag nation or the processing nation (if processed in 
another nation) is required. In particular, such documents must certify that the catch 
documentation is correct1128; that the tuna or tuna products meet th e dolphin -safe labelling 
standards1129; and that the chain of custody information is correct.1130 
7.645.   Regarding the possible sanctions arising from the breach of the requirements under the 
two regimes , we note that under the AIDCP regime, sanctions, if any, are depe ndent upon the 
legal regime and enforcement of the national authorities (either flag  of the ship or any national 
authority of the AIDCP party in whose territory the tuna is to be processed).1131 Breaches of the 
tracking and verification provisions, as well as  pending investigations, must be reported to IATTC 
international review panel.1132 The scope of sanctions for violations of the AIDCP, pursuant to 
domestic law of the parties, can take the form, inter alia , of a fine1133 or limitation or revocation of 
a dolphin mortality limits (DMLs). Similarly, under the NOAA regime, breach of the tracking and 
verification requirements may lead to the imposition of sanctions. In particular, sanctions for 
offering for sale or export tuna products falsely labelled dolphin -safe ma y be assessed against any 
producer, importer, exporter, distributor, or seller who is subject to the jurisdiction of the United 
States. Violators may be prosecuted under the DPCIA provisions directly, under federal provisions 
prohibiting false statements a nd smuggling, or under federal labelling standards.  
7.646.   Finally, we note that, as argued by Mexico in Exhibit MEX -93, there is an important 
difference between the AIDCP and NOAA regime relating to the person that is required to certify 
the fulfilment of certai n requisites. For instance, we note that whereas  under the AIDCP it is the 
independent observer that is required to certify that non -dolphin -safe tuna is segregated in a 
different well following a set where a mortality or serious injury was observed, under  the NOAA 
regime it is the captain who  does this.  
7.647.   We thus note that there are differences between the AIDCP and NOAA regime s with 
respect to the tracking a nd verification systems. Indeed, the United States itself recognizes that 
there remain differences be tween the two regimes after the 2016 modifications to the Tuna 
Measure, but argues that these are explained by the inherent differences between international 
and national systems.1134 In particular, the United States recognizes that one of the remaining 
differences relates to government oversight, and is the requirement under the AIDCP regime that 
tuna destined for export and using the AIDCP dolphin -safe label must be accompanied by a 
certification of its status issued by the competent national authority, whil e the NOAA regime does 
not include such a requirements for typical "other fisheries".1135 
                                                
1125 50 CFR Section  216.93(d)(1) -(2); 50 CFR Section  216.93(e),  (Exhibit s USA-02, MEX -02).    
1126 50 CFR Section  216.93(g)(3),  (Exhibits USA -02, MEX -02). 
1127 United States' first written submission, para. 146.   
1128 50 CFR Section  216.91(a)(5)(ii)(A),  (Exhibits USA -02, MEX -02). 
1129 50 CFR Section 216.91(a)(5)(ii)(B) , (Exhibit s USA-02, MEX -02). 
1130 50 CFR Section 216.91(a)(5)(ii )(C), (Exhibit s USA-02, MEX -02). 
1131 AIDCP, Resolution To Adopt The Modified System For Tr acking And Verification Of Tuna  (20 June 
2001) , (Exhibit MEX -59), Article 1(g) for the definition of the national authorities, Sections 2, 3, 5, and 6 for 
the obligatio ns of the national authorities; Comparison of Track and Verification of "Dolphin -Safe" Tuna under 
the AIDCP and the Revised Measure, (Exhibit MEX -93), p.3.  
1132 AIDCP, Resolution To Adopt The Modified System For Tr acking And Verification Of Tuna  (20 June  
2001), (Exhibit MEX -59), Article 7. We note that the example of such general report is provided in AIDCP, 
Report on the International Dolphin Conservation Program, Document  MOP-34-05 (10 October 2016) , (Exhibit 
MEX-103).  
1133 The Panels note that regarding infrac tions submitted to the IATTC international review panel , 
national authorities in Nicaragua and Venezuela, AIDCP contracting parties, imposed a fine in 2015. AIDCP, 
Report on the International Dolphin Conservation Program, Document  MOP-34-05 (10 October 201 6), (Exhibit 
MEX-103), p. 22 . 
1134 United States' first written submission, para. 167 . 
1135 United States' first written submission, para. 168 . WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.648.   Having described the differences between the two regimes, we move to the substance of 
our assessment of whether the tracking and verification requirements are calibrated  to the risks to 
dolphins arising from the use of different fishing methods in different areas of the ocean.  
7.8.4.4   Panels' assessment  
7.649.   We begin by recalling that the mere existence of the above -mentioned differences does  
not, in and of itself, render the 2016 Tun a Measure inconsistent with Article 2.1 of the TBT 
Agreement. Rather, and as we have discussed in detail in Section  7.5.2 above, such differences 
must be assessed in the light of the difference in the risk profiles of the diffe rent fishing methods 
in different areas of the ocean in order to determine whether the former are calibrated to the 
latter.  
7.650.   In this connection, we note Mexico's argument that the regulatory differences that pertain 
to the accuracy of infor mation provided t o US consumers should be an integral part of the 
calibration test, and that  where there are deficiencies in control and monitoring, a more stringent 
or more "sensitive" mechanism should be used in order to ensure that the information is 
accurate.1136 For the reasons given i n Section 7.5.2 above , where we concluded that the risk of 
inaccurate labelling does not  form part of the "risk profiles" of different fisheries , and where we 
disagreed with Mexico's argument that  the calibration  analysis must be "constrained by" a distinct 
analysis of the relationship between the detrimental impact and the objectives of the Measure , we 
reject Mexico's argument in this regard. Rather, we have found that the pertinent inquiry is 
whether the 2016 Tu na Measure, including the tracking and certification requirements, is 
calibrated to the risks to dolphins arising from the use of different fishing methods in different 
areas of the ocean.  We nonetheless note that, as expressed above, the calibration analy sis "takes 
account of the objectives of the Measure" insofar as those objectives inform the shape and content 
of the calibration test.  
7.651.   The Panels continue their analysis by noting that, similar to the certification provisions, the 
tracking and verification  requirements draw distinctions on the basis of different fisheries, that is, 
the use of a particular fishing method  in particular areas of the ocean, rather than different fishing 
methods  per se . Thus, the tracking and verification requirements that apply  in the ETP large purse 
seine fishery apply to all large purse seine vessels fishing in the ETP, regardless of whether those 
vessels actually set on dolphins. The question before us, therefore, is whether the distinctions with 
respect to tracking and verif ication made by the 2016 Tuna Measure between the ETP large purse 
seine fishery, on the one hand, and all other fisheries, on the other hand, are calibrated to the 
different risk profiles  of the relevant fisheries . 
7.652.   Regarding the difference in the risk prof iles that the Panels  should take into account in 
their analysis, we recall our conclusion in Section 7.7.2.8  above that the ETP large purse seine 
fishery has a special risk profile that sets it apart from other fisheries around  the world. In 
particular, we recall our finding that the ETP large purse seine fishery is the only fishery where 
large purse seine vessels can, technically and legally, set on dolphins in a routine and systematic 
manner. We also recall our findings regard ing the levels of observable and unobservable harms 
posed to dolphins in the ETP  large purse seine fishery both with and without setting on dolphins. In 
our view, these findings  indicate that there is a substantial difference between the risk profiles of 
the ETP large purse seine fishery  and the other fisheries discussed in Section 7.7.2 above.  
7.653.   Turning now to the issue of whether the particular differences in the tracking and 
verification requirements outlined above are calibrat ed to the differences between the risk profiles 
of the ETP large purse seine fishery, on the one hand, and other fisheries on the other hand, we 
recall again that the first compliance panel structured its analysis along the axes of depth , 
accuracy , and degree of government oversight . As we noted above,  the Appellate Body did not find 
any fault with this conceptual approach adopted by the first compliance panel in assessing the 
2013 Tuna Measure's tracking and verification requirements , and thus , we find it appropriate to 
follow the same approach in the present proceedings. We observe, however, that the analysis and 
findings made by the first compliance panel have to be approached with caution, as they did not 
"encompass consideration of the relative risks to  dolphins from different fishing techniques  in 
different areas of the oceans ", and of whether the distinctions that the 2013 T una Measure draws 
in terms of the different conditions of access to the dolphin -safe label were explained in the light of 
                                                
1136 Mexico's firs t written submission, para. 291. WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  the rela tive risk profiles.1137 Therefore, we will conduct our assessment being mindful that while 
some of the reasoning made by the first compliance panel is relevant, and may be useful, to our 
current task, the essence of the legal test that we are currently applyi ng is different.  
7.654.   Regarding depth , that is, the point to which tuna can be traced back, we note that similar 
to the situation in the first compliance proceedings, under the 2016 Tuna Measure, tuna caught 
under the AIDCP regime can potentially  be tracked bac k all the way to the particular set in which 
the tuna was caught and the particular well in which it was stored. This is so because on every 
fishing trip, ETP large purse seine vessels must maintain two forms, one to record tuna harvested 
in dolphin -safe s ets, and one to record tuna harvested in non -dolphin -safe sets.1138 The 
determination of the dolphin -safe status of tuna is made at the end of each set.1139 Once the tuna 
harvested in a particular set is on -board, it is loaded into wells of the proper designatio n and 
recorded on the trip TTF.1140 We nonetheless observe that during the course of these proceedings, 
the United States has submitted further explanations1141 that indicate to us that at the end of a 
fishing trip, the completed dolphin -safe TTF would indicate how many sets occurred with no 
dolphin mortality or serious injury and all the wells in which the dolphin -safe tuna was stored, but 
tuna from a particular set would not necessarily be identifiable, as it may have been stored in the 
same well with other tun a from another dolphin -safe set. This is a consequence of the fact that the 
only requirement regarding well storage is that dolphin -safe and non -dolphin -safe tuna must be 
loaded into different wells that are correctly designated.1142 Tuna from one set can be loaded into a 
well containing tuna from another set and tuna from one set can be loaded into multiple wells, 
provided always that it is loaded into wells of the correct designation (i.e. dolphin -safe or non -
dolphin -safe).1143 Thus, we find that under the AIDC P regime, tuna can be potentially  tracked back 
all the way to the particular set in which the tuna was caught and the particular well in which it 
was stored, under certain conditions, or to a particular TTF if the well or wells in which the tuna 
subject to  the TTF was stored  contained tuna from several sets.  
7.655.    The situation under the NOAA regime, in contrast, seems to have changed since the first 
compliance proceedings, in particular because of the amendments introduced in the 2016 Tuna 
Measure regarding the  new chain of custody record -keeping requirements. Under these new 
requirements, US processors and importers of tuna or tuna products from "other fisheries" (i.e. 
fisheries other than the ETP large purse seine fishery) are now required to collect and retai n, for 
two years, information on each point in the chain of custody of the tuna or tuna product. The 2016 
Tuna Measure requires that this information be sufficient for the NMFS to trace any non -dolphin -
safe tuna loaded onto the harvesting vessel back to on e or more storage wells or other storage 
locations for a particular fishing trip to prove that such non -dolphin -safe tuna was kept physically 
separate from dolphin -safe tuna through unloading.1144 Thus, and different from the situation 
under the 2013 Tuna Mea sure that led the first compliance panel to conclude that it appeared that 
outside the ETP, tuna could be traced back to the vessel  and trip on which it was caught1145, under 
the 2016 Tuna Measure , tuna can be to traced back to one or more storage wells or ot her storage 
locations for a particular fishing trip.  
7.656.   Thus, on the basis of the evidence before us, it appears, under both the AIDCP and the 
NOAA regimes, it is possible to track tuna back to one or more wells in which it was stored. Thus, 
                                                
