2013 Shark Finning

Report to Congress 
 

2013 Shark Finning Report to Congress 

Pursuant to the 

Shark Finning Prohibition Act 

(Public Law 106-557) 

U.S. Department of Commerce
 

National Oceanic and Atmospheric Administration
 

Prepared by the
 

National Marine Fisheries Service
 
 

 

 

 

 

 

 

 

 

Table of Contents
 

List of Tables.......................................................................................................................... iii
 

Abbreviations and Acronyms......................................................................................... iv
 

Executive Summary........................................................................................................... vii
 

1. Introduction................................................................................................................................. 1
 

2. Management and Enforcement ................................................................................................... 6
 

2.1 Management Authority in the United States......................................................................... 6
 

2.2 Current Management Authority in the Atlantic Ocean......................................................... 7
 

Atlantic Highly Migratory Species Management ................................................................... 7
 

Shark Management by the Regional Fishery Management Councils and States.................. 14
 

2.3 Current Management of Sharks in the Pacific Ocean......................................................... 14
 

Pacific Fishery Management Council (PFMC)..................................................................... 14
 

North Pacific Fishery Management Council (NPFMC) ....................................................... 18
 

Western Pacific Fishery Management Council (WPFMC)................................................... 21
 

2.4 NOAA Enforcement of the Shark Finning Prohibition Act ............................................... 24
 

2.5 Education and Outreach...................................................................................................... 25
 

3. Imports and Exports of Shark Fins ........................................................................................... 27
 

3.1 U.S. Imports of Shark Fins ................................................................................................. 27
 

3.2 U.S. Exports of Shark Fins ................................................................................................. 27
 

3.3 International Trade of Shark Fins ....................................................................................... 28
 

4. International Efforts to Advance the Goals of the Shark Finning Prohibition Act................... 35
 

4.1 Bilateral Efforts................................................................................................................... 35
 

4.2 Regional Efforts.................................................................................................................. 36
 

Northwest Atlantic Fisheries Organization (NAFO) ............................................................ 37
 

Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) ...... 38
 

Inter-American Tropical Tuna Commission (IATTC).......................................................... 38
 

International Commission for the Conservation of Atlantic Tunas (ICCAT) ...................... 39
 

Western and Central Pacific Fisheries Commission (WCPFC)............................................ 41
 

International Scientific Committee for Tuna and Tuna-like Species in the North Pacific 

Ocean (ISC) .......................................................................................................................... 43
 

4.3 Multilateral Efforts ............................................................................................................. 43
 

World Customs Organization ............................................................................................... 44
 

Food and Agriculture Organization of the United Nations (FAO) Committee on ............... 44
 

Fisheries (COFI) ................................................................................................................... 44
 

United Nations (UN)) ........................................................................................................... 44
 

Convention on the Conservation of Migratory Species of Wild Animals (CMS)................ 45
 

International Union for the Conservation of Nature (IUCN) - Global Sawfish Status Review
 

Workshop.............................................................................................................................. 45
 

5. NOAA Research on Sharks .................................................................................................... 466
 

5.1 Data Collection and Quality Control, Biological Research, and Stock Assessments......... 47
 

Pacific Islands Fisheries Science Center (PIFSC) ................................................................ 47
 

Southwest Fisheries Science Center (SWFSC)..................................................................... 49
 

Northwest Fisheries Science Center (NWFSC).................................................................... 52
 

Alaska Fishery Science Center (AFSC, Auke Bay Laboratory)........................................... 53
 

Northeast Fisheries Science Center (NEFSC) ...................................................................... 55
 

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Southeast Fisheries Science Center (SEFSC) ....................................................................... 57
 

NOAA Chesapeake Bay Office ............................................................................................ 59
 

NOAA Center for Coastal Environmental Health and Biomolecular Research ................... 60
 

5.2 Incidental Catch Reduction................................................................................................. 60
 

Pacific Islands Fisheries Science Center (PIFSC) ................................................................ 60
 

Southwest Fisheries Science Center (SWFSC)..................................................................... 61
 

5.3Post-Release Survival .......................................................................................................... 63
 

Southwest Fisheries Science Center (SWFSC)..................................................................... 63
 

Northeast Fisheries Science Center (NEFSC) ...................................................................... 65
 

Southeast Fisheries Science Center (SEFSC) ..................................................................... 665
 

6. References............................................................................................................................... 687
 

7. Internet Information Sources .................................................................................................. 754
 

Appendix 1: Detailed Information on NOAA Research on Sharks .................................... 776

Pacific Islands Fisheries Science Center (PIFSC) .............................................................. 776
 

Southwest Fisheries Science Center (SWFSC)................................................................... 909
 

Northwest Fisheries Science Center (NWFSC).................................................................. 988
 

Alaska Fishery Science Center (AFSC, Auke Bay Laboratory)......................................... 100
 

Northeast Fisheries Science Center (NEFSC) .................................................................. 1044
 

Southeast Fisheries Science Center (SEFSC) ................................................................. 12221
 

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List of Tables 

Table 1.1.1.Status of shark stocks and stock complexes in U.S. fisheries in 2012. ....................... 4
 

Table 2.2.1 U.S. Atlantic shark management units, shark species for which retention is
 

Table 2.2.2 Commercial landings for Atlantic large coastal, small coastal and pelagic sharks in
 

Table 2.2.3 Preliminary landings estimates in metric tons (mt) and pounds (lb) dressed weight
 

Table 2.3.1 Shark species in the West Coast Highly Migratory Species Fishery Management
 

Table 2.3.2 Shark species in the groundfish management unit of the Pacific Coast Groundfish 

Table 2.3.3 Commercial Shark landings (round weight equivalent in metric tons) for California, 

Table 2.3.5 Incidental catch and utilization (in metric tons) of sharks in the Gulf of Alaska and 

Table 2.3.6 Sharks in the management unit of the Fishery Ecosystem Plan for Western Pacific
 

Table 2.3.7 Coastal sharks listed as management unit species and designated as currently
 

Table 2.3.8 Shark landings (in metric tons) from the Hawaii-based and American Samoa-based
 

Table 3.1.1 Weight and value of dried shark fins imported into the United States, by country of
 

Table 3.2.1 Weight and value of dried shark fins exported from the United States, by country of 

Table 3.3.1 Weight and value of shark fins imported by countries other than the United States.
 

Table 3.3.2 Weight and value of shark fins exported by countries other than the United States.
 

prohibited, and data-collection-only species................................................................................... 9
 

metric tons dressed weight, 2007–2012........................................................................................ 10
 

(dw) for the 2012 Atlantic shark commercial fisheries. ............................................................... 11
 

Plan. .............................................................................................................................................. 15
 

Fishery Management Plan............................................................................................................. 16
 

Oregon, and Washington, 2003–2012. ......................................................................................... 17
 

Table 2.3.4 North Pacific shark species..................................................................................... 19
 

Bering Sea/Aleutian Islands commercial groundfish fisheries, 2003-2012.................................. 20
 

Pelagic Fisheries (as amended December 2009). ......................................................................... 22
 

harvested coral reef taxa in the four Western Pacific Fishery Ecosystem Plans. ......................... 23
 

pelagic longline fisheries, 2002–2012. ......................................................................................... 24
 

origin............................................................................................................................................. 29
 

destination..................................................................................................................................... 30
 

....................................................................................................................................................... 31
 

....................................................................................................................................................... 32
 

Table 3.3.3 Production of shark fins in metric tons by country.................................................. 34
 

Table 4.2.1 Regional Fishery Management Organizations and Programs.................................. 37
 

Table 4.3.1 Other multilateral fora. ............................................................................................ 43
 

Table A.1.1 Shark species observed in PIFSC-CRED Reef Assessment and Monitoring 

Program surveys around U.S. Pacific Islands............................................................................. 787
 

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Abbreviations and Acronyms 

ABC ...................................................allowable biological catch
 

ABL....................................................Auke Bay Laboratory
 

ADF&G..............................................Alaska Department of Fish and Game 

AFSC..................................................Alaska Fisheries Science Center
 

ALWTRP ...........................................Atlantic Large Whale Take Reduction Plan
 

BLL....................................................bottom longline
 

BREP..................................................Bycatch Reduction Engineering Program
 

BSAI ..................................................Bering Sea/Aleutian Islands
 

CCAMLR...........................................Commission for the Conservation of Antarctic Marine
 

Living Resources 

CDGN ................................................California drift gillnet fishery 

CI........................................................confidence interval 

CITES ................................................Convention on International Trade in Endangered Species 

of Wild Fauna and Flora 

CMS ...................................................Convention on the Conservation of Migratory Species of 

Wild Animals 

COASTSPAN ....................................Cooperative Atlantic States Shark Pupping and Nursery 

COFI ..................................................Food and Agriculture Organization’s Committee on 

Fisheries
 

CPUE .................................................catch per unit effort
 

CRED ................................................Coral Reef Ecosystem Division
 

CSTP..................................................Cooperative Shark Tagging Program
 

dw.......................................................dressed weight
 

EEZ ....................................................Exclusive Economic Zone
 

EFH....................................................essential fish habitat
 

EPO....................................................Eastern Pacific Ocean
 

FAO....................................................Food and Agriculture Organization of the United Nations
 

FEP.....................................................fishery ecosystem plan
 

FL..........................................fork length
 

FMP....................................................fishery management plan
 

FR.......................................................Federal Register
 

GARFO................................... Greater Atlantic Regional Fisheries Office
 

GCEL .................................................General Counsel for Enforcement and Litigation 

GOA...................................................Gulf of Alaska
 

GULFSPAN.......................................Gulf of Mexico States shark pupping and nursery
 

HIMB .................................................Hawaii Institute of Marine Biology
 

HMS...................................................highly migratory species
 

IATTC................................................Inter-American Tropical Tuna Commission
 

ICES...................................................International Council for the Exploration of the Sea
 

ICCAT................................................International Commission for the Conservation of Atlantic
 

Tunas 

IPOA ..................................................International Plan of Action 

IUCN..................................................International Union for Conservation of Nature 

ISC........................................International Scientific Committee for Tuna and Tuna-like 

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Species in the North Pacific Ocean
 

Kg.......................................................kilogram
 

LCS ....................................................large coastal sharks
 

MAFMC.............................................Mid-Atlantic Fishery Management Council
 

MDMF ...............................................Massachusetts Division of Marine Fisheries
 

MSA...................................................Magnuson-Stevens Fishery Conservation and Management
 

Act
 

MSY...................................................maximum sustainable yield
 

mt .......................................................metric tons
 

n..........................................................sample size
 

NEFSC ...............................................Northeast Fisheries Science Center
 

NEFMC..............................................New England Fishery Management Council
 

NMFS.................................................National Marine Fisheries Service
 

NOAA................................................National Oceanic and Atmospheric Administration
 

NAFO.................................................Northwest Atlantic Fisheries Organization
 

NOVA................................................Notice of Violation and Assessment
 

NPFMC..............................................North Pacific Fishery Management Council
 

NPOA.................................................National Plan of Action
 

NWFSC..............................................Northwest Fishery Science Center
 

NWHI.................................................Northwestern Hawaiian Islands
 

OFL....................................................overfishing levels
 

OLE....................................................Office of Law Enforcement
 

OTC....................................................oxytetracycline
 

PacFIN ...............................................Pacific Fisheries Information Network
 

PIFSC.................................................Pacific Island Fisheries Science Center
 

PSAT..................................................pop-up satellite archival tags
 

PFMC.................................................Pacific Fishery Management Council
 

PRIA ..................................................Pacific remote island areas
 

RecFIN...............................................Recreational Fisheries Information Network
 

RFMO ................................................regional fishery management organization
 

SAFE..................................................Stock Assessment and Fishery Evaluation
 

SCB.......................................Southern California Bight
 

SCRS..................................................Standing Committee on Research and Statistics
 

SCS ....................................................small coastal sharks
 

SEDAR ..............................................Southeast Data, Assessment, and Review
 

SEFSC................................................Southeast Fisheries Science Center
 

SFPA..................................................Shark Finning Prohibition Act
 

SPOT..................................................smart position and temperature transmitting tags
 

SSL.....................................................sound scattering layer
 

SWFSC ..............................................Southwest Fisheries Science Center
 

TAC....................................................total allowable catch
 

TL.......................................................total length
 

UNGA................................................United Nations General Assembly
 

USCG.................................................United States Coast Guard
 

USVI ..................................................United States Virgin Islands
 

VMS...................................................vessel monitoring system
 

v 
WCPFC..............................................Western and Central Pacific Fisheries Commission 

WCR.......................................West Coast Region 

WPacFin.............................................Western Pacific Fishery Information Network 

WPFMC .............................................Western Pacific Fishery Management Council 

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Executive Summary 

Because of their biological and ecological characteristics, sharks present an array of issues and 

challenges for fisheries management and conservation. Many shark species are characterized by 

late maturity, slow growth, and low reproductive rates, which can make them particularly 

vulnerable to overexploitation. Concern has grown about the status of shark stocks and the 

sustainability of their exploitation in world fisheries, as demand for some shark species and shark 

products has increased. 

Shark finning is the practice of taking a shark, removing a fin or fins (whether or not including 

the tail), and discarding the remainder of the shark to the sea. The 2000 Shark Finning 

Prohibition Act (SFPA) amended the Magnuson-Stevens Fishery Conservation and Management 

Act (MSA) to prohibit the practice of shark finning by any person under U.S. jurisdiction. 

Regulations to implement the SFPA were completed in 2002. In 2011, President Obama signed 

the 2010 Shark Conservation Act (SCA). The 2010 Act amended two previous acts—the High 

Seas Driftnet Fishing Moratorium Protection Act and the MSA—to improve domestic and 

international shark conservation measures. Rulemaking is currently underway to implement the 

2010 Shark Conservation Act. This report describes the efforts of NOAA’s National Marine 

Fisheries Service (NMFS) during calendar year 2012 to carry out the SFPA and more recent 

shark conservation and management measures required under the MSA as amended by the 2010 

SCA. 

Sharks in Federal waters are currently managed under 11 different fishery management plans 

under the authority of the MSA. In the U.S. jurisdictional waters of the Atlantic Ocean, Gulf of 

Mexico, and Caribbean Sea, oceanic sharks and other highly migratory species (HMS) are under 

the jurisdiction of the Secretary of Commerce, who delegates management authority to NMFS. 

One species of shark is managed jointly by the New England and Mid-Atlantic Fishery 

Management Councils. In the U.S. waters of the Pacific Ocean, three regional fishery 

management councils—Pacific, North Pacific, and Western Pacific—are responsible for 

developing fishery management plans. In 2012, domestic management of sharks included the 

following major actions: 

•	 NMFS received two petitions to list as a threatened or endangered distinct population 

segment, and designate critical habitat for, the Northeast Pacific population of white 

sharks (Carcharodon carcharias) under the Endangered Species Act (ESA). The first 

petition was from WildEarth Guardians and Friends of Animals on June 25, 2012, and the 

second petition, on August 13, 2012, was filed jointly by Oceana and the Center for 

Biological Diversity. NMFS determined that the petitioned action may be warranted and 

announced a 90-day finding and status review initiation on September 28, 2012 (77 FR 

59582). 

•	 On October 4, 2012, NMFS published a final rule (77 FR 60632) to implement the 

International Commission for the Conservation of Atlantic Tunas (ICCAT) requirements, 

which prohibit the retention, transshipping, landing, storing, or selling of silky sharks 

(Carcharhinus falciformus) caught in association with fisheries managed by ICCAT. 

•	 NMFS published a proposed rule (77 FR 70552) on November 26, 2012, to consider 

management measures based on six new stock assessments for Atlantic and Gulf of 

Mexico shark stocks. The proposed rule considered changes to total allowable catch 

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limits, commercial quotas, species groupings, effort controls for bottom and pelagic 

longline fisheries, and recreational shark minimum sizes in an effort to reduce fishing 

mortality and rebuild overfished Atlantic shark species. 

Additional information on shark management in the United States can be found in Sections 2.1 

through 2.3 of this report. 

The Department of Commerce and the Department of State have been active in promoting 

development of international agreements consistent with the SFPA. In 2012, the United States 

was successful in the following international efforts: 

•	 The International Scientific Committee for Tuna and Tuna-like Species in the North 

Pacific Ocean (ISC) Shark Working Group sponsored two workshops in 2012 to work on 

a North Pacific blue shark stock assessment, and to address uncertainties in ageing 

pelagic sharks. The blue shark assessment data preparatory meeting was held in May 

2012 in Shizuoka, Japan. 

•	 The Twelfth ISC Plenary, held in Sapporo, Japan, from July 18–23, 2012, was attended 

by members from Canada, Chinese Taipei, Japan, Korea, Mexico, and the United States. 

The Plenary reviewed the progress of the Shark Working Group (SHARKWG) and 

endorsed the assessment schedule of a North Pacific blue shark assessment for the ISC to 

review and continuing preparation for a shortfin mako shark stock assessment in 

2013/2014. 

•	 In 2012, the Inter-American Tropical Tuna Commission (IATTC) adopted, with U.S. 

support, an amendment to a Resolution on Transshipment. The amendment added 

language to include the monitoring of sharks along with tuna for transshipments in the 

eastern Pacific Ocean. 

•	 In 2012, with support from U.S. scientists, ICCAT’s Standing Committee on Research 

and Statistics (SCRS) conducted an updated ecological risk assessment (ERA) for 16 

species, including five species not evaluated previously. New information on 

geographical distribution, biological information and productivity, and post-release 

mortality rates was incorporated into the analysis for some species. Also in 2012, ICCAT 

adopted a recommendation that requires all parties to report on their implementation of 

previously agreed conservation and management measures for sharks. This information 

will be evaluated by ICCAT’s Compliance Committee; potential actions include the 

revocation of fishing authorization for parties not reporting catch data to the SCRS as 

required. 

•	 At its annual meeting, the Northwest Atlantic Fisheries Organization (NAFO) adopted 

provisions to require shark bycatch to be reported at the species level, which will increase 

our understanding of species-specific bycatch rates. 

•	 In 2012, the Western and Central Pacific Fisheries Commission’s (WCPFC) designated 

whale shark as a key shark species and adopted two conservation and management 

measures (CMMs) related to sharks. The WCPFC adopted a U.S. proposal prohibiting 

the retention of oceanic whitetip sharks, and adopted a CMM prohibiting purse seine 

vessels from international sets on tunas associated with whale sharks. 

•	 In 2012, the United Nations General Assembly adopted, by consensus, language in the 

annual Sustainable Fisheries Resolution calling for the UN Food and Agriculture 

Organization to conduct an analysis and technical review of actions taken by States and 

viii 
 

regional fishery management organizations (RFMOs) to implement the International Plan 

of Action for sharks and to make recommendations for improved species-specific data 

collection. 

Further information on international efforts to advance the goals of the Shark Finning Prohibition 

Act can be found in Section 4 of this report. 

Research conducted by the NMFS Regional Fisheries Science Centers has produced valuable 

information on shark status, survivorship, mobility, migration, habitat, ecology, and age and 

growth characteristics, all of which will be incorporated into effective shark fishery management 

decisions. A summary of NMFS’ 2011 research efforts regarding sharks can be found in Section 

5 of this report, with details offered in Appendix 1. 

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1. Introduction
 

Shark species have existed for more than 400 million years. They hold a unique position as one 

of the top predators of the sea, and their abundance is often low compared to organisms lower on 

the food chain. Sharks tend to live long, mature late, and produce few offspring (Frisk et al. 

2005). In addition, long-distance migrations often mean that individuals cross international 

boundaries. While these characteristics were successful for millions of years, they also make 

sharks particularly vulnerable to overexploitation by humans. 

Shark finning is the practice of taking a shark, removing a fin or fins (whether or not including 

the tail), and discarding the remainder of the shark to the sea.1 Shark fins are very valuable and 

are among the most expensive fish products in the world. The fins are considered a delicacy in 

East Asia and are used to make shark fin soup. The growth in demand for some shark products, 

such as fins, continues to drive increased exploitation of sharks (Bonfil 1994, Rose 1996, Walker 

1998, Clarke et al. 2007). In addition to being directly targeted in a few fisheries, sharks are also 

a common bycatch species in the tuna and marlin fisheries. The high value of shark fins has led 

to an increase in directed shark fisheries solely for the purposes of fining as well as finning of 

incidental catch, instead of releasing sharks overboard alive. 

Over the past few decades, as evidence of overfishing has increased, concern has grown about 

the status of shark stocks and the sustainability of their exploitation in world fisheries. This 

situation has resulted in several international initiatives to promote greater understanding of 

sharks in the ecosystem and greater efforts to conserve the many shark species caught in fisheries 

globally. Internationally, 67 species of sharks are listed as critically endangered or endangered 

on the International Union for Conservation of Nature (IUCN) red list (Simpfendorfer et al. 

2011). There is insufficient data collected internationally to realistically estimate the number and 

species of sharks killed each year by fishermen in other countries. Countries report catch to the 

Food and Agriculture Organization of the United Nations (FAO) on a voluntary basis, but 

research suggests this number underestimates the actual number of sharks landed annually 

(Clarke et al. 2006). 

As international awareness of the plight of sharks has increased, countries have determined the 

animals are worth more alive (for tourism) than dead (for fisheries) and have thus banned shark 

fishing in their waters. Palau, Maldives, Bahamas, Belize, Costa Rica, El Salvador, Guatemala, 

Honduras, Nicuragua, Panama, and the Dominican Repulbic as well as Taiwan have adopted 

finning bans. Although these measures are a strong step in shark conservation, they are often 

poorly enforced making them not yet fully effective. In the United States, Hawaii (2010), 

California (2011), Oregon (2011), the Commonwealth of the Northern Mariana Islands (2011), 

American Samoa (2012), Illinois (2012), Maryland (2013), Delaware (2013), and New York 

(2013) have made it unlawful for any person to “possess, sell, offer for sale, trade, or “distribute” 

shark fins. Guam (2011) prohibits those activities and also makes it unlawful to “take, purchase, 

barter, transport, export, [or] import” shark fins. In addition, Washington State passed a bill in 

2011 prohibiting the sale or purchase of shark fins. 

1 As defined in Section 9 of the Shark Finning Prohibition Act. 

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For 2012, in U.S. fisheries, three out of 34 shark stocks or stock complexes (9 percent) were 

listed as subject to overfishing2 and five shark stocks (15 percent) were listed as overfished3 

(Table 1). Twenty shark stocks or stock complexes (59 percent) had an unknown or undefined 

overfishing status in terms of their overfishing status and 19 shark stocks or stock complexes (56 

percent) had an unknown or undefined overfished status in terms of their overfished status (Table 

1). 

The Shark Conservation Act of 2010 was was signed into law by President Obama on January 4, 

2011. The Shark Conservation Act amended the High Seas Driftnet Fishing Moratorium 

Protection Act in two important ways. First, it requires the Secretary of Commerce to identify a 

nation if two or more fishing vessels of that nation have been engaged in fishing activities or 

practices in international waters that target or incidentally catch sharks and if that nation has not 

adopted a regulatory program to provide for the conservation of sharks, including measures to 

prohibit removal of shark fins at sea. Second, it directs the United States to urge international 

fishery management organizations, to which the United States is a member, to adopt shark 

conservation measures, such as prohibiting removal of shark fins at sea. It also directs the 

United States to enter into international agreements that require measures for the conservation of 

sharks, including prohibiting the removal of shark fins at sea. 

The Shark Conservation Act of 2010 also amended the 2000 Shark Finning Prohibition Act 

provisions in the MSA. The 2010 law states that it is illegal “to remove any of the fins of a shark 

(including the tail) at sea; to have custody, control, or possession of any such fin aboard a fishing 

vessel unless it is naturally attached to the corresponding carcass; to transfer any such fin from 

one vessel to another vessel at sea, or to receive any such fin in such transfer, without the fin 

naturally attached to the corresponding carcass; or to land any such fin that is not naturally 

attached to the corresponding carcass, or to land any shark carcass without such fins naturally 

attached.” The 2010 Act also states that shark finning amendments “do not apply to an 

individual engaged in commercial fishing for smooth dogfish (Mustelus canis) in the Atlantic, if 

the individual holds a valid State commercial fishing license, unless the total weight of smooth 

dogfish fins landed or found on board a vessel to which this subsection applies exceeds 12 

percent of the total weight of smooth dogfish carcasses landed or found on board.” 

NMFS is addressing the requirements of the 2010 Shark Conservation Act by publishing three 

regulations: (1) the Office of International Affairs is amending the definition of illegal, 

unreported, or unregulated (IUU) fishing, (2) the Office of Sustainable Fisheries’ Domestic 

Fisheries Division is amending shark finning regulations to prohibit the removal of the fins of a 

shark at sea, and (3) the Office of Sustainable Fisheries’ Highly Migratory Species Division is 

modifying the smooth dogfish regulations. 

Congressional Mandate for the Annual Shark Finning Report to Congress: 

On December 21, 2000, the Shark Finning Prohibition Act was signed into law. The Act 

requires NMFS to promulgate regulations to implement its provisions (Section 4), initiate 

discussion with other nations to develop international agreements on shark finning and data 

2 A stock that is subject to overfishing has a fishing mortality (harvest) rate above the level that provides for the
 

maximum sustainable yield.

3 A stock that is overfished has a biomass level below a biological threshold specified in its fishery management 

plan.
 

2
 
 

 

 

 

 

 

 

 

 

 

collection (Section 5), provide Congress with annual reports describing efforts to carry out the 

Shark Finning Prohibition Act (Section 6), and establish research programs (Sections 7 and 8). 

Section 9 of the Act defines shark finning. 

Section 6 of the Shark Finning Prohibition Act requires the Secretary of Commerce, in 

consultation with the Secretary of State, to provide to Congress an annual report describing 

efforts to carry out the Act. Section 6 specifically states that the report must: 

1) Include a list that identifies nations whose vessels conduct shark finning and detail the 

extent of the international trade in shark fins, including estimates of value and 

information on harvesting, landings, or transshipment of shark fins. 

2) Describe and evaluate the progress taken to carry out this Act. 

3) Set forth a plan of action to adopt international measures for the conservation of sharks. 

4) Include recommendations for measures to ensure that the actions of the United States are 

consistent with national, international, and regional obligations relating to shark 

populations, including those listed under the Convention on International Trade in 

Endangered Species of Wild Flora and Fauna (CITES). 

These four topics are described in this Report to Congress. Regarding item 1, no reliable 

information exists to determine whether a nation’s vessels caught sharks on the high seas or 

conducted finning. However, data on the international trade of shark fins are available from the 

FAO and data on U.S. imports and exports of shark fins are available from the U.S. Census 

Bureau. This information is provided in Section 3 of this report. However, it is important to 

note that, due to the complexity of the shark fin trade, fins are not necessarily harvested by the 

same country from which they are exported. 

Consistent with item 2 above, this Report to Congress summarizes all recent shark-related 

management (Sections 2.1 to 2.3), enforcement (Section 2.4), international (Section 4), and 

research activities (Section 5) in support of the Shark Finning Prohibition Act. This report, 

prepared in consultation with the Department of State, also provides an update to last year’s 

report and includes information for 2011 activities. 

Regarding item 3 above, the United States participated in the development of and endorsed the 

FAO’s International Plan of Action (IPOA) for the Conservation and Management of Sharks. 

Consistent with the IPOA, the United States developed a National Plan of Action (NPOA) for the 

Conservation and Management of Sharks in February 2001. In addition to meeting the statutory 

requirement of the Shark Finning Prohibition Act, the annual Report to Congress serves as a 

periodic update of information called for in the IPOA and NPOA. 

Regarding item 4 above, NMFS has no specific recommendations for shark conservation and 

management at this time. Consistent with the provisions of Section 5 of the Shark Finning 

Prohibition Act, the Department of Commerce and the Department of State have been active in 

promoting the development of international agreements consistent with the Act. 

Recommendations are brought forward through bilateral, multilateral, and regional efforts. As 

agreements are developed, the United States implements those agreements and reports on them 

in this annual Report to Congress. Information on recent international efforts, including CITES, 

is provided in Section 4 of this report. 

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Table 1.1.1.Status of shark stocks and stock complexes in U.S. fisheries in 2012. 

Source: NMFS 2012. 

Status of Shark Stocks and Stock Complexes 

in U.S. Fisheries in 2012 

Fishery 

Management 

Council (FMC) 

Fishery Management 

Plan (FMP) or 

Fishery Ecosystem 

Plan (FEP) 

Stock or Stock Complex Overfishing Overfished 

New England 

FMC & Mid 

Atlantic FMC 

Spiny Dogfish FMP Spiny dogfish – Atlantic coast No No 

NMFS Highly 

Migratory 

Species 

Division 

Consolidated Atlantic 

Highly Migratory 

Species FMP 

Atlantic large coastal shark complexA Unknown Unknown 

Atlantic pelagic shark complexB Unknown Unknown 

Atlantic sharpnose sharkC No No 

Atlantic small coastal shark 

complexD No No 

Blacknose shark – AtlanticC Yes Yes 

Blacknose shark – Gulf of MexicoC Unknown Unknown 

Blacktip shark – Gulf of MexicoE No No 

Blacktip shark – South AtlanticE Unknown Unknown 

Blue shark – AtlanticF No No 

Bonnethead – AtlanticC No No 

Dusky shark – AtlanticG Yes Yes 

Finetooth shark – AtlanticC No No 

Porbeagle – AtlanticF No Yes 

Sandbar shark – AtlanticE No Yes 

Scalloped hammerhead shark – 

AtlanticE Yes Yes 

Shortfin mako – AtlanticF No No 

Pacific FMC Pacific Coast Groundfish 

FMP 

Leopard shark – Pacific Coast Unknown Unknown 

Spiny dogfish – Pacific Coast Unknown No 

Soupfin (Tope)- Pacific Coast Unknown Unknown 

Pacific FMC & 

Western 

Pacific FMC 

U.S. West Coast 

Fisheries for Highly 

Migratory Species 

&Pacific Pelagic FEP 

Thresher shark – North Pacific Unknown Unknown 

Shortfin mako shark – North Pacific Unknown Unknown 

Blue shark – North Pacific No No 

Western 

Pacific FMC 

FEP for Pelagic 

Fisheries of the Western 

Pacific Region (Pacific 

Pelagic FEP) 

Longfin mako shark – North Pacific Unknown Unknown 

Oceanic whitetip shark – Tropical 

Pacific Unknown Unknown 

Salmon shark – North Pacific Unknown Unknown 

Silky shark – Tropical Pacific Unknown Unknown 

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Fishery 

Management 

Council 

(FMC) 

Fishery Management 

Plan (FMP) or Fishery 

Ecosystem Plan (FEP) 

Stock or Stock Complex Overfishing Overfished 

Western 

Pacific FMC 

American Samoa 

FEP 

American Samoa Coral Reef 

Ecosystem Multi-Species ComplexH Undefined Undefined 

Western 

Pacific FMC Mariana Archipelago FEP 

Guam Coral Reef Ecosystem MultiSpecies ComplexH Undefined Undefined 

Northern Mariana Islands Coral Reef 

Ecosystem Multi-Species ComplexH Undefined Undefined 

Western 

Pacific FMC 

Pacific Remote Islands 

Areas FEP 

Pacific Island Remote Areas Coral 

Reef Ecosystem Multi-Species 

ComplexI 

Undefined Undefined 

North 

Pacific FMC 

Gulf of Alaska Groundfish 

FMP Gulf of Alaska Shark ComplexJ Unknown Undefined 

North 

Pacific FMC 

Bering Sea/Aleutian Island 

Groundfish FMP 

Bering Sea / Aleutian Islands Shark 

ComplexK Unknown Undefined 

Totals: 

3 “yes” 

11 “no” 

16 “Unknown” 

4 “Undefined” 

5 “yes” 

10 “no” 

13 “Unknown” 

6 “Undefined” 

Western 

Pacific FMC Hawaiian Archipelago 

FEP 

Hawaiian Archipelago Coral Reef 

Ecosystem Multi-Species ComplexH Unknown Unknown 

Table 1. Continued 

AIn addition to sandbar shark, Gulf of Mexico blacktip shark, Atlantic blacktip shark, and scalloped hammerhead 

shark (which are assessed individually), the Large Coastal Shark Complex also consists of additional stocks 

including spinner shark, silky shark (authorized in the commercial fishery but not the recreational fishery), bull 

shark, tiger shark, lemon shark, nurse shark, great hammerhead shark, and smooth hammerhead shark. B

In addition to shortfin mako shark, blue shark, and porbeagle shark (which are assessed individually), the Pelagic 

Shark Complex also consists of oceanic whitetip shark and thresher shark. C

This stock is part of the Small Coastal Shark Complex, but is assessed separately. DThe Small Coastal Shark Complex consists of finetooth shark, Atlantic sharpnose shark, blacknose shark, and 

bonnethead shark. 

