UNITED STATES – MEASURES CONCERNING THE IMPORTATION, MARKETING AND SALE OF TUNA AND TUNA PRODUCTS RECOURSE TO ARTICLE 21.5 OF THE DSU BY THE UNITED STATES UNITED STATES – MEASURES CONCERNING THE IMPORTATION, MARKETING AND SALE OF TUNA AND TUNA PRODUCTS SECOND RECOURSE TO ARTICLE 21.5 OF THE DSU BY MEXICO REPORTS OF THE PANELS
Document: MARKETING AND SALE OF TUNA AND TUNA PRODUCTS SECOND RECOURSE TO ARTICLE 21.5 OF THE DSU BY MEXICO REPORTS OF THE PANELS
Date: 26 October 2017
Document codes: WT/DS381/RW/USA; WT/DS381/RW2
Complainant: Mexico
Respondent: U.S.
Third parties: Australia, Brazil, Canada, China, Ecuador, EU, Guatemala, India, Japan, South Korea, New Zealand, Norway
Dispute stage: Implementation & Compliance
Agreements cited: Art. I:1, III:4  GATT 1994Art. 2.1, 2.2, 2.3, 2.4  Technical Barriers to Trade (TBT)

UNITED STATES – MEASURES CONCERNING THE IMPORTATION,
MARKETING AND SALE OF TUNA AND TUNA PRODUCTS
RECOURSE TO ARTICLE 21.5 OF THE DSU BY THE UNITED STATES
UNITED STATES – MEASURES CONCERNING THE IMPORTATION,
MARKETING AND SALE OF TUNA AND TUNA PRODUCTS
SECOND RECOURSE TO ARTICLE 21.5 OF THE DSU BY MEXICO
REPORTS OF THE PANELS
 •

LIST OF ANNEXES
ANNEX A
WORKING PROCEDURES OF THE PANELS
Contents Page
Annex A-1 Working Procedures 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 of 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 PARTIES
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 of 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 summary of the arguments of Norway C-21
 •

CASES CITED IN THESE REPORTS
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 , , 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 States – 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 United 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/RW2

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, Marketing
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 States – 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/RW2

EXHIBITS 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 (March 23, 2016)
USA-09 Evgeny 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 (March 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 (October 20, 2015)
USA-16 IATTC, EPO Dataset 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 (August 30, 2015)
USA-31 Chinese Taipei, Annual Report to the Commission, WCPFC -SC11-AR/CCM-23 (November 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 Hernandez-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 Pacific, 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 (2008)
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/RW2

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 Fisheries 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 Update, 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 (December 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
amended (2015)
USA-91 AIDCP, Tuna Tracking Form
USA-101 NMFS, Proposed Rule: List of Fisheries for 2017, 81 Fed. Reg. 54,019 (August 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 (August 30, 2016)
USA-109 WCPFC, 7th Annual Report for the Regional Observer Programme (September 3, 2015)
USA-110 WCPFC, 8th Annual Report for the Regional Observer Programme (September 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 (January 8, 2013)
USA-114 NMFS, False Killer Whale: Hawaiian Islands Stock Complex (December 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 (January 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 (October 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, Annual Report to the Commission, WCPFC-SC12-AR/CMM-03 (August 2016)
USA-151 Federated States of Micronesia (FSM), Annual Report to the Commission, WCPFC -SC12-
AR/CMM-06 (September 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 (September 23, 2016)
USA-154 Marshall Islands, Annual Report to the Commission, WCPFC-SC12-AR/CMM-13 (August 2016)
USA-155 Solomon Islands, Annual Report to the Commis sion, WCPFC-SC12-AR/CMM-22 (September
24, 2016)
USA-156 Chinese Taipei, Annual Report to the Commission (August 2016)
USA-157 United States, Annual Report to the Commission, WCPFC-SC12-AR/CMM-27 (August 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 Observer 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) No 812/2004 (2012)
USA-166 18 USC Section 545
USA-167 18 USC Section 3571
USA-169 16 USC Section 3372
WT/DS381/RW/USA • WT/DS381/RW2

USA-170 US Department of Commerce, Civil Monetary Penalty Adjustments for Inflation, 81 Fed. Reg.
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 (August 2015)
USA-185 Marshall Islands, Annual Report to the Commission, WCPFC-SC11-AR/CCM-13 (August 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 Program 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 (August 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 (August 12, 2015)
USA-237 High Seas Pocket Fishing Rules Released, Bus. World (March 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 Final 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 (October 16, 2010)
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 (December 2008)
MEX-08 AIDCP, Report on the International Dolphin Conservation Program,
Document MOP-28-05 (October 18, 2013)
MEX-13 NOAA Technical Memorandum NMFS, Estimates of 2006 Dolphin Abundance In The Eastern
Tropical Pacific, With Revised Estimates From 1986-2003 (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) (January 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 October 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/RW2

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 Interactions with Tuna Purse Seine Fisheries Outside of the Eastern Tropical Pacific,
NOAA Southwest Fisheries Science Center Administrative Report LJ-96-20 (November 1996)
MEX-113

Kobe II Bycatch Workshop Background Paper
MEX-116 WCPFC, Status of ROP Data 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 Issue 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/RW2

ABBREVIATIONS USED IN THESE REPORTS
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 (March 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 Zones
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 of 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 Conservation 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 Tracking 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 Pacific Fisheries Commission
WCPO Western and Central Pacific Ocean
WIO Western Indian Ocean
WTO World Trade Organization
WT/DS381/RW/USA • WT/DS381/RW2

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 reference 1, 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 of 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 composed 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 their 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 Agreement 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/RW2

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
parties, 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 the 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. Because 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 opposed 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/RW2

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 Procedures 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 statements 12 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 (BCI)
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 additional working 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 Concerning 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 paragraph 1.1(e) of the Additional Working Procedures on Partially Open Meetings.
13 Annex A-3.
WT/DS381/RW/USA • WT/DS381/RW2