1137 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.169.  
1138 International Dolphin Conservation Program, System for Tracking and Verifying Tuna, as amended 
(2015) , Section 3(2), (Exhibit USA -90); Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , 
para. 6.19. 
1139 International Dolphi n Conservation Program, System for Tracking and Verifying Tuna, as amended 
(2015) , Section 4(1), (Exhibit USA -90). 
1140 See International Dolphin Conservation Program, System for Tracking and Verifying Tuna, as 
amended (2015) , Section 4(3), (Exhibit USA -90); AIDCP TTF (Exhibits USA -91, MEX -106).  
1141 United States' first written submission, para. 152. 
1142 International Dolphin Conservation Program, System for Tracking and Verifying Tuna, as amended 
(2015) , Section  4(2), (Exhibit USA -90).   
1143 International Dolphin C onservation Program, System for Tracking and Verifying Tuna, as amended 
(2015) , Section  4(2), (Exhibit USA -90). In particular, we note that pursuant this Section "…the tuna is 
designated either dolphin safe or non -dolphin safe. The tuna is brailed and load ed into a prepared well or wells 
which already contain either dolphin safe tuna or non -dolphin safe tuna , as applicable, or into a prepared but 
empty  well or wells  which shall then be designated dolphin safe or non -dolphin safe, as applicable")  (emphasis 
added).  
1144 United States' first written submission, para. 28.  
1145 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.356.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  it seems to us th at there is no longer any meaningful difference  with respect to the depth of the 
requirements between the ADICP regime and the NOAA regime.  
7.657.   Turning now to accuracy , that is, the degree of confidence that a particular captain (or, 
where applicable, observer ) statement properly describes the lot of tuna to which it is assigned, 
we note that the first compliance panel stated that while Mexico's evidence suggested that the 
tuna tracking forms required for tuna caught by large purse seine vessels in the ETP acco mpany 
particular catches of tuna throughout the fishing and production process, from the point of catch 
right through to the point of retail1146, it was not clear how, under the NOAA regime, particular 
certificates are kept with particular lots of tuna up unt il the tuna reaches the canning plant.1147 We 
note, however, that under the 2016 Tuna Measure, and in particular , under the new chain of 
custody record -keeping requirements for tuna products produced from "other fisheries" , this 
situation has changed . Specifi cally, US processors and importers of tuna or tuna products are now 
required to collect and retain, for two years, information on each point in the chain of custody of 
the tuna or tuna product and this information must be provided to the NMFS upon request and 
must be sufficient for the NMFS to conduct a trace -back of any product marketed as dolphin -safe 
to verify that the tuna product in fact meets the dolphin -safe labelling requirements. Thus, these 
modifications seem to directly address the first complian ce panel's concerns with the 2013 Tuna 
Measure , in particular, because they require US processors and importers of tuna or tuna products  
to collect and retain  information on each point in the chain of custody of the tuna or tuna product . 
7.658.   Finally, turning t o government oversight , that is, the extent to which a national, regional, 
or international authority is involved in the tracking and verification process, we note that the first 
compliance panel explained that according to Mexico's evidence, under the AID CP regime, 
information concerning every stage of the tuna catch and canning process was made available to 
national and regional authorities, which must be sent copies of tuna tracking forms and are thus 
able to verify at any stage of the catch and canning process whether a particular batch of tuna is 
dolphin -safe. In contrast, the first compliance panel stated that under the NOAA regime, 
US authorities received information concerning the origin and history of tuna only from US  tuna 
canneries themselves1148, and that they were only able to verify that proper tracking mechanisms 
were implemented from the time the cannery received the tuna.1149 Importantly, the first 
compliance panel stated that it appeared that the United  States had "as it were, delegated 
responsibi lity for developing tracking and verification systems to the tuna industry itself, including 
canneries and importers, and [had] decided to involve itself only on a supervisory and ad hoc  basis 
through the review of monthly reports and the conduct of audits  and spot checks" .1150 However, 
the first compliance panel also found that "there is nothing inherently problematic, from the 
perspective of WTO law, about governments delegating functions to private entities, including 
industry", provided that delegation is done in a way that is consistent with the WTO Agreement (in 
this case, Article 2.1 of the TBT Agreement).1151 
7.659.   We note that a crucial point underscored by the first compliance panel was the inability of  
the US government under the NOA A regime to go "behind the  documents" in order to verify the 
movements of the tuna prior to the arrival to the cannery. This led the first compliance panel to 
conclude that the US  authorities were not able to ensure that they receive information that would 
enable them to track the movement and dolphin -safe status of tuna from the time of catch up to 
the point of delivery to a US  cannery.1152 
7.660.   We thus note that the main concern identified by the first compliance panel with respect to 
government oversight  was the inability of  the US gover nment under the NOA A regime to go 
"behind the documents" in order to verify the movements of the tuna prior to the arrival to the 
cannery.  
7.661.   In this connection, the 2016 Tuna Measure maintains the requirement that US tuna 
processors submit monthly reports to  the US Tuna Tracking and Verification Program for all tuna 
received at their processing facilities. As under the 2013 Tuna Measure, these reports contain the 
                                                
1146 Panel Report,  US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.360.  
1147 Panel Report,  US – Tuna II (Mexico) (Artic le 21.5 – Mexico) , para. 7.361.  
1148 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.364.  
1149 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.364 . 
1150 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.367. 
1151 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.368.  
1152 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.365 . WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  same information as is contained in the Form 370, as well as certain additional information, such  
as unloading dates and the condition of the tuna products. However, under the modifications 
introduced under the 2016 Tuna Measure regarding record keeping, we note that the mentioned 
concern  seems to have been addressed.  
7.662.   Under the modifications in 50  CFR 216.91(a)(5), US processors and importers of tuna or 
tuna products from such "other fisheries" are now required to collect and retain, for two years, 
information on each point in the chain of custody of the tuna or tuna product, including 
information on a ll storage facilities, trans -shippers, processors, and wholesalers/distributors. This 
information must be provided to the NMFS upon request and must be sufficient for the NMFS to 
conduct a trace -back of any product marketed as dolphin -safe to verify that t he tuna product in 
fact meets the dolphin -safe labelling requirements. To us, this addresses the previous inability of 
the US government under the NO AA regime to go "behind the documents", as NMFS will have the 
ability to check the information of the movem ent of the tuna, even before it arrive s at the cannery. 
Indeed, these modifications require US processors and importers to have information relating  to 
the storage facilities, trans -shippers, processors, and wholesalers/distributors of tuna, and such 
information must be sufficient for the NMFS to trace any non -dolphin -safe tuna loaded onto the 
harvesting vessel back to one or more storage wells or other storage locations. Therefore, the US 
government may now go behind the documents and check the movements o f the tuna along the 
various steps of the catch and processing of tuna.  
7.663.   Additionally, this modification seems to bridge the previous existing difference with the 
AIDCP regime, pursuant to which, according to the first compliance panel, information concerni ng 
every stage of the tuna catch and canning process was made available to national and regional 
authorities, which must be sent copies of tuna tracking forms and were thus able to verify at any 
stage of the catch and canning process whether a particular b atch of tuna is dolphin -safe. Under 
the 2016 Tuna Measure, the US authorities will now have access to information concerning every 
step in the chain of custody, from the catching vessel to the processor.  
7.664.   Regarding the delegation of the responsibility for d eveloping tracking and verification 
systems to the tuna industry itself, with a supervisory and ad hoc  involvement of the US 
government, we note that the new modifications do not change this situation. Indeed, and as 
pointed out by Mexico, the process of c ollecting and keeping the information seems to rely heavily 
on importers and processors1153, and while they are now required to keep information that is 
sufficient for the NMFS to trace any non -dolphin -safe tuna loaded onto the harvesting vessel back 
to one o r more storage wells or other storage locations, the degree of government oversight of the 
catch and processing operations that take place outside the United States seems to be somewhat 
limited.  
7.665.   In this regard, we note that even the United States recognise s this situation by stating that 
differences remain between the two systems.1154 For instance, under the AIDCP regime, the 
Secretariat brokers requests for the data and documentation that would allow a party to obtain 
information from processors of another pa rty sufficient to trace back tuna product through its 
chain of custody to the harvesting vessel and trip:  
7. PERIODIC AUDITS AND SPOT CHECKS  
… 
The Parties, at any time, may request that the Secretariat verify the dolphin safe 
status of tuna by reference to  the AIDCP Dolphin Safe Certificate number or TTF 
number. The Secretariat shall respond to such a request with confirmation of the 
status of that tuna on the basis of tracking information contained within the data and 
documentation transmitted to the Secre tariat, provided that such report by the 
Secretariat shall be consistent with the Agreement Rules of Confidentiality adopted in 
October 2000 and as they may be amended.1155 
                                                