E

This stock is part of the Large Coastal Shark Complex, but it is assessed separately F

This stock is part of the Pelagic Shark Complex, but is assessed separately.

G In addition to dusky shark, the prohibited species under the 2006 Consolidated Atlantic HMS FMP include whale, 

basking, sandtiger, bigeye sandtiger, white, night, bignose, Galapagos, Caribbean reef, narrowtooth, longfin mako, 

bigeye thresher, sevengill, sixgill, bigeye sixgill, Caribbean sharpnose, smalltail, and Atlantic angel sharks. These 

species cannot be retained in Atlantic or Gulf of Mexico commercial or recreational fisheries. HIn 2009, the Western Pacific Crustaceans, Bottomfish & Seamount Groundfish, Precious Corals, and Coral Reef 

Ecosystem FMPs were replaced by FEPs for American Samoa, Hawaii, the Mariana Archipelago (Guam and the 

Northern Mariana Islands, and the Pacific Remote Island Areas). The Western Pacific Pelagics FMP was converted 

to the Pelagics FEP. This complex contains up to 146 "currently harvested coral reef taxa" and innumerable 

"potentially harvested coral reef taxa." All commercial fishing is prohibited in the Islands Unit of the Marianas 

Trench (Mariana Islands) and within the Rose Atoll (American Samoa) Marine National Monuments. I

The Pacific Remote Island Areas (PRIA) are U.S. island possessions in the Pacific Ocean that include Palmyra 

Atoll, Kingman Reef, Jarvis Island, Baker Island, Howland Island, Johnston Atoll, Wake Island, and Midway Atoll. 

All reefs of the PRIA except Wake Island, which is under the jurisdiction of the Department of Defense, are 

National Wildlife Refuges. Fishing for coral reef-associated species is prohibited in all these areas except Palmyra 

5
 
 

 

 

 

 

 

 

 

Atoll, Johnston Atoll, Wake Island, and Midway Atoll. All commercial fishing is prohibited within the boundaries
 

of the Pacific Remote Islands Marine National Monument.
 J

The Gulf of Alaska Shark Complex consists of: Pacific sleeper shark, salmon shark, spiny dogfish, and
 

other/unidentified sharks. KThe Bering Sea/Aleutian Islands Shark Complex consists of: Pacific sleeper shark, salmon shark, spiny dogfish, 

2. Management and 

Enforcement 

and other/unidentified sharks. 

2.1 Management Authority in the United States 

Development of fishery management plans (FMPs) is the responsibility of one or more of the 

eight regional fishery management councils, which were established under the MSA, or the 

responsibility of the Secretary of Commerce in the case of Atlantic highly migratory species. 

Since 1990, shark fishery management in Federal waters of the Atlantic Ocean, Gulf of Mexico, 

and Caribbean Sea (excluding dogfishes) has been the responsibility of the Secretary of 

Commerce. Spiny dogfish in the Atlantic Ocean are managed by the New England Fishery 

Management Council (NEFMC) and the Mid-Atlantic Fishery Management Council (MAFMC). 

In the Pacific, three regional councils are responsible for developing fishery management plans 

for sharks: the Pacific Fishery Management Council (PFMC), the North Pacific Fishery 

Management Council (NPFMC), and the Western Pacific Fishery Management Council 

(WPFMC). The PFMC’s area of jurisdiction is the exclusive economic zone (EEZ) off 

California, Oregon, and Washington; the NPFMC covers Federal waters off Alaska, including 

the Gulf of Alaska and the Bering Sea/Aleutian Islands; and the WPFMC’s jurisdiction covers 

Federal waters around Hawaii, Guam, American Samoa, the Northern Mariana Islands, and other 

U.S. non-self-governing insular areas of the Pacific. 

In general, waters under the jurisdiction of the individual States extend from the shoreline out to 

3 miles (9 nautical miles off Texas, the west coast of Florida, and Puerto Rico); while U.S. 

waters under Federal management continue from the seaward boundary of each of the coastal 

States out to 200 nautical miles offshore except where intercepted by the EEZ of another nation. 

Management of elasmobranchs in State waters usually falls under the authority of State 

regulatory agencies, which are typically the marine division of the State fish and wildlife 

departments. Each State develops and enforces its own fishing regulations for waters under its 

jurisdiction (Federally permitted commercial fishermen in the Atlantic are required to follow 

Federal regulations regardless of where they are fishing, as a condition of the permit). While 

States set fishery regulations in their own waters, they are encouraged to adopt compatible 

regulations between State and Federal jurisdictions. Many coastal States promulgate regulations 

for shark fishing in State waters that complement or are more restrictive than Federal shark 

regulations for the U.S. EEZ. Given that many shark nursery areas are located in waters under 

State jurisdiction, States play a critical role in effective shark conservation and management. 

Cooperative management of the fisheries that occur in the jurisdiction of two or more States and 

Federal waters may be coordinated by an interstate fishery management commission. These 

6
 
 

 

 

 

commissions are interstate compacts that work closely with NMFS. Three interstate 

commissions exist: the Pacific States Marine Fisheries Commission (PSMFC), the Atlantic 

States Marine Fisheries Commission (ASMFC), and the Gulf States Marine Fisheries 

Commission (GSMFC). The Atlantic Coast Fisheries Cooperative Management Act (ACFCMA) 

established a special management program between NMFS, the Atlantic coast States, and the 

ASMFC. Under this legislation, Atlantic States must comply with the management measures 

approved by this Commission, or risk a Federally mandated closure (by NMFS) of the subject 

fishery (50 CFR part 697). 

2.2 Current Management Authority in the Atlantic Ocean 

Atlantic Highly Migratory Species Management 

In 1993, NMFS implemented the FMP for Sharks of the Atlantic Ocean. Under the FMP, three 

management units were established for shark species: large coastal sharks (LCS), small coastal 

sharks (SCS), and pelagic sharks (Table 2.2.1). NMFS identified LCS as overfished, and 

therefore, among other things, implemented commercial quotas for LCS and established 

recreational harvest limits for all sharks within that management unit. At that time, NMFS also 

banned finning of all sharks in the Atlantic Ocean. 

In April 1999, NMFS published the FMP for Atlantic Tunas, Swordfish, and Sharks (64 FR 

29090), which included numerous measures to rebuild or prevent overfishing of Atlantic sharks 

in commercial and recreational fisheries. The 1999 FMP replaced the 1993 FMP and addressed 

numerous shark management measures, including: reducing commercial LCS and SCS quotas, 

establishing a commercial quota for blue sharks and a species-specific quota for porbeagle 

sharks, expanding the list of prohibited shark species, implementing a limited access permitting 

system in commercial fisheries, and establishing season-specific over- and under-harvest 

adjustment procedures. 

On December 24, 2003, the final rule implementing Amendment 1 to the 1999 FMP for Atlantic 

Tunas, Swordfish, and Sharks was published in the Federal Register (68 FR 74746). This final 

rule revised the shark regulations based on the results of the 2002 stock assessments for SCS and 

LCS. In Amendment 1, NMFS implemented several new regulatory changes, including: using 

maximum sustainable yield as a basis for setting commercial quotas; eliminating the commercial 

minimum size restrictions; implementing trimester commercial fishing seasons effective January 

1, 2005; implementing a time/area closure off the coast of North Carolina effective January 1, 

2005; and establishing three regional commercial quotas (Gulf of Mexico, South Atlantic, and 

North Atlantic) for LCS and SCS management units. In addition, as of November 15, 2004, 

directed shark vessels with gillnet gear on board, regardless of location, are required to have a 

Vessel Monitoring System (VMS) installed and operating during right whale calving season 

(November 15–March 31); and, as of January 1, 2005, directed shark vessels with bottom 

longline fishing gear on board, located between 33° and 36° 30′ N latitude, are required to have a 

VMS installed and operating during the mid-Atlantic shark closure period (January 1–July 31). 

On October 2, 2006, the 1999 FMP was replaced with the final Consolidated Atlantic HMS 

FMP, which consolidated management of all Atlantic HMS under one plan, reviewed current 

information on shark essential fish habitat, required the second dorsal and anal fin to remain on 

shark carcasses through landing, required shark dealers to attend shark identification workshops, 

and included measures to address overfishing of finetooth sharks (71 FR 58058). This FMP 

7
 
 

manages several species of sharks (Table 2.2.1). The 2007–2012 commercial shark landings and 

the 2012 preliminary commercial shark landings are shown in Tables 2.2.2 and 2.2.3, 

respectively. 

8
 
 

Table 2.2.1 U.S. Atlantic shark management units, shark species for which retention is 

prohibited, and data-collection-only species. 

Sharks in the Consolidated Atlantic HMS FMP 

Large Coastal Sharks (LCS) Small Coastal Sharks (SCS) 

Spinner 

Silky* 

Bull 

Blacktip 

Sandbar** 

Tiger 

Carcharhinus brevipinna 

Carcharhinus falciformis 

Carcharhinus leucas 

Carcharhinus limbatus 

Carcharhinus plumbeus 

Galeocerdo cuvier 

Finetooth 

Blacknose 

Atlantic sharpnose 

Bonnethead 

Carcharhinus isodon 

Carcharhinus acronotus 

Rhizoprionodon terraenovae 

Sphyrna tiburo 

Pelagic Sharks 

Common thresher Alopias vulpinus 

Nurse Ginglymostoma cirratum Oceanic whitetip Carcharhinus longimanus 

Lemon Negaprion brevirostris Shortfin mako Isurus oxyrinchus 

Scalloped hammerhead Sphyrna lewini Porbeagle Lamna nasus 

Great hammerhead 

Smooth hammerhead 

Sphyrna mokarran 

Sphyrna zygaena 

Blue Prionace glauca 

Smoothhound Sharks 

Smooth dogfish 

Florida smoothhound 

Mustelus canis 

Mustelus norrisi 

Prohibited Species 

Bignose Carcharhinus altimus Bigeye thresher Alopias superciliosus 

Galapagos Carcharhinus galapagensis Narrowtooth Carcharhinus brachyurus 

Dusky Carcharhinus obscurus Caribbean reef Carcharhinus perezii 

Night Carcharhinus signatus Smalltail Carcharhinus porosus 

Sand tiger Carcharias taurus Sevengill Heptranchias perlo 

White Carcharodon carcharias Sixgill Hexanchus griseus 

Basking Cetorhinus maximus Bigeye sixgill Hexanchus nakamurai 

Bigeye sand tiger Odontaspis noronhai Longfin mako Isurus paucus 

Whale Rhincodon typus Caribbean sharpnose 

Atlantic angel 

Rhizoprionodon porosus 

Squatina dumeril 

Deepwater and Other Species (Data Collection Only) 

Iceland catshark Apristurus laurussoni Green lanternshark Etmopterus virens 

Smallfin catshark Apristurus parvipinnis Marbled catshark Galeus arae 

Deepwater catshark Apristurus profundorum Cookiecutter shark Isistius brasiliensis 

Broadgill catshark Apristurus riveri Bigtooth cookiecutter Isistius plutodus 

Japanese gulper shark Centrophorus acus American sawshark Pristiophorus schroederi 

Gulper shark Centrophorus granulosus Blotched catshark Scyliorhinus meadi 

Little gulper shark Centrophorus uyato Chain dogfish Scyliorhinus retifer 

Portuguese shark Centroscymnus coelolepis Dwarf catshark Scyliorhinus torrei 

Kitefin shark Dalatias licha Smallmouth velvet Scymnodon obscures 

Flatnose gulper shark Deania profundorum dogfish 

Bramble shark Echinorhinus brucus Greenland shark Somniosus microcephalus 

Lined lanternshark Etmopterus bullisi Pygmy shark Squaliolus laticaudus 

Broadband dogfish Etmopterus gracilispinnis Roughskin spiny Squalus asper 

Caribbean lanternshark Etmopterus hillianus dogfish 

Great lanternshark Etmopterus princeps Blainville's dogfish Squalus blainvillei 

Smooth lanternshark Etmopterus pusillus Cuban dogfish Squalus cubensis 

Fringefin lanternshark Etmopterus schultzi 

*Not allowed for recreational harvest.
 

**Can only be harvested within a shark research fishery, and not allowed for recreational harvest.
 

9 
 

 

 

 

 

 

 

 

 

 

 

 

 

Table 2.2.2 Commercial landings for Atlantic large coastal, small coastal, and pelagic 

sharks in metric tons dressed weight, 2007–2012. 

Source: Cortés pers. comm. (2013). 

Commercial Shark Landings (mt) 

Species 

Group 2007 2008 2009 2010 2011 2012 

Large 

Coastal 

Sharks 

1,056 618 686 689 674 629 

Small 

Coastal 

Sharks 

280 283 303 162 265 281 

Pelagic 

Sharks 118 106 91 141 141 142 

Total 1,454 1,007 1,080 992 1,080 1,052 

On June 1, 2010, NMFS published a final rule for Amendment 3 to the 2006 Consolidated HMS 

FMP (75 FR 30484) for SCS, pelagic sharks, and smooth dogfish. Among other things, this 

amendment created the smoothhound shark management unit, which consists of smooth dogfish 

and Florida smoothhound sharks (Table 2.2.1). Conservation and management measures 

implemented by the amendment for smoothhounds include a requirement to offload 

smoothhounds with their fins naturally attached, Federal dealers must report landings of 

smoothhounds, and a Federal permit is required for the commercial and recreational retention of 

smoothhound sharks. These smoothhound requirements were delayed to allow time for the 

agency to complete a Biological Opinion under Section 7 of the Endangered Species Act and 

other rules regarding smoothhound sharks. Other measures in the final rule for Amendment 3 

became effective in June and July 2010. In December 2012, NMFS finalized the Biological 

Opinion for Atlantic shark fisheries, including the smoothhound fishery. Subsequently, NMFS 

has begun drafting a proposed rule to consider implementing the measures in Amendment 3, the 

smooth dogfish portion of the Shark Conservation Act, and the requirements in the Biological 

Opinion. 

NMFS publishes rules each year to adjust Atlantic shark fishery quotas based on over- or underharvests from the previous fishing year (the fishing year is from January to December of each 

year; each shark fishery closes when the respective shark species/management unit’s quota 

reaches 80 percent with a 5-day notice upon filing in the Federal Register). 

10
 
 

 

 

 

 

 

Table 2.2.3 Preliminary landings estimates in metric tons (mt) and pounds (lb) dressed 

weight (dw) for the 2012 Atlantic shark commercial fisheries. 

Landings are based on dealer data provided through the quota monitoring system. 

2012 Landings Estimates 

Species Group 2012 Quota Estimated Total Landings 

% of 

Quota 

Non-Sandbar LCS4 

(Region = Gulf of Mexico) 

392.8 mt dw 

(866,063 lb dw) 

378.9 mt dw 

(835,386 lb dw) 96% 

Non-Sandbar LCS5 

(Region = Atlantic) 

183.2 mt dw 

(403,889 lb dw) 

146.8 mt dw 

(323,614 lb dw) 80% 

Shark Research Fishery 

(Non-Sandbar LCS) 

37.5 mt dw 

(82,673 lb dw) 

16.3 mt dw 

(35,911 lb dw) 43% 

Shark Research Fishery 

(SRF) (Sandbar Only) 

87.9 mt dw 

(193,784 lb dw) 

30.9 mt dw5 

(68,212 lb dw) 35% 0.0 mt dw6 

(0 lb dw) 

Non-Blacknose Small 

Coastal Sharks (SCS) 

332.4 mt dw 

(732,808 lb dw) 

289.4 mt dw 

(638,010 lb dw) 87% 

Blacknose Sharks 19.9 mt dw 

(43,872 lb dw) 

23.4 mt dw 

(51,614 lb dw) 118% 

Blue Sharks 273.0 mt dw 

(601,856 lb dw) 

8.9 mt dw 

(19,642 lb dw) 3% 

Porbeagle Sharks 0.7 mt dw 

(1,585 lb dw) 

1.9 mt dw 

(4,199 lb dw) 265% 

Pelagic Sharks Other 

Than Porbeagle or Blue 

488 mt dw 

(1,075,856 lb dw) 

165.7 mt dw 

(299,227 lb dw) 28% 

Shark Stock Assessments 

A joint International Commission for the Conservation of Atlantic Tunas (ICCAT)/International 

Commission for the Exploration of the Seas (ICES) stock assessment was conducted for Atlantic 

porbeagle sharks in 2009. Four Atlantic stocks were considered for assessment: northwest, 

northeast, southwest, and southeast. For the northwest Atlantic stock, a surplus production 

model yielded a similar view of stock status to that found in an updated assessment undertaken 

by the Canadian Department of Fisheries and Oceans. Both assessments found that porbeagle 

sharks in the northwest Atlantic are overfished (biomass depleted to levels below maximum 

sustainable yield (MSY7

) but that overfishing is not occurring (recent fishing mortality is below 

4

Non-sandbar Large Coastal Sharks (LCS) include the following: silky, tiger, blacktip, spinner, bull, lemon, nurse,
 

and hammerhead.
 5

Inside the shark research fishery. 6 Outside the shark research fishery; these are from State landings.
 7

MSY refers to maximum sustainable yield. MSY is the largest long-term average catch or yield that can be taken
 

from a stock or stock complex under prevailing ecological, environmental conditions and fishery technological 

characteristics (e.g., gear selectivity), and the distribution of catch among fleets.
 

11
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

the maximum rate of fishing mortality (FMSY)). Despite the improving status of the stock, the 

Canadian assessment still projected that stock rebuilding will take decades due to the low 

productivity of this stock. NMFS had already implemented a rebuilding plan for porbeagle 

sharks in 2008 that included a total allowable catch (TAC) of 11.3 metric tons dressed weight 

(mt dw) and a reduction of the U.S. Atlantic commercial quota to 1.7 mt dw per year. More 

information on porbeagle management is presented in Section 4.2 of this report. 

On October 6, 2011, NMFS announced the 21st Southeast Data, Assessment, and Review 

(SEDAR 21) stock assessment results for dusky sharks (SEDAR 21 also assessed sandbar and 

blacknose sharks, as discussed below). Dusky sharks were assessed as one stock across the 

Atlantic and Gulf of Mexico. The Review Panel for the Review Workshop of SEDAR 21 found 

that the data and methods used were appropriate and the best available for the dusky shark 

assessment. Based on this assessment, NMFS determined that the stock status for dusky sharks 

is overfished (biomass was 41 to 50 percent of the MSY level) with overfishing occurring (1.4 to 

4.3 times the level of fishing mortality resulting in MSY). 

In June 2006 a stock assessment was performed for LCS, which followed the SEDAR process. 

During the 2006 LCS assessment, the Atlantic stock of sandbar sharks was individually assessed 

and found to be overfished with overfishing occurring. Regulatory actions were put into place in 

2008 to adjust the commercial quota of sandbar sharks as necessary to achieve rebuilding by 

2070. In 2011, SEDAR 21 assessed sandbar sharks (in addition to dusky and blacknose sharks) 

and found that the stock was still overfished but that overfishing was no longer occurring (most 

scenarios estimated a fishing mortality ranging from 29 to 93 percent of the level resulting in 

MSY). Furthermore, current fishing mortality levels will still allow for rebuilding by 2070, as 

determined in the previous sandbar stock assessment. The Review Panel for the Review 

Workshop of SEDAR 21 found that the data and methods used were appropriate and the best 

available for the sandbar shark assessment. 

Blacktip sharks were also assessed in the June 2006 LCS stock assessment and were divided into 

two stocks, a Gulf of Mexico stock and an Atlantic stock. Due to an absence of reliable 

estimates of abundance, biomass, and exploitation rates, the current status of blacktips in the 

Atlantic is unknown. The Gulf of Mexico blacktip shark stock is not overfished and overfishing 

is not occurring; however, it was recommended that current catch rates of this stock be 

maintained. In May 2012, the SEDAR 29 assessment of Gulf of Mexico blacktip sharks was 

finalized. The assessment found that Gulf of Mexico blacktip sharks are not overfished and are 

not experiencing overfishing. 

In 2007, SEDAR performed stock assessments for the SCS management unit (and for Atlantic 

sharpnose, bonnethead, blacknose, and finetooth sharks individually). The Review Panel for the 

2007 SCS SEDAR concluded that, although the assessment of the status of the management unit 

was adequate based on the available data, given that species-specific assessments were also 

conducted, any conclusions should be based on the results of the individual species assessments. 

Results of the 2007 finetooth shark assessment indicated the stock was not overfished and 

overfishing was not occurring (in contrast to the 2002 SCS assessment, which found that 

overfishing was occurring). For blacknose sharks, the 2007 assessment indicated the stock was 

overfished and overfishing was occurring. The assessments for Atlantic sharpnose and 

12
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

bonnethead sharks determined the stocks were not overfished and that overfishing was not 

occurring. On October 6, 2011, NMFS announced the SEDAR 21 stock assessment results for 

blacknose sharks (SEDAR 21 also assessed sandbar and dusky sharks, as discussed above). 

Blacknose sharks were assessed separately in the Atlantic and the Gulf of Mexico. The Review 

Panel for the Review Workshop of SEDAR 21 found that the data and methods used were 

appropriate and the best available for the Atlantic blacknose shark assessment. Based on this 

assessment, NMFS determined that the Atlantic blacknose shark is overfished (biomass was 43 

to 64 percent of the MSY level) with overfishing occurring (3 to 22 times the level of fishing 

mortality resulting in MSY). In the Gulf of Mexico, however, the assessment model for the Gulf 

of Mexico blacknose stock was unable to fit the apparent trends in some of the abundance 

indices and there was a fundamental lack of fit of the model to some of the input data. 

Therefore, the Review Panel did not accept the stock assessment for the Gulf of Mexico 

blacknose stock and its status is unknown. 

In 2012, an ERA for blue, porbeagle, and shortfin mako sharks was conducted by the ICCAT 

SCRS. The results of the ERA are described in Section 4.2 of this report. 

On April 28, 2011, NMFS accepted a scalloped hammerhead shark assessment performed by 

Hayes et al. (2009) as appropriate for U.S. management decisions. Based on this stock 

assessment, in 2005 the population was estimated to be at 45 percent of the biomass that would 

produce MSY, and fishing mortality was estimated to be 129 percent of fishing mortality 

associated with MSY. The stock is estimated to be depleted by approximately 83 percent of 

virgin stock size (i.e., the current population is only 17 percent of the virgin stock size). In 

addition, it was estimated that a TAC of 2,853 scalloped hammerhead sharks per year (or 69 

percent of 2005 catch) would allow a 70 percent probability of rebuilding within 10 years. In 

November 2012, NMFS published a proposed rule to address hammerhead sharks. 

In 2012, SEFSC staff completed the Gulf of Mexico blacktip shark stock assessments (SEDAR 

29). The assessment generally provided a consistent picture of stock status wherein the stock 

was not overfished (spawning stock fecundity was 2 to 2.6 times the MSY level) and overfishing 

was not occurring (fishing mortality was only 7 to 27 percent the level resulting in MSY), 

although one of the reviewers expressed concern about the reliability of the overfishing 

conclusion. 

Observer Coverage 

Observer coverage in the shark bottom longline fishery began in 1994 on a voluntary basis. 

Since 2002, observer coverage has been mandatory for selected bottom longline and gillnet 

vessels. NMFS aims to obtain 4 to 6 percent observer coverage of the commercial effort and 

deploys approximately five to seven observers to monitor 300 to 400 commercial fishing trips 

per year. The data collected through the observer program is critical for monitoring takes and 

estimating mortality of protected sea turtles, seabirds, marine mammals, Atlantic sturgeon, and 

smalltooth sawfish. Data obtained through the observer program are also vital for conducting 

stock assessments of sharks and for use in the development of fishery management measures for 

Atlantic sharks. Gillnet observer coverage is also contingent upon requirements implemented by 

the Atlantic Large Whale Take Reduction Plan (ALWTRP). The most recent regulations 

amending the ALWTRP were published in the Federal Register on June 25, 2007 (72 FR 

13
 
 

 

 

 

 

 

 

 

 

34632), and on October 5, 2007 (72 FR 57104). The ALWTRP, as amended, implements 

specific regulations for the shark gillnet component of the HMS fisheries. 

Shark Management by the Regional Fishery Management Councils and States 

The only shark species managed by the Regional Fishery Management Councils in the Atlantic is 

spiny dogfish (Squalus acanthias). The Mid-Atlantic Fishery Management Council has the lead 

in consultations with the New England Fishery Management Council for the management of 

spiny dogfish in Federal waters of the Atlantic Coast pursuant to the Spiny Dogfish FMP, which 

became effective in February 2000. The FMP incorporates the MSA regulations governing the 

harvest, possession, landing, purchase, and sale of shark fins from 50 CFR Part 600, Subpart N. 

Spiny dogfish are typically landed whole, with fins attached, and processed on shore. Current 

dock prices for whole spiny dogfish are around $0.20 per pound, which includes the value of 

fins. 

Due to its overfished status of spiny dogfish, from 2000 through 2008 the management program 

established a restrictive possession limit of 600 pounds per trip and a 4-million-pound coast-wide 

commercial quota further split into two seasonal quotas (Period I and Period II). Upon 

attainment of the coast-wide quota, the fishery is closed to further landings by Federally 

permitted vessels. Based on updated stock assessment results indicating that the stock was not 

overfished and overfishing was not occurring, the quota and possession limit increased to 12 

million pounds and 3,000 pounds per trip, respectively, in the 2009 fishing year. In 2010, the 

quota was increased to 15 million pounds and the trip limit maintained at 3,000 pounds. Stock 

assessment updates conducted in 2010 concluded that spiny dogfish spawning stock biomass was 

above the biomass target in 2008 and 2009, and was therefore considered rebuilt. The quota was 

further increased in 2011 (20 million lb) and in 2012 (25.7 million lb) but the possession limit 

remained at 3,000 pounds per trip to help avoid closures of the fishery. Due to several years of 

poor recruitment, the stock is projected to decline between 2014 and 2020. 

Coordinated State management of sharks is vital to ensuring healthy populations of Atlantic 

coastal sharks. The Atlantic States Marine Fisheries Commission developed and individual 

States implemented an Interstate Coastal Shark FMP in 2008. One goal of this FMP was to 

improve consistency between Federal and State management of sharks in the Atlantic Ocean. 

Complementary quotas were set in both State and Federal waters in the 2010, 2011, and 2012 

fishing years. However, for spiny dogfish, the Interstate Coastal Shark FMP allocates quota 

regionally in State waters, rather than seasonally, as in Federal waters. This misalignment is 

expected to be addressed in Amendment 3 to the Spiny Dogfish FMP, which was approved by 

the Councils in 2012, and is presently under review by NMFS. 

2.3 Current Management of Sharks in the Pacific Ocean 

Pacific Fishery Management Council (PFMC) 

The PFMC’s area of jurisdiction is the EEZ off the coasts of California, Oregon, and 

Washington. In late October 2002, the PFMC recommended the U.S. West Coast Highly 

Migratory Species (HMS) Fisheries FMP, which was implemented in 2004. This FMP’s 

management area also covers adjacent high seas waters for fishing activity under the jurisdiction 

of the West Coast HMS FMP. The West Coast HMS FMP is implemented by the NMFS West 

14
 
 

 

 

 

 

 

 

Coast Regional Office8 in Long Beach, California. Under this FMP, NMFS manages fishing for 

three shark species as part of the management unit (Table 2.3.1), including the common thresher 

and shortfin mako (sharks commercially valued but not primarily targeted in the West Coast– 

based fisheries), as well as blue sharks (a common bycatch species). On September 13, 2011, 

regulations implementing West Coast HMS FMP Amendment 2 were published in the Federal 

Register (76 FR 56327). Amendment 2 and its supporting regulations reclassified bigeye 

thresher and pelagic thresher sharks as ecosystem component species. These species were 

originally included in the West Coast HMS FMP as management unit species due to concern 

over their low resiliency to exploitation; their reclassification as ecosystem component species is 

based in part on the minor levels of West Coast commercial and recreational catch reported for 

these species since the FMP was implemented. However, given the presence of these species off 

the West Coast, particularly during El Niño warming periods, these species will continue to be 

monitored under the West Coast HMS FMP as an ecosystem component species. Lastly, the 

West Coast HMS FMP also designates three shark species as prohibited (Table 2.3.1). If 

intercepted during HMS fishing operations, these species—great white, megamouth, and basking 

sharks—must be released immediately, unless other provisions for their disposition are 

established consistent with State and Federal regulations. 

Table 2.3.1 Shark species in the West Coast Highly Migratory Species Fishery 

Management Plan. 

West Coast Highly Migratory Species FMP 

Group Common name Scientific name 

Sharks Listed as 

Management Unit 

Species 

Common thresher 

Shortfin mako 

Blue shark 

Alopias vulpinus 

Isurus oxyrinchus 

Prionace glauca 

Sharks Included 

in the FMP as 

Ecosystem 

Component 

Species 

Pelagic thresher 

Bigeye thresher 

Alopias pelagicus 

Alopias superciliosus 

Prohibited 

Species 

Great white 

Basking shark 

Megamouth 

Carcharodon carcharias 

Cetorhinus maximus 

Megachasma pelagios 

Sharks within the West Coast HMS FMP are managed to achieve Optimum Yield (OY) set at a 

precautionary level of 75 percent of MSY. The precautionary approach is meant to prevent 

localized depletion of these vulnerable species. The FMP proposed annual harvest guidelines for 

common thresher and shortfin mako sharks given the level of exploitation in HMS fisheries at 

the time the FMP was adopted (e.g., large mesh drift gillnet), and accounting for the uncertainty 

about catch in Mexico of these straddling stocks. High exploitation rates and their impact on 

HMS shark stocks, if not checked, could take decades to correct given the vulnerable life history 

8 In fall 2013, the Southwest and Northwest Regional Offices were integrated to form the West Coast Region. 

15
 
 

 

 

 

 

 

 

 

 

 

 

 

 

characteristics of the species. While comprehensive stock assessments of common thresher and 

shortfin mako sharks have not been conducted since the development of the FMP, recent 

analyses of the large mesh drift gillnet fishery data demonstrate that the nominal catch per unit 

effort (CPUE) of common thresher sharks was lowest in the early 1990s and has been increasing 

since. A blue shark assessment conducted by scientists at the NMFS Pacific Islands Fisheries 

Science Center (PIFSC) in collaboration with Japanese colleagues and published in 2009 

concluded that the North Pacific population was above MSY and the fishing mortality rate below 

that associated with MSY (Kleiber et al. 2009). 

The Pacific Coast Groundfish FMP includes three shark species (leopard, soupfin, and spiny 

dogfish) in the groundfish management unit (Table 2.3.2). The FMP is implemented by the 

NMFS West Coast Regional Office9 in Seattle, Washington. These shark species are mainly 

caught incidentally in groundfish fisheries and discarded at sea. Beginning in 2003, NMFS 

established a “rockfish conservation area,” closing large areas to fishing for groundfish, 

including sharks, by most gear types that catch groundfish. In addition, the Pacific Coast 

Groundfish FMP manages its shark species with a combined annual catch limit for all “other 

fish,” which includes sharks, skates, ratfish, morids, grenadiers, kelp greenling, and some other 

groundfish species. This annual catch limit is reduced by a precautionary adjustment from the 

overfishing level. Beginning in 2006, NMFS implemented 2-month cumulative trip limits for 

spiny dogfish for both open access and limited entry fisheries to control the harvest of dogfish 

and associated overfished groundfish species. A benchmark assessment for spiny dogfish was 

conducted for the first time and reviewed in 2011. That assessment indicated that the portion of 

the Pacific coast stock found off the United States was likely well above its target spawning 

output level. The results of the 2011 assessment have been used to inform management of the 

species in 2013–2014. 