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 products 14 (the 2016 Tuna Measure). Both
parties consider that the 2016 Tuna Measure comprises 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 (March 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 specifies 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 PARTIES' REQUESTS FOR FINDINGS AND RECOMMENDATIONS
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 been 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/RW2

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 PARTIES
4.1. The arguments of the parties are reflected in their executive summaries, provided to the
Panels 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 THIRD 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 statements 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 Panels.
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' responses 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 section of the Panels' Reports
constitutes an integral part of the Panels' 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. According 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

WT/DS381/RW/USA • WT/DS381/RW2

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 view, 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
paragraph 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 (paragraph 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/RW2

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
consistency 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 respect 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 alive 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' proposal
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 modification to the text of the last sentence 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 referred 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/RW2

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 at 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 disagrees 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
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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’ proposal 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 note 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
(paragraphs 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 amounts to revising 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 USA-179 Rev. We further note that the table contained in
Exhibit USA-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
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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 modifications 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 by the United States in respect of 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 brackets 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 was 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 incorrect 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 -operation". 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.
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showing that cooperation 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 request 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 parties 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 arguments 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/RW2

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 States 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 that
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 that,
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 Panels' question No. 84, para. 125.
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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 this 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 Exhibit 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 7.249 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 understanding 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 to 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 Agreement 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
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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 respect to paragraph 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
question 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 consider 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 language 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 the 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/RW2

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 States 22
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 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 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 Panels "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 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 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 agree 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 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 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 Mexico's requests, the United States appears to refer to this
paragraph mistakenly as 7.294.
WT/DS381/RW/USA • WT/DS381/RW2

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 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 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 and 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 argument 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 words "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/RW2

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 comment 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 ocean, 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 paragraph 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 arguments, 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/RW2

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 proceedings 24 and in the Decision by the Arbitrator in this dispute 25, 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 same 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 DPCIA), (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 Circuit
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 Support Use of the Dolphin Safe Label 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 define the measure at issue slightly differently: see Section 7.4.1below.
29 See Section 7.6below.
WT/DS381/RW/USA • WT/DS381/RW2

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 authorized 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 organized 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 substantive 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 where 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 proceedings in this dispute were not open for public observation.

30 Decision of the Arbitrator, US – Tuna II (Mexico) (Article 22.6 – US), paras. 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), paras. 2.13-2.34.
WT/DS381/RW/USA • WT/DS381/RW2

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 that 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 meetings. Mexico submits in
this regard that acceding to the United States' request could force other Members to accept open
meetings 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 designates 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 which 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 safeguards 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 with the parties.

33 India considers that it would certainly be inconsistent 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 by 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/RW2

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 statements 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 authorization 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 statements 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, the 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 in 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/RW2

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 these 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 appropriately 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 disclose 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 "positions" 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 used in open meetings whenever the
statements made by the parties or third parties address BCI.
WT/DS381/RW/USA • WT/DS381/RW2

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 prompt 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/RW2

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 proceedings 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 an 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 authorizations 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 Mexico 55, 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' Additional 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 Additional 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 given 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/RW2

requesting consultations. In Mexico's view, there is nothing in the DSU or in the jurisprudence that
prevents the Panels 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 United 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
between 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 parallel 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 example, 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 submission, 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/RW2

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 above 67, in other parts of its submissions, Mexico
refers, in addition to those three elements, to two additional elements. First, in 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 announcements 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), paras. 6.7-6.8.
65 United States' first written submission, para. 19.
66 United States' first written submission, paras. 22-29.
67 Mexico's first written submission, para. 118.
68 WT/DS381/38, p. 2. See also Mexico's first written submission, para. 2.
69 Mexico's first written submission, para. 149.
WT/DS381/RW/USA • WT/DS381/RW2

those instruments", we note that Mexico does not argue that, as a measure taken to comply with
DSB recommendations 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 measure 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 explains 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 measure, or as a part of the 2016 Tuna Measure, in the same response, Mexico also
argues 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 United 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 Measure.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 regulatory 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 products, 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 the
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/RW2

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 resolving 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 product 78 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 Measure 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 seas 80; and (ii) vessels using purse
seine nets to encircle or "set on" dolphins anywhere in the world 81. 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 action 82, 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 compared to, both the original and the 2013 Tuna Measure. 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 Section 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" means "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 Sections 216.24(f)(2)(i) and (ii), and not including "perishable items with a shelf life of
less than 3 days", (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), (Exhibits USA-
02, MEX-02); see also Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico), para. 6.9.
81 50 CFR Sections 216.91(a)(1)(iii), (a)(3)(i) and (a)(3)(ii)(A), (Exhibits 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 seine 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 seine nets was
having a significant adverse impact on any depleted dolphin stock 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 on 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 on appeal in the Hogarth ruling. As a
result, Section 1385(h) requires that tuna products derived from tuna harvested by large purse seine 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/RW2

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, captains 85 of all vessels in all fisheries other than the large purse seine 86
fishery in the Eastern Tropical Pacific Ocean (ETP) 87 and a large -scale driftnet fishery 88 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
encirclement 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), (Exhibits 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 seine 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 USA-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), (Exhibits USA-02, MEX-02).
WT/DS381/RW/USA • WT/DS381/RW2

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 another 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 separate 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 amended
(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 USA-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 Program, 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).
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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 the 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 among 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 and 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 USA-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/RW2

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 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 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 certification 125, 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 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. 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 or 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), (Exhibits USA-02, MEX-02).
123 50 CFR Section 216.93(g)(3) (Exhibits USA-02, MEX-02); Form 370 (Exhibit USA-04); United States'
response to Panels' question No. 29, paras. 148-149.
124 NOAA Form 370 (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 USA-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), (Exhibits USA-02, MEX-02).
126 50 CFR Section 216.91(a)(5)(ii), (Exhibits USA-02, MEX-02).
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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 certain 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 regulation", "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 makes 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 aspects 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 Report, 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/RW2