1153 Mexico's first written submission, paras. 289 -290. 
1154 United States' first written submission, para . 167.  
1155 International Dolphin Conservation Program, System for Tracking and Verifying Tuna, as amended 
(2015) , Section 7, (Exhibit USA -90). WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.666.    Under the NOAA system, however, the NMFS would request this information from US 
proce ssors or importers directly.  
7.667.   We also note that another difference is the requirement in the AIDCP regime that tuna 
"destined for export" and using the AIDCP "dolphin -safe" label must be accompanied by a 
certification of its status "issued by the competent national authority":  
Processed dolphin safe tuna destined for export shall be accompanied by a 
certification of its "dolphin safe" status issued by the competent national authority, 
including reference to the corresponding TTF number, provided that such 
documentation shall not reference details  of fishing operations, except as relates to 
identification of types of fishing gear.1156 
7.668.    Under the NOAA regime, however, no such requirement is included for "other fisheries", 
unless they have been determined to be hig h risk, i.e. fisheries where a regular and significant 
dolphin mortality or serious injury or tuna -dolphin association is occurring. Under the modifications 
introduced in the 2016 Tuna Measure, we note that where NOAA has made such a determination, 
the NMFS will also require a government certificate validating ( 1) the catch documentation; 
(2) whether the tuna or tuna products meet the dolphin -safe labeling standards under 50 CFR 
Section  216.91; and (3) the chain of custody information reported to the US Gov ernment or 
maintained by the importer of record or the US processor, as applicable.1157 
7.669.   Accordingly, we agree with the United States1158 that under the revised regulations, where 
NOAA has determined that a regular and significant mortality or serious injury or t una-dolphin 
association is occurring in a particular fishery, the responsible government will need to validate the 
catch documentation provided on the Form 370 (or the equivalent documentation provided by US 
vessels to US canneries)1159, along with validating  that the product meets the dolphin -safe 
standard1160, and the chain of custody information for the tuna and tuna products .1161 We are 
nonetheless mindful that these enhanced government oversight requirements will only apply if a 
fishery has been determined by N OAA. 
7.670.   Thus,  although the 2016 Tuna Measure has narrowed the differences between the AIDCP 
and the NOAA regimes in several aspects of the tracking and verification requirements,  there are 
still differences between the two regimes regarding the extent of gove rnment oversight. 
Nevertheless, the existence of these differences do es not necessarily render the 2016 Tuna 
Measure inconsistent with Article 2.1 of the TBT Agreement, as our task consists in assess ing 
whether such differences are calibrated to the differ ences in the risk profiles of the different 
fisheries. 
7.671.   In assessing the legal significance of these differences, we recall our analysis in 
Section  7.8.3 that the relationship between any margin of error existing  under the 2016 Tuna 
Measure and the degree of risk in a particular fishery may be an important consideration in our 
calibration assessment.  We have explained that, in our view, it may be calibrated to use a more 
sensitive mechanism in areas where risks ar e high but a less sensitive mechanism in areas where 
the risks are low.  In the context of the tracking and verification requirements , our view is that it is 
calibrated for the United States to apply less strict (i.e. less sensitive) requirements in respect  of 
fisheries other than the ETP large purse seine fishery and to pose stricter (i.e. more sensitive) 
requirements  inside the ETP large purse seine fishery. This is so because, as we have explained, 
the ETP large purse seine fishery has a special risk prof ile.1162 
7.672.   In our view,  the difference in the risk profile of the ETP large purse seine fishery  compared 
to other fisheries indicates that there is a greater likelihood that a vessel in the ETP large purse 
seine fishery will produce both dolphin -safe and non -dolphin-safe tuna on any fishing trip , and that 
the two groups of tuna will have to be segregated and tracked. Conversely, there would be a lower 
                                                
1156 International Dolphin Conservation Program, System for Tracking and Verifying Tuna, as amended 
(2015) , sec. 6(d),  (Exhibit USA -90). 
1157 50 CFR Section  216.91(a)(5)(ii) , (Exhibit s USA-02, MEX -02). 
1158 United States' first written submission, para. 86. 
1159 50 CFR Section  216.91(a)(5)(ii)(A) , (Exhibit s USA-02, MEX -02). 
1160 50 CFR Section  216.91(a)(5)(ii)(B) , (Exhibit s USA-02, MEX-02). 
1161 50 CFR Section  216.91(a)(5)(ii)(C) , (Exhibit s USA-02, MEX -02). 
1162 See Section 7.8.3 above.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  likelihood that a set produces non -dolphin -safe tuna in other fisheries that would need to be 
segregated as a co nsequence of this. This justifies, in our view, the need for a stricter regime of 
tracking and verification in the ETP large purse seine fishery . As we have explained in the context 
of the certification requirements, the risk of inaccurate labelling is not  constant or independent of 
the risks that dolphins face in different fisheries. Rather, the risk of inaccurate labelling logically is 
a function  of the risk to dolphins in a particular fishery, in the sense that the higher the risk to 
dolphins, the higher  the likelihood of having non -dolphin -safe tuna during a set or a trip, and 
consequently, the higher the risk of inaccurate labelling. We thus consider that it is reasonable for 
the United States to apply a more sensitive tracking and verification mechanis m in respect of high -
risk fisheries. Doing so is "commensurate with" the risks to dolphins arising from the use of 
different fishing methods in different areas of the ocean.  
7.673.   In the light of these considerations,  we consider that any  potential  difference in  the 
"margin of error" caused by the different requirements is commensurate with the difference in risk 
because there is a  significant difference in the risk profile of the ETP large purse seine fishery 
compared to other fisheries that can produce dolphin -safe tuna.  
7.674.   Moreover, we note that under the determination provisions, additional requirements can be 
imposed on tuna produced in a fishery that has been designated as having a regular and 
significant tuna -dolphin association or mortality or serious injury.  In our view, the determination 
provisions thus create flexibility that enables the 2016 Tuna Measure to treat similar situations 
similarly. The determination provisions work together with the tracking and verification 
requirements to ensure that the 2016 Tuna Measure is calibrated to the risks to dolphins arising 
from the use of different fishing methods in different areas of the ocean.  
7.675.   Finally, we recall Mexico's contention that a number of the countries that are the largest 
suppliers of tuna and tuna pro ducts, such as Thailand, the Philippines and Chinese Taipei , are 
significantly deficient in the control and monitoring of fishing activities, and have been identified as 
extremely vulnerable to IUU fishing1163, and that the US Department of Commerce lacks 
jurisdiction to audit foreign fishing vessels, carrier vessels, and foreign processors . However, we 
note that, we have explained above in the context of the certification requirements, the NOAA 
regime provides that breach es of the tracking and verification re quirements may lead  to the 
imposition of sanctions. I n particular, sanctions for offering for sale or export tuna products falsely 
labelled dolphin -safe may be assessed against any producer, importer, exporter, distributor, or 
seller who is subject to the jurisdiction of the United States. Thus, even in the absence of 
jurisdiction by the  US Department of Commerce to audit foreign fishing vessels, carrier vessels, 
and foreign processors  or vulnerability  to IUU fishing  in some countries, the United States, th rough 
the 2016 Tuna Measure, has the necessary tools to induce compliance of US processors and 
importers . 
7.676.   For these reasons , we find that although there remain differences between the NOAA and  
AIDCP regimes with respect to tracking and verification, the Pa nels are of the view that such 
differences have been considerably narrowed in the 2016 Tuna Measure and the Panels find that 
the remaining differences are calibrated to the difference s in the risk profile of the ETP large purse 
seine fishery  compared to ot her fisheries . 
7.8.5   The determination provisions  
7.677.   The Panels now turn to consider the determination provisions. As we have already 
explained, the determination provisions allow for additional certification and tracking and 
verification requirements to be imposed  in respect of tuna caught outside the ETP large purse 
seine fishery under certain circumstances. In particular, under the determination provisions, the 
Assistant Administrator of NOAA may determine that a fishery other than the ETP large purse seine 
fishery has either a regular and significant association between dolphins and tuna (similar to the 
association between dolphins and tuna in the ETP) or a regular and significant mortality or serious 
injury of dolphins. If such a determination is made, tuna from  the determined fishery sought to be 
labelled as being dolphin -safe (a) must be accompanied by an observer certification, and (b) is 
subject to additional tracking and verification requirements.  
                                                
1163 Mexico's first written submission, para. 300. WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.678.   In the first compliance proceedings, both the panel and the A ppellate Body identified gaps 
in the coverage of the determination provisions. The Appellate Body, after finding that the 
determination provisions help "to ensure that similar situations are treated similarly under the 
amended tuna measure"1164, made the foll owing statement:  
[W]e have been able to examine the even -handedness of the labelling conditions 
applied under the amended tuna measure in certain scenarios that would present 
comparably high risks to dolphins inside and outside the ETP large purse -seine fi shery. 
We found, in this respect, that aspects of the design of the amended tuna measure 
reflect a lack of even -handedness. In particular, we considered that the determination 
provisions do not provide for the substantive conditions of access to the dolphi n-safe 
label to be reinforced by observer certification in all circumstances of comparably high 
risks, and that this may also entail different tracking and verification requirements 
than those that apply inside the ETP large purse -seine fishery.1165 
7.679.   The Appel late Body's conclusion was based on the finding of the first compliance panel 
that, under the determination provisions contained in the 2013 Tuna Measure, "a determination of 
regular and significant mortality cannot be made in respect of purse seine fisher ies outside the 
ETP, and a determination of regular and significant tuna -dolphin association cannot be made in 
respect of non -purse seine fisheries".1166 According to the compliance panel, this "gap in the 
certification procedures" meant that, "in some cases,  fisheries other than the ETP large purse seine 
fishery may be treated differently, and less stringently, under the amended tuna measure even 
where the conditions in that fishery mirror those in the ETP large purse seine fishery, either in 
terms of the lev el of dolphin mortality or the degree of tuna -dolphin association".1167 
7.680.   In the present proceedings, the United States claims that the 2016 Tuna Measure 
eliminates the gaps in the coverage of the determination provisions, identified in the first 
compliance pro ceedings. The United States notes that t he two  determination  provisions  analysed 
in the first compliance proceedings , which had p reviously been codified at 50 CFR  § 
216.91(a)(2)(i) and (a)(4)(iii),  have in the 2016 Tuna Measure  been combined into one provision, 
now codified at 50 CFR Section  216.91(a)(3)(v). According to the United States, t his consolidated 
and r evised  determination  provision provides that, as a condition for label ling tuna product 
dolphin -safe, NOAA may require an observer certification (i n addition to the captain certification) 
where the Assistant Administrator has determined that a fishery has a regular and significant tuna -
dolphin association (similar to that in the ETP) or has regular and significant dolphi n mortality or 
serious injury.  Thus, this authority applies equally to all fisheries – including purse seine fisheries 
and non -purse seine fisheries such as longline, pole and line, gilln et, and trawl fisheries – that are 
potentially eligible to produce dolphin -safe tuna product for th e US market.1168 
7.681.   Additionally, the United States argues that the 2016 Tuna Measure revised the 
determination provisions such that, if the Assistant Administrator makes a determination of 
"regular and significant" association  or "regular and significant" morta lity or serious injury, NMFS 
will require, as a condition of tuna product being marketed as dolphin -safe, a government 
certificate validating: (1) the catch documentation recorded on the NOAA Form 370 or US cannery 
report accompanying the tuna or tuna prod uct (e.g., the fishery in which the tuna was caught, the 
relevant trip dates, the type of gear with which the tuna was caught, and the harvesting vessel); 
(2) that the tuna or tuna products meet the dolphin -safe labelling standards of 50 CFR Section  
216.91 ; and (3) the chain of custody information that must be reported to the US Government or 
maintained by the importer of record or the US processor, as applicable (a new requirement 
described below).1169 
7.682.   Mexico accepts that the revised determination provision " eliminates the differences created 
by the statute with respect to purse seine fishing and other fishing methods".1170 However, Mexico 
                                                