Table 2.3.2 Shark species in the groundfish management unit of the Pacific Coast 

Groundfish Fishery Management Plan. 

Pacific Coast Groundfish FMP 

Sharks Listed as Management Unit Species 

Common name Scientific name 

Soupfin shark (Tope) 

Spiny dogfish 

Leopard shark 

Galeorhinus galeus 

Squalus acanthias 

Triakis semifasciata 

Beginning in 2011, NMFS reformed management of the groundfish trawl sector from 2-month 

cumulative trip limits for all groundfish to an individual quota system (also called catch shares) 

for most groundfish species. While the PFMC considered including spiny dogfish as a species 

managed with individual quotas, it decided to continue managing spiny dogfish and “other fish” 

(which includes leopard and soupfin shark) with 2-month cumulative trip limits at this time. 

This new program for the groundfish trawl sector, also called the trawl rationalization program 

or trawl catch share program, includes a “gear switching” provision that allows a vessel having a 

trawl-endorsed limited entry permit to also fish using “non-trawl” gear, generally longline or 

9 In fall 2013, the Northwest and Southwest Regional Offices were integrated to form the West Coast Region. 

16
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

pot/trap gear. This may change the impacts on shark species. In addition, the trawl 

rationalization program requires 100 percent at-sea monitoring on vessels participating in the 

program, making more data available on shark catch (including discards). 

Shark catch data are obtained from commercial landings receipts, observer programs, and 

recreational fishery surveys. Landings data for the U.S. West Coast are submitted by the States 

to the Pacific Fisheries Information Network (PacFIN) and Recreational Fisheries Information 

Network (RecFIN) data repositories. Table 2.3.3 shows commercial shark landing for the West 

Coast from 2002 to 2012. Estimates of commercial discard, as well as catch in the at-sea hake 

fishery, are developed by the West Coast Groundfish Observer Program, at the NMFS Northwest 

Fisheries Science Center. Additional recreational data collection and estimation of recreational 

catch are also conducted by NMFS. Data from all of these sources are used for monitoring and 

management by the PFMC. Recreational shark fishing, primarily for common thresher and 

shortfin mako shark, is popular among anglers seasonally in Southern California waters. Data 

collected formerly through the Marine Recreational Fisheries Statistics Survey (MRFSS) and 

now the California Recreational Fisheries Survey (CRFS) is used as the best available 

information regarding shark catch and effort in Southern California Waters. 

Table 2.3.3 Commercial Shark landings (round weight equivalent in metric tons) for 

California, Oregon, and Washington, 2003–2012. Source: PacFIN Database, 

data for the Pacific Fishery Management Council area extracted using the 

“Explorer” tool on November 5, 201310 . 

Commercial Shark Landings (mt) for California, Oregon, and 

Washington 

Species Name 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 

Bigeye thresher shark 6 5 10 4 5 6 7 1 1 -­

Blue shark 1 1 1 <1 10 <1 1 <1 <1 <1 

Brown catshark -­ -­ -­ -­ -­ -­ -­ 11 4 17 

Common thresher 

shark 

301 115 179 160 204 147 107 96 75 70 

Leopard shark 10 11 13 11 11 3 2 3 2 3 

Pacific angel shark 17 13 12 15 8 12 12 9 10 10 

Pelagic thresher shark 4 2 <1 <1 2 <1 <1 <1 -­ --

Shortfin mako 65 53 33 45 44 35 29 20 17 27 

Soupfin shark 36 27 26 30 17 8 5 3 3 2 

Spiny dogfish 451 418 468 394 425 638 264 230 393 216 

Other shark 3 3 5 4 2 2 2 3 1 2 

Unspecified shark 3 6 5 5 5 2 2 20 4 3 

Total 897 654 752 668 733 853 431 396 510 348 

10 This extraction includes all commercial landings in West Coast U.S. ports of sharks caught in areas managed by 

the PFMC. This is a change from some prior years, in which West Coast landings of sharks caught in Alaska, 

Canada, and Puget Sound were included (via the use of PacFIN Report #307). This summary does not include 

estimates of commercial discards or any recreational catch. 

17
 
 

 

 

 

 

 

 

 

 

 

 

 

 

North Pacific Fishery Management Council (NPFMC) 

The NPFMC manages fisheries in Federal waters off Alaska. In October 2010 NMFS issued a 

final rule to implement Amendments 95 and 96 to the Bering Sea Aleutian Islands (BASI) FMP 

and Amendment 87 to the Gulf Of Alaska (GOA) FMP in order to comply with statutory 

requirements for annual catch limits and accountability measures (under National Standard 1), 

and to rebuild overfished stocks. These amendments move all of the major taxonomic groups 

from the “other species” category to the “target species” category, removes the “other species” 

category and “non-specified species” category from the FMPs, establishes an “ecosystem 

component” category, and describes the current practices for groundfish fisheries management in 

the FMPs, as required by the National Standard 1 Guidelines. In 2011, the “other species” 

category was dissolved in the GOA and BSAI into its major taxonomic groups: sharks, skates, 

octopuses, and sculpins in the BSAI and sharks, octopuses, squid, and sculpins in the GOA. For 

each of these species groups, the NPFMC recommended and NMFS specified, overfishing levels 

(OFLs), acceptable biological catch (ABCs), and TAC amounts. Due to conservation concerns, 

the final rules to implement groundfish harvest specifications in the BSAI and GOA in 2012 and 

2013 prohibited directed fishing for sharks in both management areas. In other groundfish 

fisheries open to directed fishing, the retention of sharks taken as incidental catch is limited to no 

more than 20 percent of the aggregated amount of sharks, skates, octopuses, and sculpins in the 

BSAI and sharks, octopuses, squids, and sculpins in the GOA. 

At its December 2011 meeting, the NPFMC recommended OFLs, ABCs, and TACs for sharks in 

both the BSAI and GOA for the 2012 and 2013 fishing years. The GOA TAC was based in large 

part on the natural mortality and biomass estimates for spiny dogfish and the recent average 

historical catch of other shark species, while the BSAI TAC was set at a value of 200 mt, 

substantially less than that recommended ABC which was based on historical maximum catch of 

all the shark species. Table 2.3.4 lists the recent historical catch of sharks in the BSAI and GOA. 

In 2012 the 200 mt TAC for sharks in the BSAI was not exceeded. The most recent assessments 

for sharks are in Chapter 20 to the 2012 Stock Assessment and Fishery Evaluation (SAFE) 

reports for the BSAI and GOA (available online at 

http://www.afsc.noaa.gov/refm/stocks/assessments.htm). 

The shark complexes in the BSAI and GOA are assessed biennially (with update only 

assessments in the off years), to coincide with the availability of new survey data, thus, the most 

recent BSAI SAFE was in 2012 and the most recent GOA SAFE was in 2011. In the BSAI, 

NMFS conducts surveys annually in the Eastern Bering Sea and triennially along the deeper 

slope area in the BSAI for all groundfish, including sharks. In the GOA, NMFS conducts 

surveys biennially for groundfish, including sharks. The most recent surveys were conducted in 

2012 in the BSAI and in 2011 in the GOA, with the results incorporated into the SAFE reports 

for sharks. The next NMFS surveys are scheduled for 2013 in the BSAI and GOA, respectively. 

In order to comply with annual catch limit requirements, the shark assessment authors compiled 

two new datasets for inclusion as appendices beginning in the 2011 SAFE reports for the BSAI 

and GOA (see either the GOA or BSAI 2011 SAFE Appendices for details). The first dataset, 

non-commercial removals, estimates shark catch not included in the NMFS catch accounting 

system, including NMFS trawl and hook-and-line surveys, the International Pacific Halibut 

Commission (IPHC) hook-and-line survey, experimental fishing permits, and sport and 

18
 
 

 

 

 

subsistence fishing. The second dataset are estimates of shark catch in the unobserved 

commercial halibut individual fishing quota (IFQ) fisheries. In the BSAI in 2011, the 

non-commercial removals were estimated to be approximately 9 mt while the catch in the 

commercial halibut fishery was estimated to be 116 mt. In the GOA in 2010, the noncommercial removals were estimated to be approximately 408 mt while the catch in the 

commercial halibut fishery was estimated to be 1,896 mt. 

Eleven shark species are found in the Alaskan waters (Table 2.3.4; Goldman 2012). NMFS 

monitors shark catch in season by species for Pacific sleeper, salmon, and spiny dogfish sharks 

and the remaining species of sharks are grouped into the “other/unidentified sharks”. Pacific 

sleeper, salmon, and spiny dogfish sharks are taken incidentally in Federal groundfish fisheries 

while the other eight species are very rarely taken in any sport or commercial fishery. 

Table 2.3.4 North Pacific shark species. 

North Pacific shark species 

Common name Scientific name 

Pacific sleeper shark Somniosus pacificus 

Salmon shark Lamna ditropis 

Spiny dogfish shark Squalus suckleyi 

Brown cat shark Apristurus brunneus 

Basking shark Cetorhinus maximus 

Sixgill shark Hexanchus griseus 

Blue shark Prionace glauca 

Pacific angel shark Squatina californica 

White shark Carcharodon carcharias 

Common thresher shark Alopias vulpinus 

Soupfin shark Galeorhinus glaeus 

In Federal waters sharks are currently in a “bycatch only” status, preventing directed fishing for 

the species. In the BSAI, most of the shark incidental catch occurs in the midwater trawl pollock 

fishery and in the hook-and-line fisheries for sablefish, Greenland turbot, and Pacific cod along 

the outer continental shelf and upper slope areas. In the GOA, most of the shark incidental catch 

occurs in the midwater trawl pollock fishery, non-pelagic trawl fisheries, and hook-and-line 

Pacific cod, sablefish, and halibut fisheries. The most recent estimates of the incidental catch of 

sharks in the BSAI and GOA are from 2012. These data are included in Chapter 20 in the 2012 

BSAI and GOA SAFE reports and the NMFS catch accounting system. Estimates of the 

incidental catch of sharks in the groundfish fisheries from 2003 through 2012 have ranged from 

521 to 1,538 mt in the GOA and from 53 to 689 mt in the BSAI (Table 2.3.5). Very few of the 

sharks incidentally taken in the groundfish fisheries in the GOA and BSAI are retained. 

In 2006 two vessels targeted sharks using hook-and-line gear in the GOA: one vessel used a 

Federal Fisheries Permit and another vessel used a permit issued by the Commissioner of the 

Alaska Department of Fish and Game (ADF&G) for use in State waters. The catches of these 

vessels is confidential, but catches of sharks were low, thus the effort was short-lived and the 

19
 
 

 

 

 

 

 

 

 

fishery was deemed unsuccessful by the participants. Since 2006 there has been no effort 

targeting sharks in the BSAI or GOA. 

Table 2.3.5	 Incidental catch and utilization (in metric tons) of sharks in the Gulf of Alaska 

and Bering Sea/Aleutian Islands commercial groundfish fisheries, 2003-2012. 

(Values are rounded to nearest metric ton)
 

Source: NMFS Catch Accounting System Data
 

Incidental Catch of Sharks (mt) - Gulf of Alaska 

Species 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 

Spiny 

dogfish 357 184 443 1,169 831 532 1,027 398 484 433 

Pacific 

sleeper 

shark 

270 282 482 252 295 65 50 162 25 142 

Salmon 

shark 35 41 60 34 140 7 9 107 7 50 

Unidentified 

shark 53 39 69 83 107 12 24 9 5 10 

Total 716 546 1,053 1,538 1,373 615 1,109 676 521 636 

% Retained 1.5 2.1 3.3 4.0 3.3 6.8 5.3 5.8 2.9 2.7 

Incidental Catch of Sharks (mt) - Bering Sea/Aleutian Islands 

Spiny 

dogfish 13 9 11 7 3 17 20 15 8 20 

Pacific 

sleeper 

shark 

342 420 333 313 257 120 47 21 47 47 

Salmon 

shark 199 26 47 63 44 41 71 12 47 26 

Unidentified 

shark 34 60 26 305 28 7 9 5 4 2 

Total 589 515 418 689 332 185 146 53 105 96 

% Retained 13.3 2.6 4.9 3.9 9.8 7.0 4.2 7.2 6.6 3.6 

Recreational shark fisheries 

The ADF&G manages the recreational shark fishery in State and Federal waters under the 

Statewide Sport Shark Fishery Management Plan (5 AAC 75.012), in effect since 1998. Until 

2010, the plan stipulated a daily bag limit of one shark of any species per person per day, and an 

annual limit of two sharks of any species per person. In March 2010 the Alaska Board of 

Fisheries amended the plan to increase the daily bag and possession limit for spiny dogfish to 

five fish, with no annual limit. Demand for spiny dogfish is low and liberalization of the bag 

limit is not expected to result in a significant increase in harvest. State regulations prohibit the 

intentional waste or destruction of any sport-caught species. 

20
 
 

 

 

 

 

 

 

 

 

 

Recreational harvest of all shark species combined is estimated through a mail survey of sport 

fishing license holders. About 332 sharks of all species were harvested by the sport fishery in 

State and Federal waters of Southeast and Southcentral Alaska in 2010 (most recent estimate). 

The South Central Region accounted for 95 percent of the harvest. The catch typically consists 

almost entirely of spiny dogfish and salmon shark. Although most spiny dogfish are released, 

they are believed to be the primary species harvested. There is a directed recreational fishery for 

salmon sharks in Prince William Sound involving mostly charter boats. Salmon sharks are also 

taken occasionally by anglers targeting halibut. 

Harvest of salmon sharks by guided anglers is required to be reported in charter logbooks. 

Charter boats reported Statewide salmon shark harvests of 63 fish in 2009, 22 fish in 2010, and 

eight fish in 2011. Although estimates of salmon shark harvest are not available for unguided 

anglers, the charter fleet is believed to have accounted for the majority of salmon shark harvest, 

at least in the past. Reasons for the decline in charter harvest are unclear; charter effort for 

salmon sharks has declined, and trends in abundance are unknown. In addition to the mail 

survey and logbook, shark fisheries are monitored in south central Alaska through biological 

sampling for species, size, age, and sex composition, as well as spatial distribution of the harvest. 

Commercial shark fishing in State waters 

State of Alaska Statewide regulation 5 AAC 28.084 prohibits directed commercial fishing of 

sharks Statewide except for a spiny dogfish permit fishery (5 AAC 28.379) adopted by the 

Alaska Board of Fisheries for the Cook Inlet area in 2005. Sharks taken incidentally to 

commercial groundfish and salmon fisheries may be retained and sold provided that the fish are 

fully utilized as described in 5 AAC 28.084. The State limits the amount of incidentally taken 

sharks that may be retained to 20 percent of the round weight of the target species on board a 

vessel except in the Southeast District, where a vessel using longline or troll gear may retain up 

to a 35 percent bycatch of spiny dogfish (5AAC 28.174 (1) and (2)). In addition, in the East 

Yakutat Section and the Icy Bay Subdistrict salmon gillnetters may retain all spiny dogfish taken 

as bycatch during salmon gillnet operations (5AAC 28.174 (3)). All sharks landed must be 

recorded on an ADF&G fish ticket. A single permit was issued in 2006 for the Cook Inlet spiny 

dogfish fishery, which resulted in a single landing. Harvest data are confidential if less than 

three landings occur. Since 2006 no additional permits have been issued. Any incidental catch 

of sharks occurring in State-managed fisheries is undocumented. 

Western Pacific Fishery Management Council (WPFMC) 

The WPFMC’s area of jurisdiction is the EEZ around Hawaii, American Samoa, Guam, the 

Northern Mariana Islands, and the Pacific Remote Islands Areas (PRIA). The NMFS Pacific 

Islands Regional Office in Honolulu implements the fishing regulations and other management 

measures and policies. In the western Pacific, the conservation of sharks is governed under the 

provisions of the five fishery ecosystem plans, the 2000 Shark Finning Prohibition Act, the Shark 

Conservation Act of 2010, and the MSA. The MSA (Section 317) makes it unlawful for any 

person to chum for sharks, except for harvesting purposes. The WPFMC’s Fishery Ecosystem 

Plan for Western Pacific Pelagic Fisheries identifies nine sharks as management unit species 

(Table 2.3.6). Five species of coastal sharks are listed in the fishery ecosystem plans for 

21
 
 

 

 

 

 

 

American Samoa, Hawaii, the Mariana Archipelago, and the Pacific Remote Islands Areas 

(Table 2.3.7) as currently harvested.11 

The longline fisheries in the western Pacific, mostly in Hawaii and American Samoa, were 

responsible for the vast majority of the sharks landed. Shark landings (estimated whole weight) 

by the Hawaii-based longline fisheries peaked at about 2,870 mt in 1999, due largely to the 

finning of blue sharks. A State of Hawaii law prohibiting landing shark fins without an 

associated carcass passed in mid-2000 (Hawaii Revised Statutes 188.40-5). This law apparently 

decreased shark landings by almost 50 percent to 1,450 mt in 2000. With the subsequent 

enactment of the Federal Shark Finning Prohibition Act, shark landings from 2001 to 2010 were 

down by more than 93 percent from their peak (Table 2.3.8). Landings in 2011 were 

approximately 100 mt, up slightly from 2010, which had the lowest landings in recent history. 

Today, sharks are marketed as fresh shark fillets and steaks in Hawaii supermarkets and 

restaurants and are also exported to the U.S. mainland. 

Table 2.3.6	 Sharks in the management unit of the Fishery Ecosystem Plan for Western 

Pacific Pelagic Fisheries (as amended December 2009). 

Western Pacific Pelagic Fisheries FEP 

Common name Scientific name 

Common thresher shark Alopias vulpinus 

Pelagic thresher shark Alopias pelagicus 

Bigeye thresher shark Alopias superciliosus 

Silky shark Carcharhinus falciformis 

Oceanic whitetip shark Carcharhinus longimanus 

Shortfin mako shark Isurus oxyrinchus 

Longfin mako shark Isurus paucus 

Salmon shark Lamna ditropis 

Blue shark Prionace glauca 

11 In 2009, the WPFMC’s Crustaceans, Bottomfish & Seamount Groundfish, Precious Corals, and Coral Reef 

Ecosystem FMPs were replaced by fishery ecosystem plans (FEP) for American Samoa, Hawaii, the Mariana 

Archipelago (Guam and the Northern Mariana Islands), and the Pacific Remote Island Areas. The western Pacific 

Pelagics FMP was converted to the Pelagics FEP. 

22
 
 

 

 

 

 

 

Table 2.3.7 Coastal sharks listed as management unit species and designated as currently 

harvested coral reef taxa in the four Western Pacific Fishery Ecosystem Plans. 

Other coastal sharks in the management unit of the FEP belonging to the families 

Carcharhinidae and Sphyrnidae are designated as potentially harvested coral reef 

taxa. 

Western Pacific Fishery Ecosystem Plans 

Sharks Listed as Management Unit Species and Designated as Currently 

Harvested Coral Reef Taxa 

Common Name Scientific Name 

American 

Samoa 

FEP 

Hawaii 

FEP 

Marianas 

FEP 

PRIA 

FEP 

Silvertip shark Carcharhinus albimarginatus X - X X 

Grey reef shark Carcharhinus amblyrhynchos X X X X 

Galapagos shark Carcharhinus galapagenis X X X X 

Blacktip reef shark Carcharhinus melanopterus X X X X 

Whitetip reef shark Triaenodon obesus X X X X 

The American Samoa longline fishery lands a small amount of sharks compared to Hawaii’s 

longline fisheries (Table 2.3.8). The pattern of shark landings by the American Samoa longline 

fishery was similar to shark landings by the Hawaii-based longline fisheries. Landings increased 

to 13 mt in 1999, followed by a decline to 1 mt in 2001, with landings remaining low through 

2011. The decline in shark landings by the American Samoa longline fishery is attributed to the 

Shark Finning Prohibition Act. 

23
 
 

 

 

 

 

 

 

 

 

Table 2.3.8	 Shark landings (in metric tons) from the Hawaii-based and American Samoabased pelagic longline fisheries, 2002–2012. 

Source: Pacific Islands Fisheries Science Center, Fisheries Research and 

Monitoring Division. Species

20022003200420052006200720082009201020112012 

Hawaii-based Blue shark 30 20 60 30 12 6 7 9 6 11 14 

Longline 

Fisheries 

Mako shark 80 90 70 110 95 119 109 102 68 51 50 

Thresher shark 50 50 60 30 33 42 39 28 16 18 12 

Misc. shark 20 10 10 - 11 7 4 6 3 2 2 

Total 

shark 

landings 

180 170 200 170 151 174 159 145 93 83 79 

American 

Samoa 

Total 

shark 

landings 

3 4 1 <1 1 2 1 1 2 4 4 

2.4 NOAA Enforcement of the Shark Finning Prohibition Act 

The NOAA Office of Law Enforcement (OLE) has responsibility for enforcing the Shark 

Finning Prohibition Act of 2000 and its implementing regulations. During calendar year 2012, 

violations of the SFPA were detected, investigated, and referred for administrative prosecution in 

the Southeast, Southwest and Pacific Islands Enforcement Divisions. Violations which were 

investigated included finning by U.S. domestic fishing vessels and importing shark carcasses 

under a false U.S. Customs declaration. 

•	 In April 2012, officers from the Louisiana Department of Wildlife and Fisheries (LDWF) 

acted upon a complaint regarding a commercial fishing vessel that was allegedly 

harvesting sharks over the legal daily limit. LDWF intercepted the suspect vessel near 

Venice, Louisiana and conducted a boarding. Although there were 11 whole sharks on 

the deck, further inspection revealed a hidden compartment in the bow of the vessel that 

was found to contain a dozen large bags of shark fins. A subsequent inventory 

documented 2,073 fins in total, without corresponding carcasses. LDWF projected that 

518 sharks had been illegally finned and that the vessel had been over its daily legal limit 

by 496 sharks. Two occupants aboard the vessel were eventually charged with State 

violations and entered guilty pleas in November. The defendants were assessed fines in 

the amount of $950 each, and had their set line licenses and State shark permits revoked 

for life. The Federal violations were referred to the NOAA Office of Law Enforcement 

and the case is currently under review by the NOAA Office of the General Counsel 

Enforcement Section. 

24
 
 

 

 

 

 

 

 

 

 

 

 

•	 During a vessel boarding and inspection in the Pacific Islands Division, a NOAA 

enforcement officer discovered 20 dried shark fins onboard a limited entry Hawaii 

pelagic longline vessel. There were no corresponding carcasses and the fins were 

subsequently seized by OLE. This case is pending review by the NOAA Office of the 

General Counsel Enforcement Section. 

•	 In the Southwest Enforcement Division, an OLE special agent seized three shark 

carcasses that were imported into San Francisco, California from Hong Kong. The 

sharks, with their corresponding fins, were shipped through the U.S. Postal Service and 

were declared as “clothes” on the U.S. Customs declaration form. The sharks were 

addressed to an import/export company. The shipment was seized by NOAA OLE 

pending further investigation. 

2.5 Education and Outreach 

The U.S. National Plan of Action for the Conservation and Management of Sharks states that 

each U.S. management entity (i.e., NMFS, Regional Fishery Management Councils, Interstate 

Marine Fisheries Commissions, and States) should cooperate with regard to education and 

outreach activities associated with shark conservation and management. As part of the effort to 

implement the U.S. National Plan of Action, NMFS, OLE, and other U.S. shark management 

entities have completed the following actions: 

•	 NMFS’ Offices of International Affairs and Science and Technology began capacity 

building efforts in West Africa in 2008. Since 2008, NMFS has provided observer 

training in Ghana, Senegal, Gabon, and Liberia. As part of these workshops, shark 

identification guides specific to West Africa are distributed and attendees are trained with 

specimens to use the identification guide. Finally, observers are instructed on 

measurement and biological sampling techniques; workshop attendees are also shown 

how to remove spines or vertebrae for ageing, gonads for reproductive analysis, and 

stomachs for diet studies. 

•	 NOAA OLE partnered with the Cape and Islands Harbormaster Association and their 

working group to facilitate a uniform approach across Cape Cod, Massachusetts in 

responding to Great White shark sightings and reported human interactions. Six Cape 

Cod communities were represented and additional expertise was provided by personnel 

from the Massachusetts Division of Marine Fisheries, the National Park Service, and the 

Massachusetts Environmental Police. 

•	 An OLE special agent was interviewed by Canadian radio station CJSR 88.5 FM located 

in Edmonton, Alberta, regarding NOAA’s role in enforcing the Shark Finning Prohibition 

Act. The radio program was entitled “Terra Informa” which is syndicated online in 

Canada. The interview aired during August of 2012. 

•	 In the U.S. Territory of Guam, enforcement personnel monitored the offloads of foreign 

flagged fishing vessel in order to detect and deter violations of the Shark Finning 

Prohibition Act and its implementing regulations. No significant violations were 

reported. 

•	 Staff from NMFS Northeast Fisheries Science Center (NEFSC) attended Northeast U.S. 

recreational shark fishing tournaments, captains meetings, and local sportfishing shows to 

25
 
 

 

 

 

 

 

 

inform participants on current shark management regulations and discuss current 

research. In 2011, a 20-page booklet was published detailing tagging and recapture 

instructions, catch and release guidelines, research results, length and weight information, 

management regulations, and contact websites and telephone numbers. This booklet, tags 

and identification guides, and placards are made available to the fishing public and are 

also mailed to NMFS Cooperative Shark Tagging Program participants. Feedback is 

given to tournament officials on historic tournament landings to encourage further shark 

conservation measures and to facilitate better catch and release practices. 

•	 During the spring of 2012, a segment on catch-and-release fishing for common thresher 

sharks in Southern California was filmed and produced by Bill Boyce of the International 

Fame Fish Association Saltwater Adventures Sportfishing Series. The segment featured 

biologists from NMFS West Coast Region Sustainable Fisheries Division and the Pfleger 

Institute of Environmental Research (PIER) discussing their collaborative catch-andrelease survivorship studies conducted under a NOAA Bycatch Reduction Engineering 

Program grant. The segment documented the capture, tagging, and release of thresher 

sharks aboard the PIER's research boat R/V Malolo. As part of the show, host Bill Boyce 

fished and filmed with several cooperative anglers/clubs in the area (e.g., Paul Hoofe of 

the Balboa Anglers Club and editor Bill DePriest of Pacific Coast Sportfishing Magazine) 

to demonstrate and film how to effectively catch and release thresher sharks using circle 

hooks. The show aired the summer of 2012 and was broadcast on the World Fishing 

Network channel's North American network. The original episode was rebroadcast five 

times per week with five weekly repeats during the year (25 airings). It also included a 

30-second commercial spot that ran within the episode containing NMFS and PIER 

conservation messages (e.g., NOAA Ethical Angler; circle hook outreach; and Best 

Fishing Practices). Footage from the show was used for additional outreach at the Fred 

Hall Boating and Fishing Show and was posted on the NOAA Recreational Fisheries 

website. 

•	 The West Coast Region (WCR) and the SWFSC have collaborated on public outreach 

toward the development of alternative fishing methods that reduce post-release mortality 

of thresher sharks (Alopias spp). This collaboration continued in 2012 with brochures 

and videos distributed at the Fred Hall Fishing and Tackle Shows in Long Beach and Del 

Mar, California, and San Diego’s Day at the Docks celebration; these events annually 

attract 50,000 to 75,000 participants. 

•	 The Southeast Fisheries Science Center provides outreach and information to the media 

on shark biology and guidelines to avoid encounters with sharks through interviews and 

online chats. In 2012, SEFSC scientists were featured in an "Ask a Shark Scientist" 

question and answer forum during the Discovery Channel’s Shark Week. SEFSC 

scientists also provided live updates of ongoing research to determine movements of 

sawfish in the Bahamas. Daily posts were posted on Facebook and Twitter with video 

footage of the day’s research activities. 

26
 
 

 

 

 

 

 

 

 

 

 

 

 

3. Imports and Exports of 

Shark Fins 

The summaries of annual U.S. imports and exports of shark fins in Tables 3.1.1 and 3.2.1 are 

based on information submitted by importers and exporters to the U.S. Customs and Border 

Protection and to the U.S. Census Bureau as reported in the NMFS Trade database. From 2008 

to 2010, exports of shark fins exceeded imports in both weight and value. Even though in 2011 

there was an increase in volume of imports and a decrease in volume of exports, the per unit 

value of exports remained higher than the per unit value of imports. In 2012, both the weight 

and value of imported shark fins decreased compared to the 2011 market values and the dollar 

per unit value was the lowest since 2008. The total weight of exports increased in 2012 

compared to 2011, however, the total value decreased in comparison. 

3.1 U.S. Imports of Shark Fins 

During 2012, imports of shark fins entered through the following U.S. Customs and Border 

Protection districts: Los Angeles, Miami, and New York. In 2012, countries of origin (in order 

of importance based on quantity) were New Zealand, China and Hong Kong. Shark fins were 

also imported in smaller numbers from Spain (Table 3.1.1). The mean value of imports per 

metric ton has consistently declined since 2008 with a more pronounced drop between 2011 and 

2012. The unit price of $18,000/mt in 2012 was the lowest mean value since 2008. It should be 

noted that, due to the complexity of the shark fin trade, fins are not necessarily produced in the 

same country from which they are exported. In the United States, factors such as availability of 

labor, overseas contacts, and astute trading can play a role in determining the locale from which 

exports are sent. 

3.2 U.S. Exports of Shark Fins 

The vast majority of shark fins exported in 2012 were sent from the United States to Hong Kong, 

with small amounts going to China (Table 3.2.1). The mean value of exports per metric ton has 

decreased from $56,000/mt in 2008 to $49,000/mt in 2009, the lowest value since 2007 with the 

largest weight of 77 mt. The 2009 decrease in value of exported shark fins was followed by a 

large increase in value in 2010 from $49,000/mt to $93,000/mt. However, 2011 values showed a 

decrease from 2010 and values continued to decline to $56,000/mt in 2012. Using data from 

Table 3.2.1, mean values of dried shark fins for all countries combined has fluctuated significantly 

between 2008 and 2012: from a low of $49,000/mt in 2009 to a high of $93,000/mt in 2010. 

27
 
 

 

3.3 International Trade of Shark Fins 

The Food and Agriculture Organization of the United Nations (FAO) compiles data on the 

international trade of fish. The summaries of imports, exports, and production of shark fins in 

tables 3.3.1, 3.3.2, and 3.3.3 are based on information provided in FAO’s FishStat database. The 

quantities and values in those tables are totals for all dried, dried and salted, fresh, or frozen 

shark fins. Reported global imports of shark fins have fluctuated between 15,345 mt and 11,892 

mt from 2005 to 2009, while the reported global exports of shark fins have fluctuated between 

13,146 mt and 9,373 mt from 2005 to 2009. Imports decreased to $24,446/mt in 2009 from 

$25,234/mt in 2008. Exports also decreased to $19,523/mt in 2009 from $20,919/mt in 2008. 

Hong Kong remains the largest importer and exporter of shark fins. 

28
 
Table 3.1.1 Weight and value of dried shark fins imported into the United States, by country of origin.
 

Note: Weight is rounded to the nearest metric ton and value is rounded to thousands of dollars. (1) indicates that the
 

weight was less than 500 kilograms.
 