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
products 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 "like".
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 remain 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 original 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
labelling 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 the
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 with 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 submission, 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).
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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 changed 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 distinction": 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/RW2

arbitrary 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 distinction 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 created 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/RW2

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 risks 157, they
fundamentally disagree about how that test 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 could 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-handedness, 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 submission, 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 calibration 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' response 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/RW2

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 information 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 first 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 second 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/RW2

they cannot employ means that are inconsistent with the objective of sustainable de velopment.
According 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
discrimination, 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 minimizing 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 certification, reporting, and/or record -keeping.185 In the
United States' view, this is not the test that was articulated by the Appellate Body 186, and the
United States finds no support in either of the Appellate Body's previous reports in this dispute. 187
Rather, according 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
assess 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 note 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, para. 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/RW2

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 present 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-handed 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 observed 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 the 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 different 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/RW2

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 tuna 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 -handedness" 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 with 200, 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/RW2

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 treatment 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 of 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 whether 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. Appellate 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 determination of whether they constituted "arbitrary or unjustifiable discrimination". See
Appellate Body Report, US – Shrimp, paras. 171-172. See also Appellate Body Report, US – Gasoline, pp. 27-
29.
206 Mexico's first written submission, para. 114.
207 Mexico's first 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/RW2

7.108. In determining the proper scope of the calibration analysis, we look to the guidance
provided by the 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 whether 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 other 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 calibration 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 associated
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 alleges 221, 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 tuna 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/RW2

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 reports "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
confirmed 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, we 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.
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/RW2

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 issue 231, it nevertheless
held that there was a "special relevance" in this dispute in conducting a proper 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 establish 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 objectives.
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 objectives 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 Body 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/RW2

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 whether 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 recording 235 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 verification 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
requirements 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 calibration 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 of
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/RW2

7.125. We further note 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
differences 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. 130.
WT/DS381/RW/USA • WT/DS381/RW2

risen to the status of a principle of international law applicable to all countries 245, and accordingly
should be taken into account by the Panels when interpreting Article 2.1 of the TBT Agreement in
accordance with customary rules of interpretation of public international law 246, 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
obligation, 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, texture 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 because it discriminates in a manner that goes against
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 regulations 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, para. 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/RW2

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 general 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 measure 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, Mexico 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 written 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' submission. 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 Report, 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/RW2

brought by Mexico, 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 sets 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 holistic 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 holistically 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 No. 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/RW2

"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 "mechanistically".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 methodology 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 States – 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 Body Reports, 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/RW2

2.1 of the TBT Agreement 272, 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 panel 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 ocean 275, 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
unobservable 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 unobservable 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 panel'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 of
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 7.353. 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 seen 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/RW2

posed by other fishing methods in different parts of the ocean. 281 As a basis to conduct this
comparison, we observe that we will need to establish the risk profiles of the relevant fishing
methods 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 position
to come to a definitive or precise view as to the extent of relevant risks 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 Agreement, 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
arguments 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 observable and unobservable harms.
7.7.1.1.2 Previous factual findings: observable and unobservable harms to dolphins
7.153. In the previous stages of these proceedings, 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 Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico), para. 5.9 (referring to
Appellate Body Reports, 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/RW2

findings that led to the original and 2013 Tuna Measures 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) unobservable 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 extended beyond certif ied serious injuries or mortalities, and could include 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 later
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 adverse effects identified by the United States may be described as unobserved
deaths o r injuries of dolphins" .288 Moreover, i n 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 genuine 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 well-
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 dolphins, 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 distinctions between the unobservable harms of setting 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/RW2

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 qualitatively 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 trained 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 Appellate 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 effects 301, 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 pertaining 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 Appellate 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/RW2

relative risks associated with different fisheries, including in respect of both observ able and
unobservable 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 the 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 assessment 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 quantitatively.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 le ast
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,
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/RW2

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
applying 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, Mexico 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 ocean.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 arising 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 States' second written submission, para. 119.
313 United States' second written submission, para. 122.
314 United States' second written submission, para. 126.
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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 methodology
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 contends 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 Measure 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 to 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 may 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 Measure 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 "the preservation of individual dolphin lives is just 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/RW2

on dolphins in the ETP large purse seine fishery, but rather, they deny access to the label for all
tuna product produced from 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 written 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 allowing that stock to reach or maintain its optimum sustainable population. The PBR level
is the product of the following factors: (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/RW2

methodology seems to 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 between 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 evaluating 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 adversely 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 Tuna 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 provisions 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 tolerates 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, Mexico argues for the use of an 'objective,
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 Measure 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 panel 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 populations, 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), paras. 7.550 and 7.735.
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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 risks 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 potentially 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 sustainability 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 foregoing 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 observable and unobservable 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/RW2

levels of adverse effects on dolphins arising from different fishing 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 in 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 -
established 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 or 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 Panels' question No. 100 (referring to Tim Lawson, Secretariat of the
Pacific Community, Methods for Analysing Bycatches with Observer Data (August 2001), (Exhibit USA-227)).
337 United States' response to Panels' question No. 100 (referring to Tim Lawson, Secretariat of the
Pacific Community, Methods for Analysing Bycatches with Observer Data (August 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 fisheries, 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 Panels' question No. 93.
340 United States' response to Panels' question No. 93.
WT/DS381/RW/USA • WT/DS381/RW2

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 scientifically-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, serious 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/RW2

the tropical tuna purse seine fisheries of the world from 2013 345, 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 fishing, 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 when 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 reports 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 than 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 Figure 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 Meeting 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 No.
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 Regular Session, Koror, Palau (November 2011), (Exhibit USA-17),
tables 2a and 2b.
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 Interaction with Marine Turtles in the Atlantic
and Indian Oceans: A 15 Years Analysis (September 2012), (Exhibit USA-230), p. 11.
WT/DS381/RW/USA • WT/DS381/RW2