1164 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.256.  
1165 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.266.  
1166 Panel Report,  US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.263.  
1167 Panel Report,  US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.263. 
1168 United States' first written submission, para. 22.  
1169 United States' first written submission, para. 25.  
1170 Mexico's first written submission, para. 139; response to Panels' question No. 82, para. 118. Mexico 
notes that no change has been made to the un derlying statute. Rather, the new requirements have been 
enacted by regulation. Mexico's first written submission, para. 138.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  questions the practicability of the additional tracking and verification requirements that apply to a 
fishery that has been d esignated under the determination provisions.1171 Moreover, Mexico argues 
that the US Department of Commerce has never  undertaken to make any determination – or even 
an evaluation – regarding whether any other fishery outside the ETP has regular and significa nt 
dolphin mortality or serious injury  or regular and significant association between dolphins and 
tuna. According to Mexico,  there are no procedures for making such a determination, nor has the 
US Department of Commerce ever sought public comments on that  subject in the context of the 
Tuna Measure. In Mexico's view, t he failure to evaluate whether or not there is regular and 
significant harm to dolphins occurring in fisheries outside the ETP, or the decision not to do so 
under the provisions of the 2016 Tuna Measure is itself an indication of arbitrariness.1172 
7.683.   In response to Mexico's argument, the United States first argues that there is no evidence 
that any fishery has a regular and significant tuna -dolphin association similar to that in the 
ETP.1173 The United  States next argues that there is a procedure for assessing whether regular and 
significant mortality or serious injury exists in a fishery outside the ETP. The United States 
recognizes that the text of the DPCIA is not explicit as to the metric by which r egular and 
significant dolphin mortality or serious injury should be assessed, or as to the benchmark against 
which levels of dolphin mortality should be measured, to determine whether they are regular and 
significant. According to the United States, it wa s therefore necessary to consider what metric and 
benchmark were most in keeping with the objectives of the US dolphin -safe labelling measure, in 
light of the available evidence.1174 The United States explains that it adopted a per set metric1175, 
to be assessed  against the benchmark of "a 20 -year average of direct dolphin mortalities caused 
by dolphin sets in the ETP, beginning in 1997 and ending at the present day".1176 The United 
States submits that, on the basis of this procedure, it considered the available fis hery-specific 
evidence concerning per set mortalities in fisheries other than the ETP large purse seine fishery, 
but found no evidence suggesting that, on a per set basis, any other fishery causes dolphin 
mortalities close to the level of mortalities cause d by dolphin sets in the ETP, as an average since 
1997 (which the United States calculates as 0.1265 mortalities per set ).1177 
7.684.   The United States further submits that it was not possible to find per set data for all 
fisheries, and, therefore, to make the most appropriate comparison between dolphin mortalities 
caused by dolphin sets in the ETP and those caused in other fisheries. According to the United 
States, for fisheries where bycatch is known to be low or non -existent, this did not raise a concern, 
since al l the available evidence suggests that dolphin mortality would not rise to the level of being 
regular and significant if per set data were available.1178 
7.685.   However, according to the United States, evidence from certain gillnet fisheries in the 
Indian Ocean area  suggested that levels of mortality are occurring such that, if per set data were 
available, the per set mortality rate likely would meet or exceed the "regular and significant" 
standard. The United States submits that because per set data was not availabl e for these 
fisheries, the United States considered whether any alternative metrics might act as a proxy for 
per set data and enable an evaluation of those fisheries. Ultimately, NOAA determined that data 
were available to support evaluation under a dolphi n bycatch rate metric, i.e. the number of 
dolphins killed per ton of target catch (tuna) landed. According to the United States, under this 
metric, the Indian Ocean gillnet fisheries in question exhibited bycatch rates significantly  higher 
than that caused  by dolphin sets in the ETP during the relevant period. On this basis, the United 
States concluded that the mortality per ton of tuna exceeded the mortality per ton of tuna in the 
ETP dolphin sets and that it was highly likely that, were per set data avail able, it would exceed the 
ETP benchmark, thus justifying a regular and significant mortality determination.1179 
                                                
1171 Mexico's first written submission, para. 140.  
1172 Mexico's first written submission, paras. 141 -142. 
1173 United States' second writt en submission, para. 158.  
1174 United States' second written submission, para. 160.  
1175 United States' second written submission, paras. 161 -163.  
1176 United States' second written submission, paras. 166; Dolphin Mortalities Per Set Due to ETP 
Dolphin Sets and in  Other Fisheries (Exhibit USA -111).  
1177 United States' second written submission, paras. 167 (citing Dolphin Mortalities Per Set Due to ETP 
Dolphin Sets and in Other Fisheries (Exhibit USA -111) and Tables Summarizing Fishery -by-Fishery Evidence on 
the Record ).  
1178 United States' second written submission, para. 168.  
1179 United States' second written submission, para. 172.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.686.   The United States explains that, subsequent to this conclusion, it sent letters to all the 
countries whose fleets would be affected by a determinat ion regarding these fisheries, asking for 
additional information as to the level of dolphin mortality occurring in their gillnet fisheries. Each 
country had sixty days to respond to provide current data with regard to its gillnet fisheries. 
According to th e United States, none of these countries replied with any more recent dolphin 
mortality studies. Therefore, on September 28, 2016, NOAA issued a determination, on the basis 
of the best information available, that a regular and significant mortality of dolp hins was occurring 
in these fisheries. The determination provided that any tuna product produced from these fisheries 
to be marketed as dolphin -safe in the United States would have to be accompanied by a 
certification by an observer from a qualified and au thorized observer program and a certification 
attesting to the catch documentation, the substance of the dolphin -safe labelling standards, and 
the chain of custody information.1180 
7.687.   In the United States' view, the above procedures establish that the applicatio n of the 
determination provisions, like their design, is consistent with Article 2.1 of the TBT Agreement.1181 
7.688.   Mexico disagrees with the United States that the determination provisions are applied in a 
manner that is consistent with Article 2.1 of the TBT Agr eement. With respect to the determination 
made in respect of certain Indian Ocean gillnet fisheries, Mexico contends that the United States 
chose these particular fisheries because it thinks they export no or little tuna to the United 
States.1182 
7.689.   Moreover, Me xico takes issue with the United States' explanation as to the process 
underlying the application of the determination provisions to the fisheries in the Indian Ocean 
area. Mexico argues that the explanation has not been published in any regulation, was no t the 
subject of public comments, and is not supported by any scientific analysis.1183 In Mexico's view, 
the United States is artificially inflating the benchmark by using an average of data from the ETP 
over the last two decades . According to Mexico, under t he United States' methodology, a fishery 
that has a higher bycatch rate in 2015 than the ETP fishery has in 2015 would not be designated 
as having regular and significant mortality and serious injury of dolphins. In Mexico's opinion, the 
United States has not explained how such an approach could be considered consistent with the 
objective of the Tuna Measure.1184 
7.690.   Finally, Mexico argues that the United States' methodology for deciding when to consider 
evidence of dolphin mortalities in a fishery deserving of in vestigation appears to be based on 
arbitrary judgments. Specifically, Mexico argues that in respect of fisheries and country fleets 
about which Mexico submitted evidence (other than the Indian Ocean gillnet fisheries subject to 
the determination), the Unit ed States rejects even the possibility that there could be regular and 
significant mortalities. Mexico submits that the United States did not even send letters to other 
countries asking for data on dolphin populations and mortalities in their tuna fisherie s.1185 In 
Mexico's view, for the United States to claim that there are no other fisheries worthy of 
examination under the determination provisions is unjustifiable and contrary to the objectives of 
the Tuna Measure. Other fisheries should have been evaluated and made the subject of 
designations.1186 
7.691.   The Panels begin by noting that the determination provisions have been considered above 
in the context of analysing whether the certification requirements and the tracking and verification 
requirements are calibrated to the risks to dolphins arising from the use of different fishing 
methods in different areas of the ocean. In those parts of these Reports, we have found that the 
revised determination provisions fill the gaps in coverage identified in the first complianc e 
proceedings, and help to ensure that similar situations are now treated similarly under the 2016 
Tuna Measure. In this way, the revised determination provisions create flexibility that helps to 
ensure that the 2016 Tuna Measure is calibrated to the diffe rent risks to dolphins arising from the 
use of different fishing methods in different areas of the ocean. We reaffirm our conclusion in this 
context, and reiterate our finding that the 2016 Tuna Measure has addressed and fixed the 
                                                
1180 United States' second written submission, paras. 173 -174. 
1181 United States' second written submission, paras. 157 and 175.  
1182 Mexico's second written submission, para. 104.  
1183 Mexico's second written submission, para. 105.  
1184 Mexico's second written submission, para. 107.  
1185 Mexico's second written submission, para. 108.  
1186 Mexico's second written submission, para. 112. WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  problem identified in the  first compliance proceedings (that is, the gap in coverage that existed 
because, under the 2013 Tuna Measure, the determination provisions did not provide for the 
substantive conditions of access to the dolphin -safe label to be reinforced by observer cert ification 
in all circumstances of comparably high risks1187). 
7.692.   Mexico now raises additional concerns regarding the application of the determination 
provisions. In particular, Mexico initially argued that no methodology exists under which the United 
States may designate fisheries under the determination provisions. After the United States 
explained its methodology in its second written submission, Mexico argues the application of the 
determination provis ions more generally, is  "arbitrary".1188 
7.693.   As we understand it, Mexico's arguments concerning the application of the determination 
provisions can be divided into two categories. First, Mexico argues that the methodology by which 
the United States applies the determination provisions is arbitrary. Second, Mexico argues that the 
United States has no methodology for deciding when  to investigate other fisheries, and that it 
refuses to investigate other fisheries despite evidence that those fisheries are causing substantial 
harms to dolphins.1189 
7.694.   With respect to the methodology  by which the United States applies the determination 
provisions, Mexico's arguments relate to two aspects of the methodology: its primary reliance on 
per set comparisons, and its use of a benchmark calculated on the basis of the average of per set 
data co llected in the ETP between 1997 and 2017. With respect to the use of per set comparisons, 
we have explained above, in the context of reviewing the evidence on the record concerning the 
different risk profiles of different fisheries, that a per set comparis on appears to us to be a 
scientifically legitimate way to assess the risks to dolphins across different fisheries.1190 Per set 
comparisons enable a relative assessment of the risks posed to dolphins by a unit of fishing effort. 
In this sense, they allow for a  fair and reasonable comparison of the different risks to dolphins 
associated with the use of different fishing methods in different areas of the ocean.  
7.695.   With respect to the benchmark used in the application of the determination provisions, we 
note the Unit ed States' argument that its decision to establish a benchmark based on an average 
of per set data from the ETP large purse seine fishery between 1997 and 2017 is based on a 
suggestion of the Appellate Body in the first compliance proceedings.1191 The relevan t part of the 
Appellate Report reads as follows:  
Although the amended tuna measure does not state what criteria inform a 
determination of regular and significant mortality or serious injury, we would 
understand the reference to "regular" and "significant" mortality or serious injury as 
indicating that there exist risks of dolphin death or serious injury that are equivalent 
to or greater than those existing in the ETP large purse -seine fishery.1192 
7.696.   In the United States' view, this passage indicates that the App ellate Body suggested that, 
to ensure even -handed treatment of different fisheries, the benchmark applied to fisheries other 
than the ETP large purse seine fishery should itself refer to the ETP large purse seine fishery.1193 
7.697.   We do not read the Appellate Body 's report in the same way as the United States. In 
particular, we do not understand the quoted passage to be a suggestion  as to what "regular and 
significant" should mean, but rather as a statement of what the Appellate Body understood it to 
mean already. Importantly, however, after articulating its understanding of this benchmark, the 
Appellate Body then proceeded to find that a determination against this benchmark  "also appears 
to enhance the correlation, in respect of  "all other fisheries ", between the r isks of harm to dolphins 
and the manner in which the measure seeks to address those risks ".1194 To us, this indicates that 
the Appellate Body considered it legitimate for the United States to establish the ETP large purse 
seine fishery as a benchmark against which "regular and significant" tuna -dolphin association and 
                                                