Source: U.S. Census Bureau 

Country 

2008 2009 2010 2011 2012 

Metric 

ton 

Value 

($1000) 

Metric 

ton 

Value 

($1000) 

Metric 

ton 

Value 

($1000) 

Metric 

ton 

Value 

($1000) 

Metric 

ton 

Value 

($1000) 

Australia 0 0 0 0 0 0 7 85 0 0 

Canada (1) 20 (1) 2 0 0 0 0 0 0 

China 1 59 6 200 21 442 12 732 16 131 

China, 

Hong Kong 23 1522 11 706 11 695 15 700 2 39 

Colombia (1) 4 0 0 0 0 0 0 0 0 

India 0 0 0 0 0 0 (1) 3 0 0 

Indonesia (1) 8 0 0 0 0 0 0 0 0 

Japan 2 82 0 0 (1) 3 0 0 0 0 

New Zealand 1 14 3 57 1 37 24 275 26 595 

Panama (1) 4 0 0 0 0 0 0 0 0 

Peru 0 0 0 0 0 0 0 0 0 0 

Spain 0 0 0 0 (1) 3 0 0 (1) 8 

South Korea 2 19 0 0 0 0 0 0 0 0 

Vietnam (1) 6 0 0 0 0 0 0 0 0 

Total 29 1738 21 965 34 1180 58 1795 44 773 

Mean value $59,360/mt $46,026/mt $35,020/mt $31,109/mt $18,000/mt 

29
 
 

 

Table 3.2.1 Weight and value of dried shark fins exported from the United States, by country of destination.
 

Note: Data in table are “total exports” which is a combination of domestic exports (may include products of both 

domestic and foreign origin) and re-exports (commodities that have entered the United States as imports and not sold, 

which, at the time of re-export, are in substantially the same condition as when imported). (1) indicates that the weight 

was less than 500 kilograms.
 

Source: U.S. Census Bureau
 

Country 

2008 2009 2010 2011 2012 

Metric 

ton 

Value 

($1000) 

Metric 

ton 

Value 

($1000) 

Metric 

ton 

Value 

($1000) 

Metric 

ton 

Value 

($1000) 

Metric 

ton 

Value 

($1000) 

Australia 1 13 0 0 0 0 0 0 0 0 

Canada 1 164 2 277 1 206 1 199 0 0 

China 1 112 3 495 2 335 5 895 (1) 60 

China, Hong Kong 30 1531 71 2948 39 2785 29 1739 51 2790 

China,Taipei (1) 35 0 0 (1) 6 0 0 0 0 

Egypt 0 0 (1) 3 0 0 0 0 0 0 

Finland 0 0 0 0 0 0 0 0 0 0 

Germany 0 0 (1) 3 0 0 (1) 3 0 0 

Indonesia 0 0 (1) 5 0 0 0 0 0 0 

Japan 4 204 0 0 0 0 (1) 4 0 0 

Mexico 0 0 0 0 0 0 0 0 0 0 

Panama 0 0 (1) 21 0 0 0 0 0 0 

Poland 0 0 1 15 (1) 22 3 86 0 0 

Portugal 0 0 (1) 3 0 0 0 0 0 0 

South Korea 0 0 (1) 6 0 0 0 0 0 0 

Total 37 2059 77 3776 42 3354 38 2925 51 2850 

Mean value $55,549/mt $49,140/mt $79,256/mt $76,804/mt $56,000/mt 

30
 
Table 3.3.1 Weight and value of shark fins imported by countries other than the United States. 

Note: (1) indicates that the weight was less than 500 kilograms. 

Source: Food and Agriculture Organization of the United Nations, FishStat database, www.fao.org 

Country 

2005 2006 2007 2008 2009 

Metric 

ton 

Value 

($1000) 

Metric 

ton 

Value 

($1000) 

Metric 

ton 

Value 

($1000) 

Metric 

ton 

Value 

($1000) 

Metric 

ton 

Value 

($1000) 

Australia 9 1,056 7 891 11 1182 7 1351 7 902 

Brazil 2 8 0 0 0 0 0 0 0 0 

Cambodia 1 12 4 186 1 38 0 0 - -

Canada 112 5,261 110 5,480 94 4,994 118 6,508 184 6,217 

China 3,338 17,758 2,662 13,882 2,542 11,991 2,005 10,777 731 4,427 

China, Hong Kong 10,348 306,968 9,363 253,427 10,183 276,302 9,950 287,510 9,358 245,936 

China, Macao 120 3,324 106 3,728 118 5,306 122 5,911 125 5,886 

China, Taipei 434 4,658 708 4,141 564 6,223 792 8,710 988 7,385 

Djibouti (1) 15 0 0 0 0 0 0 0 0 

India 2 8 0 0 0 0 0 0 0 0 

Indonesia 332 2,486 293 1,274 84 366 220 1,515 102 927 

Laos (1) 5 (1) 6 0 0 0 0 0 0 

Malaysia 93 311 145 585 163 653 44 494 49 493 

North Korea 1 331 2 1,222 2 1,084 1 579 (1) 22 

Peru 1 4 8 52 2 12 28 141 54 246 

Singapore 437 20,673 489 23,434 446 20,638 396 22,632 226 17,575 

South Korea 2 109 6 157 2 82 4 167 2 119 

Thailand 113 1,317 102 1,141 82 877 66 748 66 547 

Timor-Leste 0 0 0 0 0 0 0 0 - 29 

United Arab Emirates 0 0 (1) 15 0 0 0 0 0 0 

Total 15,345 364,304 14,005 309,621 14,294 329,748 13,753 347,043 11,892 290,711 

Mean value $23,741/mt $22,108/mt $23,069/mt $25,234/mt $24,446/mt 

31
 
 

Table 3.3.2 Weight and value of shark fins exported by countries other than the United States. 

Note: Data are for “total exports,” which is a combination of domestic exports (may include products of both domestic 

and foreign origin) and re-exports (commodities that have entered into a country as imports and not sold, which, at the 

time of re-export, are in substantially the same conditions as when imported). (1) indicates that the weight < 500 

kilograms. 

Source: Food and Agriculture Organization of the United Nations, FishStat database, www.fao.org 

Country 

2005 2006 2007 2008 2009 

Metric 

ton 

Value 

($1000) 

Metric 

ton 

Value 

($1000) 

Metric 

ton 

Value 

($1000) 

Metric 

ton 

Value 

($1000) 

Metric 

ton 

Value 

($1000) 

Angola 4 265 4 224 3 179 2 149 4 282 

Argentina 9 504 9 656 11 503 88 2,668 85 3,376 

Bahrain 0 0 0 0 0 0 (1) 9 0 0 

Bangladesh 0 0 195 623 351 1,407 17 403 15 347 

Brazil 157 2,292 118 1,894 131 2,313 113 2,825 85 2,338 

Brunei Darussalam 12 82 0 0 4 21 0 0 0 0 

Burma 2 23 0 0 0 0 0 0 0 0 

Cambodia (1) 5 0 0 0 0 0 0 0 0 

Chile 39 1,639 13 570 4 158 0 0 5 194 

China 1,349 20,753 381 5,306 409 6,712 347 5,898 289 6,265 

China, Hong Kong 7,134 127,102 5,962 103,818 5,670 97,074 5,294 100,877 4,919 79,843 

China, Macao 0 0 29 800 23 711 7 410 8 501 

China, Taipei 1,141 8,875 974 9,514 903 8,082 846 7,910 913 8,059 

Colombia 14 1,034 17 1,132 19 1,146 16 1,074 19 600 

Congo, Dem. Rep. of the 1 53 (1) 20 0 0 (1) 10 0 0 

Congo, Republic of 18 848 10 246 10 314 15 509 17 508 

Costa Rica 0 0 0 0 10 69 0 0 0 0 

Cuba 0 0 0 0 0 0 0 0 2 262 

Djibouti 0 0 2 47 0 0 0 0 0 0 

Ecuador (1) 8 1 5 12 257 124 2,526 131 2,627 

Gabon 0 0 0 0 5 298 20 470 0 0 

Guinea 47 2,163 47 1,872 35 1,613 52 2,665 40 2,228 

Guinea-Bissau 3 110 0 0 5 276 0 0 2 160 

India 104 3,663 145 5,037 96 3,879 95 7,496 107 12,504 

Indonesia 1,554 8,065 1,073 9,174 801 7,303 1,320 7,047 1,367 8,477 

Iran 0 0 0 0 (1) 2 (1) 14 0 0 

Japan 168 8,140 181 9,091 197 8,735 163 8,457 164 6,824 

Kiribati 1 70 1 111 1 69 (1) 30 2 181 

32
 
 

Table 3.3.2 Continued 

Country 

2005 2006 2007 2008 2009 

Metric 

ton 

Value 

($1000) 

Metric 

ton 

Value 

($1000) 

Metric 

ton 

Value 

($1000) 

Metric 

ton 

Value 

($1000) 

Metric 

ton 

Value 

($1000) 

Kuwait 0 0 (1) 9 1 91 2 78 0 0 

Liberia 3 296 3 271 3 253 4 310 4 415 

Libya 1 59 1 52 0 0 0 0 0 0 

Malaysia 37 196 50 239 107 554 31 334 30 291 

Maldives 43 598 16 192 15 107 9 70 9 57 

Marshall Islands 0 0 0 0 55 825 17 305 16 495 

Namibia 0 0 0 0 0 0 0 0 8 296 

Nigeria 1 25 0 0 0 0 0 0 0 0 

Panama 97 3,544 78 2,600 66 4,836 61 2,615 47 3,310 

Papua New Guinea 9 652 10 495 17 1,412 17 1,526 2 388 

Philippines 0 0 0 0 77 948 38 130 0 0 

Saint Pierre & Miquelon 0 0 0 0 2 10 0 0 0 0 

Saudi Arabia 0 0 0 0 0 0 5 122 5 131 

Senegal 2 8 48 2,678 2 14 0 0 0 0 

Seychelles 7 56 6 67 9 86 2 29 7 167 

Sierra Leone 0 0 0 0 0 0 0 0 (1) 15 

Singapore 333 17,253 410 21,394 374 20,296 380 22,703 189 12,904 

Solomon Islands 0 0 0 0 0 0 3 78 1 39 

Somalia 0 0 0 0 (1) 3 0 0 0 0 

South Korea 7 357 9 438 7 224 16 610 34 1063 

Suriname 7 312 8 487 4 260 4 243 93 192 

Thailand 44 1,916 18 772 74 763 20 866 19 758 

Togo 21 1760 24 1847 28 1863 25 1722 31 2,430 

United Arab Emirates 539 14,381 427 13,592 472 13,965 515 16,220 466 15,080 

Uruguay 39 570 27 509 21 324 22 335 17 269 

Vanuatu 0 0 0 0 0 0 40 179 0 0 

Venezuela 20 351 7 21 2 21 0 0 7 53 

Yemen 179 5,846 284 8,442 351 11,333 228 10,760 214 9,065 

Total 13,146 233,874 10,588 204,245 10,387 199,309 9,958 210,682 9,373 182,994 

Mean value $17,685/mt $19,764/mt $19,922/mt $20,919/mt $19,523/mt 

33
 
Table 3.3.3 Production of shark fins in metric tons by country. 

Note: The production of shark fins represents the amount that a country processed 

at the fin level (not the whole animal level). NA = data not available. 

Source: Food and Agriculture Organization of the United Nations, FishStat 

database, www.fao.org 

Country 2005 2006 2007 2008 2009 

Bangladesh 1 4 0 266 276 

Brazil 157 118 131 226 170 

China, Hong Kong SAR NA NA NA NA NA 

China, Taipei 137 117 36 89 12 

Ecuador NA 1 12 124 131 

El Salvador 149 194 44 0 19 

Fiji Islands 160 160 0 0 0 

Guyana 151 123 125 131 132 

India 1,926 270 172 1,232 1,624 

Indonesia 1,554 1,073 1,360 1,320 1,367 

Korea, Republic of 7 33 7 16 34 

Madagascar NA NA NA NA NA 

Maldives 13 11 11 9 9 

Pakistan 81 62 69 78 80 

Philippines 84 71 78 38 45 

Senegal 34 27 16 22 27 

Singapore 320 120 170 260 218 

Sri Lanka 80 80 80 50 60 

Uruguay 43 0 7 25 0 

Yemen 179 284 351 228 214 

TOTAL (mt) 5,076 2,748 2,669 4,114 4,418 

34
 
 

 

 

 

 

 

4. International Efforts to 

Advance the Goals of the 

Shark Finning Prohibition 

Act 

The key components of a comprehensive framework for international shark conservation and 

management have already been established in global and regional agreements, as well as through 

resolutions and measures adopted by international organizations. These relevant mechanisms 

and fora have identified, adopted, and/or published detailed language, provisions, or guidance to 

assist States and regional fisheries management organizations (RFMOs) in the development of 

conservation and management measures for the conservation and sustainable management of 

sharks. Some of these mechanisms have created international legal obligations with regard to 

shark conservation and management, while others are voluntary. To that end, the United States 

continues to promote shark conservation and management by having ongoing consultations 

regarding the development of international agreements consistent with the Shark Finning 

Prohibition Act. Discussions have focused on possible bilateral, multilateral, and regional work 

with other nations. The law calls for the United States to pursue an international ban on shark 

finning and to advocate improved data collection (including biological data, stock abundance, 

bycatch levels, and information on the nature and extent of shark finning and trade). 

Determining the nature and extent of shark finning is the key step toward reaching agreements to 

decrease the incidence of finning worldwide. 

4.1 Bilateral Efforts 

The United States has participated in bilateral discussions with a number of States and entities 

that addressed issues relating to international shark conservation and management. Emphasis in 

these bilateral consultations has been on the collection and exchange of information, including 

requests for shark fin landings, transshipping activities, and catch and trade data. In addition, the 

United States continues to encourage other countries to implement the FAO’s International Plan 

of Action (IPOA) for the Conservation and Management of Sharks by finalizing, implementing 

and periodically updating their own National Plans of Action. 

For example, in order to promote data collection in Mexico, the SWFSC and WCR began a 

multiyear effort with collaborators at Centro de Investigación Científica y de Educación Superior 

de Ensenada (CICESE), led by Dr. Oscar Sosa-Nishizaki, to coordinate artisanal fish camp 

monitoring and sampling in Baja California, Mexico and help advance cooperative stock 

assessment efforts with Mexico, U.S. and IATTC scientists. CICESE scientists are conducting 

35
 
 

 

 

 

 

 

data collection for blue, shortfin mako and thresher sharks at fish camps throughout Baja 

California. The 2012 sampling effort was completed in early 2013. The 2012 sampling was 

extensive and now supplements a time series begun as part of an earlier collaboration with 

investigators at Scripps Institution of Oceanography (SIO) and CICESE. As a result of the new 

sampling program, fishery data for pelagic sharks now includes some size and sex sampling as 

well as several years of species specific catch information. The data collected thus far have 

already been used to develop historic and recent time series catch information for common 

thresher, blue and shortfin mako sharks. The first U.S.–Mexico collaborative shark stock 

assessment is being conducted on the common thresher shark. While past analyses suggest that 

the population is rebounding after declines in the early 1980s, no official stock assessment has 

been conducted and analyses to date have only included data from the United States through 

1999. Several meetings have been held, including a two day workshop in Ensenada in February 

2012, and the assessment is expected to be completed in 2013. Preliminary analyses confirm 

previous indications that the stock biomass may be increasing. 

A regional study was carried out by researchers from the University of Hawaii, NMFS WCR, 

NMFS SWFSC La Jolla, and the Ecuadorian Ministry of Fisheries, to test the effects of a 

Neodymium (Nd) and Praseodymium (Pr) alloy on shark catch rates. Bycatch of sharks in 

longline fisheries has contributed to declines in shark populations and prompted the need for 

exploring novel technologies to reduce the incidental capture of sharks. One potential strategy is 

to exploit the unique electrosensory system of sharks, used to detect weak electric fields. Metals 

from the lanthanide series, made up of Nd and Pr, produce strong electric fields in water. A 

collaborative study to test the effects of a lanthanide metal alloy on shark catch rates was 

conducted (Hutchinson et al. 2012). Using longline fishing gear, comparisons were made of 

catch rates of baited hooks affixed with either a block of the metal alloy (experimental) or a lead 

weight (control). Four experiments were conducted in different regions of the Pacific Ocean. 

Two bottom longline experiments were conducted inside and offshore of Kaneohe Bay, Hawaii. 

One of these experiments targeted young of the year scalloped hammerhead sharks (Sphyrna 

lewini), while the other targeted sandbar (Carcharhinus plumbeus) and tiger sharks (Galeocerdo 

cuvier). In the Southern California Bight (SCB), pelagic longlines were deployed to target mako 

(Isurus oxyrinchus) and blue sharks (Prionace glauca) and longlines targeting pelagic sharks 

were set in the Eastern Tropical Pacific (ETP) off Ecuador. There was a significant reduction in 

juvenile hammerhead sharks caught on hooks with the lanthanide metal compared to the 

controls. In contrast, there was no difference in the catch rates for experiments targeting sandbar 

sharks in Hawaii or those conducted in the SCB and Ecuador. These results suggest that there 

are inter-specific differences regarding the effects of lanthanide metals on catch rates. This may 

reflect the diverse feeding strategies and sensory modalities used by shark species for detecting 

and attacking prey. 

4.2 Regional Efforts 

The U.S. Government continues to place priority on shark conservation and management 

globally and work within RFMOs and other regional entities to facilitate shark research, data 

collection, monitoring, and management initiatives, as appropriate. In recent years, the United 

States has successfully led efforts to ban shark finning and implement shark conservation and 

management measures within a number of such organizations. Table 4.2.1 lists RFMOs and 

36
 
 

 

 

 

regional/multilateral programs in which the United States has worked to address shark 

conservation and management. Of the list in Table 4.2.1, The United States is a party to ICCAT, 

NAFO, CCAMLR, WCPFC, IATTC, ISC, and the South Pacific Tuna Treaty. Eight of the 

organizations or programs listed have adopted finning prohibitions: ICCAT, NAFO, WCPFC, 

IATTC, IOTC, GFCM, SEAFO, and NEAFC. Recent activities or planning of the RFMOs to 

which the United States is a Party are discussed below as a supplement to last year’s Report to 

Congress. 

Table 4.2.1 Regional Fishery Management Organizations and Programs. 

Regional Fishery Management Organizations and Programs 

•

•

•

•

•

•

•

•

•

•

•

•

Northwest Atlantic Fisheries Organization (NAFO) 

Commission for the Conservation of Antarctic Marine Living Resources 

(CCAMLR) 

Inter-American Tropical Tuna Commission (IATTC) 

International Commission for the Conservation of Atlantic Tunas (ICCAT) 

Western and Central Pacific Fisheries Commission (WCPFC) 

Indian Ocean Tuna Commission (IOTC) 

South East Atlantic Fisheries Organization (SEAFO) 

General Fisheries Commission for the Mediterranean (GFCM) 

North East Atlantic Fisheries Commission (NEAFC) 

Commission for the Conservation of Southern Bluefin Tuna (CCSBT) 

Treaty on Fisheries Between the Governments of Certain Pacific Island 

States and the Government of the United States of America (South 

Pacific Tuna Treaty) 

International Scientific Committee for Tuna and Tuna-like Species in the 

North Pacific Ocean (ISC) 

Northwest Atlantic Fisheries Organization (NAFO) 

At its 27th Annual Meeting in September 2005, NAFO adopted a ban on shark finning in all 

NAFO-managed fisheries and mandated the collection of information on shark catches. At the 

2006 NAFO Annual Meeting, a U.S.-Japan proposal for improving elasmobranch data collection 

was also adopted. At the 33rd Annual Meeting in September 2011, the NAFO Fisheries 

Commission adopted revisions to its bycatch reporting provisions to require that all sharks be 

reported at the species level, in response to a U.S. initiative. However, when species-specific 

reporting is not possible, shark species can be recorded as either large sharks or dogfishes. This 

is a major step forward with gaining better information on shark bycatch in NAFO fisheries. 

In addition, at its 26th Annual Meeting in September 2004 the NAFO Fisheries Commission 

became the first regional fisheries management organization in the world to establish a catch 

limit for a directed elasmobranch fishery. The TAC for skates in Division 3LNO (the “nose” and 

37
 
 

 

 

 

 

 

 

 

 

 

“tail” of the Grand Bank) was initially set at 13,500 mt, for each of the years 2005–2009. This 

TAC was subsequently reduced to 12,000 mt for 2010 and 2011, 8,500 mt for 2012 and to 7,000 

mt for 2013. It was a key priority for the United States to seek agreement to reduce the TAC to 

7,000 mt for 2013 and 2014, and this was achieved. 

Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) 

Five shark species (Lamna nasus, Somniosus antarcticus, Etmopterus cf. granulosus, 

Centroscymnus coelolepis, and Squalus acanthias) are known to occur in the northern part of the 

area managed by CCAMLR. Only the first three species appear to be abundant enough to have 

the potential to attract commercial interest. The identification of a sixth species (Halaelurus 

canescens) from observer reports at South Georgia has yet to be confirmed. 

In 2006, CCAMLR adopted a conservation measure prohibiting directed fishing on shark species 

in the Convention Area, other than for scientific research purposes. The Commission agreed that 

the prohibition shall apply until such time as the CCAMLR Scientific Committee has 

investigated and reported on the potential impacts of this fishing activity and the Commission 

has agreed on the basis of advice from the Scientific Committee that such fishing may occur in 

the Convention Area. It also agreed that any bycatch of shark, especially juveniles and gravid 

females, taken accidentally in other fisheries, shall, as far as possible, be released alive. Very 

few sharks are caught in the Convention Area. 

Inter-American Tropical Tuna Commission (IATTC) 

In August 2010, the IATTC convened the first technical meeting on sharks to discuss the new 

role of the IATTC in the conservation and management of sharks under the Antigua Convention, 

stock assessment methods for sharks, life-history studies, the availability of data from national 

and regional programs, bycatch mitigation methods, and data collection needs and 

standardization. In May and December of 2011, the IATTC convened their second and third 

technical meetings on sharks. The objectives of the workshops were to continue to develop a 

stock assessment model for silky sharks (Carcharhinus falciformis) in the EPO, identify 

collaborators and data sources, and collate data. NOAA scientists are contributing to ongoing 

work on silky shark stock structure in the EPO and participating in the assessment efforts. 

During the 2011 IATTC Meeting in La Jolla, California, Resolution C-11-10 on the 

Conservation of Oceanic Whitetip Sharks Caught in Association with Fisheries in the Antigua 

Convention Area was approved. The resolution prohibits retaining onboard, transshipping, 

landing, storing, selling, or offering for sale any part or whole carcass of oceanic whitetip sharks 

(Carcharhinus longimanus) in the fisheries covered by the Antigua Convention. In addition, 

vessels will promptly release unharmed, to the extent practicable, whitetip sharks. This 

resolution entered into force in January 2012. 

During the 2012 IATTC Meeting in La Jolla, California, two shark proposals were presented for 

fisheries in the IATTC Convention Area. Although the U.S. supported both proposals at the 

IATTC meeting, neither proposal was adopted. The first proposal by the European Union was 

intended to prohibit retaining onboard, transshipping, landing, storing, selling, or offering for 

38
 
 

 

 

 

 

 

 

 

 

sale any part or whole carcass of hammerhead sharks. Despite intensive discussions, this 

proposal did not achieve the necessary consensus for its adoption. The second proposal by 

Colombia was intended to require Members and Cooperating Non-Members to take management 

and conservation measures with respect to retaining onboard, transshipping, landing, storing, 

selling, or offering for sale any partial or whole carcass of silky sharks in the fisheries covered by 

the IATTC. Despite intensive discussions, this proposal did not achieve the consensus necessary 

for its adoption. 

At the 2012 IATTC Meeting, an amendment to a Transshipment Resolution added language to 

include sharks along with tuna in the monitoring program for transshipment in the IATTC 

Convention Area. 

International Commission for the Conservation of Atlantic Tunas (ICCAT) 

Science 

In 2008, ICCAT’s SCRS conducted an ERA for 10 shark species and one stingray species based 

on biological productivity and potential susceptibility to ICCAT longline fisheries. Results 

indicated that most Atlantic pelagic sharks have exceptionally limited biological productivity and 

can be overfished even at very low levels of fishing mortality. The SCRS recommended that 

precautionary measures be considered for shark stocks with the greatest biological vulnerability, 

and that those management measures be species-specific whenever possible. Also in 2008, the 

SCRS conducted its first assessments for blue sharks (Prionace glauca) and shortfin mako 

(Isurus oxyrinchus). Assessment findings for blue shark, characterized by high levels of 

uncertainty due to data limitations, indicated that North and South Atlantic stocks are not 

overfished and overfishing is not occurring. Results of the shortfin mako assessment have since 

been updated. 

The SCRS and the International Council for the Exploration of the Sea (ICES) conducted a joint 

assessment of porbeagle shark (Lamma nasus) in 2009, including four stocks (northwest, 

northeast, southwest, and southeast Atlantic). The northwest Atlantic porbeagle stock is 

overfished, but overfishing is not occurring. Despite the improving status of the northwest stock, 

rebuilding is projected to take decades due to low productivity. While conclusions for the 

northeast Atlantic stock were also characterized by uncertainty, it was estimated that the stock is 

overfished and that overfishing is occurring or close to occurring. Stock recovery in the 

northeast Atlantic is predicted to take between 15 and 34 years under a no-fishing scenario. No 

conclusions on the status of the two south Atlantic porbeagle stocks could be reached due to data 

limitations. 

In 2012, the SCRS conducted an updated ERA for 16 species, including five species that were 

not evaluated previously: C. signatus (night shark), C. obscurus (dusky shark), C. plumbeus 

(sandbark shark), and G. cuvier (tiger shark), and S. mokarran (great hammerhead). New 

information on geographical distribution, biological information and productivity, and postrelease mortality rates was incorporated into the analysis for some species. ICCAT has already 

adopted conservation and management measures for most of the species ranked as the most 

vulnerable by the 2012 ERA, as described in the management section below. 

Also in 2012, the SCRS reassessed the North and South Atlantic stocks of shortfin mako shark. 

Catch data are not available for most major longline fleets in the Atlantic. Indications of 

39
 
 

 

 

 

 

 

potential overfishing that were present in the previous assessment have greatly diminished, and 

the available catch per unit effort (CPUE) series showed flat or increasing trends in recent years. 

However, the results also contain some apparent inconsistencies between estimated biomass 

trajectories and CPUE trends. There is considerable uncertainty associated with the assessment 

results due to incomplete historical catch estimates and deficiency of some important biological 

parameters (particularly for the southern stock). 

The SCRS concluded that the probability of overfishing on Atlantic shortfin mako stocks is low 

and the level of current catches may be considered sustainable. However, taking into 

consideration this species’ continued high vulnerability ranking in the ERA, results from the 

modeling approaches used in the assessment, the associated uncertainty, and the relatively low 

productivity of shortfin mako sharks, the SCRS recommended, as a precautionary approach, that 

fishing mortality should not be increased until more reliable stock assessment results are 

available for both the North and South Atlantic stocks. Despite a request from the Commission, 

the SCRS was unable to provide advice on specific TAC levels for shortfin mako. 

Management 

In 2004, ICCAT adopted a recommendation that prohibits finning of sharks caught in association 

with ICCAT fisheries by requiring full utilization of sharks and specifying that the total weight 

of shark fins onboard a vessel must not exceed 5 percent of the total carcass weight (Rec. 04-10). 

Fishing vessels are prohibited from retaining, transshipping, or landing any fins harvested in 

contravention of this recommendation. Parties are required to annually report catch and effort 

data for sharks, in accordance with ICCAT data reporting procedures. In addition, Rec. 04-10 

encourages the release of live sharks, especially juveniles in fisheries not directed at sharks, and 

calls for additional research to improve the selectivity of fishing gears and identify shark nursery 

areas. Recommendation 04-10 was amended via Rec. 05-05 to include additional requirements 

for parties to implement and report measures taken to reduce fishing mortality on North Atlantic 

shortfin mako sharks caught in association with fisheries managed by ICCAT. 

ICCAT Recommendation 07-06 requires parties to take action toward the conservation of 

porbeagle sharks and North Atlantic shortfin mako sharks and to contribute data and research to 

future stock assessments of the species. In 2008, ICCAT required the release of bigeye thresher 

sharks that are caught alive; this measure was superseded by Rec. 09-07, which prohibits all 

retention of bigeye thresher sharks. Recommendation 09-07 includes an exception for a smallscale Mexican coastal fishery, which is permitted to retain 110 Atlantic bigeye thresher sharks. 

However, in 2010, Mexico withdrew its claim to a retention allowance for bigeye thresher. 

In 2010, ICCAT adopted a recommendation that reinforces existing requirements to reduce 

mortality on the North Atlantic stock of shortfin mako and requires reporting on actions taken in 

this regard for review by the Compliance Committee (Rec. 10-06). This recommendation 

underscores obligations to report data on shortfin mako stocks to the SCRS and prohibits parties 

that do not report shortfin mako catch data from retaining this species, beginning in 2013. The 

latest shortfin mako stock assessment conducted by the SCRS in 2012 found that overfishing is 

no longer occurring. 

40
 
 

 

 

 

 

 

 

 

 

Two other shark recommendations were agreed at the 2010 Annual Meeting. ICCAT adopted a 

measure that prohibits retention of oceanic whitetip sharks (Carcharhinus longimanus) (Rec. 10­

07), as well as a measure to prohibit retention of all species of hammerhead sharks (Sphyrna spp) 

(with the exception of bonnethead sharks) that are caught in association with ICCAT fisheries 

(Rec. 10-08), with limited exceptions for developing countries that rely on sharks as an important 

food source. Parties taking advantage of exception in Rec. 10-08 must ensure that these sharks 

and their parts do not enter international trade. 

In 2011, ICCAT adopted a recommendation co-sponsored by the United States that requires the 

release of silky sharks (Carcharhinus falciformis) caught in association with ICCAT fisheries as 

well as the prohibition of retention on board, transshipment, and landing of this species. There 

are limited exceptions for developing coastal States that retain silky sharks for food, as well as 

for parties that prohibit silky shark fisheries and whose domestic law requires all dead fish be 

landed and prohibits fishermen from realizing any commercial profit from such fish. 

Recommendation 11-08 called on parties not reporting species-specific data for sharks to submit 

a data collection improvement plan for consideration by the SCRS. 

At the most recent Annual Meeting, ICCAT adopted recommendation 12-05, which requires 

reporting on implementation of and compliance with all existing shark conservation and 

management measures and Recommendation 11-15 (“no data, no fish”) as it relates to the 

reporting of shark data. The United States continues to fulfill the requirements of all ICCAT 

recommendations through research and data collection programs and a variety of fishing 

restrictions. Implementation of these measures will be fully described in the United States’ 2013 

annual report to ICCAT. 

In 2009, 2010, 2011, and again in 2012, Belize, Brazil and the United States co-sponsored a 

proposal to require that all sharks be landed with their fins naturally attached. Several 

amendments have been suggested by other parties (e.g., limiting the scope of this measure to 

fresh product; exempting parties that have a 100 percent dockside monitoring.) There has been 

no consensus on the measure either with or without the proposed amendments. However, there 

is growing support among some other ICCAT parties for a fins-attached approach. The issue is 

expected to be reconsidered at ICCAT’s 2013 Annual Meeting. 

Western and Central Pacific Fisheries Commission (WCPFC) 

At its 5th Regular Session of the Commission in December 2008, the Parties to WCPFC adopted 

a U.S. proposal to modify and strengthen a 2006 measure for the conservation and management 

of sharks. The revised measure applies to all vessels regardless of size or gear type. 

Commission Members, Cooperating non-Members, and participating Territories (CMMs) must 

report annually regarding their retention and discards of total shark catches as well as their 

annual catch and effort by gear type for key shark species. The 2008 measure identified blue 

shark, oceanic whitetip shark, mako shark, and thresher shark as key species. At the 6th Regular 

Session of the Commission in December 2009, the Commission amended the 2008 measure to 

include silky shark on the list of key species and at the 7th Regular Session of the Commission in 

December 2010, the Commission amended the measure to include porbeagle and hammerhead 

sharks on the list of key species. At its 8th Regular Session of the Commission in March 2012, 

41
 
 

 

 

 

 

 

 

 

 

the Commission added whale shark to the list of key species as well as adopted a U.S. proposal 

prohibiting the retention of oceanic whitetip sharks. At its 9th Regular Session of the 

Commission in December 2012, the Commission adopted a CMM prohibiting intentional sets by 

purse seine vessels in the vicinity of whale sharks. The WCPFC’s science provider has recently 

completed a stock assessment on oceanic whitetip shark and a preliminary assessment on silky 

sharks (to be updated in 2013). 