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' contention 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 except 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 often 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 Analysis (September 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 (August 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/RW2

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 parties 357, the United States submitted
Exhibit USA-179, which contains a compilation of the 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 States 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 USA-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 Exhibit 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 in 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 response 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 of 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 dolphin mortalities in the purse seine 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 annual 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 marine 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 interactions 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/RW2

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 reports 365, 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 Mexico'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 note 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 the Regional Observer Programme (September 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 contends 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 WCPFC
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 further detail below in Section 7.7.2.2
WT/DS381/RW/USA • WT/DS381/RW2

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, first, 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 generally 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 per set number for the PNG alone for
2014 and 2015, and the numbers are 23.1 375 and 8.1 376 dolphin 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 USA-179 Rev. contains both 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 403,316 mt. of tuna (referring to
Papua New Guinea, Annual Report to the Commission, WCPFC-SC12/AR/CMM-19 (August 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 to Peter Williams 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), p. 2; and
United States' response to Panels' Question 31(c)). For the United States, assuming that vessels covered by
the PNG observer program conducted a consistent percentage of the 56,000 total sets in the fishery in 2014
(referring to Peter Williams 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), 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 per 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 (August 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, WCPFC, Overview of Tuna Fisheries in the Western and
Central Pacific Ocean, Including 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 sets in the
fishery in 2015 (referring to Peter Williams 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), 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 Commission, 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 (August 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, Including 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 vessels 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/RW2

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
vessels, "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 identifies 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 countries 384, Table 2 of the exhibit shows that, in fact, the countries in question had
submitted observer data for between 69% and 78% of all trips by their 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 reports.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 Mexico,
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 Management, 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, Tables 2a, 2b (Exhibit USA-58);
Peter Williams 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), p. 55.
383 Exhibit USA-179 Rev., table 2. WCPFC, 7th Annual Report for the Regional Observer Programme
(September 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 argues 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 September 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' question 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 response to Panels' question No. 57 (referring to Mexico's first written submission, paras.
74-75).
WT/DS381/RW/USA • WT/DS381/RW2

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 anecdotal data from the early 1990s.391
7.234. We note that one of the pieces of evidence submitted by the United States, Exhibit USA-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 activities 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 Philippines 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 Exhibit 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 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. 355 (explaining that information was collected "opportunistically" from "fishermen and other
knowledgeable local people"). According to the United States' comments on Mexico's response to Panels'
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 (September 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 (September 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.), NMFS, US National Bycatch
Report (2011), (Exhibit 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/RW2

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 proceedings 399, 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 what 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
inconsistent 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 methods and the areas of the ocean
that we will analyse in the following parts of our Reports.
7.7.1.2.2 Differences between different 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 Cetacean Interactions in the Tropical WCPFC
Purse Seine Fishery, Paper prepared by SPC-OFP, 8th Regular 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/RW2

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' question 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' response to Panels' questions No. 105 and 116.
WT/DS381/RW/USA • WT/DS381/RW2

but observable harms , as these figures give a picture of how frequently dolphins are endangered
by the fishing method.410
7.249. Regarding "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 the primary example of the latter is calves who are
orphaned when their mother is killed in a fishing set 411, 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 directly 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 stated 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
account the parties' responses 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 Reports.
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 Panel 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 No. 116 (referring to Panel Report, US – Tuna II (Mexico) (Article
21.5 – Mexico), para. 7.134).
WT/DS381/RW/USA • WT/DS381/RW2

no direct evidence regarding the existence and level of such 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 area 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 issue 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 practices 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. Next, 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 the 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 ETP 416, 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 setting 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 Report, 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/RW2

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; potential
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 under 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" dolphins 424, 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 gear, 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, Wursig 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/RW2

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 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".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 challenged 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 harms 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 other 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), paras. 7.196-7.197.
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/RW2

AIDCP are 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 on 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 explains that in 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/RW2

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 ETP 455 (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 States. 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 does 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 dramatically461, and in 2015 were 765.462 Mexico also submits that the direct
mortalities are well within the limits of sustainability 463, and are in fact "statistically
insignificant".464 Indeed, in Mexico's view, AIDCP -compliant setting on dolphins is an
environmentally-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 the 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 written submission, para. 230.
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/RW2

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 submission, 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 "dolphins encircled"
between 2009 and 2013 and dividing the total by 5.
WT/DS381/RW/USA • WT/DS381/RW2

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, we 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 chased 474 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, these 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, and purse seine net on the other".478 We further note that, because setting on dolphins
necessarily involves interaction with dolphins in 100% of sets 479, 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 (October 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/RW2

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 assessment".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 Cotton (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 probabilities, 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/RW2

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 in 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 in 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 separation 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 Abundance 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 Purse‑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 Mammal
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 terrestrial 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/RW2

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 separation 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 captured 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
("homeostasis" 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 arriving 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 note 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 established 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 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 study's legitimacy. 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 by 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 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; 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), 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 hypothesis 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 scientific 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 Acute 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/RW2

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 Perkins.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 time. 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
identified 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 muscle following exertion.515

509 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. 201.
510 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. 202.
511 Mexico's first written submission, para. 62.
512 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), (Exhibit MEX-14), p. 29.
513 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), (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, encirclement, 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 tagging, 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 statement 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 swimmers 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
identified by Mexico was apparently not considered by the authors of the study to undermine their conclusion
that setting on dolphins causes measurable stress effects on dolphins. Mexico has not identified or established
any methodological flaw or shortcoming in this 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/RW2

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, which 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 that "[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
population 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
dynamics 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., Report 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 from 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 "stronger" 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 observed 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 has 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 their 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 of Recovery, 343 Marine Ecology Progress Series 1 (2007), (Exhibit USA-
48), p. 11.
WT/DS381/RW/USA • WT/DS381/RW2