1187 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.266.  
1188 Mexico's response to Panels' question No. 82, para. 118.  
1189 Mexico's response to Panels' question No. 82, para. 120.  
1190 See Section 7.7.1.2.1.5  above . 
1191 United States' res ponse to Panels' question No. 31, para. 161. 
1192 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.257.  
1193 United States' response to Panels' question No. 31, para. 161.  
1194 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.257.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  mortality or serious injury would be defined. We also do not see any problem with the United 
States taking the ETP as the benchmark against which to assess the levels of tuna -dolphin 
association and mortality and serious injury to dolphins, provided that the benchmark is applied in 
an even -handed manner to all fisheries.  
7.698.   We note that even once it is accepted that the ETP large purse seine fishery can 
legitimately be used as a benchmark for the def inition of "regular and significant" tuna -dolphin 
association and mortality or serious injury, a further question arises concerning the precise data 
set from the ETP used to specify  the benchmark. As we have explained, the United States uses an 
"average of  per set data" collected in the ETP between 1997 and 2007  (which the United States 
calculates as 0.1265 mortalities per set ).1195 According to Mexico, however, this use of averaging 
artificially inflates the benchmark. In other words, according to Mexico, und er the United States' 
methodology, a fishery that has a higher bycatch rate in 2015 than the ETP fishery has in 2015 
would not be designated as having regular and significant mortality and serious injury of 
dolphins.1196 
7.699.   We do not agree with Mexico's argument  on the use of averaging. In our view, there is 
nothing arbitrary or lacking in even -handedness in the United States' decision to use an average in 
this connection. The reason is that, in our view, it would be misleading to compare the risk profile 
of the ETP following the adoption of heightened certification and tracking and verification 
requirements with the risk profile of other fisheries that are not subject to similar requirements. 
Mexico itself recognizes that the additional requirements imposed by th e AIDCP have significantly 
reduced the extent of mortality  and serious injury in the ETP large purse seine fishery . In our view, 
to compare those lower mortalities and serious injuries, which are in part a result  of the imposition 
of more stringent certifi cation and tracking and verification conditions, with the risk profiles of 
fisheries not subject to similar conditions would not represent an apples -to-apples comparison. A 
true apples -to-apples comparison would be against the ETP large purse seine fishery  prior to the 
adoption of the AIDCP. However, as the United States has explained, it adopted an average that is 
much more conservative because "it takes into account any declines in direct mortalities due to 
dolphin sets in the ETP that have occurred over the past 20 years". As a result, under the 2016 
Tuna Measure, a fishery can be designated under the determination provisions and thus be 
subjected to heightened certification and tracking and verification requirements even if its risk 
profile is lower than  the risk profile in the ETP prior to  the imposition of heightened certification 
and tracking and verification requirements. This appears to us to heighten  the level of protection 
of dolphins offered by the 2016 Tuna Measure. In our view, far from being ar bitrary or lacking in 
even-handedness, the use of this conservative benchmark seems to be perfectly consistent with 
the objectives of the 2016 Tuna Measure.  
7.700.   With respect to the methodology for deciding when  to investigate other fisheries, Mexico 
alleges th at the United States "refuses" to investigate any other fishery.1197 We do not see any 
evidence to support this allegation. To the contrary, in our view, the United States' submissions 
throughout these proceedings show that the United States has considered th e available evidence 
of risks to dolphins arising from the use of different fishing methods in different areas of the 
ocean, and has concluded that the vast majority of the world's fisheries have a lower risk profile 
than the ETP large purse seine fishery.  We have reviewed the evidence on the record and come to 
a similar conclusion. The fact that the United States has not designated other fisheries, and the 
fact that it does not agree with Mexico on what the evidence shows, does not mean that the United 
States has "refused" to consider the evidence. At any rate, Mexico has not explained to us why the 
United States not having such a methodology for deciding when  to investigate other fisheries 
would necessarily be inconsistent with the obligation laid down in Article 2.1 of the TBT 
Agreement, or would deprive the 2016 Tuna Measure of calibration.  
7.701.   With respect to the United States' decision to designate certain Indian Ocean gillnet 
fisheries but no other fisheries under the determination provisions, again we do not see that this is 
in any way inconsistent with Article 2.1 of the TBT Agreement, specifically because it would 
deprive the 2016 Tuna Measure of calibration. Rather, our review of the evidence on the record 
concluded that other fisheries have a relativel y lower risk profile than the ETP large purse seine 
fishery. We have found in particular that setting on dolphins, which is practiced routinely and 
systematically only in the ETP large purse seine fishery, causes significantly more mortalities and 
                                                
1195 Dolphin Mortalities Per Set Due to ETP Dolphin Sets and in Other Fisheries (Exhibit USA -111).  
1196 Mexico's second written submission, para. 107. 
1197 United States' response to Panels' question No. 120.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  serious injuries than other fishing methods in other areas of the ocean, and that no other fishery 
for which we have evidence has a per set mortality level even approaching that of the ETP. We 
have also found that setting on dolphins causes unobservable harms as a  result of the chase and 
encirclement process that are not caused by any of the other fishing methods. Moreover, we see 
no problem with the United States' decision to use a dolphin bycatch metric in the case of the 
Indian gillnet fisheries that were eventu ally designated because the United States has explained 
that this was due to the absence of per set data for these fisheries.1198 In our view, the use of an 
alternative, even if imperfect1199, metric where per set data is unavailable seems to us to be 
consistent  with the objectives of the 2016 Tuna Measure, since it furthers the protection of 
dolphins in fisheries that, on the basis of available evidence, have a regular and significant 
mortality or serious injury rate similar to that in the ETP large purse seine fishery.  
7.702.   For the reasons given above, we reject Mexico's argument that the determination 
provisions are applied in an arbitrary or uneven -handed manner. We consider that the 2016 Tuna 
Measure fills the gaps in the coverage of the determination provisions i dentified in the first 
compliance proceedings, and that such provisions have been applied in a reasonable way that 
helps to ensure that the 2016 Tuna Measure is calibrated to the different risks to dolphins arising 
from the use of different fishing methods  in different areas of the ocean.  
7.8.6   Overall assessment of the consistency of the 2016 Tuna Measure with Article 2.1 
of the TBT Agreement  
7.703.   In the preceding sections, we have assessed whether the various elements of the 2016 
Tuna Measure are calibrated to the r isks to dolphins arising from the use of different fishing 
methods in different areas of the ocean, and found that they are. Specifically, we have found that 
the eligibility criteria and the certification and tracking and verification requirements are, 
considered individually, calibrated. We have also found that the determination provisions create 
flexibility that contributes to the calibration of the certification and tracking and verification 
requirements, and therefore of the 2016 Tuna Measure as a whole . 
7.704.   As we have already indicated, following the guidance provided by the Appellate Body in the 
first compliance proceedings in this dispute, we are of the view that an assessment of whether the 
2016 Tuna Measure is calibrated to the risks to dolphins arising  from the use of different fishing 
methods in different areas of the ocean cannot be based on a segmented analysis of the individual 
elements of the Measure. We have to complement such individual analyses by an overall 
assessment synthesizing our findings about the various elements of the Measure, and explaining 
the operation of the Measure, taking into account the important interlinkages among such 
elements. Below, we provide that overall assessment.  
7.705.   The 2016 Tuna Measure is a labelling measure. As noted a bove, it pursues two objectives: 
first, to ensure  that consumers are not misled or deceived about whether tuna products contain 
tuna that was caught in a manner that adversely affects dolphins ; and, second,  to contribute  to 
the protection of dolphins, by e nsuring that the US  market is not used to encourage fishing fleets 
to catch tuna in a manner that adversely affects dolphins . As also noted above, we see these two 
objectives as being mutually complementary and reinforcing, rather than distinct. Thus, the 
objective of the Measure is to protect dolphins from harms by providing the US consumers with 
accurate information as to whether any dolphins were killed or seriously injured in the harvesting 
of the tuna used to make the tuna products that they purchase.1200 
7.706.   To this end, the eligibility criteria, which contain the substantive conditions for access to 
the dolphin -safe label, make a distinction between tuna caught by certain fishing methods that are 
ineligible to receive a dolphin -safe label, and tuna caught by  fishing methods that are provisionally 
eligible to receive a dolphin -safe label. Two fishing methods are disqualified: setting on dolphins, 
and driftnet in the high seas. All other methods are conditionally qualified for the label: tuna 
products made of t una caught by using any of these other methods are qualified to use a dolphin -
safe label provided it is certified that no dolphin was killed or seriously injured in the set or gear 
deployment during which the tuna was caught, and that no net or other gear was intentionally 
deployed on or used to encircle dolphins during the fishing trip in which the tuna was caught. 
                                                