Kobe III – The Third Joint Meeting of the Tuna Regional Fisheries Management 

The Kobe III meeting was held in La Jolla, California, in July 2011. The Kobe III meeting 

recognized the work of the Bycatch Joint Technical Working Group, which preceded the Kobe 

III meeting. 

The Bycatch Joint Technical Working Group had broad discussions in the areas of data. Sharks, 

including ecological risk assessment, stock assessment and by-catch, emerged as a key issue for 

immediate consideration within RFMOs with participants noting that the issue was broader than 

by-catch and needed to acknowledge that full stock assessments should be conducted for those 

shark species where data are available. For those species lacking data, consistent with the FAO’s 

International Plan of Action for the Conservation and Management of Sharks (IPOA-sharks), 

precautionary, science-based conservation and management measures for sharks should be taken 

in fisheries within each tuna RFMO, including as appropriate: (1) measures to improve the 

enforcement of existing finning bans; (2) prohibitions on retention of particularly vulnerable or 

depleted shark species, based on advice from scientists and experts; (3) concrete management 

measures in line with best available scientific advice with priority given to overfished 

populations; (4) precautionary fishing controls on a provisional basis for shark species for which 

there is no scientific advice; and (5) measures to improve the provision of data on sharks in all 

fisheries and by all gears. The Working Group, with WCPFC and ICCAT taking the lead, also 

agreed to harmonize guidance for shark identification, in collaboration with the IUCN shark 

specialist group and others. 

The Working Group noted that sharks (as well as other elasmobranchs such as skates and rays) 

are often targeted as well as taken as incidental catch. The Working Group noted the previous 

Kobe recommendations on sharks, and these should not be lost in any further discussion on 

sharks. The specific shark recommendations were: 

1. The Working Group is concerned with the practice of intentional sets on whale sharks 

(Rhincodon typus), in RFMOs where there is evidence of the practice occurring, and 

recommends that tuna RFMOs initiate research to determine the impact and outcome of this 

practice. 

2. RFMOs should conduct risk assessment processes to develop their priorities for shark species 

which may need further assessment or mitigation. RFMOs may wish to consider the WCPFC 

key shark nomination processes. 

3. RFMOs should take action to improve data collection on sharks, manta rays, and devil rays in 

targeted industrial and artisanal fisheries. As an example, the Working Group noted that a fins 

naturally attached requirement would improve species identification and enforcement and should 

be considered as part of existing shark finning bans. 

4. RFMOs should consider supporting studies to investigate post-release survival of sharks in 

longline fisheries in relation to hook type and duration of set, among other factors. 

42
 
 

 

 

 

 

 

5. RFMOs should consider supporting studies to further develop shark by-catch mitigation 

strategies for longline fisheries. 

6. RFMOs should evaluate the costs and benefits of banning the use of wire leaders in tuna 

longline fisheries. 

7. RFMOs should develop handling and release protocols for all sharks and manta and devil 

rays, taking into consideration the safety of the crews. 

International Scientific Committee for Tuna and Tuna-like Species in the North Pacific 

Ocean (ISC) 

The Twelfth ISC Plenary, held in Sapporo, Japan from 18-23 July 2012, was attended by 

members from Canada, Chinese Taipei, Japan, Korea, Mexico and the United States. The 

Plenary reviewed the progress of the Shark Working Group (SHARKWG) and endorsed the 

assessment schedule of a North Pacific blue shark assessment for the ISC to review and 

continuing preparation for a shortfin mako shark stock assessment in 2013/2014. The blue shark 

assessment data preparatory meeting was held in May 2012 in Shizuoka, Japan and the 

SHARKWG met in advance of the Plenary in Sapporo, Japan for one day to finalize some 

unresolved work from the May meeting and to conduct work for the Plenary. Active participants 

to the meetings have included Canada, Chinese Taipei, Japan, Mexico, USA, IATTC and the 

Secretariat of the Pacific Community (SPC). The SHARKWG has made significant progress in 

compiling information on life history aspects of and fisheries catching blue and shortfin mako 

sharks and establishing collaborations on biological and assessment research. 

4.3 Multilateral Efforts 

The U.S. Government continues to work within other multilateral fora to facilitate shark 

research, data collection, monitoring, and management initiatives, as appropriate. Table 4.3.1 

lists these multilateral fora. Of the list in Table 4.3.1, the recent activities for five organizations 

are discussed below as a supplement to last year’s Report to Congress. 

Table 4.3.1 Other multilateral fora. 

43
 
 

 

 

 

 

Other Multilateral Fora 

•

•

•

•

•

•

•

•

•

Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) 

World Customs Organization (WCO) 

Food and Agriculture Organization of the United Nations (FAO) Committee on Fisheries 

(COFI) 

United Nations General Assembly (UNGA) 

Convention on the Conservation of Migratory Species of Wild Animals (CMS) 

International Union for Conservation of Nature (IUCN) 

World Summit on Sustainable Development 

International Council for the Exploration of the Sea (ICES) 

Asia Pacific Economic Cooperation Forum and the Convention on Migratory Species 

(APEC) 

World Customs Organization 

Related to actions taken in CITES and RFMOs to increase protection for commercially-exploited 

shark species, the World Customs Organization’s (WCO) Harmonized System Review 

Subcommittee is considering a Food and Agriculture Organization (FAO) proposal supported by 

the United States that would assist countries in tracking international trade in shark fins of 

several commercially-important species. The FAO proposal would establish global harmonized 

system tariff codes to permit the monitoring of trade in shark fins broken down by commercially 

significant shark species. WCO members would need to reach agreement on this proposal by 

March 2014 to permit its implementation in January 2017. 

Food and Agriculture Organization of the United Nations (FAO) Committee on 

Fisheries (COFI) 

In 1999, the FAO adopted the International Plan of Action for the Conservation and 

Management of Sharks (IPOA-Sharks), which is understood to include all species of sharks, 

skates, rays, and chimaeras (Class Chondrichthyes). The IPOA-Sharks calls on all FAO 

members to adopt a corresponding National Plan of Action if their vessels conduct directed 

fisheries for sharks or if their vessels regularly catch sharks in non-directed fisheries. The United 

States was one of the first countries to prepare a National Plan, which was publicly released in 

2001. 

At the 29th Session of COFI, held January 31-February 2, 2011, the Committee, based on a 

request from the United Nations General Assembly (UNGA), requested FAO to prepare a report 

on the extent of the implementation of the 1999 FAO IPOA-Sharks, and the challenges being 

faced by Members in implementing the instrument, for presentation to the 30th Session of COFI, 

held July 9-13, 2012. Accordingly, a summary report was introduced at that meeting, and as a 

result the Committee called for further analysis on the implementation of the IPOA-Sharks. 

United Nations (UN)) 

44
 
 

 

 

 

 

 

 

The United States continues to work within the United Nations system (UN) process to develop 

specific calls to States and RFMOs to strengthen conservation and management measures for 

sharks. The United States was successful in negotiating specific language for the conservation 

and management of sharks at the United Nations Fish Stocks Agreement resumed Review 

Conference in 2010. Specifically, the resumed Review Conference recommended that States and 

regional economic integration organizations, individually and collectively through regional 

fisheries management organizations or arrangements, strengthen the conservation and 

management of sharks. Discussions are underway to plan a second resumed Review Confernece. 

The United States has also worked with other countries to propose and successfully adopt 

language and recommendations specific to sharks in the annual UNGA sustainable fisheries 

resolutions, including some aimed at reducing bycatch and improving data collection. Since 

2005, provisions have been adopted every year that call on States and RFMOs to significantly 

improve the conservation and management of sharks, including a call for sharks to be landed 

with their fins naturally attached. 

Convention on the Conservation of Migratory Species of Wild Animals (CMS) 

In February 2010, the United States, along with 10 other States signed a global Memorandum of 

Understanding (MOU) for Migratory Sharks under the auspices of the Convention on Migratory 

Species. There are currently 27 Signatories - 26 national governments, including the United 

States, and the European Union. The MOU aims to coordinate international action on the threats 

faced by sharks and works to improve their species conservation status. The MOU came into 

effect March 1, 2010 and it initially covers great white, basking, whale, porbeagle, shortfin 

mako, longfin mako, and the Northern Hemisphere population of spiny dogfish, but more species 

can be added later. The first meeting of the Signatories to the Memorandum of Understanding 

on the Conservation of Migratory Sharks took place in Bonn, Germany, September 24-27, 2012. 

One of the main goals of this meeting was to finalize the Conservation Plan for the MOU. 

During the meeting an Intersessional Working Group was established in order to refine the Draft 

Rules of Procedure for Meetings of the Signatories and to develop the procedure to authorize 

Cooperating Partners to sign the MOU, as well as define their role. An Advisory Committee was 

also established for the purpose of serving and assisting the Signatories in the implementation of 

the MOU including the Conservation Plan. Members of the Advisory Committee serve in their 

individual capacity as experts in shark management and conservation. Two representatives from 

the United States were elected as Chairs for each working group, respectively. 

International Union for the Conservation of Nature (IUCN) - Global Sawfish Status Review 

Workshop 

A series of IUCN Action Plans have been compiled by IUCN Specialist Groups to assess the 

conservation status of species and their habitats, and outline conservation priorities. These 

reports, addressing groups from dugongs to dragonflies, are widely viewed as the world’s most 

authoritative sources of species-related conservation information available to natural resource 

managers, conservationists, and decision makers around the world. In May 2012, IUCN hosted a 

workshop in London to develop a Sawfish Conservation Action Plan. Sawfishes are among the 

most endangered of the world’s marine fishes because of their low productivities, which makes 

them particularly vulnerable to excessive mortalities and rapid population declines and 

susceptible to intrinsic and extrinsic factors. The purpose of the workshop was to facilitate 

discussion among individuals and organizations with expertise in sawfish research and 

45
 
conservation. Topics of discussion were population statues by species and region, ongoing 

threats, regulatory protections, case studies of mitigation efforts, recommendations for research, 

education and conservation action. NMFS participated and provided funding for this workshop. 

5. NOAA Research on 

Sharks 

46
 
 

 

 

 

 

 

Large predators such as sharks are a valuable part of marine ecosystems. Many shark species are 

vulnerable to overfishing because they are long-lived, take many years to mature, and only have 

a few young at a time. In order to manage sharks sustainably, we need information on their 

biology and the numbers caught (either as target species or bycatch) to make sure their 

populations are not depleted. NMFS Fisheries Science Centers are investigating shark catch, 

abundance, age, growth, diet, migration, fecundity, and requirements for habitat. Additional 

research aims to identify fishing methods that minimize the incidental catch of sharks and/or 

maximize the survival of captured sharks after release. A summary of the research completed in 

2011 is presented here, but more complete descriptions of recent research are available in 

Appendix 1. 

5.1 Data Collection and Quality Control, Biological Research, and Stock 

Assessments 

Pacific Islands Fisheries Science Center (PIFSC) 

Fishery Data Collection 

Market data from the PIFSC shore side sampling program contain detailed biological and 

economic information on sharks in the Hawaii-based longline fishery dating from 1987. These 

data are primarily collected from fish dealers who are required to submit sales/transaction data to 

the State of Hawaii. The Western Pacific Fishery Information Network (WPacFIN) is a Federal– 

State partnership collecting, processing, analyzing, sharing, and managing fisheries data on 

sharks and other species from American island territories and States in the central and western 

Pacific (Hamm et al. 2012). The WPacFIN program has also assisted other U.S. islands’ 

fisheries agencies in American Samoa, Guam, and the Northern Mariana Islands to modify their 

data-collecting procedures to collect bycatch information. These modifications have improved 

the documentation of shark interactions with fishing gear. Shark catches in the Hawaii-based 

longline fishery have been monitored by a logbook program since 1990 and by an observer 

program since 1994. 

Insular Shark Surveys 

Densities of insular sharks have been estimated at most of the U.S. island possessions within the 

Tropical Central, Northern, and Equatorial Pacific on mostly biennial (now triennial) surveys 

conducted by the PIFSC Coral Reef Ecosystem Division since 2000. These estimates include 

surveys of 10 major shallow reefs in the Northwestern Hawaiian Islands (2000–2010), the main 

Hawaiian Islands (2005–2010), the Pacific remote island areas (2000–2012), American Samoa 

(2002–2012), Guam and the Commonwealth of the Northern Marianas Islands 2003–2011), 

Johnston Atoll (2004–2012), and Wake Atoll (2005–2011). 

Although 11 species of shark have been observed during Coral Reef Ecosystem Division surveys 

(Table A.1.1), only four species are typically recorded by towed divers in sufficient frequency to 

allow meaningful analyses: grey reef shark (Carcharhinus amblyrhynchos), Galapagos shark 

(Carcharhinus galapagensis), whitetip reef shark (Triaenodon obesus), and blacktip reef shark 

(Carcharhinus melanopterus). 

47
 
 

 

 

 

 

 

 

 

 

 

 

 

Spatial analyses of data up to 2011 showed a highly significant negative relationship between 

gray reef and Galapagos shark densities and proximity to human population centers (e.g., proxy 

for potential fishing pressure and other human impacts). Even around islands with no human 

habitation but within reach of populated areas, gray reef and Galapagos shark densities are 

significantly lower. Trends in whitetip and blacktip reef shark numbers are similar but less 

dramatic (I.D. Williams et al., 2011; Nadon et al., 2012). More recent data is entirely consistent 

with those findings. Analyses through time (~ 12 years) indicate downwards trends in reef shark 

densities in the Northwestern Hawaiian Islands and in the Northern Mariana Islands. Possible 

explanations for these patterns are currently being investigated. 

Age Validation using Bomb Radiocarbon Dating 

PIFSC scientists in collaboration with Northeast Fisheries Science Center (NEFSC) led a recent 

study to validate age estimates for the sandbar shark (Carcharhinus plumbeus), a cosmopolitan 

species of subtropical and tropical seas. The sandbar shark was the cornerstone species of 

western North Atlantic and Gulf of Mexico coastal bottom longline fisheries until 2008, when 

they were allocated to a research-only fishery. Despite decades of fishing on this species, 

important life history parameters, such as age and growth, have not been well known. Results 

from both tag-recapture data and bomb radiocarbon dating show longevity to exceed 30 years for 

this species (Andrews et al., 2011). The findings of this study indicated there was missing time 

in the growth structure of the vertebrae for this species, leading to an underestimation of 

longevity by more than 10 years. 

PIFSC (with the Southeast Fisheries Science Center) is currently involved in a project funded by 

the NMFS Office of Protected Resources through their Species of Concern Program to validate 

the age, growth, and longevity of sand tiger shark (Carcharias taurus) from the western North 

Atlantic (WNA) and southwestern Indian Oceans (SIO). Preliminary results from bomb 

radiocarbon dating indicate a similar scenario, with vertebrae reaching a certain size limit and no 

noticeable or measureable growth beyond this size. Visual counts of vertebral growth bands 

were used to assign age and estimate year of formation (YOF) for sampled growth bands in eight 

sharks from the WNA and two sharks from the SIO. Carbon-14 results were plotted relative to 

YOF for comparison with regional Δ14C reference chronologies to assess accuracy of age 

estimates. Results from the WNA validated vertebral age estimates up to 12 years, but indicated 

ages of large adult sharks were underestimated by 11-12 years. Age was also underestimated in 

adult sharks from the SIO by 14-18 years. Overall, validated lifespan for C. taurus is at least 40 

years for females and 34 years for males. Findings indicate the current age-reading methodology 

is not suitable for estimating the age of C. taurus beyond approximately 12 years. Future work 

should investigate whether vertebrae of C. taurus record growth throughout ontogeny, or cease 

to be reliable indicator at some point in time (Passerotti et al., in review). 

Mitigation of Shark Predation on Hawaiian Monk Seal Pups at French Frigate Shoals 

Shark predation on Hawaiian monk seal pups (Monachus schauinslandi) has become unusually 

common at one breeding site, French Frigate Shoals (FFS) in the Northwestern Hawaiian Islands 

(NWHI). Since 1997, NMFS has frequently observed Galapagos sharks (Carcharhinus 

galapagensis) patrolling and attacking monk seal pups. Tiger sharks (Galeorcerdo cuvier) also 

prey on monk seals and are abundant at FFS; however, Tiger sharks have not been observed to 

attack pups (Gobush 2010; unpublished data). For these reasons, monitoring and mitigation 

48
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

efforts at FFS continue to be focused on Galapagos sharks. Shark tagging studies at FFS indicate 

that, although Galapagos sharks are the most abudant shark species, they generally prefer deeper 

water and only a small fraction of the population, equating to a few tens of individuals, likely 

frequents the shallow areas around monk seal pupping islets (Dale et al. 2011). 

Reducing shark predation on pups at FFS is one of several key activities identified in the 

Hawaiian Monk Seal Recovery Plan (NMFS 2007). Since 2000, NMFS has attempted to 

mitigate shark predation through harassment and culling of sharks, shark deterrents, and 

translocation of weaned pups to islets in the atoll with low incidence of shark attacks (Baker et 

al. 2011; Gobush 2010). NMFS implemented a highly selective shark removal project to 

mitigate predation on monk seal pups from 2000-2013, with the exception of 2008–2009 when 

deterrents were tested (see appendix for more details). A total of 14 Galapagos sharks 

frequenting the nearshore areas of pupping islets have been lethally removed to date. In 2009, 

the number of shark sightings and predation incidents at two pupping islets did not differ 

significantly between the control and two experimental treatments: (1) acoustic playback and a 

moored boat, and (2) continuous human presence, versus a control (Gobush and Farry 2012). No 

sharks were removed at French Frigate Shoals in 2013. 

Southwest Fisheries Science Center (SWFSC) 

Abundance Surveys 

Juvenile Shortfin Mako (Isurus oxyrinchus) and Blue Shark (Prionace glauca) Survey 

In 2012, the SWFSC conducted its nineteenth juvenile shark survey for mako and blue sharks 

since 1994. The annual abundance survey was completed between 20 June and 19 July 2012. 

Working aboard F/V Ventura II, a team of scientists and volunteers fished a total of 5,592 hooks 

during 28 daytime sets within seven areas of the Southern California Bight (SCB). The survey 

catch totaled 151 shortfin makos, 26 blue sharks, 16 pelagic rays (Pteroplatytrygon vilacea), and 

4 opah (Lampris guttatus). The preliminary data indicate that the nominal survey catch rate was 

0.53 per 100 hook-hours for shortfin and 0.15 per 100 hook-hours for blue sharks. The mako 

shark nominal CPUE was slightly higher than the previous year. However, there is a declining 

trend in nominal CPUE for both species over the same series of the survey. 

Neonate Common Thresher Shark (Alopias vulpinus) Survey 

The common thresher shark pre-recruit index and nursery ground survey was initiated in 2003 to 

develop a fisheries-independent index of pre-recruit abundance and has been conducted in each 

year since. In 2012, the SWFSC team conducted the survey aboard the F/V Outer Banks. Fifty 

longline sets deploying 5,000 hooks were made in relatively shallow, nearshore during the 18­

day cruise. A total of 367 fish across a range of species were sampled during the survey. Two 

hundred and eighty-two common thresher sharks were captured. Most of these sharks were 

tagged with a combination of conventional tags and oxytetracycline. In addition, a pop-off 

archival GPS tag was released on a large female common thresher. Biological collections 

included DNA samples from most sharks captured and stomachs, digestive tracts, and blood 

were taken from a small number of sharks that did not survive. The preliminary survey data 

indicate that the average nominal catch rate was 2.49 per 100 hook-hours for common thresher 

sharks. This is a drop in CPUE from 2011 when the nominal catch rate was 5.57. The overall 

average trend since the start of the survey is increasing. 

49
 
 

 

 

 

 

 

 

 

Electronic Tagging Studies 

Since 1999, SWFSC scientists have used data logging tags and satellite technology to 

characterize the essential habitats of large pelagic fish and subsequently to better understand how 

populations might shift in response to changes in environmental conditions on short or long time 

scales; sharks tagged are primarily blue sharks, shortfin mako, and common thresher sharks, 

while other species are tagged opportunistically. In recent years, the SWFSC has collaborated 

with Mexican colleagues at Centro de Investigación Científica y de Educación Superior de 

Ensenada, Canadian colleagues at the Department of Fisheries and Oceans Pacific Biological 

Station in Nanaimo, British Columbia, and the Taggin of Pacific Predators program 

(www.topp.org) on shark tagging. 

In 2012, a number of pelagic sharks were tagged with satellite tags: five shortfin mako, five 

blue, and one common thresher shark were tagged with either platform transmitting terminal 

(PTT) tags or towed GPS tags. Three shortfin mako sharks and two blue sharks were also 

released with pop-up satellite archival tags (PSAT)

12 . In addition, five mako sharks were 

released with acoustic tracking tags to monitor their movements within the vicinity of coastal 

acoustic receivers. The average size of blue sharks tagged with a PTT in 2012 was 229 cm fork 

length (FL). Two of the five blue sharks were tracked for close to 200 days. Combined data 

from many years suggest that both sexes spend considerable time in the California Current, with 

the females possibly extending farther north and south. When offshore, generally, the females 

move south into the subtropical convergence zone, whereas the males make more westerly 

migrations. Both habitat separation by sex, and site fidelity have implications for the assessment 

and management of blue shark populations. Three PTT tags deployed in July 2012 on mako 

sharks were still transmitting in early 2013. 

Age Validation Studies 

Age and growth of shortfin mako (Isurus oxyrinchus), common thresher (Alopias vulpinus), and 

blue sharks (Prionace glauca) are being estimated from band formation in vertebrae. In addition 

to being important for studying basic biology, accurate age and growth curves are needed in 

stock assessments. SWFSC scientists are validating ageing methods for these three species 

based on band deposition periodicity determined using oxytetracycline (OTC). 

Oxytetracycline Age Validation of Juvenile Shortfin Makos – The results of age validation of 29 

juvenile shortfin mako sharks tagged with OTC in the SCB were recently published (Wells et al. 

2013) and showed vertebral band pair deposition rates of two per year. The results of this study 

differ from two other studies on shortfin makos that used a direct age validation technique: one 

study validated a single band pair deposition rate in an estimated 18 year old shortfin mako shark 

tagged with OTC and recaptured in the Atlantic after one year at liberty; and the second used a 

bomb radiocarbon signal as a marker in 37 sharks collected in the Northwest Atlantic between 

1950 and 1984 ranging in estimated ages of one to 31 years. Age and growth in shortfin mako 

12 PSAT tags record measurements such as temperature, pressure (depth), and ambient light-level irradiance (some 

model tags also have the ability to measure salinity). At a preset time, an electronic link is activated that dissolves 

the tag’s nosecone attachment, allowing the tag to float to the surface where it sends its broadcast of data to satellites 

under three conditions: (1) meets set pop-up date, (2) exceeds threshold depth (~1,200–1,500 m; can tell shed tag 

from mortality), and (3) remains stationary at a depth above the threshold depth for (usually) 4 consecutive days. 

50
 
 

 

 

 

 

 

 

sharks continues to be uncertain because growth curves estimated from length frequency analysis 

and tag-recapture methods tend to show faster growth rates than obtained from vertebral counts 

based on deposition of a single band pair per year. Furthermore, this validation study applies to 

juvenile sharks in the northeast Pacific. This study raises questions about potential regional 

differences in band pair deposition rates or the possibility of an ontogenetic shift from a period of 

more rapid growth with two band pair deposition per year to slower growth and a switch to a 

band pair deposition rate of one per year. 

Foraging Ecology of Shortfin Mako, Blue, and Common Thresher Sharks 

To better understand niche separation and the ecological role of shortfin mako, blue, and 

common thresher sharks, contents of stomachs collected by fishery observers have been 

examined at the SWFSC since 2002. Stomach content analysis work continued since the 

publication of Preti et al. 2012. A total of 91 stomachs of several species of pelagic sharks have 

been analyzed from fishing seasons in 2011 and 2012. Preliminary results already indicate a 

possible shift in feeding trends. In past seasons, jumbo squid (Dosidicus gigas) were frequently 

found in the stomachs of examined predators, especially shortfin mako and blue sharks (Preti et 

al., 2012), whereas current data indicate a decrease in the importance of jumbo squid to the diets 

of these species. 

Basking Shark (Cetorhinus maximus) Research Program 

Due to concern about basking shark populations along the west coast of North America, NOAA 

Fisheries included the northeast Pacific basking shark as a NOAA Species of Concern in the 

United States in 2010. The SWFSC initiated a basking shark research program to (1) mine 

existing data for additional biological information, (2) conduct an electronic tagging study, (3) 

improve international data collection, and (4) improve national sightings information by 

developing a sightings website and an education and outreach program centered around 

Monterey Bay, California. During the past year SWFSC scientists continued to monitor for 

basking sharks in order to collect and analyze data on patterns of occurrence and potentially 

deploy more satellite tags. Some basking shark sightings in southern California were reported by 

constituents during the spring and early summer of 2012, although reports were sparse and 

sporadic. A couple of failed attempts were made to find sharks for tagging based on some of the 

reports. Data from the three sharks tagged with satellite tags in 2010 and 2011 have been 

analyzed and are being prepared for publication. The sharks showed impressive plasticity in 

vertical behaviors depending upon the region and distance from shore, as has been shown in the 

Atlantic. Dramatic shifts in behavior make estimating abundance based on aerial surveys and 

predicting overlap with fisheries challenging. Significant progress has been made on the 

quantitative modeling of historical basking shark records with environmental variables. 

Population Genetics Studies 

The SWFSC is collaborating on population genetics studies on a number of pelagic shark 

species, including shortfin mako, common thresher, pelagic thresher, silky, and blue sharks. A 

study using mitochondrial DNA control loop sequences to determine Pacific shortfin mako shark 

stock structure shows a single stock in the North Pacific, and distinct eastern and western stocks 

in the South Pacific. A suite of 11 nuclear microsatellite markers have been optimized and are 

being used to further refine the spatial and temporal resolution of shortfin mako stocks within the 

Pacific. For silky sharks in the EPO, nuclear and mitochondrial data for ~730 animals support 

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stock structure generally north and south of the equator with animals south of the Galapagos 

Islands in the EPO more closely allied with the northern stock. This spillover of the northern 

stock south of the equator is likely seasonal and is concordant with regional oceanography and 

size composition data. For pelagic thresher sharks, recent work using both nuclear and 

mitochondrial DNA data has revealed the presence of very strong stock structure between 

eastern and western Pacific populations. The central Pacific seems to be an area of overlap for 

these two populations. 

Northwest Fisheries Science Center (NWFSC) 

Monitoring and Assessment Activities 

The NWFSC conducts and supports several activities addressing the monitoring and assessment 

of sharks along the West Coast of the United States and in Puget Sound. The Pacific Fishery 

Information Network (PacFIN) serves as a clearinghouse for commercial landings data, 

including sharks. In addition, the At-Sea Hake and West Coast Groundfish Observer Programs 

collect data on shark species caught on vessels selected for observer coverage. 

The NWFSC conducts annual trawl surveys of the West Coast, designed primarily to acquire 

abundance data for West Coast groundfish stocks. The tonnages of all shark species collected 

during these surveys are documented. In addition, the survey program has conducted numerous 

special projects in recent years to help researchers acquire data and samples necessary for 

research on various shark species. Since 2002, the survey has collected biological data and 

tissue samples from spiny dogfish, including dorsal spines, which can be used to age the fish. 

Biological data and tissue samples were also collected from leopard sharks and cat sharks during 

the bottom trawl surveys. 

In addition to these monitoring activities, the NWFSC conducted the first assessment for 

longnose skate in 2007. This assessment was reviewed during the 2007 stock assessment review 

(STAR) process, and was adopted by the Pacific Fishery Management Council (PFMC) for use 

in management. The NWFSC conducted an assessment of spiny dogfish along the Pacific coast 

of the United States in 2011 (see section 2.3). 

Movement Research 

Over the past decade, the NWFSC has conducted extensive research on localized movements and 

seasonal migrations of three West Coast sharks: the bluntnose sixgill (Hexanchus griseus), 

broadnose sevengill (Notorynchus cepedianus), and northern spiny dogfish (Squalus suckleyi) 

(Andrews et al. 2007, 2009, 2010; Levin et al. 2012; Williams et al. 2011, 2012). These studies 

made use of acoustic tags, active tracking methods, and passive acoustic receiver arrays within 

estuaries and along coastal waters. Capture data, tracking data, and stable isotope data indicated 

that the population of sixgill sharks in Puget Sound is largely juveniles that remain resident for 

several years, while mature females appear to enter Puget Sound to pup. Active tracking 

methods revealed individual sixgill shark home range sizes and regular diel vertical migration 

patterns. Sevengill sharks made extensive use of coastal estuaries and shelf waters along the 

West Coast, and their movements and habitat use were related to season, sex, and size. Sevengill 

sharks appeared to display site fidelity, returning to the same areas of the same estuaries in 

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several consecutive years. Puget Sound dogfish appear to undergo seasonal migrations, 

departing to waters along the West Coast in winter and spring months. 

Spiny Dogfish Bioenergetics 

The NWFSC developed an energy budget (bioenergetics) model for spiny dogfish based on 

published physiology data, in order to characterize predatory demands and to estimate how those 

demands might change owing to climate change effects on dogfish metabolic rates. This model 

is also being used to quantify how predatory impact is reduced in Puget Sound when the spiny 

dogfish population migrates out of the system in the winter and spring months (Harvey 2009). 

Alaska Fishery Science Center (AFSC, Auke Bay Laboratory) 

Stock Assessments of Shark Species Subject to Incidental Harvest in Alaskan Waters 

Stock assessments are currently completed on the shark species most commonly encountered as 

incidental catch: Pacific sleeper sharks (Somniosus pacificus), spiny dogfish (Squalus suckleyi), 

and salmon sharks (Lamna ditropis). In both the Gulf of Alaska (GOA) and Bering Sea/Aleutian 

Islands (BSAI) fishery management plans, sharks are managed as a complex. Directed fishing 

for all sharks is prohibited. In the BSAI the shark complex is managed with catch limits based 

on historical maximum catch. In the GOA, catch limits for the complex are the sum of 

individual species recommendations: spiny dogfish catch limits are based on survey biomass 

estimates and the remaining species are based on historical average catch. Stock assessments are 

summarized annually and are available online (see Tribuzio et al. 2012a and 2012b, or 

http://www.afsc.noaa.gov/REFM/stocks/assessments.htm for the most recent assessments). 

Catch of sharks in unobserved fisheries 

Scientists at AFSC have worked with staff at the Alaska Regional Office, the North Pacific 

Fishery Management Council and the Alaska Department of Fish and Game to determine 

methods to estimate the catch of non-target species in the unobserved fishery for Pacific halibut 

in Alaskan waters. Methods were developed to use survey data as a proxy for fishery dependent 

data and total catch of sharks (and other non-halibut species) were estimated. Results suggest 

that this unobserved fishery may be a significant source of mortality for both spiny dogfish and 

Pacific sleeper shark (Tribuzio et al. 2013) 

Trophic Ecology of Pacific Sleeper Sharks in the Eastern North Pacific Ocean 

Stable isotope ratios of nitrogen (δ15N) and lipid normalized carbon (δ13C’) were used to 

examine variability in the trophic ecology of Pacific sleeper sharks (Courtney and Foy 2012). 

Models identified significant variability in muscle tissue δ15N values (3.3–5.7) across locations 

and across life stages, but the uncertainty was high (95 percent prediction intervals were 2.9– 

6.4). These results are similar to previously published results based on stomach content data 

(Courtney and Foy, 2012). 