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 to 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 dolphins 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 confirms
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 publications 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 7.304However, Mexico has not argued that this fact undermines the credibility 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 et 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 (January 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 Panels' 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/RW2

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 unobserved incidental kill of pantropical spotted dolphin 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, because 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., 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 Pacific,
102 Fishery Bulletin 233 (2004), (Exhibit USA-44), pp. 242-244.
530 This was 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 Fisheries 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 following statements regarding the
WT/DS381/RW/USA • WT/DS381/RW2

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 imply 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 detection. 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 the 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, (Exhibit 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 as 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 which 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), paras. 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/RW2

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 table 543,
later revised in Exhibit USA-179 Rev.:
United States' Summary of the Evidence
Fishery Year Sets with
Dolphin
Interactions
Dolphins Chased Dolphin
Interactions
% 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 States' 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 Regular 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 Exhibit 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 Period, 23 Aquat. Living Resour. 353 (2010), (Exhibit USA-19), pp. 355-358; 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.
2114-2118.
547 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.
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 Regular Session, Koror, Palau
(November 2011), (Exhibit USA-17)).
549 United States' first written submission, para. 52.
WT/DS381/RW/USA • WT/DS381/RW2

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 cetaceans 555, 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
555 Mexico's first written 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 (August 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 (August 2015), (Exhibit MEX-23) and Western and Central Pacific
Fisheries Commission (WCPFC), Yearbook 2014 (15 October 2015), (MEX-24)).
558 See Section 7.7.2.1.
WT/DS381/RW/USA • WT/DS381/RW2

7.328. We first consider 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 figures presented in th is table560, nor has it introduced
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 EPO 562, 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 fishing without setting on dolphins in the ETP was on average below 0.2 per 1,000 sets 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, 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),
Table A-7, for set numbers; and IATTC, EPO Dataset 2009-2013, (Exhibit USA-16), for the number of dolphins
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 areas, (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/RW2

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 quantification.
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 fishery 566 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 respect, 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 Western 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 Regular
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/RW2

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 alive
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)
Kirbati: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 of 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 intersection 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 Regular Session, Koror, Palau (November 2011), (Exhibit USA-17),
Tables 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, Including 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 (August
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 (September 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 Ocean, Including Economic 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 (cetacean 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/RW2

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 mortalities; 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 onboard) 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)
Kirbati: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 mortalities; 4 dolphins released alive Observer Reports
(100% coverage)

579 Korea, Annual Report to the Commission, WCPFC-SC11-AR/CCM-12 (August 30, 2015), (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),
(Exhibit 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(August 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, WCPFC-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 Williams 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 (August 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 Marshall Islands, Annual Report to the Commission (August. 2016), (Exhibit USA-154), p. 15.
WT/DS381/RW/USA • WT/DS381/RW2

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 to 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 Measure. 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 WCPFC 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 (August 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 (August. 2016),
(Exhibits USA-156) pp.11, 18-19.
597 United States, Annual Report to the Commission, WCPFC-SC11/AR/CCM-20 (August. 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 US 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/RW2

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 relation 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 comments 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 (November 2011), (Exhibit USA-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/RW2

with a very high rate (65%) 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 notes 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 WCPO 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 used 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 are 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 operations 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 Session,
Koror, Palau (November 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 Regular 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 (November 2011), (Exhibit USA-17),
pp. 2-3.
WT/DS381/RW/USA • WT/DS381/RW2

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 study 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
observe 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 year 618, 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 Regular Session, Koror, Palau (November 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 (November 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 submission, 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 (September 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/RW2

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 regarding 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 dolphin 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 Department of Commerce, NOAA Tech.
Memo. NMFS-OPR-36 (July 2007), (Exhibit MEX-21), pp. 112-113.
623 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. 355 (explaining that information was conducted "opportunistically" from "fishermen and other
knowledgeable local people"). According to the United States' comments on Mexico's response 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 Southeast 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 Submission, 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/RW2

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 Measure.
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 harvesting 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 t he 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 shows that the 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 shows 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 unobserved 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/RW2

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
evidence 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 mandatory 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, Mexico 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 Ocean, 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), (Exhibit USA-9)).
WT/DS381/RW/USA • WT/DS381/RW2

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 Observer 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, we note that in the table above, the United States uses data from sources other
than Exhibit USA-9. In fact, the table presents data 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 cetaceans 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, para. 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 Bulletin 90 (2002), (Exhibit USA-09), p. 91 (footnotes omitted).
634 Mexico's first written submission, para. 82.
WT/DS381/RW/USA • WT/DS381/RW2

purse-seine fishery in the Indian Ocean (IO) to address the majo r issue of estimating fishery
removals 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 European 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 RFMOs.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 Spanish purse seine vessels to reach
general conclusions undermines the reliability of the results reached in the studies. Indeed, as
noted by the United States 639, 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 Bycatch Report
First Edition Update, (Exhibit USA-62), Table 8.3; US National Bycatch Report First Edition Update, (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), (Exhibits
USA-114, MEX-118), pp. 284-285; Karin A. Forney, SFSC, Estimates of Cetacean Mortality and Injury in Two
US Pacific 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 (November 2011), (Exhibit USA-17), pp.5-6;
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), (Exh. USA-19), p. 358; 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), 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), (Exhibit USA-21), pp. 5-6; Hernandez-Milian et al., Results of a Short Study of
Interactions of Cetaceans and Longline Fisheries in Atlantic 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/RW2

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 caused 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 unobserved 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 without 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 Observed
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 Tropical 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/RW2

recorded only two "catch events" of marine mammals , both involving baleen whales 644, 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
Tropical
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 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.
7.391. 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 vessels 650 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 Atlantic 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. Ser., (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 Period, 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 first 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/RW2