1198 United States' second written submission, paras. 169 -172. 
1199 United States' second written submission, para. 170.  
1200 In this regard, and as discussed in Section 7.7.1.2.1.3  above, we recall that the Measure aims to 
protect individual dolphins from harms, a nd is not directly concerned with the sustainability of dolphin stocks.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  Above, we have found that the eligibility criteria are calibrated because of the significant difference 
in risk between setting on dolphins, on  the one hand1201, and the fishing methods that are 
conditionally qualified for the label, on the other hand.  
7.707.   Without the certification, and tracking and verification requirements, as well as the 
determination provisions, however, the distinction made through  the eligibility criteria would not 
have achieved the Measure's objective of dolphin protection. In our view, the interlinkage among 
these four elements  of the Measure is  so crucial that without one of them the 2016 Tuna Measure, 
as we know it, could not f unction. We see the certification, and the tracking and verification 
requirements, as well as the determination provisions, as tools that enforce the eligibility criteria 
with a view to achieving the objective of protecting dolphins from harmful fishing me thods.  
7.708.   In order to pursue its aim  of protecting  dolphins from harmful fishing methods,  the 
Measure  goes beyond identifying, and disqualifying from accessing a dolphin -safe label the 
methods that are particularly harmful to dolphins and conditionally qualif ying other methods. It 
also establishes  a mechanism to make sure that this distinction would be respected and properly 
enforced. Th is enforcement mechanism was designed in the form of certification and tracking and 
verification requirements, as well as the  determination provisions.  
7.709.   The certification provisions aim to ensure that the impact on dolphins of a fishing method 
used in harvesting tuna is reported accurately, to help enforce the eligibility criteria and achieve 
the objectives of the 2016 Tuna Measu re. The certification provisions follow the same approach as 
the eligibility criteria and provide for two sets of certification procedures. In the ETP large purse 
seine fishery, which is the only fishery where vessels can, both technically and legally, set  on 
dolphins in a routine and systematic manner, certification has to be provided by both the vessel 
captain and an independent observer as to whether dolphin sets were used or any dolphins were 
otherwise killed or seriously injured in a set or gear deploy ment. In other fisheries, where the risks 
to dolphins are lower, the certification provisions require certification from captains who are 
required to have completed certain training programme.  
7.710.   We thus understand that the certification requirements enforce the eligibility criteria by 
providing two sets of certification requirements that properly take account of the differences in the 
levels of harms caused to dolphins by different fishing methods in different areas of the ocean. The 
certification requirement s create a more sensitive detection mechanism in respect of the ETP large 
purse seine fishery, which has a relatively high risk profile, and a less sensitive mechanism in 
other fisheries where the risks to dolphins are relatively lower. However, under the determination 
provisions, a fishery other than the ETP large purse seine fishery may be subject to more stringent 
certification requirements, and in particular may be required to have an observer certification, 
where that fishery has a regular and signific ant tuna -dolphin association or mortality or serious 
injury of dolphins. The determination provisions help to ensure that the 2016 Tuna Measure treats 
similar situations similarly. Working together, the certification requirements and the determination 
provisions help to establish a mechanism for enforcing the eligibility criteria that are properly 
calibrated to the different risk profiles in different fisheries.  
7.711.   Without certification requirements, the substantive distinction made by the eligibility 
criteri a would have been difficult to enforce and monitor , and US consumers would not be in a 
position to know whether tuna used in producing tuna products was obtained by fishing methods 
that harmed dolphins. As a result, the objectives of the Tuna Measure would  not have been 
achieved. The certification requirements (together with the determination provisions) thus work 
together with and reinforce the eligibility criteria. And like the eligibility criteria, they are calibrated 
to the risks to dolphins in differen t fisheries, since they apply more stringent criteria inside the ETP 
large purse seine fishery, and less stringent requirements in other fisheries that are less 
dangerous to dolphins.  
7.712.   We note that the eligibility criteria and the certification requirements , taken together, 
would not by themselves suffice to achieve the 2016 Tuna Measure's objectives  either. This is 
because there would be a need to control how the tuna caught by different fishing methods is 
stored on board the fishing vessels, unloaded and h anded over to the canneries. This function is 
fulfilled by the tracking and verification requirements. As noted above, the tracking and verification 
requirements provide for two sets of procedures, one for tu na caught in the ETP large purse seine 
                                                
1201 As noted above, the parties did not submit arguments concerning high seas driftnet fishing.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  fishery, and another for tuna caught in all other fisheries . As we have found above, alt hough the 
2016 Tuna Measure has narrowed the differences between the AIDCP and the NOAA regimes with 
regard to several aspects of the tracking and verification requirements,  there are still differences 
between the two regimes with regard to other aspects, such as the degree of government 
oversight in the process, and the documentation required in the case of exportation of dolphin -safe 
tuna. We have found, however, that, given the difference in the risk profile of the ETP large purse 
seine fishery  compared to other fisheries , the tracking and verification requirements are calibrated 
despite the remaining differences between the NOAA and the AIDCP regimes. In our view, the 
tracking  and verification requirements complement the eligibility criteria and the certification 
requirements by providing for two different regimes taking into account the differences in the risk 
profiles of the various fisheries.  
7.713.   Additionally, as is the case in the context of the certification requirements, the 
determination provisions allow for the imposition of more stringent tracking and verification 
requirements for tuna caught in a fishery that has been designated under the determination 
provisions as having  a regular and significant tuna -dolphin association or dolphin mortality or 
serious injury. In this way, they provide flexibility and ensure that under the 2016 Tuna Measure 
similar situations are treated similarly. In making this distinction between fishe ries based on their 
relative risk profiles, the design and architecture of the tracking and verification requirements also 
complements, and is consistent with, the design and architecture of the eligibility and certification 
requirements which the tracking  and verification requirements reinforce and with which they work 
together to achieve the objectives of the 2016 Tuna Measure.  
7.714.   Finally, we recall that, as explained above, the revised determination provisions introduce 
the necessary flexibility into the 20 16 Tuna Measure to reinforce the calibration of the certification 
and tracking and verification requirements. More specifically, the determination provisions allow 
the NOAA to heighten the level of certification and tracking and verification requirements f or 
fisheries where the Assistant Administrator of NOAA has determined that a fishery has a regular 
and significant tuna -dolphin association (similar to that in the ETP), or has regular and significant 
dolphin mortality or serious injury.  We also recall tha t these determination provisions have been 
used in respect of certain gillnet fisheries in the Indian Ocean region.  
7.715.   In our view, without the determination provisions, the 2016 Tuna Measure would have 
been static, as there would be no mechanism to review t he status of different fisheries in terms of 
harms caused to dolphins, and to make the necessary modifications to the relevant requirements 
in light of new developments in the risk profiles of such fisheries. Therefore, the determination 
provisions complem ent the structure of the 2016 Tuna Measure composed of the eligibility criteria, 
certification and tracking and verification requirements, and gives the Measure the flexibility to 
adapt itself to changing circumstances in the risk profiles of fisheries. Mo reover, we recall that the 
determination provisions operate on the basis of per set comparisons against an average of per set 
data collected in the ETP between 1997 and 2017. In our view, this further enhances the 
complementarity of the determination provi sions with the overall architecture and structure of the 
2016 Tuna Measure. Working together with the eligibility, tracking and verification requirements, 
the determination provisions allow for the imposition of more stringent conditions in fisheries that 
cause dolphin mortality or serious injury at levels similar to those caused in the ETP large purse 
seine fishery. This ensures that similar situations are treated similarly, and that the 2016 Tuna 
Measure establishes a regime that is calibrated to, tailore d to, and commensurate with the risks to 
dolphins arising from the use of different fishing methods in different areas of the ocean.  
7.716.   In assessing whether the 2016 Tuna Measure is calibrated to the risks to dolphins arising 
from the use of different fishing  methods in different parts of the ocean, we have also taken into 
account the risk of inaccurate information about the dolphin -safe status of tuna products being 
passed to US consumers. In this regard, we noted that there may be differences in the margins of 
error in various fisheries with regard to the accuracy of the information passed to the consumers. 
However, we have also noted that the risk of inaccurate information being passed to consumers 
through  the label will depend not only on the margin of erro r of a given fishery, but also on the 
extent of events that require recording whether a dolphin mortality or serious injury was observed 
in a given fishery. Therefore, our analysis of calibration has taken account of the objectives of the 
2016 Tuna Measure , and we consider that the eligibility criteria and the certification and tracking 
verification requirements, together with the determination provisions, work together in a calibrated 
manner to further the objectives of the 2016 Tuna Measure.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.717.   On the basis of these considerations, the Panels come to the general conclusion that the 
2016 Tuna Measure, as a whole, is calibrated to the risks to dolphins arising from the use of 
different fishing methods in different areas of the ocean . Therefore, the Panels find that the 
distinctions made by that Measure between setting on dolphins and the other fishing methods 
(except, of course, high seas driftnet which is also disqualified from the dolphin -safe label) stem 
exclusively from legitimate regulatory distinctions. Co nsequently, the Panels conclude that the 
2016 Tuna Measure accords to Mexican tuna products treatment no less favourable than that 
accorded to like products from the United States and other countries, and therefore is consistent 
with Article 2.1 of the TBT  Agreement.  
7.9  Whether the 2016 Tuna Measure is consistent with Articles I:1 and III:4, and 
complies with the requirements of Article XX, of the GATT 1994  
7.718.   Having found that the 2016 Tuna Measure is consistent with Article 2.1 of the TBT 
Agreement, the Panels proceed to examine whether that Measure is consistent with Articles I:1 
and III:4 and whether it complies with the requirements of the chapeau of Article XX of the 
GATT  1994. We will first review the findings made in the previous proceedings in this disput e 
regarding Mexico's claims under Articles I:1 and III:4, as well as the United States' defence under 
Article XX, of the GATT 1994, and then examine the claims and defence put forward in the present 
proceedings.  
7.9.1   Findings  made  in the previous proceedings  
7.719.   The Panels recall that the panel in the original proceedings in this dispute applied judicial 
economy with respect to Mexico's claims under Articles I:1 and III:4 of the GATT 19941202, which 
the Appellate Body found to be inconsistent with the requirement to co nduct an objective 
examination, set forth in Article 11 of the DSU.1203 In making this finding, the Appellate Body also 
opined that the nature of the obligations laid down in Article 2.1 of the TBT Agreement, on the one 
hand, and in Articles I:1 and III:4 of the GATT 1994, on the other hand, are not the same.1204 
Since judicial economy was applied to Mexico's claims under Articles I:1 and III:4 of the 
GATT 1994, the compatibility of the original Tuna Measure with the requirements of Article XX of 
the GATT 1994 wa s not addressed in the original proceedings.  
7.720.   In the first compliance proceedings, the panel noted that Article I:1 of the GATT 1994 
contained a different legal standard than that contained in Article 2.1 of the TBT Agreement, the 
key difference being that "whereas Article  I:1 requires only an analysis of whether the conditions 
attached to an advantage  detrimentally impact the competitive opportunities  of imported products 
in the relevant market, Article  2.1 of the TBT  Agreement  requires an additional consid eration of 
whether any detrimental impact nevertheless stems exclusively from a legitimate regulatory 
distinction ".1205 However, the first compliance panel also noted the similarity between the 
question, under Article I:1 of the GATT 1994, whether conditions imposed on access to an 
advantage modify the conditions of competition to the detriment of imported like products, and the 
first part of the analysis under Article 2.1 of the TBT Agreement, which also concerns the effect of 
a measure on the competitive opp ortunities of imported products. The panel therefore took its 
findings under Article 2.1 of the TBT Agreement into account in considering Mexico's claim under 
Article I:1 of the GATT 1994.1206 For the same reason, the panel found it appropriate to rely on its  
factual findings made in connection with Mexico's claim under Article 2.1 of the TBT Agreement in 
assessing the claim under Article I:1 of the GATT 1994.1207 On this basis, the first compliance 
panel found that the 2013 Tuna Measure violated Article I:1 of t he GATT 1994.1208 
7.721.   Similarly, the first compliance panel stated that, while not identical, the legal tests under 
Article 2.1 of the TBT Agreement (the first tier in particular) and Article III:4 of the GATT 1994 
have elements in common, and that, therefore, in  resolving Mexico's claim under the latter, the 
panel would take account of its legal and factual findings under the former.1209 In the panel's view, 
                                                