Migration and Habitat Use of Spiny Dogfish and Pacific Sleeper Sharks 

During 2003–2006, scientists deployed 138 numerical Floy tags, 91 electronic archival tags, 24 

electronic acoustic tags, and 17 electronic satellite popup tags on Pacific sleeper sharks 

(Courtney and Hulbert 2007). Two numerical tags and 10 satellite tags have been recovered. 

Information on temperature, depth, and movement will be used to identify habitat and potential 

interactions with other species. Analysis of tagging data is ongoing. 

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Since 2009 scientists from ABL have deployed 180 pop-off archival tags on spiny dogfish in the 

GOA British Columbia and Washington State waters. Data have been successfully recovered 

from 140 tags to date. Results will indicate habitat preference with respect to depth and 

temperature, which may play a role in examining the effects of climate changes in the North 

Pacific. Further, the results will elucidate the degree to which GOA spiny dogfish populations 

mix with other populations. Preliminary results suggest a general westward movement between 

August and December, with some animals moving south to waters off the coast of California. 

The data are showing a strong daily migration between deeper and shallower waters. 

Age and Growth Methods 

Scientists at Auke Bay Laboratory and AFSC’s Resource Ecology and Fisheries Management 

Division age and growth lab are investigating a potential new method for ageing of spiny dogfish. 

The new method, which uses the vertebrae and histological staining, has been applied to spiny 

dogfish from the U.S. East Coast in efforts to reduce the uncertainty of age estimates. Scientists are 

working to establish a captive population of spiny dogfish, which will be used to validate the 

histological ageing methods, and generate improved age-at-length data that will be used to reestimate growth models used in stock assessments. The second purpose of this study is to establish 

a method for ageing Pacific sleeper sharks. This new method has been successful on deep water 

Squaloid sharks in the North Atlantic, and there is some suggestion that it will work for Pacific 

sleeper sharks. 

Reproduction in salmon shark 

Efforts are underway to investigate the reproductive patterns and physiology of salmon shark in 

the eastern North Pacific Ocean. Female salmon shark specimens are being collected from 

commercial fishery bycatch and examined for reproductive timing, periodicity, and fecundity. 

Results to date suggest that female salmon sharks ovulate during the autumn months of 

September and October. Further, those animals captured in July were either in a resting or postpartum state indicating a short gestation time of nine to 10 months. The presence of two 

maturity stages in both the summer and autumn months indicates a resting period of at least 14 

months between parturition and ovulation. These results provide new information on the 

reproductive biology of salmon sharks and will aid in the development of stock assessments for 

this species (Conrath et al. in review). 

Alaska Regional Office in cooperation with University of Alaska Fairbanks 

Modeling Spiny Dogfish Distribution 

The spiny dogfish is a common bycatch species in the GOA. Their spatial distribution is poorly 

understood, as most catch is discarded at sea. AKRO analyzed dogfish spatial distribution from 

fishery-dependent and independent observations of longline gear between 1996 and 2008 using 

generalized additive and generalized linear models. Models showed that dogfish catches were 

concentrated east of Kodiak Island in waters ≤100 m. Results facilitate design of future dogfish 

assessment surveys, identification of areas in which to focus at-sea observations for fishing 

mortality estimation, and provide the basis for first-ever designation of dogfish essential fish 

habitat (EFH) off Alaska. Identified areas of high bycatch may expedite spatial management by 

indicating areas in which directed dogfish fisheries could be focused or, conversely, areas in 

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which heightened conservation and catch accounting efforts would be most effective to prevent 

overfishing of this long-lived, late-maturing species (Gasper and Kruse, 2013). 

World Market Analysis of the Spiny Dogfish 

The spiny dogfish is a globally distributed shark species that is an important trade commodity for 

Europe and Asia. Data on trade, capture, and informal interviews with dogfish suppliers were 

used to characterize market channels and sources of demand in Asia and Europe. Future 

increases in market share for dogfish will require differentiating the product from potential 

substitutes while using eco-labeling and marketing to inform consumers. In cooperation with the 

NMFS Alaska Regional Office, the University of Alaska Fairbanks School of Fisheries and Ocean 

Sciences was funded to study the policy implications of a spiny dogfish fishery in Alaska (Gasper 

2011). 

Policy Perspective of the Spiny Dogfish Market in Alaska 

The purpose of this study is to describe historical dogfish harvests in Alaska and provide an 

analysis of potential harvest given the current and future regulatory environment. A robust 

dogfish market in Alaska is unlikely to occur unless regulations allow directed fishing. Such a 

regulatory change may create incentives to use dogfish as a guise to harvest other, more valuable 

species. In developing management options, agencies must establish target and limit reference 

points for fishing mortality commensurate with the vulnerability of this species to overfishing. 

Northeast Fisheries Science Center (NEFSC) 

Fishery Independent Coastal Shark Bottom Longline Survey (CSBL) 

The NEFSC CSBL Survey of Atlantic large and small coastal sharks, started in 1986 and 

conducted every 2-3 years, is the longest fishery-independent shark survey in the U.S. Atlantic 

Ocean. Its primary objective is to conduct a standardized, systematic survey of shark 

populations off the U.S. Atlantic coast to provide unbiased indices of relative abundance for 

species inhabiting the waters from Florida to the Mid-Atlantic. Results from the 2012 survey 

included 1,845 fish (1,831 sharks) representing 16 species, of which 1,564 (85 percent) were 

tagged and released. Sharks represented 99 percent of the total catch of which sandbar sharks 

were the most common, followed by dusky and tiger sharks. As part of this survey, bottom 

longline sets were conducted in the closed area off North Carolina. These results represent the 

highest catches of sharks from any previous survey to date. 

Collection of Recreational Shark Fishing Data and Samples 

The NEFSC has been attending recreational shark fishing tournaments since 1961, compiling 

data on species, sex, and size of the captured sharks as well as collecting biological samples for 

pelagic and coastal sharks. In 2012, biological samples and catch data for more than 140 pelagic 

sharks were collected at 7 tournaments in the northeastern United States. 

Pelagic Nursery Grounds 

Pelagic shark biology, movements, and abundance studies continued in 2012 with further 

investigations of pelagic nursery grounds in collaboration with the high seas commercial longline 

fleet. An additional 230 sharks were tagged, bringing the total to over 2,950 with 200 recaptured. 

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Cooperative Atlantic States Shark Pupping and Nursery (COASTSPAN) Program 

Comprehensive and standardized investigations of coastal shark nursery habitat have been 

completed in Atlantic coastal waters from Florida to Massachusetts and in the United States Virgin 

Island. In 2012, COASTSPAN participants included four State agencies (Georgia, Massachusetts, 

North Carolina, and South Carolina) as well as the University of North Florida, Virginia Institute of 

Marine Science, and Stony Brook University. In 2012, a total of 4,281 sharks of 15 species were 

caught during COASTSPAN surveys and 1,724 (40 percent) of these sharks were tagged for 

migration studies. 

Juvenile Shark Survey for Delaware Bay Sandbar Sharks (Carcharhinus plumbeus) 

The juvenile sandbar shark population in Delaware Bay is surveyed as part of the COASTSPAN 

program. In 2012, a total of 259 sandbar sharks were caught and released with conventional tags. 

Delaware Bay Sand Tiger (Carcharias taurus) Survey 

This survey aims to identify EFH and monitor abundance and size composition to allow for 

comparison between historic and current abundances. In 2012, a total of 32 sand tigers were 

caught and released with conventional tags, bringing the total since the beginning of the survey 

to 238 sand tigers. A Ph.D. dissertation and publication (Kneebone et al. 2012) were completed 

using COASTSPAN supported research with passive acoustic telemetry in Massachusetts waters 

to study the habitat utilization and EFH of juvenile sand tigers. 

Age validation in sand tiger (Carcharias taurus) using bomb radiocarbon analysis 

Bomb radiocarbon analysis of sand tiger vertebrae from the North Atlantic and South Indian 

Oceans has begun in an effort to validate growth band periodicity and longevity. These results 

will either validate age estimates or will provide evidence for discrepancies in age from growth 

band counting and new estimates of age at maturity and longevity will be used to update the 

productivity for this species. 

Age and growth of Elasmobranchs 

A review chapter assessing the age and growth of Chondrichthyan fishes was published in 2012 

(Goldman et al. 2012). This reported overviews on ageing structures, sampling and processing 

specimens, and methodologies of age determination and verification/validation. Implications of 

growth, longevity, and demography, as well as the use of various growth models were also 

discussed. 

The primary method for estimating age of sharks relies on counting band pairs that are assumed to 

be annual in vertebrae; most shark species lack validation of band pair eriodicity. Presentations 

were given in 2012 (Hamady et al. 2012) summarizing the results of new bomb radiocarbon 

validation data and determination of metabolic stability from vertebrae taken from white, basking, 

and dusky shark vertebrae. 

Cooperative Shark Tagging Program (CSTP) 

The CSTP provides information on distribution, movements, and EFH for shark species in U.S. 

Atlantic and Gulf of Mexico waters and involves thousands of volunteer fishermen, scientists, 

and fisheries observers since 1962. In 2012, information was received on 4,200 tagged and 575 

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recaptured fish, bringing the total numbers tagged to 235,000 sharks of more than 50 species and 

14,200 sharks recaptured of 33 species. 

Spiny Dogfish (Squalus acanthias) Tagging Study 

To assess stock structure, movement patterns, and life history, spiny dogfish are being tagged 

during winter and summer in three regions: Southern New England, Gulf of Maine, and Georges 

Bank. In 2012, an additional 18,570 spiny dogfish were tagged bringing the total tagged to 

34,604 for the two year project. Of the total tagged, 488 have been recaptured to date. A total of 

91 fish, that were injected with OTC for an age validation study have been recaptured and 

returned for age validation. Seventy-two of these fish were in good enough condition to obtain 

measurements for reproductive studies. 

Blacktip Shark (Carcharhinus limbatus) movement patterns 

Mark/recapture data from NMFS CSTO were summarized for the blacktip shark in the Gulf of 

Mexico (Swingsburg et al. 2012). No blacktip sharks in this study moved between the Gulf of 

Mexico and the Atlantic or Caribbean. Similarly, there was no evidence of exchange between 

the eastern and western Gulf of Mexico. Some of these sharks migrated from the United States 

to Mexican waters within a time period of less than one year. These data were pivotal in 

determining the need for multiple (Gulf of Mexico and U.S. Atlantic) stock assessments for this 

species. 

Southeast Fisheries Science Center (SEFSC) 

Stock Assessments of Large Coastal, Small Coastal, Pelagic, and Prohibited Sharks 

In 2012, SEFSC staff completed the Gulf of Mexico blacktip shark stock assessment (SEDAR 

29). The assessment generally provided a consistent picture of stock status wherein the stock 

was determined to not be overfished (spawning stock fecundity was 2-2.6 times the MSY level) 

and overfishing was not occurring (fishing mortality was only 7 to 27 percent the level of F 

resulting in MSY). 

Observer Programs 

The shark longline observer program was created to obtain better data on catch, bycatch, and 

discards in the shark bottom longline fishery. Recent amendments to the Consolidated Atlantic 

HMS Fishery Management Plan have significantly modified the major directed shark fishery and 

implemented a shark research fishery. NMFS selects a limited number of commercial shark 

vessels (5 in 2012) on an annual basis to collect life history data and catch data for future stock 

assessments. Outside the research fishery, vessels targeting shark and possessing valid directed 

shark fishing permits were randomly selected for coverage with a target coverage level of 4 to 6 

percent. In 2012, 53 trips with a total of 81 hauls were observed on the 5 vessels in the shark 

research fishery. Observations outside the research fishery comprised a total of 68 hauls from 21 

trips aboard six vessels in the Gulf of Mexico and 21 hauls from 15 trips aboard six vessels in the 

U.S. south Atlantic. In the research fishery, sharks comprised 97.9 percent of the catch. Catch 

composition was 29.4 percent large coastal shark species (excluding sandbar), 48.6 percent 

sandbar shark, 11.8 percent small coastal shark species, 0.1 percent deep water sharks, and 9.8 

percent prohibited shark species. For observations outside the research fishery in the Gulf of 

Mexico, sharks comprised 97.6 percent of the catch. Large coastal shark species (excluding 

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sandbar shark) comprised 88.3 percent of the shark catch, small coastal shark species comprised 

7.8 percent, sandbar sharks comprised 2.7 percent, and other prohibited sharks comprised 0.9 

percent of the shark catch. In the U.S. south Atlantic, sharks made up 94.4 percent of the catch. 

Small coastal shark species comprised 47.8 percent, large coastal shark species (excluding 

sandbar shark) comprised 39.4 percent of the shark catch, sandbar sharks comprised 7.0 percent, 

smooth dogfish, Mustelus canis, comprised 5.2 percent, and other prohibited sharks comprised 

0.2 percent of the shark catch. 

Since 1993, an observer program has been underway to estimate catch and bycatch in the direct 

and indirect shark gillnet fisheries along the southeastern Atlantic coast. A total of 316 sets 

comprising various gillnet fisheries were observed in 2012. 

Distribution, Community Structure and Characterizing and Predicting Essential Habitat 

Features for Juvenile Coastal Sharks 

Since adult shark populations are influenced by the input of new recruits, their successful 

management depends on ensuring the survival of juveniles to maturity. Many shark species use 

inshore areas for early life stages and segregate to reduce competition. Using a fisheriesindependent gillnet survey from the Gulf of Mexico, distribution patterns and preferred habitat 

features of the juveniles coastal shark species are being described. Preliminary results suggest 

that multiple shark species concurrently use the area for early life stages and although they 

overlap they have different site and habitat preferences. Predictive models suggest that 

temperature, depth, and salinity are important factors driving juvenile shark occurrence. This 

work provides important insight into the preferred habitat features of juvenile shark populations, 

which may be used to better manage these species. 

Elasmobranch Feeding Ecology 

Studies are currently underway describing the diet and foraging ecology, habitat use, and 

predator–prey interactions of elasmobranchs. The diets of multiple shark species caught by 

commercial longline gear—including Atlantic sharpnose (Rhizoprionodon terraenovae), dusky 

(Carcharhinus obscurus), sandbar (C. plumbeus), silky (C. falciformis), and tiger (Galeocerdo 

cuvier) sharks—are currently being investigated. Along with basic diet analysis, stomach 

contents will be examined for evidence of line feeding, or depredation, on longline gear. This 

study will help to test the hypothesis that diet studies based on longline-caught animals could be 

biased due to longline depredation. 

Cooperative Gulf of Mexico States Shark Pupping and Nursery Survey (GULFSPAN) and 

Tagging Database 

The SEFSC Panama City Shark Population Assessment Group manages and coordinates a survey 

of coastal bays and estuaries from Florida to Louisiana. Surveys identify the presence or absence 

of neonate (newborn) and juvenile sharks and attempt to quantify the relative importance of each 

area as it pertains to essential fish habitat. A database currently includes over 10,000 tagged 

animals and 205 recaptured animals from 1993 to the present for both the Gulf of Mexico and 

U.S. southeast Atlantic Ocean. This fully searchable database is current through spring 2010 

with hopes to have it online in 2014. 

Monitoring the Recovery of Smalltooth Sawfish (Pristis pectinata) 

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The smalltooth sawfish was the first marine fish listed as endangered under the Endangered 

Species Act (ESA). Smalltooth sawfish has been listed under the ESA since 2005, and the 

completion of the Smalltooth Sawfish Recovery Plan in early 2009 identified new research and 

monitoring priorities that are currently being implemented. Surveys identify the presence or 

absence of neonates, young-of-the-year, and juveniles in southwest Florida and research in the 

Florida Keys and Florida examines the distribution and abundance of adult animals. 

Life History Studies of Elasmobranchs 

In collaboration with the NMFS Mississippi Laboratory and the University of Southern 

Mississippi, age, growth, and reproduction for the finetooth shark (C. isodon) in the Gulf of 

Mexico are being examined in anticipation of a stock assessment in 2014. In addition, scientists 

from these groups are also examining age and growth of Cuban dogfish. Research with PIFSC 

to validate ageing in sand tiger shark (Carcharias taurus) using bomb radiocarbon analysis was 

begun in 2011. Three manuscripts were published in peer-reviewed journals; one investigating 

the reproductive cycle of the sandbar shark, one on age and growth of smalltooth sawfish, and 

the other examining gillnet selectivity of blacktip sharks (Baremore and Hale, 2012; Scharer et 

al., 2012; Baremore et al., 2012). 

Cooperative Research: Uruguay–U.S. Pelagic Shark Research Project 

A collaborative project with Uruguay’s fisheries agency (DINARA) aims to advance knowledge 

on the susceptibility of pelagic sharks to longline fisheries in the western South Atlantic. Ten 

satellite tags have been deployed on blue sharks to date. Five tags are currently providing real 

time data, which along with data for Ecological Risk Assessments are used as outreach to 

promote the collaboration between NOAA and DINARA (http://cicmar.org/en/projectsdeveloped-by-cicmar/tiburuy-project-research-and-conservation-of-sharks-in-uruguay/blueshark-satellite-tracking). An identification guide for carcharhinid sharks of the Atlantic Ocean 

was created in 2011 (ICCAT 2012). 

Shark Assessment Research Surveys 

The SEFSC Mississippi Laboratories have conducted bottom longline surveys in the Gulf of 

Mexico, Caribbean, and Southern North Atlantic since 1995 (30 surveys have been completed 

through 2012). The primary objective is assessment of the distribution and abundance of large 

and small coastal sharks across their known ranges in order to develop a time series for trend 

analysis. 

NOAA Chesapeake Bay Office 

Life History, Trophic Ecology, and Prey Handling by Cownose Rays (Rhinoptera bonasus) 

Perceived increases in the population of cownose rays that use the Chesapeake Bay, coupled 

with increases in damage to shellfish culture, grow-out, and restoration operations, have 

generated growing interest in management of cownose rays, including the development of a 

commercial fishery for the species. To better understand the biology and ecology of this species, 

NOAA’s Chesapeake Bay Office provided funding to the Virginia Institute of Marine Science 

for a 3-year study that will document the age and growth and predation for cownose rays, 

focusing on the population that uses the Chesapeake Bay for pupping and mating during summer 

months. Male and female rays were found to reach sexual maturity between ages 6 and 8, with 

59
 
 

 

 

 

 

 

females not contributing to recruitment until year 8 or 9 due to length of gestation. Mean disk 

width at maturity for males and females was about 85cm, corresponding to age at maturity of 6 

to 7 years for males and 7 to 8 years for females. Oysters and clams were not found to make up 

a significant portion of the diet of cownose ray sampled from across the Chesapeake Bay. 

Cownose ray were found to be limited by the size of their mouths, which reduced the likelihood 

of predation on larger prey, such as oysters. Trials also indicated that rays seem to show 

preference for single, cultchless oysters as opposed to aggregated, clutched oysters, indicating 

that the spat-on-shell growout method may minimize cownose ray predation. 

NOAA Center for Coastal Environmental Health and Biomolecular Research 

Ongoing Sample Collection and Methods Development for Molecular Shark Species 

Identification 

The Marine Forensics program at the NOAA's National Ocean Service (NOS) Center for Coastal 

Environmental Health and Biomolecular Research (CCEHBR) in Charleston, South Carolina, 

conducts research on suitable molecular markers for identification of shark species. DNA 

identifications can be used to determine whether prohibited species are found among fish that are 

not landed intact as well as the identity of dried, processed fins. The Marine Forensics program 

currently uses mitochondrial DNA sequencing to identify the species of suspected sharks seized 

by agents of Federal and State law enforcement agencies. Sample collection and research to 

expand the number and range of shark species sequenced for the diagnostic DNA fragment is 

continuing. In 2012, several rays and Australian shark species were added to the marine 

forensics archive of vouchers, and the NOAA Office of Law Enforcement submitted several 

shark fin cases to the Marine Forensics program for identifications. 

5.2 Incidental Catch Reduction 

Pacific Islands Fisheries Science Center (PIFSC) 

Reducing Longline Shark Bycatch 

The resumption of the previously closed Hawaii shallow-set longline fishery for swordfish in late 

2004 and continuing through 2007 was anticipated to increase blue shark catches, as in the past 

blue sharks made up about 50 percent of the total catch in this fishery. With the ban on shark 

finning, these sharks are not retained and are categorized as regulatory bycatch. Although the 

anticipated increase in shark bycatch has been less than expected (perhaps due to the requirement 

to use fish bait instead of squid, or because of a shift toward an earlier fishing season in the 

reopened swordfish fishery), researchers at PIFSC have undertaken several projects to address 

shark bycatch on longlines (Huang et al., 2013; Hutchinson et al., 2012; Swimmer et al. 2008, 

2011).The use of large circle hooks instead of conventional tuna hooks in the world’s pelagic 

tuna longline fleets has displayed conservation potential for some highly migratory species 

(Curran and Bigelow 2010, 2011). However, recent collaborative research on capture rates of 

species caught on Japanese tuna hooks vs. relatively large circle hooks conducted on a 

Taiwanese commercial longline vessel indicated significantly higher catch rates of blue sharks 

caught on circle hooks (Huang et al., 2013). Additionally, research in the South Atlantic Ocean 

conducted on a Uruguayan longline vessel found higher rates of capture of shortfin mako sharks 

on circle hooks compared to J hooks (Domingos et al., 2012). 

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Electromagnetic Deterrents to Bycatch (additional details provided in Appendix 1, PIFSC) 

Bycatch of sharks in longline fisheries has contributed to declines in shark populations and 

prompted the need for exploring novel technologies to reduce the incidental capture of sharks. 

One potential strategy is to exploit the unique electrosensory system of sharks, which are capable 

of detecting weak electric fields. Several shark species have been shown to be repulsed by 

powerful magnets and rare earth metals such as the electropositive metals from the lanthanide 

series, made up of neodymium (Nd) and praseodymium (Pr). For this reason, electromagnetic 

deterrents have become a potential bycatch solution on pelagic longline fisheries, as they may 

selectively reduce the bycatch of sharks and other elasmobranchs without affecting the catch of 

commercially targeted pelagic teleosts. 

While electropositive metal deterrents have been tested experimentally as a potential bycatch 

solution on pelagic longline fisheries (Hutchinson et al., 2012), controlled trials under 

commercial fishing conditions are still lacking. Another study in the northwest Atlantic was 

conducted in collaboration with the Canadian pelagic longline swordfish fishery where blue 

sharks comprise a significant proportion of unwanted bycatch. In 2011 a total of seven sets 

(6,300 hooks) with three hook treatments—standard hooks, hooks with rare-earth alloys (Nd/Pr), 

and hooks with lead weights—were deployed near Sambro, Nova Scotia. Results suggest that 

rare-earth metals do not have any significant deterrent effect on the most common shark bycatch 

species and as such do not appear to be a practical bycatch mitigation option in the Canadian 

fishery. Nonetheless, stakeholder participation in this study improved the methodology, creating 

tests that follow realistic commercial-scale conditions (Godin et al., 2013). 

In addition, we have been examining technologies to 

reduce shark bycatch in coastal gillnet fisheries. This 

new project has been initiated to investigates the effects 

of visual cues on the catch composition of coastal 

gillnets in Baja California. Preliminary results show 

that UV illumination of gillnets significantly reduce the 

catch rates of sharks and other elasmobranchs. In 

particular, results indicated a 53 percent decrease in the 

catch rates of scalloped hammerheads in UV illuminated 

nets. In addition, experiments with orange (605nm 

wavelength) net illumination suggest that elasmobranch 

interaction rates can be reduced by 55 percent. Both 

types of net illumination do not affect the target catch 

rates or significantly change the market value. This 

suggests that net illumination may be a useful strategy to reduce shark interactions in coastal 

gillnet fisheries. This work is currently being analyzed and additional experiments are being 

planned to follow up on these results. 

Southwest Fisheries Science Center (SWFSC) 

Testing Deep Longline Gear 

In the California pelagic drift gillnet fishery that targets swordfish, blue sharks have historically 

been one of the main bycatch species. The majority (63 percent) of the blue sharks entangled are 

discarded dead. To reduce the bycatch and/or post-release mortality of multiple species, the 

Figure 5.2.1: Orange LEDs attached 

to experimental gillnet. 

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SWFSC has been conducting tests to target swordfish using deep-set longline gear off California 

at depths below 200 meters. These deeper depths coincide with the daytime distribution of 

swordfish, putting hooks below the epipelagic waters inhabited by sea turtles and shortfin mako 

sharks. A first test of the deep-set longline was conducted in October 2011. During 11 sets, 105 

blue sharks were caught with 96 percent released alive, although 51 percent were considered to 

be in poor condition. No shortfin mako sharks were caught. The 2012 research cruise was 

conducted between October 23 and November 7, 2012. A total of 28 sets were made during 

2011 and 2012 cruises. Time-depth recorders were used to document hook depth across all sets 

and hook numbers. In 2012, fishing depths ranged from 107 meters to 460 meters. A range of 

marketable species were caught including swordfish, tunas, and opah. One common mola (Mola 

mola), one shortfin mako, and 157 blue sharks were also caught, nearly all of which were 

released alive. Unfortunately, in 2011, weather restricted most effort to more southern waters, 

south of Point Conception. In 2012, waters shifted to winter conditions earlier than usual and 

overall fishing was very poor at that time for the drift gillnet fleet and the experiment. Some 

funding has been received to continue the experiment during 2012. 

The effect of circle hooks on shark catchability and at-vessel mortality rates in longline 

Fisheries 

Fisheries bycatch is a main cause of population declines in several species of sharks and skates 

(elasmobranchs) around the world. Circle hooks have gained recent attention as a cost-effective 

bycatch mitigation tool in pelagic longline fisheries, particularly for marine turtles. Over the last 

few years, a growing number of studies have investigated the use of circle hooks and their effects 

on other species, including elasmobranchs. To elucidate the potential value of circle hooks as a 

tool for shark conservation and management in pelagic longline fisheries, we conducted a 

quantitative review of all available studies to date. We compiled 15 published and 8 grey 

literature studies and where possible tested the effects of circle hooks on catchability and atvessel mortality rates with random effects meta-analysis and analysis of covariance. Results 

indicate that as a tool to reduce at-vessel mortality for sharks, circle hooks tend to benefit over Jhooks and should thus be seen as one potential tool to help reduce at-vessel mortality of sharks. 

However, the high level of heterogeneity found between the studies highlights the need for 

shark-specific controlled experiments to provide more definitive results. 

Capture time, size, and hooking mortality of dusky shark (Carcharinus obscurus) in bottom 

longline fisheries 

Dusky sharks (Carcharinus obscurus) are large coastal-pelagic sharks that inhabit the waters of 

the western Atlantic and Gulf of Mexico. A recent stock assessment indicates population 

depletions of ~80 percent of unfished levels. Management regulations include listing dusky 

sharks as a prohibited species and creating a time-area closure to protect neonates and juveniles. 

Despite strict regulations, dusky sharks are still caught as bycatch on longlines where at-vessel 

mortality rates are up to 85 percent. To help improve the status of the dusky shark, hook timers 

and temperature depth recorders were used to collect data to assess factors affecting mortality 

during longline capture. Eighty-five specimens from 16 longline sets were caught off North 

Carolina and the Florida Keys. Time-on-hook, length, sex, average water temperature, and soak 

time were recorded. Preliminary logistic regression models predict that as time-on-hook and 

soak time increase, mortality rates also increase. Median mortality occurs at 6.6 hours of timeon-hook and 13.5 hours of soak time. Water temperature was not a significant factor in the 

62
 
 

 

 

 

 

 

 

 

 

 

analysis. The difference in the mortality rates of time-on-hook versus soak time suggests that 

current soak time is longer than dusky shark tolerance to longline fishing. While preliminary, 

these results reflect the potential of bycatch mortality rates to influence already depleted 

populations and could be used to propose regulations on longline soak time, aiding in population 

recovery of this species. 

West Coast Region (WCR) and PIER Testing Swordfish Deep-set Buoy Gear 

The Pfleger Institute of Environmental Research (PIER), in collaboration with NMFS WCR, is 

conducting research into use of novel deep-set buoy gear to test the efficacy of capturing 

swordfish at depth (300 meters and deeper) during the day while avoiding bycatch species of 

concern. As with the deep-set longline research being conducted by the SWFSC (see above), 

targeting deeper depths coincides with known day time habitat preference of swordfish and puts 

hooks below the upper water column habitat preferred by leatherback turtles and sharks. To 

date, a total of 54 experimental buoy gear sets have resulted in the capture of 15 swordfish in the 

nearshore waters of the SCB along with 7 bigeye thresher sharks, 2 blue sharks and 1 common 

thresher shark. There were no interactions with sea turtles or other species of concern. The 

research is on-going and plans are underway to test the gear in central California nearshore 

waters. 

5.3 Post-Release Survival 

Southwest Fisheries Science Center (SWFSC) 

Common thresher, shortfin mako, and blue sharks are captured in both commercial and 

recreational fisheries in the California Current. The California drift gillnet fishery is the 

commercial fishery that catches the greatest number of each of these species. While thresher and 

mako sharks are landed, almost all blue sharks are discarded. For thresher and mako sharks, 

regional recreational fisheries are growing in popularity. Recreational fishermen are often 

interested only in the challenge of the fight and will frequently release their catch. The survival 

rate of sharks released both from the California drift gillnet fishery and by recreational anglers is 

unknown. Reliable estimates of mortality are necessary in order to adequately assess the status 

of the stocks and determine the effects of the fisheries on their abundance. 

Blue Sharks Released from the California Drift Gillnet Fishery 

The California drift gillnet fishery targets swordfish in the California Current. With the 

exception of ocean sunfish (Mola mola), blue sharks are caught in greater numbers than any 

other fish species taken in this fishery. Nearly all blue shark are discarded at sea due to lack of 

market value. A 2009 analysis of the 1990-2008 observer data reveals that 32 percent of blue 

sharks captured were released alive, and an additional 5 percent were discarded with their 

disposition unknown. The remaining 63 percent were discarded dead. In 2007, the SWFSC and 

the WCR began deploying PSAT tags on sharks released from the California drift gillnet fishery 

to assess survivorship in order to determine more accurate estimates of fishery mortality for use 

in a blue shark stock assessment. As part of the study, a set of criteria was developed to 

document the condition of all live blue sharks released: “good”, “fair” or “poor.” 

63
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

Prior to the 2012-2013 season, 12 blue sharks (100 to 200 cm FL, median 149 cm) had been 

tagged by fishery observers. Three of the 12 sharks were released in “good” condition while the 

remaining 9 were released in “fair” condition. Satellite tag records suggest that all animals 

survived the acute effects of capture in the CDGN fishery. 

During the 2012-2013 season, fishery observers deployed 3 survivorship pop-up archival tags, 

which are new, more economical tags, that record daily minimum and maximum depths and 

temperatures and are programmed to pop off if the tag exceeds a certain depth or remains at a 

constant depth for several days. Of the three sharks tagged (2 females of 134 and 162 cm FL, 

and one 161 cm FL male), two were in “poor” condition when released and one was considered 

in “fair” condition. Two of the 3 sharks died immediately and the fate of the third one could not 

be determined as the tag popped after just 8 days, but with no evidence that the shark sank to the 

bottom. These results, combined with the results from the prior years, suggest that sharks that 

are released in “good” condition are likely to survive, whereas those released in “poor” condition 

are likely to die. The study will continue during the 2013-2014 season when the final 3 tags will 

be deployed on sharks in “fair” or “poor” condition. The data on the condition of all sharks 

released is currently being compiled in order to be able to apply the survivorship estimates to the 

discarded population more accurately. 

Thresher Sharks Released from the Recreational Fishery 

The SWFSC, WCR, and PIER are conducting a three phase study to assess the post-release 

survival of thresher sharks caught by recreational anglers. During the first phase of the study, 

sharks were released after being captured using tail-hooking techniques (common practice in the 

southern California fishery). The results from this work revealed that survivorship is low for 

large sharks (>185 cm FL) that endure fight times that exceed 85 minutes (Heberer et al. 2010). 