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 only 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 involved 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 extrapolate 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 vessels 658 or that the subsequent updated study
was based on limited observer data 659, 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 observation 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. Regarding 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 Period, 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 Period, 23 Aquat. Living Resour. 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 2113 (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 Period, 23 Aquat. Living Resour. 353 (2010), (Exhibit USA-19), pp. 360-61.
WT/DS381/RW/USA • WT/DS381/RW2

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
(maximum
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
suggests 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., 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. 353, 355-58 (2010); 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 (2011), 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/RW2

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
height.666
7.405. A gillnet 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 tuna 669, 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 in 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 Protect 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 Fishing, (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 Driftnet 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
Reference 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 Council, 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 MEX-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), pp. 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 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); 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, (Exhibit USA-67).
WT/DS381/RW/USA • WT/DS381/RW2

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 Measure 680, 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,
necessarily 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 Pakistan 688, 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 indicates that drift gillnetting is used, among other, by the following 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 compliance 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 Panels' 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 Panels' 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 fisheries 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 dolphin
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 Pakistan (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 Foreign Fisheries
(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/RW2

7.410. Mexico also points to evidence of indirect harms caused to dolphins and other marine
mammals by interaction with gillnets. In particular, Mexico adduces evidence showing that
although "small 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 fishing 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 longline) 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 correctly 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 harms that arise as a result of the "chase itself" in dolphin sets, independently 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 a ssertions 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 the 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, paras. 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 response 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/RW2

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
distinguishes 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 longline) 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. Regarding 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 submission, 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/RW2

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 proceedings 715, there was
evidence on Pakistani gillnet fisheries in the Indian Ocean, as well as in neighbouring fisheries ,
suggesting 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, on this basis,
and in the absence of contradictory information submitted by the countries, NOAA designated such
fisheries.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 provisions.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 significantly below those caused 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 written 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, (Exhibit
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. 13, 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 United 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/RW2

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 considered 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 kilometre length with which "large scale" 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 proceedings
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 (August 15, 2016), (Exhibit USA-101).
728 Mexico's comments on United States' response to Panels' question No. 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 and 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 fishery 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 (August 15, 2016),
(Exhibit USA-101), p. 2.
729 Mexico's comments on United 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/RW2

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 tuna 736 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 Australia 741; 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 (Mexico), paras. 7.521-564.
733 Panel Report, US – Tuna II (Mexico), para. 7.521.
734 Panel Report, US – Tuna II (Mexico), fn. 735 (quoting original 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 the
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 1992; and 1,654 (1115-2393)
common, striped and bottlenose dolphins, and long-finned pilot whales in 1993" (quoting original 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 original 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 original Panel Exhibit MEX-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 documented. 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 reduction in effort, high cetacean bycatch
rates are probable" (emphasis from original) (quoting original Panel Exhibit MEX-5, p. 26).
740 Panel Report, US – Tuna II (Mexico), fn. 738, noting "[t]he recent revelation that a driftnet fishery
has been operating 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 restricted 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 original Panel Exhibit MEX-5, p. 18).
741 Panel Report, US – Tuna II (Mexico), 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 original 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/RW2

Negros Oriental744. 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 connection, 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 populations 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 of 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 stipulated 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 original 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 driftnet 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 sharks, 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 cetacean catch in for different
surveys, or roughly 7,050-11,750 dolphins per year" (emphasis from original), (quoting original 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 original 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 original Panel Exhibit MEX-5, pp.
26,27, 131)
745 Panel Report, US – Tuna II (Mexico), fn. 739, noting "[i]n the Eastern Central 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 may all be caught in large-meshed drift gillnets targeting tuna, sharks, billfish, manta
rays, and dolphins" (emphasis from original), (quoting original 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 in 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 dolphins, together with short-finned pilot and melon-headed whales"noting (emphasis from
original), (quoting original 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 citations 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 significantly 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/RW2

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, presented "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
mortality 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 label 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/RW2

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 unobservable 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 evidence 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
markets.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 concerning 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 gillnets").
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 study 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 USA-163), p.
23; and 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. 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 (August 15, 2016), (Exhibit USA-101).
WT/DS381/RW/USA • WT/DS381/RW2

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 that 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 on 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 proceedings 774 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 during 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 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) ; 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 bycatch 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 paras. 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 (Mexico), para. 7.534.
776 Panel Report, US – Tuna II (Mexico) (Article 21.5 - Mexico), para. 7.130.
WT/DS381/RW/USA • WT/DS381/RW2

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 MEX-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 Tuna 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] frequency 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, Worldwide 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 porpoises"); 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, pelagic 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 species 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 the 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 the 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 and 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 throughout 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 southeastern 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 Alborán 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 instance, 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 bycaught 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 experts …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 incidental 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,
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. 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 interact 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 significant bycatch threats for marine mammals. It is
WT/DS381/RW/USA • WT/DS381/RW2

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
restricting 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 considered 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 estimated 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, IUCN 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 seine
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 Acoustic 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 gillnets 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 Gillnet 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 World'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 Northern 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 IUU 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 and
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, where several fisheries still use gillnets") (internal citations omitted).
783 See Panel Report, US – Tuna II (Mexico), fn. 735 (quoting original 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 government 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 of 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 cetacean
WT/DS381/RW/USA • WT/DS381/RW2

United States 784, 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 Reduction 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 fishery 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. 46 ("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 type
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 aids (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-economic 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 Conservation 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 netting 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 Report, 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 written 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/RW2

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 rare 791, 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 pertaining 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' third written submission,
para. 59.
792 See e.g. NMFS, Proposed Rule: List of Fisheries for 2017, 81 Fed. Reg. 54,019 (August 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 cetacean 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/RW2

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 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"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 2015), (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 occurred 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 still 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 invertebrates").
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 nets 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/RW2