1202 Panel Report, US – Tuna II (Mexico) , para.  7.748.  
1203 Appellate Body Report, US – Tuna II (Mexico) , para.  405. 
1204 Appellate Body Report, US – Tuna II (Mexico) , para.  405. 
1205 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para.  7.432 (internal citations omitted) . 
1206 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para.  7.433. 
1207 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para.  7.434.  
1208 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para s. 7.442, 7.451, 7.456, 7.465.  
1209 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para.  7.494.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  "it would be rare for a panel that had found that a measure detrimentally modifies the conditions 
of competit ion within the meaning of  the first tier of Article  2.1 of the  TBT Agreement  to find that 
the same measure nevertheless does not accord less favourable treatment within the meaning of 
Article  III:4 of the GATT  1994".1210 On this basis, the first compliance pa nel found that the 2013 
Tuna Measure was inconsistent with the obligation set forth in Article III:4 of the GATT 1994.1211 
7.722.   On appeal, the Appellate Body did not find inappropriate the first compliance panel's 
articulation of the legal tests under Articles I:1  and III:4 of the GATT 1994, noting that "in 
assessing whether a measure affects competitive conditions under Article I:1 and/or Article  III:4 of 
the GATT 1994, it may be reasonable for a panel to rely on any relevant findings it made in 
examining that mea sure's detrimental impact under Article 2.1 of the TBT  Agreement ".1212 
However, the Appellate Body found two legal errors in the panel's legal analyses under Articles I:1 
and III:4. First, the Appellate Body noted that the panel's segmented analysis, whereby the panel 
failed to conduct a holistic assessment of how the various labelling conditions, taken together, 
adversely affected the conditions of competition for Mexican tuna products in the US market as 
compared to like US and other tuna products, as well a s the panel's failure to consider whether the 
detrimental impact caused by the 2013 Tuna Measure resembled the detrimental impact found to 
exist in the original proceedings, also affected the panel's analysis under Articles I:1 and III:4 of 
the GATT 1994.1213 Second, the Appellate Body stated that its finding of error in respect of the 
panel's discrete detrimental impact analyses regarding the certification and tracking and 
verification requirements, for being based on a subset of the relevant groups of like p roducts, 
applied equally to the panel's findings under Articles I:1 and III:4 of the GATT 1994.1214 
7.723.   On this basis, the Appellate Body reversed the first compliance panel's findings under 
Articles  I:1 and III:4 of the GATT 1994.1215 In completing the analysis, th e Appellate Body noted 
its finding, in the context of its legal analysis under Article 2.1 of the TBT Agreement, that the 
labelling conditions under the 2013 Tuna Measure modified the conditions of competition to the 
detriment of Mexican tuna products in t he US market1216, and, on that basis, found that the 
Measure is inconsistent with Articles I:1 and III:4 of the GATT 1994.1217 
7.724.   With regard to the first compliance panel's analysis under Article XX of the GATT 1994, 
given that neither party challenged the panel's  finding that the 2013 Tuna Measure was 
provisionally justified under Article XX(g), the Appellate Body turned to the parties' claims under 
the chapeau of Article XX.1218 In this connection, the Appellate Body expressed concern about the 
panel's view that "the relevant conditions for certain aspects of the measure (the eligibility criteria) 
somehow differ from the relevant conditions for other aspects of the measure (the certification 
requirements), and its ultimate conclusion that the conditions are not the s ame for the former, but 
are the same  for the latter ".1219 The Appellate Body then stated that " the prevailing conditions 
between countries are the risks of adverse effects on dolphins arising from tuna fishing 
practices[] " and proceeded " on the basis that the  conditions prevailing between countries are the 
same for purposes of the chapeau of Article XX of the GATT  1994".1220 
7.725.   Turning to the issue of whether the 2013 Tuna Measure was applied in a manner that 
would constitute a means of "arbitrary or unjustifiable d iscrimination" within the meaning of the 
chapeau of Article XX, the Appellate Body first underlined that it did not find error in the panel's 
articulation of the relevant legal standard, which was similar to the legal standard the panel had 
articulated und er Article 2.1 of the TBT Agreement.1221 
7.726.   With regard to the panel's application of that legal standard, however, the Appellate Body 
identified several errors. First, with respect to the eligibility criteria, the Appellate Body found error 
in the panel's state ment that " the Appellate  Body in the original proceedings had settled that the 
                                                
1210 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para.  7.494.  
1211 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para.  7.504.  
1212 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para.  7.278.  
1213 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para.  7.280.  
1214 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para.  7.281.  
1215 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para.  7.282.  
1216 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para.  7.239.  
1217 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para.  7.340.  
1218 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para.  7.284.  
1219 Appellate Body Repor t, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para.  7.305.  
1220 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para.  7.308.  
1221 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para s. 7.315 -7.322.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  United  States is entitled to disqualify tuna products containing tuna caught by setting on dolphins 
from ever accessing the dolphin -safe label, and that it may bring its dolphin -safe labelling regime 
into conformity with Article  2.1 without disqualifying methods of tuna fishing other than setting on 
dolphins ".1222 Second, regarding the panel's analysis of the certification and tracking and 
verification requirements, the Appellate Bo dy stated that the panel's segmented analysis, which 
was found to be inconsistent with Article 2.1 of the TBT Agreement, also led to legal error in the 
panel's assessment of the certification and tracking and verification requirements under the 
chapeau of Article XX.1223 On these bases, the Appellate Body reversed the first compliance panel's 
findings under the chapeau of Article XX of the GATT 1994.1224 
7.727.   In completing the legal analysis, the Appellate Body recalled  that "the same conditions 
between countries prev ail, namely, the risk of adverse effects on dolphins arising from tuna fishing 
practices" .1225 The Appellate Body then turned to the issue of "arbitrary or unjustifiable 
discrimination"1226, and recalled that, the panel had based its legal analysis under the cha peau of 
Article XX on its legal analysis under Article 2.1 of the TBT Agreement, and stated that "so long as 
the similarities and differences between Article 2.1 of the TBT  Agreement and Article XX of the 
GATT 1994 are taken into account, it may be permiss ible to rely on reasoning developed in the 
context of one agreement for purposes of conducting an analysis under the other" .1227 The 
Appellate Body noted that since the panel in its analysis under the chapeau of Article XX had relied 
only on unobservable harm s caused to dolphins by different fishing methods, the Appellate Body 
was "unable to complete the legal analysis and assess  fully whether all of the regulatory 
distinctions drawn under the amended tuna measure can be explained and justified in the light of  
differences in the relative risks associated with different methods of fishing for tuna in different 
areas of the oceans ".1228 
7.728.   However, the Appellate Body was able to examine whether the labelling conditions under 
the 2013 Tuna Measure "constitute[d] arbitra ry or unjustifiable discrimination in certain scenarios 
that would present comparably high risks to dolphins inside and outside the ETP large purse -seine 
fishery" .1229 In the Appellate Body's view, certain aspects of the 2013 Tuna Measure were "difficult 
to reconcile with the objective of protecting dolphins from harm" .1230 In particular, the Appellate 
Body underlined the fact that " the determination provisions do not provide for the substantive 
conditions of access to the dolphin -safe label to be reinforced by o bserver certification in all 
circumstances of comparably high risk, and that this may also entail different tracking and 
verification requirements than those that apply inside the ETP large purse -seine fishery ".1231 On 
this basis, the Appellate Body concluded  that the United States had not established that the 2013 
Tuna Measure, which was found to be inconsistent with Articles I:1 and III:4 of the GATT 1994, 
was justified under Article XX of the GATT 1994.  
7.9.2   Assessment of Mexico's claims under Articles I:1, III: 4, and the United States' 
defence  under Article  XX of the GATT 1994 in the present proceedings  
7.729.   In the present proceedings, both parties agree that the 2016 Tuna Measure violates both 
Article I:1 and Article III:4 of the GATT 1994.1232 Bearing in mind the lega l standards under these 
provisions, as explained by the first compliance panel1233, the approach to these provisions by the  
Appellate Body in the first compliance proceedings1234, and our finding above that the 2016 Tuna 
Measure modifies the conditions of compet ition to the detriment of Mexican tuna products in the 
                                                
1222 Appellate Body  Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para.  7.326.  
1223 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para.  7.332.  
1224 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para.  7.335.  
1225 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para.  7.342.  
1226 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para.  7.343.  
1227 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para s. 7.346 -7.347.  
1228 Appellate  Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para.  7.359.  
1229 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para.  7.359.  
1230 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para.  7.359.  
1231 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para.  7.359.  
1232 In this regard, we note the United States' acknowledgement that "the basis for the DSB's previous 
finding that the US measure is inconsistent with Articles I:1 and III:4 is unchange d and the United States does 
not dispute those findings for purposes of this proceeding". United States' first written submission, para. 190.  
1233 See Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , paras. 7.404 -7.416, 7.434, 7.469 -
7.481, and 7.4 94-7.495.  
1234 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 8.1(d)(ii).  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  US market1235, we agree with the parties and find that the 2016 Tuna Measure is inconsistent with 
Articles I:1 and III:4 of the GATT 1994.  
7.730.   Both parties also agree that the Measure is provisionally justifi ed under  subparagraph 
(g) of Article XX.1236 Bearing in mind the findings on this issue  made  by the panel1237 and the 
Appellate Body in the first compliance proceedings1238, we agree with the parties and find that the 
2016 Tuna Measure is provisionally justified un der subparagraph (g) of Article XX.  Thus, the 
disagreement between the parties centres around the issue of whether the 2016 Tuna Measure is 
applied in a manner that would constitute a means of "arbitrary or unjustifiable discrimination" 
within the meaning of the chapeau of Article XX.  
7.731.   We recall that "the Appellate Body has identified three analytical elements in respect of 
arbitrary or unjustifiable discrimination in the chapeau of Article  XX: (i) the application of the 
measure results in discrimination; (i i) the discrimination occurs between countries where the same 
conditions prevail; and (iii) the discrimination is arbitrary or unjustifiable ".1239 
7.732.   With respect to the first element of the test,  we recall the Appellate Body's finding in the 
first compliance pr oceedings that "by excluding most Mexican tuna products from access to the 
dolphin -safe label, while granting conditional access to such label to like  products from the United 
States and other countries, the amended tuna measure, similar to the original me asure, modifies 
the conditions of competition to the detriment of Mexican tuna products in the US market" .1240 We 
note that the 2016 Tuna Measure maintains the overall architecture and structure of the original 
and 2013 Tuna Measure s. We therefore find that t he 2016 Tuna Measure continues to cause the 
same detrimental impact resulting from the discriminatory treatment between tuna products 
containing  tuna caught in the ETP large purse seine fishery and those containing tuna caught in 
other fisheries. We note t hat the parties also agree with this view.1241 
7.733.   With respect to the second element of the test,  we first recall the Appellate Body's 
statement in the first compliance proceedings  that the conditions prevailing between countries are 
the same for purposes of the  chapeau of Article XX of the GATT  1994, namely, " the risks of 
adverse effects on dolphins arising from tuna fishing practices ".1242 Neither of the parties have 
argued otherwise in the present proceedings.1243 
7.734.   With resp ect to the third element of the  test, we re call the Appellate Body's statement  in 
the first compliance proceedings  that, in determining whether a particular measure is applied in a 
manner that constitutes  a means of  "arbitrary or unjustifiable discrimination" within the meaning 
of the chapeau of Ar ticle XX, "so long as the similarities and differences between Article 2.1 of the 
TBT Agreement and Article XX of the GATT 1994 are taken into account, it may be permissible to 
rely on reasoning developed in the context of one agreement for purposes of con ducting an 
analysis under the other ".1244 
7.735.   We also recall that the Appellate Body found two errors in the first compliance panel's 
findings under the chapeau of Article XX. First, with respect to the eligibility criteria, the Appellate 
Body found error in the panel's statement that " the Appellate  Body in the original proceedings had 
settled that the United  States is entitled to disqualify tuna products containing tuna caught by 
setting on dolphins from ever accessing the dolphin -safe label, and that it may brin g its 
dolphin -safe labelling regime into conformity with Article  2.1 without disqualifying methods of tuna 
                                                