The second and third phases of the research effort focused on assessing post-release survival in 

two modes of capture routinely observed in the southern California recreational fishery: (1) 

sharks that are caught using caudal-based angling techniques and unintentionally released with 

trailing gear left embedded, and (2) sharks that are caught and released using mouth-based 

angling techniques. Post-release survivorship was assessed using pop-up satellite archival tags. 

For the trailing gear investigation, seven sharks died shortly after release and two sharks 

survived the deployment period for an overall survivorship rate of 22 percent. For the mouthbased trials, all common thresher sharks survived the acute effects of capture (100 percent 

survivorship). The results from all phases of this study will be used to estimate the survival rates 

and incorporate best fishing practices into the fishery to reduce the mortality of released thresher 

sharks. A major component of this project is to promote fishing practices that enhance thresher 

shark catch and release survival by developing education and outreach tools for the recreational 

fishing community. A brochure on best practices for thresher shark fishing and handling was 

developed, and is available at: 

(http://www.pier.org/userdocs/images/images/flyers/BREP_thresher_brochure.pdf). An outreach 

video highlighting phase one of the research was produced by the Ocean Media Center and 

posted on the NMFS Home Page under the Video Gallery 

(http://www.nmfs.noaa.gov/gallery/videos/). A second video, highlighting phases two and three 

of the research effort, is currently under development by the Ocean Media Center and will be 

available for outreach events in the summer of 2013 and will be posted again on the NMFS 

website. 

64
 
 

 

 

 

 

 

 

 

 

 

 

 

 

Recreational Fishery for the Common Thresher Shark (Alopias vulpinus) 

The common thresher shark (Alopias vulpinus) is the focus of a popular southern California 

recreational fishery that targets individuals using multiple fishing gears and techniques. 

Mirroring the national trend in U.S. recreational fisheries, an increasing number of southern 

California anglers are practicing catch and release in this fishery; however a comprehensive 

estimate of post-release survival is not available for all modes of capture. Researchers from 

PIER, working in collaboration with NMFS WCR and NMFS SWFSC La Jolla, carried out a 

study to assess the post-release survival in two modes of capture routinely observed in the 

southern California recreational fishery: (1) Sharks that are caught using caudal-based angling 

techniques and unintentionally released with trailing gear left embedded and (2) sharks that are 

caught and released using mouth-based angling techniques. Post-release survivorship was 

assessed using pop-up satellite archival tags (PSATs) programmed for 90-day (caudal-based with 

trailing gear) and 10-day (mouth-based) deployments. Survivorship estimates for the caudalbased trailing gear studies were based on data from 9 common thresher sharks (111-175 cm FL) 

while the mouth-based portion utilized data from an additional seven sharks (125-187 cm fork 

length, FL). For the caudal-based trailing gear studies, six sharks died shortly after release and 

three sharks survived the deployment period for an overall survivorship rate of 33 percent. For 

the mouth-based trials, all seven common thresher sharks survived the acute effects of capture 

demonstrating 100 percent survivorship. These results suggest that in the southern California 

recreational thresher shark fishery, caudal-based angling techniques, which often result in 

trailing gear left embedded in the shark, negatively affects survivorship and that mouth-based 

angling techniques can, when performed properly, result in high survivorship of released sharks. 

Northeast Fisheries Science Center (NEFSC) 

Post-release Recovery and Survivorship Studies in Sharks: Physiological Effects of Capture 

Stress 

This ongoing cooperative research is directed toward coastal and pelagic shark species caught on 

recreational and commercial fishing gear. This work is collaborative with researchers from 

Massachusetts Division of Marine Fisheries (MDMF) and many other State and academic 

institutions. These studies use blood and muscle sampling methods, including hematocrit, 

plasma ion levels, and red blood cell counts, coupled with acoustic tracking and PSAT to 

quantify the magnitude and impacts of capture stress. The primary objectives of the new 

technology tag studies are to examine shark migratory routes, potential nursery areas, swimming 

behavior, and environmental associations. Secondarily, these studies can assess the 

physiological effects of capture stress and post-release recovery in commercially and 

recreationally captured sharks. These electronic tagging studies include: (1) acoustic tagging 

and bottom monitoring studies for coastal shark species in Delaware Bay and the USVI as part of 

COASTSPAN; (2) tracking of porbeagle sharks with acoustic and PSATs in conjunction with the 

MDMF; (3) placing real-time satellite (SPOT) and PSAT tags on shortfin makos and blue sharks 

in the northeast United States and on their pelagic nursery grounds; (4) placing PSAT tags on 

sand tigers in Delaware Bay and Plymouth Bay (Massachusetts) as part of a fishery-independent 

survey and habitat study; and (5) placing PSAT and SPOT tags on dusky and tiger sharks in 

conjunction with Monterey Bay Aquarium, University of California Long Beach, and MDMF. 

Integration of data from new-technology tags and conventional tags from the Cooperative Shark 

Tagging Program (CSTP) is necessary to provide a comprehensive picture of the movements and 

65
 
 

 

 

migrations of sharks along with possible reasons for the use of particular migratory routes, 

swimming behavior, and environmental associations. In addition, the results of this research will 

be critical to evaluate the extensive current catch-and-release management strategies for sharks. 

Southeast Fisheries Science Center (SEFSC) 

Determination of Alternate Fishing Practices to Reduce Mortality of Prohibited Dusky Shark 

in Commercial Longline Fisheries 

NMFS' Panama City Laboratory has been conducting a series of fishing experiments using 

commercial fishing vessels participating in the Shark Research Fishery to investigate methods to 

reduce at-vessel mortality of dusky shark, a prohibited species. Pop-off archival satellite tags 

have also been deployed on select individuals to aid in determining the efficacy of closed areas 

for dusky shark. Preliminary logistic modeling analysis indicates median mortality occurs after 

6.6 hours of being hooked, and 13.5 hours of soak time. Water temperature was not a significant 

factor in analysis. The difference in the mortality rates of hooking time versus soak time suggest 

that soak time is longer than the tolerance of dusky sharks to longline fishing. These preliminary 

results reflect the potential of bycatch mortality rates to influence already depleted populations, 

and these results could be used to propose regulations on longline soak time that could aid in 

population recovery of this species 

The Capture Depth, Time, and Hooked Survival Rate for Bottom Longline Caught Scalloped 

Hammerhead Shark 

Recent stock assessments for the Atlantic population of scalloped hammerhead, Sphyrna lewini, 

in U.S. waters estimated the population was overfished and overfishing was occurring (Hayes 

and Cortes 2009). In order to reduce levels of fishing mortality, management measures could 

reduce quotas or prohibit the landings of scalloped hammerhead sharks. However, these 

management measures may not be totally effective for longline fisheries because scalloped 

hammerhead sharks suffer from high hooking mortality. Data collected by onboard observers 

indicate that 91 percent of scalloped hammerheads are dead prior to being landed on the fishing 

vessel. Experiments began in 2011 to determine the relationship between soak time and capture 

depth on fishing mortality and CPUE of scalloped hammerhead sharks using hook timers and 

time depth recorders. The data and results produced from this study will provide critical 

information for fishery managers to help with the development of management measures to 

rebuild overfished scalloped hammerhead sharks and end overfishing for this species. 

The effect of circle hooks on shark catchability, at-vessel mortality and post-release survival 

rates in bottom longline fisheries 

Over the last few years, a growing number of studies have investigated the use of circle hooks 

and their effects on a range of species, including sharks. However, for sharks, managers and 

scientists are confronted with multiple studies of small sample sizes with either conflicting 

results or no statistical significance and no clear conclusions. To assess the potential effect of a 

change from J hooks to circle hooks in the shark bottom longline fishery, commercial shark 

bottom longline vessels are being chartered to perform controlled experiments testing the 

catchability and mortality rates of sharks caught on J versus circle hooks. Post-release 

survivorship, will be assessed tagging sharks with a satellite pop-up archival transmitting (PAT) 

tag. Survival of post-captured PAT tagged animals will be inferred data provided by the PAT 

66
 
 

tag. The project is currently 66.3 percent complete. Ten PAT tags have been deployed and four 

made the full deployment of 34 days. Of the remaining six tags, four pulled early with two 

showing indications of mortality and one tag is still due to report. The current 90 percent report 

rate is higher than other PAT tag studies to date. 

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Passerotti, MS, JK Carlson, AN Piercy, and SE Campana. 2010. Age validation in great 

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554. 

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7. Internet Information 

Sources 

Federal Management 

2000 Shark Finning Prohibition Act 

http://www.gpo.gov/fdsys/pkg/BILLS-106hr5461enr/pdf/BILLS-106hr5461enr.pdf 

The 2010 Shark Conservation Act 

http://www.gpo.gov/fdsys/pkg/BILLS-111hr81enr/pdf/BILLS-111hr81enr.pdf 

Atlantic Ocean Shark Management 

Copies of the 2006 Consolidated Atlantic HMS Fishery Management Plan (FMP) and its 

Amendments and Atlantic commercial and recreational shark fishing regulations and brochures 

can be found on the Highly Migratory Species (HMS) Management Division website at 

http://www.nmfs.noaa.gov/sfa/hms/. Information on Atlantic shark fisheries is updated annually 

in the Stock Assessment and Fishery Evaluation (SAFE) Report for Atlantic HMS, which are 

also available on the website. The website includes links to current fishery regulations (50 FR 

635), shark landings updates, and the U.S. National Plan of Action for Sharks. 

Domestic stock assessments under the SEDAR process are available online at 

http://www.sefsc.noaa.gov/sedar/. 

Pacific Ocean Shark Management 

The U.S. West Coast Highly Migratory Species FMP and the Pacific Coast Groundfish FMP and 

annual SAFE Reports are currently available on the Pacific Fishery Management Council 

website: http://www.pcouncil.org/. 

Data reported in Table 2.3.3 (Shark landings (round weight equivalent in metric tons) for 

California, Oregon, and Washington, 2001–2010) was obtained from the Pacific States Marine 

Fisheries Commission’s PacFIN Database, which may be found on their website at: 

http://pacfin.psmfc.org/pacfin pub/data.php. 

Information about pelagic fisheries of the Western Pacific Region FMP is available on the 

Western Pacific Fishery Management Council’s website: 

http://www.wpcouncil.org/pelagic.htm. 

Data reported in Table 2.3.8 (Shark landings (mt) from the Hawaii-based longline fishery and the 

American Samoa longline fishery, 2001-2010) was partially obtained from the Western Pacific 

Fisheries Information Network (WPacFIN). WPacFIN is a Federal-State partnership collecting, 

processing, analyzing, sharing, and managing fisheries data from American island territories and 

75
 
 

 

States in the Western Pacific. More information is available on their website at: 

http://www.pifsc.noaa.gov/wpacfin/. 

The Bering Sea/Aleutian Islands Groundfish FMP and the Groundfish of the Gulf of Alaska 

FMP are available on the North Pacific Fishery Management Council’s (NPFMC) website: 

http://alaskafisheries.noaa.gov/npfmc/ 

Stock assessments and other scientific information for sharks are summarized annually in the 

NPFMC SAFE Reports that are available online: 

http://www.afsc.noaa.gov/REFM/stocks/assessments.htm. 

International Efforts to Advance the Goals of the Shark Finning Prohibition Act 

NOAA Fisheries Office of International Affairs 

http://www.nmfs.noaa.gov/ia/ 

FAO International Plan of Action for the Conservation and Management of Sharks 

http://www.fao.org/figis/servlet/static?dom=org&xml=ipoa_sharks.xml 

U.S. NPOA for the Conservation and Management of Sharks 

http://www.nmfs.noaa.gov/sfa/hms/Final%20NPOA.February.2001.htm 

NAFO Conservation and Enforcement Measures 

http://www.nafo.int/fisheries/frames/regulations.html 

IATTC: http://iattc.org/HomeENG.htm 

ICCAT: http://www.iccat.int/en/ 

International Scientific Committee for Tuna and Tuna-like Species in the North Pacific Ocean 

(ISC): http://isc.ac.affrc.go.jp/ 

WCPFC: http://www.wcpfc.int/ 

UNGA: http://www.un.org/en/law/ 

Memorandum of Understanding on the Conservation of Migratory Sharks 

http://www.ecolex.org/server2.php/libcat/docs/TRE/Multilateral/En/TRE154630.pdf 

U.S. Imports and Exports of Shark Fins 

Summaries of U.S. imports and exports of shark fins are based on information submitted by 

importers and exporters to the U.S. Customs and Border Protection. This information is 

compiled by the U.S. Census Bureau and is reported in the NMFS Trade database: 

http://www.st.nmfs.gov/st1/trade/index.html 

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Appendix 1: Detailed Information on NOAA 

Research on Sharks 

Pacific Islands Fisheries Science Center (PIFSC) 

Fishery Data Collection 

Market data from the PIFSC shoreside sampling program contain detailed biological and 

economic information on sharks in the Hawaii-based longline fishery dating from 1987. These 

data are primarily collected from fish dealers who are required to submit sales/transaction data to 

the State of Hawaii. The Western Pacific Fishery Information Network (WPacFIN) is a Federal– 

State partnership collecting, processing, analyzing, sharing, and managing fisheries data on 

sharks and other species from U.S. island territories and States in the Central and Western 

Pacific(Hamm et al. 2011). The WPacFIN program has also assisted other U.S. islands’ fisheries 

agencies in American Samoa, Guam, and the Commonwealth of the Northern Mariana Islands to 

modify their data-collecting procedures to collect bycatch information. These modifications 

have improved the documentation of shark interactions with fishing gear. Shark catches in the 

Hawaii-based longline fishery have been monitored by a logbook program since 1990, and by an 

observer program since 1994. 

Biometrical Research on Catch Statistics 

Biometrical research on shark longline bycatch issues funded by the Pelagic Fisheries Research 

Program (University of Hawaii) was documented in Walsh et al. (2009). This work was based 

on analyses of shark catch data from the Pacific Islands Regional Observer Program. The results 

included a detailed description of the taxonomic composition of the shark catch, as well as 

additional information pertinent to either the management (e.g., nominal catch rates, disposition 

of caught sharks, distributions of shark catches relative to those of target species) or basic 

biology (e.g., mean sizes, sex ratios) of the common species. The results indicated that blue 

shark in particular, which comprises approximately 85 percent of the shark bycatch, exhibits a 

high rate of survival (about 95 percent) to the time of release. On the basis of these very low 

minimum mortality estimates, it was concluded that the Hawaii longline fishery has made 

substantial progress in reducing bycatch mortality compared to the period before the shark 

finning ban. 

Shark Catch Per Unit Effort (CPUE) Data Analysis from Longline Observer Program Data 

NMFS produced standardized CPUE time series for use as input for stock assessments for blue, 

whitetip, and silky shark in the Hawaii longline fishery using the Pacific Islands Regional 

Observer Program data (1995–2010) (Walsh and Clarke, 2011). This work is important because 

these species are taken in large but unknown numbers, primarily as bycatch, in many Pacific 

Ocean fisheries. The standardized CPUE for blue shark was adjusted for the effects of extrinsic 

factors (e.g., geographic position, sea surface temperature, and gear configuration), and will be 

used in an International Scientific Committee for Tuna and Tuna-like Species in the North 

Pacific Ocean (ISC) stock assessment for this species in 2013. 

Insular Shark Surveys 

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Densities of insular sharks (Table A.1.1) have been estimated at most of the U.S. island 

possessions within the Tropical Central, Northern, and Equatorial Pacific on annual or biennial 

surveys conducted by the PIFSC Coral Reef Ecosystem Division (CRED) since 2000. 

These estimates include surveys of: 

•	 10 major shallow reefs in the Northwestern Hawaiian Islands (2000, 2001, 2002, 2003, 

2004, 2006, 2008, 2010). 

•	 The Main Hawaiian Islands (2005, 2006, 2008, 2010). 

•	 The Pacific Remote Island Areas of Howland and Baker in the U.S. Phoenix Islands and 

Jarvis Island, and Palmyra and Kingman Atolls in the U.S. Line Islands (2000, 2001, 

2002, 2004, 2006, 2008, 2010). 

•	 American Samoa, including Rose Atoll and Swains Island (2002, 2004, 2006, 2008, 

2010). 

•	 Guam the Commonwealth of the Northern Marianas Islands (2003, 2005, 2007, 2009, 

2011), Johnston Atoll (2004, 2006, 2008, 2010), and Wake Atoll (2005, 2007, 2009, 

2011). 

Table A.1.1 Shark species observed in PIFSC-CRED Reef Assessment and Monitoring 

Program surveys around U.S. Pacific Islands. 

Shark species observed 

Common Name Species 

Grey reef shark Carcharhinus amblyrhynchos 

Galapagos shark Carcharhinus galapagensis 

Whitetip reef shark Triaenodon obesus 

Blacktip reef shark Carcharhinus melanopterus 

Silvertip shark Carcharhinus albimarginatus 

Tiger shark Galeocerdo cuvier 

Tawny nurse shark Nebrius ferrugineus 

Whale shark Rhincodon typus 

Scalloped hammerhead shark Sphyrna lewini 

Great hammerhead shark Sphyrna mokarran 

Zebra shark Stegostoma varium 

Although 11 species of shark have been observed during CRED surveys (see Table A.1.1), only 

four species are typically recorded in sufficient frequency by towed divers to allow meaningful 

statistical analyses: grey reef shark (Carcharhinus amblyrhynchos), Galapagos shark 

(Carcharhinus galapagensis), whitetip reef shark (Triaenodon obesus), and blacktip reef 

shark(Carcharhinus melanopterus). Analyses show a highly significant negative relationship 

between grey reef and Galapagos shark densities and proximity to human population centers 

(e.g., proxy for potential fishing pressure and other human impacts). Average combined 

numerical density for these two species near population centers is less than 1 percent of densities 

recorded at the most isolated islands (e.g., no human population, very low present or historical 

fishing pressure or other human activity). Even around islands with no human habitation but 

within reach of populated areas, grey reef and Galapagos shark densities are only between 15 

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percent and 40 percent of the population densities around the most isolated near-pristine reefs. 

Trends in whitetip and blacktip reef shark numbers are similar but less dramatic. 

Recent analysis of data from 2008 to 2010, also indicated significantly higher biomass of all 

sharks combined at remote islands (i.e., islands at least 100 km from the nearest human 

population center) compared to populated islands, with remote islands having, on average, 40 or 

more times the biomass of sharks than was recorded at populated islands in both the Hawaiian 

and Mariana Archipelagos (I.D. Williams et al. 2011). Differences between remote and 

populated portions of American Samoa were not statistically significant, reflecting low counts of 

sharks at all locations in that region. CRED is currently working on a scientific article using 

towed-diver data of shark distribution, and accounting for differences between reef areas in 

temperature and oceanic primary productivity. Because all CRED shark data were gathered by 

SCUBA divers: (1) safe diving practices limited surveys to reefs areas of 30m or shallower, 

which is the upper end of reef sharks’ potential depth distribution; and (2) surveys by SCUBA 

divers are potentially biased by acquired behavioral differences of sharks in the presence of 

divers between isolated and fished locations. For those reasons, CRED is pursuing opportunities 

for diver-independent assessments of shark populations, such as by deploying remote video 

systems. 

Insular Shark Population Model 

PIFSC scientists study the status of reef shark populations in the central-western Pacific Ocean. 

During PIFSC coral reef assessment and monitoring surveys conducted between 2004 and 2010, 

shark observations were recorded around 46 individual U.S. islands, atolls, and banks. PIFSC 

scientists analyzed shark count data from 1,607 towed-diver surveys conducted on forereefs 

(seaward slope of a reef) using techniques developed specifically to survey large-bodied species 

of reef fishes. 

The shark count data were used to build a computer model capable of explaining observed reef 

shark abundances at various reefs by examining the effects of variables related to human 

impacts, oceanic productivity, sea surface temperature, and reef habitat physical complexity. 

This model was used to predict reef shark densities in the absence of humans (i.e., baseline or 

pristine abundance) and found that current reef shark numbers around populated islands in 

Hawaii, the Mariana Archipelago, and American Samoa are down to about 3 to 10 percent of 

their baseline values (Figure 5.1.1). These results show the extent of the detrimental effect of 

humans on reef shark population. However, the exact cause of the decline could not be 

determined. The likely causes are probably related to prey population depletion (i.e., reef fish 

biomass around populated islands is about 70 percent lower than on pristine reefs) and direct 

removal through fishing (bycatch, recreational, or targeted) (Nadon et al. 2012). 

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Figure A1.1. Mean (SE) observed densities of reef sharks in the U.S. Pacific. Colors represent actual
 

densities; gray rectangles represent model predictions in the absence of humans.
 

Mitigation of Shark Predation on Hawaiian Monk Seal Pups at French Frigate Shoals 

Shark predation on Hawaiian monk seal pups (Monachus schauinslandi) has become unusually 

common at one breeding site, French Frigate Shoals (FFS) in the Northwestern Hawaiian Islands 

(NWHI). Between 1997 and 2010, the number of shark predation incidents on pups (pre-weaned 

and newly weaned) was 207 of 854 (24.2 percent) born at FFS compared to 10 of 520 (1.9 

percent) born at Laysan Island and 13 of 334 (3.9 percent) born at Lisianski Island. Shark 

attacks on monk seal pups at FFS peaked in 1999 with the death of 22 pups (24 percent of the 

annual cohort). Thereafter, pup losses declined to 5 to 11 pups a year, but the percentage of pups 

lost to predation (12-28 percent annually) remains high as pup production has fallen for other 

reasons at FFS (Gobush 2010; unpublished data). 

Since 1997, NMFS has frequently observed Galapagos sharks (Carcharhinus galapagensis) 

patrolling and attacking monk seal pups. Tiger sharks (Galeorcerdo cuvier) also prey on monk 

seals and are abundant at FFS; however, tiger sharks have not been observed to attack pups of 

this age class during daytime monitoring (approximately between 6:00am and 8:00pm) spanning 

the past 15 years (Gobush 2010; unpublished data). For these reasons, NMFS’ monitoring and 

mitigation efforts at FFS continue to be focused on Galapagos sharks. Shark tagging studies at 

FFS indicate that, although Galapagos sharks are the most abundant shark species in the atoll, 

they generally prefer deeper water and only a small fraction of the population, equating to a few 

tens of individuals, likely frequents the shallow areas around monk seal pupping islets (Dale et 

al. 2011). 

Reducing shark predation on pups at FFS is one of several key activities identified in the 

Hawaiian Monk Seal Recovery Plan (NMFS 2007). Since 2000, NMFS has attempted to 

mitigate shark predation through harassment and culling of sharks, shark deterrents, and 

translocation of weaned pups to islets in the atoll with low incidence of shark attacks (Baker et 

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al. 2011; Gobush 2010). NMFS implemented a highly selective shark removal project to 

mitigate predation on monk seal pups between 2000 and 2012, with the exception of 2008–2009 

when deterrents were tested (detailed below). A total of 14 Galapagos sharks frequenting the 

nearshore areas of pupping islets have been lethally removed to date. Thirteen Galapagos sharks 

were captured with handlines or harpoons from shore or small boats and culled in 2000, 2001, 

2003, 2005, and 2011 (Gobush 2010). An additional Galapagos shark was caught with a fivehook bottom set longline and culled in 2010. Also in 2010, invited members of the Native 

Hawaiian community deployed with NMFS staff to perform Mano i’a harvest ceremonies at 

Ka’ula rock (while en route to FFS) and Tern Island, FFS, to offer respect to the sharks that 

would be caught for the mitigation project. The skin and teeth of the Galapagos shark removed 

in 2010 were retained and preserved for Native Hawaiian community members and used for 

educational purposes. 

The feasibility of possible deterrents was tested in 2008 around Trig island (FFS). Deterrents 

included visual devices (moored boat and floats suspended in the water column), auditory 

playbacks (boat noise broadcast by underwater speakers), and electronic diver devices 

(suspended in the water column along a nearshore pathway typical for patrolling sharks).The 

electronic diver devices functioned poorly and were omitted from further testing. In 2009, the 

number of shark sightings and predation incidents at two pupping islets at FFS was compared 

across two experimental treatments: (1) acoustic playback and a moored boat, and (2) 

continuous human presence, versus a control. Sharks were sighted with a remote camera system; 

predation incidents were evident from bite wounds or the disappearance of pups. However, the 

number of shark sightings and predation incidents did not differ significantly between the two 

treatments and the control (Gobush and Farry 2012). 

Stock Assessment of Blue Shark 

In 2000 as a collaborative effort with scientists at the National Research Institute for Far Seas 

Fisheries (NRIFSF) in Shimizu, Japan, analyses indicated that the blue shark stock was not being 

overfished (Kleiber et al. 2001). PIFSC and NRIFSF subsequently renewed this collaboration, 

along with scientists from Japan’s Fisheries Research Agency, to update the blue shark 

assessment with the latest data from Japanese and Hawaii based longline fisheries, as well as 

with better estimates of Taiwanese and Korean catch and effort data. 

Objectives were to determine the degree to which the blue shark population has been affected by 

fishing activity and whether current fishing practices need to be managed to ensure continued 

viability and utilization of the resource. In addition to re-estimating catch and effort data based 

on a longer time series of data (Nakano and Clarke 2005, 2006), this study incorporated several 

new features: (1) effort data were obtained from the Fisheries Administration of Taiwan, (2) 

catches for the Japanese inshore longline fleet were included, (3) catch estimates were contrasted 

with estimates from the shark fin trade, (4) catch per unit effort was standardized using both a 

generalized linear model and a statistical habitat model, and (5) two different stock assessment 

models were applied. 

Detailed records from daily fin auctions in the world's largest trading center, Hong Kong, and 

national customs statistics were used to estimate the number of blue sharks caught in the North 

Pacific from 1980 to 2002. This was achieved by estimating the number of blue sharks used in 

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the global fin trade (Clarke 2004, Clarke et al. 2004, 2006) and partitioning these estimates to 

represent blue shark catches in the North Pacific only. Despite considerable uncertainty in this 

extrapolation algorithm, the North Pacific blue shark catch estimates based on the shark fin trade 

are very similar to estimates from Kleiber et al. (2001). 

The two shark assessment models—a surplus production model and an integrated age and 

spatially structured model—were found to be in general agreement even though they represent 

opposite ends of the spectrum in terms of data needs (Kleiber et al. 2009). The trends in 

abundance in the production model and all alternate runs of the integrated model show the same 

pattern of stock decline in the 1980s followed by recovery to a biomass that was greater than that 

at the start of the time series. One of the several alternate analyses indicated some probability 

(around 30 percent) that the population is overfished and a lower probability that overfishing 

may be occurring. There was an increasing trend in total effort expended by longline fisheries 

toward the end of the time series, and this trend may have continued thereafter. The uncertainty 

could well be reduced by a vigorous campaign of tagging and by continuous, faithful reporting of 

catches and details of fishing gear. 

Electronic Tagging Studies and Movement Patterns 

PIFSC scientists are using acoustic, archival, and pop-up satellite archival tags (PSATs) to study 

vertical and horizontal movement patterns in commercially and ecologically important tuna, 

billfish, and shark species, as well as sea turtles. The work is part of a larger effort to determine 

the relationship of oceanographic conditions to fish and sea turtle behavior patterns. This 

information is intended for incorporation into population assessments, addressing fisheries 

interactions and allocation issues, as well as improving the overall management and conservation 

of commercially and recreationally important tuna and billfish species, sharks, and sea turtles. 

PIFSC is finishing manuscripts detailing the movements of pelagic sharks in relation to 

oceanographic conditions (Musyl et al. 2011a). In a review paper, Bernal et al. (2009) 

summarizes the eco-physiology of large pelagic sharks while Sibert et al. (2009) report on the 

error structure of light-based geolocation estimates afforded by PSATs and Nielsen et al. (2009) 

show how reconstructed PSAT tracks can be optimized. 

The research, sponsored by the Pelagic Fisheries Research Program (University of Hawaii) and 

PIFSC, has shown that some large pelagic fishes have much greater vertical mobility than others. 

Pelagic sharks displayed species-specific depth and temperature ranges, although with significant 

individual temporal and spatial variability in vertical movement patterns, which were also 

punctuated by stochastic events (e.g., El Niño-Southern Oscillation [ENSO]). Pelagic species, 

including some other species that have been PSAT tagged (swordfish, bigeye tuna, and marlins) 

can be separated into three broad groups (Fig. A1.1) based on daytime temperatures occupied 

using a clustering algorithm. These groups and the temperatures occupied by the sharks are 

characterized as: (1) epipelagic species (including silky and oceanic whitetip sharks) which 

spent more than 95 percent of their time at temperatures within 2°C of sea surface temperature; 

(2) mesopelagic I species (including blue and shortfin mako sharks) which spent 95 percent of 

the time at temperatures from 9.7–26.9°C and 9.4–25.0°C, respectively; and (3) mesopelagic II 

species (including bigeye thresher shark) which spent 95 percent of the time at temperatures 

from 6.7–21.2°C. For the most part, the topology of clusters did not appear to correlate with 

ENSO variability, phylogeny, life history characteristics, ecomorphotypes, neural anatomy, 

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relative eye size, physiology, or the presence of regional endothermy—indicating other factors 

(e.g., ontogeny, latitude, locomotion, diet, and dimensionality of the environment) influence the 

structure as well as the spatial and temporal stability of thermal habitats. The results suggest that 

habitat structure for the epipelagic silky and oceanic whitetip sharks can be adequately estimated 

from two dimensions (these species spend most of their time in the warmest available water). By 

contrast, three dimensions will be required to describe the extended vertical habitat of the species 

that we classified as mesopelagic I (blue shark, shortfin mako shark) and mesopelagic II (bigeye 

thresher shark) (Musyl et al. 2011a). 

Figure A1.2. Clustered relationships among pelagic animals using daytime temperature preferences
 

from pop-up satellite archival tags (PSATs). B = blue shark, SF = shortfin mako, T = bigeye thresher, E
 

= bigeye tuna, R = swordfish, S = silky shark, O = oceanic whitetip shark, K = black marlin, L = blue
 

marlin, M = male, and F = female. Inset maps show the horizontal movement patterns.
 

Mesopelagic II species remain in the vicinity of prey organisms comprising the deep Sound 

Scattering Layer (SSL) during their extensive diel vertical migrations. The SSL comprises 

various species of squids, mesopelagic fish, and euphausiids that undertake extensive diurnal 

vertical migrations. This composition of organisms is referred to as the SSL because the 

migration of these organisms was first discovered by the sound waves that reflect off gas-filled 

swim bladders or fat droplets within the migrating organisms. PIFSC scientists have also found 

one of the most ubiquitous large-vertebrate species in the pelagic environment—the blue shark— 

83
 
 

 

 

 

 

 

 

 

 

occasionally displays vertical movement behaviors similar to those of swordfish, bigeye tuna, 

and bigeye thresher sharks. 

Electronic Tagging of Whale Sharks (Rhincodon typus) 

The PIFSC, in collaboration with Australian Institute for Marine Science and the Commonwealth 

Scientific and Industrial Research Organization, has for the past several years been deploying 

electronic tags on whale sharks at Ningaloo Reef, Western Australia, to describe their vertical 

and horizontal movements. The work has documented that whale sharks dive below 1,000 m, 

deeper than previously thought. After the whale sharks leave Ningaloo Reef, some travel to 

Indonesia while others head across the Indian Ocean (Wilson et al. 2006, 2007). 

Chemical and Electromagnetic Deterrents to Bycatch 

One study under way since 2005 with funding from NMFS National Bycatch Program seeks to 

test the use of chemical and electromagnetic deterrents to reduce shark bycatch. Previous 

research by Eric Stroud of Shark Defense LLC was conducted to identify and isolate possible 

semiochemical compounds from decayed shark carcasses. Semiochemicals are chemical 

messengers that sharks use to orient, survive, and reproduce in their specific environments. 

Certain semiochemicals have the ability to trigger a flight reaction in sharks. Initial tests showed 

that chemical repellents administered by dosing a “cloud” of the repellent into a feeding school 

of sharks caused favorable behavioral shifts, and teleost fishes such as pilot fish and remora 

accompanying the sharks were not repelled and continued to feed. This suggested other teleosts, 

such as longline target species (tunas or billfish), would not be repelled. Longline field testing of 

these chemicals and magnets was conducted in early 2006 with demersal longline sets in South 

Bimini and were quite successful. 