(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 reports 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 mammals 809, 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 reports 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 circumstances.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 report 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 Operations: 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 incidental 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 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. 20-24.
810 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. 26-28.
811 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. 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, 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), (Exhibit MEX-105), p. 22.
814 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), (Exhibit MEX-105), p. 26.
WT/DS381/RW/USA • WT/DS381/RW2

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 instance 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 FAO 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 longlines 820, 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 year 822
and these mortalities are threatening the viability of dolphin stocks in some fisheries.823

815 See Stephen B. Reilly et al., Report of the Scientific Research Program Under the International
Dolphin Conservation Program Act (2005) (Exhibit USA-47), p. 26; Elizabeth Edwards, Fishery Effects on
Dolphins Targeted by Tuna Purse-Seiners in the Eastern Tropical Pacific Ocean, 20 Int’l J. Comp. Psychology
(2007) (Exhibit 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,
(Exhibit 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/RW2

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 longlines 824 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 own 827, 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 written 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/RW2

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 effects 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 USA-179 Rev. concerning dolphin mortalities
in longline fisheries, which we reproduce 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 the 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/RW2

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/RW2

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 fishery 853 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 mortalities 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 indicative 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 to 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 different 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 Mexico's response to Panels' question
No. 67, para. 41.
WT/DS381/RW/USA • WT/DS381/RW2

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 note 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 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". 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 interactions.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 dolphins 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 presented 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
Groundfish 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/RW2

the net or hook. 863 We note that the same arguments were raised by Mexico in respect of the
"unobservable" 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:
Trawling 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 fisheries.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 Incidental 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/RW2

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 caused 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 species [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 Landing 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, Vol. 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 Cetaceans 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/RW2

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, these 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 evidence 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 Coast (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 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), (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 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. 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 Programme 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., 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.
WT/DS381/RW/USA • WT/DS381/RW2

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/RW2

7.7.2.6.2 Panels' 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 Mexico, tuna associate with dolphins in some areas of the Indian Ocean, and
handline fishers target 895 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 fishing 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 unobservable 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 written submission, para. 110.
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/RW2

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 while 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 it 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 Maldives 905, 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 Research Center, Ministry of Fisheries and Agriculture, Republic of Maldives, Handline Large
Yellowfin Tuna Fishery of the Maldives, IOTC-2009-WPTT-15 (October 2009), (Exhibit MEX-39), p. 5.
904 Marine Research Center, Ministry of Fisheries and Agriculture, Republic of Maldives, Handline Large
Yellowfin Tuna Fishery of the Maldives, IOTC-2009-WPTT-15 (October 2009), (Exhibit MEX-39), p. 5.
905 Adam, Jauharee and Miller, Review of Yellowfin Tuna Fisheries in the Maldives, IOTC–2015–WPTT17–
17 (8 October. 2015), (Exhibit MEX-40), p. 6.
906 Adam, Jauharee and Miller, Review of Yellowfin Tuna Fisheries in the Maldives, IOTC–2015–WPTT17–
17 (8 October. 2015), (Exhibit MEX-40), p. 2.
907 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. See
also 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 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 association 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/RW2

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 evidence 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 Central 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/RW2

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 impact 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, para. 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' questions 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 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.
WT/DS381/RW/USA • WT/DS381/RW2

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 Measure, 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 the 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 harms.
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 other 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 risk 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 sets 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 seine 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/RW2

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 the 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 way 922, 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 Measure 924, and emphasized that the
substantive conditions for gaining access to the dolphin -safe label cannot be properly understood

920 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico), para. 7.155.
921 Appellate Body 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 Report, US – Tuna II (Mexico) (Article 21.5 – Mexico), para. 7.14.
WT/DS381/RW/USA • WT/DS381/RW2

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 detrimental 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 impact 926, 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) (Article 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) (Article 21.5 – Mexico), para. 7.21.
WT/DS381/RW/USA • WT/DS381/RW2

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 seas 936
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 United 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 method 940, 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. 105.
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/RW2

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 However, 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 every 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 submission, 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/RW2

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
considerably 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 respect 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 and 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 contrasts 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/RW2

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 outside 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), paras. 7.159 and 7.165.
959 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico), para. 7.165.
960 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico), paras. 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), paras. 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/RW2

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" that 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), paras. 7.215 – 7.219.
972 Panel Report, US – Tuna II (Mexico) (Article 21.5 – Mexico), para. 7.233.
973 Panel Report, 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/RW2

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 argued 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
commensurate 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 dolphins 982 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 require 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 but 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' first 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/RW2

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 where 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
support 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 skills 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 written 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/RW2

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 than 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 submitted 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 proceedings.
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 not 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 different 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. 7.520 (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 submission, 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/RW2

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 observation.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 capture 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 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, 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/RW2

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 particularly 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 captains 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 the 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 requirements.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 serious 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/RW2

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 more 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 the sense of the dolphin being seen only after the set was commenced),
then there is no "intentional 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 and 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 taxonomy 1024, identifying an
intentional dolphin set 1025, iden tifying dolphin mortality and serious injury 1026, 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 injury 1029, 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 terms (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 Training 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), pp. 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/RW2

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 injuries".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 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.
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 Mexico'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 criminal 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.
Section 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 o r regulation issued thereunder". The penalty may be up to
WT/DS381/RW/USA • WT/DS381/RW2

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 démarche
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 statement 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 who
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 Products (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 Report, 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/RW2

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 under 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
requirements 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 contained 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
Interamericana 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/RW2

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 respect 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 tolerate 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 -handedness 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 in 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/RW2

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 of 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 mechanisms.
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 cannot 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 proceedings 1051),
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 completely 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 Reports, US – Tuna II (Mexico) (Article 21.5 – Mexico), para. 7.122; US – Tuna
II (Mexico), para. 292.
WT/DS381/RW/USA • WT/DS381/RW2