1235 See para. 7.78 above.  
1236 The United States contends that "the measure is provisionally justified under Article XX(g)". United 
States' first written submission para. 196. We also note that "Mexico does not dispute that the 2016 tuna 
measure can be provisionally justified under sub paragraph (g) of Article XX". Mexico's first written submission, 
para. 336.  
1237 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.541.  
1238 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para . 7.341.  
1239 Appellate Body Re port, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.301 (internal citations 
omitted).  
1240 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico) , para. 7.238.  
1241 United States' first written submission, para. 69; Mexico's first written submission, para. 204.  
1242 See fn. 1220 above.  
1243 Mexico's resp onse to Panels' question No. 110 ; United States' response to Panels' question No. 110. 
1244 See fn. 1227 above.  WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  fishing other than setting on dolphins ".1245 In the present proceedings, we have not relied on any 
such assumption in our analysis under Article 2.1 of the TBT Agreement.  
7.736.   Second, the Appellate Body faulted the first compliance panel for conducting a segmented 
analysis of the certification and tracking and verification requirements of the 2013 Tuna Measure, 
and pointed out that such an analysis also compro mised that panel's analysis under the chapeau of 
Article XX of the GATT 1994.1246 Mindful of this finding, in our assessment of Mexico's claim under 
Article 2.1 of the TBT Agreement, we conducted a holistic assessment of the various elements 
making up the 201 6 Tuna Measure. To this end, we first analysed the various elements of the 
2016 Tuna Measure. Specifically, we assessed whether each of the main elements of the Measure, 
namely the eligibility criteria and the certification, and tracking and verification r equirements, were 
calibrated to different levels of risks posed to dolphins in different areas of the ocean, and found 
that they were. We also found that the determination provisions reinforce our finding that the 
2016 Tuna Measure is calibrated because th ey allow the NOAA to heighten the level of certification 
and tracking and verification requirements for fisheries where the Assistant Administrator of NOAA 
has determined that a fishery has a regular and significant tuna -dolphin association (similar to tha t 
in the ETP), or has regular and significant dolphin mortality or serious injury.  
7.737.    We then provided a holistic assessment of all of these elements, taking into account the 
interlinkages among them, and found that, the 2016 Tuna Measure, as a whole, is cal ibrated.  
7.738.   We recall that, following the guidance provided by the Appellate Body in the first 
compliance proceedings, we conducted our legal analysis under Article 2.1 of the TBT Agreement 
on the basis of the concept of calibration, and found that the 2016 Tuna Measure is calibrated to 
different risks to dolphins arising from the use of different fishing methods in different areas of the 
ocean. On this basis, we reached our final conclusion that detrimental impact caused by the 2016 
Tuna Measure stems exclus ively from legitimate regulatory distinctions, and that, therefore, the 
Measure is consistent with Article 2.1 of the TBT Agreement.  
7.739.   In the circumstances of the present proceedings, and in light of the guidance provided by 
the Appellate Body in the first c ompliance proceedings, we find it appropriate to use our factual 
and legal findings in connection with Mexico's claims under Article 2.1 of the TBT Agreement, in 
our assessment of whether the 2016 Tuna Measure is applied in a manner that constitutes 
arbitr ary or unjustifiable discrimination within the meaning of the chapeau of Article XX of the 
GATT 1994. In taking this approach , we bear in mind the differences between the requirements of 
Article 2.1 of the TBT Agreement and those of the chapeau of Article  XX of the GATT 1994. In 
particular, we are cognizant  that the requirement that for detrimental impact caused by 
discriminatory treatment to be in violation of Article 2.1 of the TBT Agreement, it has to be shown 
that detrimental impact does not stem exclus ively from a legitimate regulatory distinction, does 
not apply under the chapeau of Article XX. However, given our finding that the 2016 Measure is 
calibrated to the levels of risks posed by different fishing methods in different parts of the ocean, 
we do not see any reason to find that the same Measure is applied in a manner that constitutes a 
means of arbitrary or unjustifiable discrimination. We recall that calibration means that the 2016 
Tuna Measure is "tailored to ", and "commensurate with ", the differ ent risks to dolphins caused by 
different fishing methods in different parts of the ocean. We do not consider that the Measure, 
which is tailored to and commensurate with the relevant risks, can be said to be applied in a 
manner that constitutes a means of  "arbitrary or unjustifiable discrimination" within the meaning 
of Article XX of the GATT 1994.  In other words , we consider that the different elements the 2016 
Tuna Measure, both individually and in connection with one an other, when applied to the differe nt 
risks to dolphins posed by different fishing methods in different parts of the ocean , do not 
constitute a means of arbitrary or unjustifiable discrimination . In any case, we note that the 
parties, in their submissions to the Panels, also took the view t hat whether the 2016 Tuna Measure 
is applied in a manner that constitutes a means of arbitrary or unjustifiable discrimination depends 
on whether th e Panels find the Measure to be  consistent with the requirements of Article 2.1 of the 
TBT Agreement.1247 
                                                
1245 See fn. 1222 above.  
1246 See fn. 1214 above.  
1247 The United States argues that "[t]he United States has previously explained that the measure meets 
the conditions of Article XX of the GATT 1994 for the same reasons that it is consistent with Article 2.1, a point 
that is completely consistent with the Appellate Body's guidance that a measure that is appropriately calibrated WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  7.740.   On th e basis of the foregoing, having found, in our analysis under Article 2.1 of the TBT 
Agreement, that the Measure is calibrated to different levels of risks posed to dolphins by different 
fishing methods in different areas of the ocean, we also find that th e Measure is not applied in a 
manner that constitutes a means of arbitrary or unjustifiable discrimination, and is therefore 
justified und er Article XX of the GATT 1994.  
                                                                                                                                                  
to the risk to dolphins will meet the standards of both Article 2.1 and the chapeau of Article XX". United  States' 
third written submission, para. 149 (internal citations omitted) .  
Mexico submits that "given that Mexico's arguments under both Article 2.1 and the chapeau are 
grounded in arbitrary and unjustifiable discrimination, it is appropriate for Mexico t o rely upon its submissions 
regarding the lack of calibration in Section IV.C.2. to establish that the 2016 tuna measure is applied in a 
manner that constitutes a means of arbitrary or unjustifiable discrimination between countries where the same 
condition s prevail and, therefore, the requirements of the chapeau are not met". Mexico's first written 
submission, para. 337 (internal citations omitted) . WT/DS381/RW/USA • WT/DS381/RW 2 
 
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  8  CONCLUSIONS AND RECO MMENDATION(S)  
8.1.  We recall that after consulting with the parties, t he Panels decided to issue  their Reports in a 
single document, with the understanding that the final sections on conclusions and 
recommendations would be printed on separate pages with the relevant DS symbol. 
Accordingly,  we provide two separate sets of conclusions  and recommendations, with separate 
symbols for each complainant (WT/DS381/RW/USA for the United States and WT/DS381/RW/2 for 
Mexico).  
 WT/DS381/RW/USA  
 
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  8.1  Proceedings brought by the United States: Conclusions and Recommendations  
8.2.  With respect to the United States'  claim under Article 2.1 of the TBT Agreement, the Panel 
concludes that the 2016 Tuna Measure is not inconsistent with Article 2.1 of the TBT Agreement.  
8.3.  With respect to the United States' defence under Article XX of the GATT 1994, the Panel 
concludes that th e 2016 Tuna Measure is justified under Article XX(g) of the GATT 1994, and 
meets the requirements of the chapeau of Article XX of the GATT 1994.  
8.4.  The Panel therefore  consider s that the United States has implemented the recommendations 
and rulings of the DSB  in US – Tuna II (Mexico) and US – Tuna II (Mexico) (Article 21.5 – Mexico ) 
to bring its measure into conformity w ith its obligations under the WTO  Agreement.  
8.5.  Having found that the United States has  not act ed inconsistently with its obligations under 
the WTO Agreement , the Panel  consider s that no recommendation under Article 19.1 of the DSU is 
necessary, and make s none.  WT/DS381/RW 2 
 
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8.2  Proceedings brought by Mexico: Conclusions and Recommendations  
8.6.  With respect to Mexico's claim under Article 2.1 of the TBT Agreement, the  Panel concludes 
that the 2016 Tuna Measure is not inconsistent with Article 2.1 of the TBT Agreement.  
8.7.  With respect to Mexico's claims under the GATT 1994, the Panel concludes that the 2016 
Tuna Measure is inconsistent with Articles I:1 and III:4 of the GA TT 1994, but that it is justified 
under Article XX(g) of the GATT 1994, and meets the requirements of the chapeau of Article XX of 
the GATT 1994.  
8.8.  The Panel therefore  consider s that the United States has implemented the recommendations 
and rulings of the DS B in US – Tuna II (Mexico) and US – Tuna II (Mexico) (Article 21.5 – Mexico ) 
to bring its measure into conformity w ith its obligations under the WTO  Agreement.  
8.9.  Having found that the United States has  not act ed inconsistently with its obligations under 
the WTO Agreement , the Panel consider s that no recommendation under Article 19.1 of the DSU is 
necessary, and make s none.  
 
 
 
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