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 certification 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 recognized 1053, 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 comparably 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 Tuna 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. Accordingly, 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 Report, 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 Report, US – Tuna II (Mexico) (Article 21.5 – Mexico), para. 7.263.
WT/DS381/RW/USA • WT/DS381/RW2

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 stored 1064, 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 retail 1067, 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
216.93(c)(1)-(3), (Exhibits 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/RW2

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 Tuna 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 II (Mexico) (Article 21.5 – Mexico), para. 7.167.
WT/DS381/RW/USA • WT/DS381/RW2

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 oversight. 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
products 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-handedness 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 may 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 submission, para. 173.
WT/DS381/RW/USA • WT/DS381/RW2

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 requirements 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 low 1095, 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
deficiencies 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 submission, paras. 289-290.
1096 Mexico's first written submission, para. 291.
WT/DS381/RW/USA • WT/DS381/RW2

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 processed.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 (March 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/RW2

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 set 1111, 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 Conservation 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 (Mexico) (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/RW2

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 Dolphin 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 for 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/RW2

processor reports 1125, audits of US canneries 1126, r etail 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 correct 1128; 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 may 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 and 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), (Exhibits 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), (Exhibits USA-02, MEX-02).
1130 50 CFR Section 216.91(a)(5)(ii)(C), (Exhibits USA-02, MEX-02).
1131 AIDCP, Resolution To Adopt The Modified System For Tracking 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 obligations 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 Tracking 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 infractions 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 2016), (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/RW2

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 Tuna Measure draws
in terms of the different conditions of access to the dolphin-safe label were explained in the light of

1136 Mexico's first written submission, para. 291.
WT/DS381/RW/USA • WT/DS381/RW2

the relative 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 applying 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 back 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 explanations 1141 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 tuna 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 AIDCP 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 Measure 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 Dolphin 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 Conservation 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 loaded 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/RW2

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 retail 1146, 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. Specifically, 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 to 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
responsibility 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) (Article 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/RW2

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 movement of the tuna, even before it arrives 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 processors 1153, 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 or 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 recognises 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/RW2

7.666. Under the NOAA system, however, the NMFS would request this information from US
processors 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 States 1158 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 NOAA.
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 profile.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), (Exhibits USA-02, MEX-02).
1158 United States' first written submission, para. 86.
1159 50 CFR Section 216.91(a)(5)(ii)(A), (Exhibits USA-02, MEX-02).
1160 50 CFR Section 216.91(a)(5)(ii)(B), (Exhibits USA-02, MEX-02).
1161 50 CFR Section 216.91(a)(5)(ii)(C), (Exhibits USA-02, MEX-02).
1162 See Section 7.8.3 above.
WT/DS381/RW/USA • WT/DS381/RW2

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 mechanism 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 fishing 1163, 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 breaches of the tracking and verification re quirements may lead to the
imposition of sanctions. In 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, through
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 differences in the risk profile of the ETP large purse
seine fishery compared to other 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/RW2

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 following 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 fishery.
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 level 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 proceedings. 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 the 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 underlying statute. Rather, the new requirements have been
enacted by regulation. Mexico's first written submission, para. 138.
WT/DS381/RW/USA • WT/DS381/RW2

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 metric 1175,
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 all 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 written 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/RW2

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 Agreement. 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/RW2

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 provisions 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 collected 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 United 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 relevant 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 risks 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' response 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/RW2

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 that 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/RW2

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 imperfect 1199, 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 tuna 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, and is not directly concerned with the sustainability of dolphin stocks.
WT/DS381/RW/USA • WT/DS381/RW2

Above, we have found that the eligibility criteria are calibrated because of the significant difference
in risk between setting on dolphins, on the one hand 1201, 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 methods.
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. This 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 deployment. 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 requirements 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
criteria 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 different 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/RW2

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 complement 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/RW2

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 1994 1202, 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 was 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 consideration 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 the 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), paras. 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/RW2

"it would be rare for a panel that had found that a measure detrimentally modifies the conditions
of competition 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 as 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 market 1216, 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 same 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 under 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 Report, 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), paras. 7.315-7.322.
WT/DS381/RW/USA • WT/DS381/RW2

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 prevail, 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] arbitrary 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 panel 1233, the approach to these provisions by the
Appellate Body in the first compliance proceedings 1234, 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), paras. 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 unchanged 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 7.494-7.495.
1234 Appellate Body Report, US – Tuna II (Mexico) (Article 21.5 – Mexico), para. 8.1(d)(ii).
WT/DS381/RW/USA • WT/DS381/RW2

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 panel 1237 and the
Appellate Body in the first compliance proceedings 1238, 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; (ii) 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 that 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 respect 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 Article 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 subparagraph (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 Report, 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 response to Panels' question No. 110; United States' response to Panels' question No. 110.
1244 See fn. 1227 above.
WT/DS381/RW/USA • WT/DS381/RW2

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 compromised 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 requirements, 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 they 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 that
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 calibrated.
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
arbitrary 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 different 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 another, 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 that whether the 2016 Tuna Measure
is applied in a manner that constitutes a means of arbitrary or unjustifiable discrimination depends
on whether the 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/RW2

7.740. On the 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 under 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 to 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
conditions prevail and, therefore, the requirements of the chapeau are not met". Mexico's first written
WT/DS381/RW/USA • WT/DS381/RW2

8 CONCLUSIONS AND RECOMMENDATION(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).

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 considers 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 with its obligations under the WTO Agreement.
8.5. Having found that the United States has not acted inconsistently with its obligations under
the WTO Agreement, the Panel considers that no recommendation under Article 19.1 of the DSU is
necessary, and makes none.

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 considers 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 with its obligations under the WTO Agreement.
8.9. Having found that the United States has not acted inconsistently with its obligations under
the WTO Agreement, the Panel considers that no recommendation under Article 19.1 of the DSU is
necessary, and makes none.