Beginning in early 2007, the PIFSC began testing the ability of electropositive metals (lanthanide 

series) to repel sharks from longline hooks. Electropositive metals release electrons and generate 

large oxidation potentials when placed in seawater. It is thought that these large oxidation 

reactions perturb the electrosensory system in sharks and rays, causing the animals to exhibit 

aversion behaviors. Since commercially targeted pelagic teleosts do not have an electrosensory 

sense, this method of perturbing the electric field around baited hooks may selectively reduce the 

bycatch of sharks and other elasmobranchs. 

Feeding behavior experiments were conducted to determine whether the presence of these metals 

would deter sharks from biting fish bait. Experiments were conducted with Galapagos sharks 

and sandbar sharks off the coast of the North Shore of Oahu. Results indicate that sharks 

significantly reduced their biting of bait associated with electropositive metals. In addition, 

sharks exhibited significantly more aversion behaviors as they approached bait associated with 

these metals. Further studies on captive sandbar sharks in tanks indicated sharks would not get 

any closer than 40 cm to bait in the presence of the metal (metal approximately the size of a 60g 

lead fishing weight). 

Initial experiments to examine the effects on shark catch rates of modified longlines are also 

being conducted. This is being accomplished through collaboration with Dr. Kim Holland of the 

University of Hawaii’s Hawaii Institute of Marine Biology (HIMB). Two experiments were 

initiated, one focusing on the effects of Nd/Pr (peodymiun/praseodymium) alloy on the catch 

84
 
 

 

 

 

 

 

 

 

 

 

rates of sharks on bottom set longline 

gear and the other examining the effects 8.0E-02 

of Nd/Pr alloy and other lanthanide 7.0E-02 alloys on the feeding and swimming 6.0E-02 behavior of scalloped hammerhead 5.0E-02 (Sphyrna lewini) and sandbar 

(Carcharhinus plumbeus) sharks. 4.0E-02 

Preliminary results from longline field 3.0E-02 

trials in Kaneohe Bay, Hawaii, suggest 2.0E-02 

that catch rates of juvenile scalloped 1.0E-02 

hammerhead sharks are reduced by 63 0 0E+00 

percent on branch lines with the Nd/Pr 

alloy attached as compared to lead 

weight controls (Figure A1.2). Initial 

behavioral experiments examining 

effects on swimming behavior have 

been initiated (Wang et al. 2009, Brill et 

al. 2009). 

CPUE of scalloped hammerhead sharks 

(Sphyrna lewini) 

2.2E-02 

6.2E-02 

Control Hooks Hooks w/ Nd-Pr 

Hook Treatment 

Figure A1.3. Catch per unit effort of scalloped 

hammerhead sharks on longlines with Nd/Pr 

alloy attached versus control hooks. 

In addition, field trials on pelagic sharks were initiated via collaboration with the Southwest 

Fisheries Science Center (SWFSC)(see section 5.2). Thirteen sets were completed for the 

experiment during the 2010 cruise to add to the 25 sets in 2009. Preliminary results indicate that 

the rare earth metals did not affect the catch rate of shortfin mako or blue sharks, as they were 

caught on the experimental hooks and control hooks in almost equal numbers. These results 

differ from those found on some coastal shark species where the deterrents proved effective at 

lowering catch rates. The data are being further examined based on size, sex, and other potential 

factors before drawing final conclusions. 

A collaborative pilot study in the Ecuadorian mahi-mahi longline fisheries was also conducted. 

Branch lines with lead weight were alternated with branch lines with Nd/Pr metal weight. 

However, analysis of catch data indicated no difference in the catch rates of thresher sharks, 

silky sharks, and scalloped hammerhead sharks between control branch lines and branch lines 

with Nd/Pr metal (Wang et al. 2010, Hutchinson et al. 2012). 

Longline Hook Effects on Shark Bycatch 

To explore operational differences in the longline fishery that might reduce shark bycatch, the 

observer database is being used to compare bycatch rates under different operational factors 

(e.g., hook type, branch line material, bait type, the presence of light sticks, soak time, etc.). A 

preliminary analysis was completed that compared the catches of vessels using traditional tuna 

hooks to vessels voluntarily using size 14/0 to 16/0 circle hooks in the Hawaii-based tuna fleet. 

The study was inconclusive due to the small number of vessels using the circle hooks. 

Subsequently, 16 contracted vessels were used to test large (size 18/0) circle hooks versus 

traditional Japanese-style tuna hooks (size 3.6 sun) in controlled comparisons. Preliminary 

analysis does not indicate these large circle hooks increase the catch rate of sharks, in contrast to 

findings of increased shark catch on circle hooks in studies comparing smaller circle hooks with 

J hooks in other fisheries. The 18 most caught species were analyzed, representing 97.6 percent 

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of the total catch by number. Catch rates on large 18/0 circle hooks were significantly reduced— 

by 17 percent for blue shark, 27 percent for bigeye thresher shark, and 69 percent for pelagic 

stingray. Bycatch rates for other incidental species such as billfish, opah (Lampris guttatus), and 

mahimahi (Coryphaena hippurus) were also reduced compared to traditional tuna hooks. There 

was no significant difference in the catch rate of the target species, bigeye tuna, by hook type. In 

contrast to tuna hooks, large circle hooks have conservation potential for use in the world’s 

pelagic tuna longline fleets for some highly migratory species based on demonstrated catch rate 

reductions (Curran and Bigelow 2010, 2011). 

Testing Deeper Sets 

An experiment with deeper set longline gear conducted in 2006 altered current commercial tuna 

longline setting techniques by eliminating all shallow set hooks (less than 100 m depth) from 

tuna longline sets (Beverley et al. 2009). The objective was to maximize target catch of deeper 

dwelling species such as bigeye tuna, and reduce incidental catch of many marketable but less 

desired species (e.g., billfish and sharks). The deep setting technique was easily integrated into 

daily fishing activities with only minor adjustments in methodology. The main drawback for the 

crew was increased time to deploy and retrieve the gear. Catch totals of bigeye tuna and sickle 

pomfret were greater on the deep set gear than on the controlled sets; but the bigeye results were 

not statistically significant. Catch of several less valuable incidental fish (e.g., blue marlin, 

striped marlin, shortbill spearfish, dolphinfish, and wahoo) was significantly lower on the deep 

set gear than the controlled sets. Unfortunately, no significant results were found for sharks. 

Results from several of the bycatch studies suggest combining methods to avoid bycatch. 

Perhaps a combination of electropositive metals fashioned into weights attached to longline gear 

and setting the gear deeper might avoid bycatch of sharks and marlins. Research is also being 

initiated to develop safer weights, such as weights that do not spring back toward fishermen 

when branch lines holding large fish break during retrieval. 

Improved Release Technology 

The recently resumed Hawaii-based swordfish longline fishery, as well as the tuna longline 

fishery, is required to carry and use dehookers for removing hooks from sea turtles. These 

dehookers can also be used to remove external hooks and ingested hooks from the mouth and 

upper digestive tract of fish, and could improve post-release survival and condition of released 

sharks. Sharks are generally released from the gear by one of the following methods: (1) 

severing the branch line,(2) hauling the shark to the vessel to slice the hook free, or (3) dragging 

the shark from the stern until the hook pulls free. Fishermen are encouraged to use dehooking 

devices to minimize trauma and stress of bycatch by reducing handling time and to mitigate posthooking mortality. 

Testing of the dehookers on sharks during research cruises has indicated that removal of circle 

hooks from shark jaws with the dehookers can be quite difficult. PIFSC is looking into the 

feasibility of barbless circle hooks for use on longlines, which would make it easier to dehook 

unwanted catch with less harm. Preliminary research in the Hawaii shore fishery has indicated 

that barbless circle hooks catch as much as barbed hooks, but the situation could be different 

with more passive gear such as longlines, where bait must soak unattended for much of the day 

and fish have an extended period in which to try to throw the hook. Initial results from very 

86
 
 

 

 

 

 

 

 

 

 

 

 

 

limited longline testing of barbless hooks on research cruises in American Samoa, and in 

collaboration with NMFS Narragansett Laboratory, indicated a substantial increase in bait loss 

using barbless hooks. Subsequent testing used rubber retainers to prevent bait loss. Summary 

information from before and after the use of bait retainers showed no difference between barbed 

and barbless hooks in the catch and catch rates of targeted species and sharks, although catches 

have so far been too few to provide much statistical power. Also in this study, the efficacy of the 

pigtail dehooker (the device required by U.S. regulations for releasing sea turtles) showed a 67 

percent success rate in dehooking and releasing live sharks on barbless hooks, compared to a 0 

percent success rate when used with sharks caught on barbed hooks. In 2007, PIFSC and Pacific 

Islands Regional Office (PIRO) personnel conducted longline trials along the eastern shore of 

Virginia to compare catches of sharks and rays on barbed and barbless circle hooks. In a 

randomization test, difference in the catches between the hook types was not significant. Circle 

hook removal trials were also conducted simultaneously and resulting effectiveness of removing 

hooks from sharks were 27 percent with barbed hooks and 72 percent with barbless hooks. 

During the study a new dehooker was developed and tested. Preliminary results were more than 

90 percent effective in removing both barbed and barbless circle hooks from sharks; however, 

the prototype appears to be more efficient on smaller animals. 

Post-release Survival and Biochemical Profiling 

Successful management strategies in both sport and commercial fisheries require information 

about long-term survival of released fish. Catch-and-release sport fishing and non-retention of 

commercially caught fish are justifiable management options only if there is a reasonable 

likelihood that released fish will survive for long periods. All recreational anglers and 

commercial fisherman who practice catch-and-release fishing hope the released fish will survive, 

but it is often not known what proportion of released fish will survive. Many factors—such as 

fish size, water temperature, fight time, and fishing gear—could influence survival. 

Post-release survival is typically estimated using tagging programs. Historically, large-scale 

conventional tagging programs were used. These programs yielded low return rates, consistent 

with a high post-release mortality. For example, in a 30-year study of Atlantic blue sharks, only 

5 percent of tags were recovered. Short-duration studies using ultrasonic telemetry have shown 

that large pelagic fish usually survive for at least 24 to 48 hours following release from sport 

fishing or longline gear. PIFSC researchers and collaborators from other agencies, academia, 

and industry have been developing alternative tools to study longer-term post-release mortality. 

Whereas tagging studies assess how many fish survive, new approaches are being used to 

understand why fish die. A set of diagnostic tools is being developed to assess the biochemical 

and physiological status of fish captured on various gear. These diagnostics are being examined 

in relation to survival data obtained from a comprehensive PSAT program. Once established as 

an indicator of survival probability, such biochemical and physiological profiling could provide 

an alternative means of assessing consequences of fishery release practices. 

PIFSC scientists have been developing biochemical and physiological profiling techniques for 

use in estimating post-release survival of blue sharks, which are frequently caught as bycatch by 

Pacific longliners. Using NOAA research vessels, they captured 211 sharks, of which 172 were 

blue sharks. Using blue sharks, PIFSC scientists and collaborators developed a model to predict 

long-term survival of released animals (verified by PSAT data) based on analysis of small blood 

87
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

samples. Five parameters distinguished survivors from moribund sharks: plasma Mg2+, plasma 

lactate, erythrocyte Hsp70 mRNA, plasma Ca2+, and plasma K+. A logistic regression model 

incorporating a combination of Mg2+ and lactate successfully categorized 19 of 20 (95 percent) 

fish of known fate and predicted that 21 of 22 (96 percent) sharks of unknown fate would have 

survived upon release. These data suggest that a shark captured without obvious physical 

damage or physiological stress (the condition of 95 percent of the sharks they captured) would 

have a high probability of surviving upon release (Moyes et al. 2006). 

In the second approach PIFSC and colleagues deployed 71 PSATs on the five most commonly 

caught species of pelagic shark in the Hawaii-based commercial longline fishery (blue shark 

(Prionace glauca), shortfin mako (Isurus oxyrinchus), silky shark (Carcharhinus falciformes), 

oceanic whitetip (C. longimanus), and bigeye thresher(Alopias superciliosus)) to determine 

species-specific horizontal and vertical movement patterns and survival after release from 

longline fishing gear. All five species have life-history characteristics that make populations 

vulnerable to exploitation, and there is little or no information about their movement patterns and 

habitats. Results indicated that only a single post-release mortality could be unequivocally 

documented: male blue shark that succumbed seven days post-release. The depth and 

temperature data suggest that this one mortality was due to injuries sustained during capture and 

handling, rather than predation. Meta-analysis on blue shark mortality from published and 

ongoing research (n=78 reporting PSATs) indicated the summary effect for post-release 

mortality from longline gear was 15 percent (95% CI, 9 – 25%). 

Antecedent stress variables to explain mortality have been examined (i.e., capture temperature, 

soak time, etc.) but NMFS could not conclusively demonstrate association with any of the 

variables and mortality in these two instances. These combined biochemical and PSAT analyses 

suggest that sharks landed in an apparently healthy condition are likely to survive long term if 

released (95 percent survival based on biochemical analyses (blue shark); >95% based on PSATs 

[all sharks studied)). In summary, studies demonstrate a high rate of post-release survival of 

pelagic sharks captured and released from longline gear fished with circle hooks. These tagging 

results are also used to chronicle these pelagic species in terms of migration routes, distribution 

patterns, and habitat association as well as developing bycatch mitigation methods (Musyl et al. 

2009, Beverley et al. 2009, Hoolihan et al. 2011). 

Pop-up Satellite Archival Tags (PSAT) Studies on Horizontal and Vertical Movement Patterns 

Management strategies for mitigating bycatch in large-scale commercial fisheries require 

estimates of post-release survival as well as information about habitats and movement patterns in 

captured teleosts, elasmobranchs, and sea turtles. Large pelagic sharks (particularly blue shark 

(Prionace glauca)) are the majority of the bycatch in pelagic gill nets and longline fisheries 

targeting swordfish (Xiphias gladius). Pop-up satellite archival tags (PSATs) deployed on 

pelagic sharks caught in commercial longline fisheries can be used to determine species-specific 

horizontal and vertical movement patterns and survival after release from longline fishing gear. 

Analysis of PSATs deployed on pelagic sharks released in the Hawaii-based longline fishery in 

the central Pacific Ocean revealed sharks displayed species-specific depth and temperature 

ranges, although with significant individual temporal and spatial variability in vertical movement 

patterns. Distinct thermal niche partitioning based on daytime temperature preferences was 

evident: (1) epipelagic species (silky and oceanic whitetip sharks), which spent more than 95 

88
 
 

 

 

 

 

 

 

 

 

 

percent of their time at temperatures within 2°C of sea surface temperature; (2) mesopelagic-I 

species (blue sharks and shortfin makos), which spent 95 percent of their time at temperatures 

from 9.7° to 26.9°C and from 9.4° to 25.0°C, respectively; and (3) mesopelagic-II species 

(bigeye threshers), which spent 95 percent of their time at temperatures from 6.7° to 21.2°C 

(Musyl et al. 2011a). This knowledge could allow targeting of longline gear to create 

mismatches between hook depth and the sharks’ habitat (i.e., minimize vulnerability of the 

species to be avoided) (Beverly et al. 2009). 

Pop-up Satellite Archival Tags (PSAT) Performance and Metadata Analysis Project 

Satellite tagging studies have been used to investigate post-release mortality of animals, either as 

indicated by signal failure, early pop-up, or depth data indicating rapid descent to abnormal 

depth before pop-up. However, these signals, or the lack thereof, may have other origins besides 

mortality. The purpose of this study is to explore failure (or success) scenarios in PSATs 

attached to pelagic fish, sharks, and turtles. We quantify these issues by analyzing reporting 

rates, retention times, and data return from 27 pelagic species from 2,164 deployments (731 

PSAT deployments from 19 species in the authors’ database, and in 1,433 PSAT deployments 

from 24 species summarized from 53 published articles). Shark species in the database include 

bigeye thresher, blue, shortfin mako, silky, oceanic whitetip, great white, and basking sharks. 

Other species include: black, blue, and striped marlins; broadbill swordfish; bigeye, yellowfin, 

and bluefin tunas; tarpon; and green, loggerhead, and olive ridley turtles. To date, of 731 PSATs 

attached to sharks, billfish, tunas, and turtles, 577 (79 percent) reported data. Of the tags that 

recorded data, 106 (18 percent) hit their programmed pop-off date and 471 tags popped off 

earlier than their program date. The 154 (21 percent) non-reporting tags are not assumed to 

reflect fish mortality. The metadata study is designed to look for explanatory variables related to 

tag performance by analyzing PSAT retention rates, percentage of satellite data (i.e., depth, 

temperature, geolocations) retrieved, and tag failure. By examining these factors and other 

information about PSATs attached to vastly different pelagic species, it is anticipated certain 

patterns/commonalties may emerge to help improve attachment methodologies, selection of 

target species, and experimental designs, particularly with respect to post-release survival 

studies. PSATs in the database had an overall reporting rate of 0.79, which was not significantly 

different (p=0.13) from the PSAT reporting rate of 0.76 in the meta-analysis. Logistic regression 

models showed that reporting rates have improved significantly over recent years and are lower 

in species undertaking large vertical excursions, with a significant interaction between species’ 

depth class (i.e., littoral, epi-pelagic, meso-pelagic, bathy-pelagic) and tag manufacturer. 

Of all the PSATs attached to sharks, 80 percent reported and 65 percent detached before the 

programmed pop-up date. Shark PSAT reporting rates were highest in species such as oceanic 

whitetip (81 percent), which were epipelagic and remained near the ocean surface. Reporting 

rates were lowest in species undertaking large (~1,000 m) vertical excursions, such as bigeye 

thresher (37 percent) and shortfin mako (40 percent). Tag retention for the three shark species 

averaged 155 days for oceanic whitetip, 220 days for bigeye thresher, and 164 days for shortfin 

mako. Species-specific reporting rates were used to make recommendations for future PSAT 

sampling designs for fisheries researchers. Information derived from this study should allow an 

unprecedented and critical appraisal of the overall efficacy of the technology (Musyl et al., 

2011b). 

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Pop-up Satellite Archival Tags (PSAT) and Post-release Survival 

Successful management strategies in both sport and commercial fisheries require information 

about long-term survival of released fish. Satellite tagging studies have been used to investigate 

post-release mortality of animals, either as indicated by signal failure, early pop-up, or depth data 

indicating rapid descent to abnormal depth before pop-up. Shark PSAT reporting rates were 

highest in species such as oceanic whitetip (81 percent) that were epipelagic and remained near 

the ocean surface. Reporting rates were lowest in species undertaking large (~1,000 m) vertical 

excursions, such as bigeye thresher (37 percent) and shortfin mako (40 percent). Meta-analysis 

on blue shark mortality from published reports and the current study (n=78 reporting PSATs) 

indicated the summary effect of post-release mortality from longline gear was 15 percent (95% 

CI, 9 – 25%), and suggested that catch-and-release in longline fisheries can be a viable 

management tool to protect parental biomass in shark populations (Musyl et al., 2011a). PIFSC 

studies also demonstrated a high rate of post-release survival of pelagic sharks captured and 

released from longline gear fished with circle hooks. 

Southwest Fisheries Science Center (SWFSC) 

The SWFSC’s shark research program focuses on pelagic sharks that occur along the U.S. 

Pacific coast, including blue sharks, basking sharks (Cetorhinus maximus), shortfin mako, and 

three species of thresher sharks: common, bigeye, and pelagic threshers. Center scientists are 

studying the sharks’ biology, distribution, movements, stock structure, population status, and 

potential vulnerability to fishing pressure. This information is provided to international, 

national, and regional fisheries conservation and management bodies having stewardship for 

sharks. Some of the recently completed and ongoing shark research activities being carried out 

at the SWFSC are discussed below. 

Abundance Surveys 

Blue, shortfin mako, and thresher sharks are all taken in regional commercial and recreational 

fisheries. Common thresher and mako sharks have the greatest commercial value and are also 

specifically targeted by sport fishers, especially off Southern California. Although the blue shark 

is targeted in Mexico, it has little market importance in the U.S. but is a leading bycatch species 

in the California drift gillnet fishery and high-seas longline fisheries. Although catches of adult 

blue, thresher, and shortfin mako sharks do occur, the commercial and sport catch of these 

species off Southern California consists largely of juvenile sharks. 

To track trends in the abundance of juvenile and sub adult blue and shortfin mako sharks, as well 

as neonate (0-year pups) common thresher sharks, surveys are carried out in the SCB each 

summer. Efforts to determine abundance trends from commercial fishery data have been 

complicated by changes in regulations, target areas, and fishing methods over time. These 

changes have resulted in inconsistent capture rates and catch distributions that are difficult to 

interpret. Therefore, fishery-independent sampling was initiated, with slightly different survey 

strategies required depending upon the species. 

Offshore longline surveys from relatively large research vessels have proved most effective for 

sampling and estimating abundance trends of the more oceanic shortfin mako and blue sharks. 

For mako sharks, the surveys have enabled the SWFSC to obtain a valuable abundance index, 

which can be linked to a historical time series of logbook and landings data from a former 

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experimental shortfin mako longline fishery in the SCB that occurred during 1988-1991. 

Abundance trend information was also obtained for the blue shark, which is compared to that 

obtained by observers of the CDGN and U.S. and Japanese high-seas longline fisheries. 

Surveys for neonate thresher sharks are conducted using a small commercial longline vessel. 

Initial studies demonstrated that neonate threshers are rarely encountered in waters deeper than 

about 90 m. Therefore, surveys are conducted in the shallower nearshore waters between Point 

Conception, California, and the U.S.-Mexico border. The primary purpose of the surveys is to 

produce a relative abundance index for the West Coast population by periodically sampling 

neonates in their nursery grounds off Southern California. Representative areas were initially 

identified and are now sampled annually. The resulting neonate index of abundance should 

mirror adult abundance due to the tight relationship between the adult population and recruitment 

in K-selected species such as sharks. This study complements the fishery-dependent data 

available through the nearshore small mesh net fisheries and offshore CDGN fishery to provide 

measures of relative abundance of common thresher sharks for stock assessment models. 

Juvenile Mako and Blue Shark Survey 

In 2012, the SWFSC conducted its nineteenth juvenile shark survey for mako and blue sharks 

since 1994. The annual abundance survey was completed between 20 June and 19 July 2012. 

Working aboard F/V Ventura II, a team of scientists and volunteers fished a total of 5,592 hooks 

during 28 daytime sets within seven focal areas of the SCB. The survey catch totaled 151 

shortfin makos, 26 blue sharks, 16 pelagic rays (Pteroplatytrygon violacea), and 4 opah (Lampris 

guttatus). The preliminary data indicate that the nominal survey catch rate was 0.53 per 100 

hook-hours for shortfin mako and 0.15 per 100 hook-hours for blue sharks. The mako shark 

nominal CPUE was slightly higher than the previous year. However, there is a declining trend in 

nominal CPUE for both species over the time series of the survey. 

Additional research projects were also conducted during the shark survey research cruise. Six 

deep sets were completed targeting opah and swordfish (Xiphias gladius) during daytime hours. 

A longline shooter was used to deploy the gear between 200 and 300 meter depths over a 

horizontal distance ranging from five to ten miles. On average 170 branchlines, each 38 feet in 

length, were deployed during these sets. Four surface sets were also conducted targeting opah. 

Additionally, a total of 18 sets were conducted as part of an experiment to examine differences in 

catch rate, catch composition, and survivability between circle-type hooks and J-type hooks. 

Preliminary results indicated no differences. 

In total, 56 longline sets, including survey sets, were completed. A total of 423 animals were 

caught; ancillary sampling resulted in 262 captures. Most animals were brought onboard, 

measured, tagged, and sampled for DNA biopsies before they were released. Spaghetti tags were 

released on 338 sharks to allow for movement and stock structure data. A total of 387 DNA 

samples were collected, including samples from 254 shortfin mako, 92 blue shark, 29 opah, 9 

pelagic rays and 3 common threshers. Thirty-nine opah were caught during the cruise, 

continuing an upward trend. Fourteen opah were caught in 2011, sixteen in 2010, and eight in 

2009. Prior to 2009, only one other opah had been recorded during a longline survey cruise, in 

June of 2000. 

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Neonate Common Thresher Shark Survey 

In 2012, the SWFSC team conducted the survey aboard the F/V Outer Banks. Fifty longline sets 

were made in relatively shallow, nearshore waters and a total of 5,000 hooks were fished during 

the 18-day cruise. A total of 367 fish across a range of species were sampled during the survey. 

Two hundred and eighty-two (282) common thresher sharks were captured. Most of these sharks 

were tagged with a combination of conventional tags, for movement and stock structure data, and 

oxytetracycline paired with plastic dorsal tags with information for fishers upon recapture of the 

animal to retain a portion of the vertebrae for ongoing age and growth studies. In addition, a 

pop-off archival GPS tag was released on a 151 cm female common thresher. Biological 

collections included DNA samples from most sharks captured and stomachs, digestive tracts, and 

blood from a small number of sharks that did not survive. 

The preliminary survey data indicate that the average nominal catch rate by set was 2.49 per 100 

hook-hours for common thresher sharks. This is a drop in CPUE from 2011 when the nominal 

catch rate was 5.57. The overall average trend since the start of the survey is increasing. 

However, the distribution of common threshers is very patchy and areas of high abundance are 

not consistent across years. Across all years, a large percentage of the catch has been neonates, 

which were found in all areas surveyed. In addition to providing important information on 

abundance and distributions, the thresher shark pre-recruit survey enhances other ongoing 

research at SWFSC, including age and growth, feeding, and habitat utilization studies. 

Electronic Tagging Studies 

Since 1999, SWFSC scientists have been using satellite technology to study the movements and 

behaviors of large pelagic fish, primarily blue, shortfin mako, and common thresher sharks, 

while other species are tagged opportunistically. In recent years, shark tag deployments have 

been carried out in collaboration with Mexican colleagues at CICESE (Centro de Investigación 

Científica y de Educación Superior de Ensenada), Canadian colleagues at the DFO Pacific 

Biological Station in Nanaimo, British Columbia, and the TOPP program (www.topp.org). The 

goals of the projects are to document and compare the movements and behaviors of these species 

in the California Current and to link these data to physical and biological oceanography. This 

approach will allow us to characterize the essential habitats of sharks and subsequently to better 

understand how populations might shift in response to changes in environmental conditions on 

short or long time scales. 

In 2012, a number of large pelagic fish were deployed with electronic tags in support of several 

collaborative projects. Five (5) shortfin mako sharks, 5 blue sharks, and 1 common thresher 

were tagged with either SPOT tags or towed GPS tags. Three (3) mako sharks, 2 blue sharks, 

and 6 opah were released with pop-off archival tags. In addition, 5 mako sharks were released 

with acoustic tags. 

SPOT tags continue to provide excellent information on the movements of blue and mako 

sharks. We have been collecting data for a decade for both species and we continue to look at 

horizontal movement patterns on many different time scales. More recently, we have focused 

our tagging attention on larger animals, for which we do not have as much information. 

Historical data shows that the larger animals retain the tag longer and provide us with longer 

tracks. The average size of blue sharks (n=5) tagged with a SPOT in 2012 was 229 cm. Two of 

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the five blue sharks were tracked for close to 200 days (Figure 5). Combined data from many 

years suggest that both sexes spend considerable time in the California Current, with the females 

possibly extending farther north and south. When offshore, generally, the females move south 

into the subtropical convergence zone, whereas the males make more westerly migrations. 

These patterns do vary though, and the two male blue sharks illustrated in Figure A1.4 

demonstrated behavior more common to what we have observed for females. The track of the 

larger shark looks as though he may have been heading back to the California Current, which has 

been documented for many of the longer blue shark tracks. Both habitat separation by sex, and 

site fidelity have implications for the management of blue shark populations. For example, 

fidelity to specific areas is increasingly recognized in fish from swordfish to salmon sharks 

(Lamma ditropis) and raises the potential for local depletion where fisheries exist. 

Figure A1.4. Tracks from two blue sharks spanning seven months and showing similar 

movement patterns into subtropical waters (left 221 cm FL male, right 241 cm FL male). 

For mako sharks, 3 tags were still transmitting in early 2013 (Figure A1.5). All three sharks 

were deployed with SPOT tags in July, 2012. Tracking success has been very good for mako 

sharks, as they generally provide longer duration tracks than blue sharks, allowing an incredible 

opportunity to examine seasonal movement patterns and regional fidelity. The male shark, the 

smallest shark of the three, traveled the greatest distance latitudinally ranging from 14 to 38 

degrees. The females both spent some time migrating south-westward, terminating near 120 

degrees west longitude before returning to the coast on a similar path. All of these sharks spent 

some time near or in San Sebastian Vizcaino Bay off Baja California Mexico which is an area of 

high use for makos, based on the combined data from several years. Additional analyses are 

needed to determine (1) how patterns link to sex and size, (2) what triggers the onset of 

migration, and (3) what characterizes the ultimate destinations. As with blue sharks, this type of 

regional site fidelity has important implications for management. 

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Figure A1.5. Tracks from three shortfin mako sharks showing nearly nine months of data 

for each and some similarities in movement patterns (left 167 cm FL male, center 173 cm 

FL female, right 241 cm FL female). 

Age Validation Studies 

Age and growth of mako, common thresher, and blue sharks are being estimated from band 

formation in vertebrae. In addition to being important for studying basic biology, accurate age 

and growth curves are needed in stock assessments. SWFSC scientists are validating aging 

methods for these three species based on band deposition periodicity determined using 

oxytetracycline (OTC). Our annual research surveys provide an opportunity to tag animals with 

OTC. When the shark is recaptured and the vertebrae recovered, the number of bands laid down 

since the known date of OTC injection can be used to determine band deposition periodicity. 

Since the beginning of the program in 1997, 3,183 OTC-marked individuals have been released 

during juvenile shark surveys. Sharks tagged include 1,221 shortfin mako, 1,187 common 

thresher, 757 blue, 15 silky (Carcharhinus falciformis), and 3 pelagic thresher sharks. 

Oxytetracycline Age Validation of Juvenile Shortfin Makos 

The results of OTC age validation of 29 juvenile shortfin mako sharks tagged with 

oxytetracycline in the SCB were recently published (Wells et al. 2013) and showed vertebral 

band pair deposition rates of two per year. The results of this study differ from two other studies 

on shortfin makos that used a direct age validation technique: one study validated a single band 

pair deposition rate in an estimated 18 year old shortfin mako shark tagged with OTC and 

recaptured in the Atlantic after one year at liberty; and the second used a bomb radiocarbon 

signal as a marker in 37 sharks collected in the Northwest Atlantic between 1950 and 1984 

ranging in estimated ages of 1 to 31 years. Age and growth in shortfin mako sharks continues to 

be uncertain because growth curves estimated from length frequency analysis and tag-recapture 

methods tend to show faster growth rates than obtained from vertebral counts based on 

deposition of a single band pair per year. Furthermore, this validation study applies to juvenile 

sharks in the northeast Pacific. This study raises questions about potential regional differences in 

band pair deposition rates or the possibility of an ontogenetic shift from a period of more rapid 

growth with 2 band pair deposition per year to slower growth and a switch to a band pair 

deposition rate of one per year. In winter 2013/2014, the ISC plans to convene its second Shark 

Age and Growth Workshop during which participants hope to resolve some of the uncertainties 

regarding shortfin mako age and growth. 

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Oxytetracycline Age Validation of Juvenile Blue Sharks 

The purpose of this study is to validate vertebral band counts of blue sharks tagged and 

recaptured in the northeast Pacific Ocean. OTC labeled vertebrae of 13 blue sharks have been 

obtained from tag-recapture activities and processed to determine timing of centrum growth band 

deposition. Several methodologies were used to examine blue shark vertebrae and digital images 

of the whole vertebrae centrum were determined to be the best. OTC tagging of the recaptured 

sharks occurred off southern California from 2007 to 2009, with time at liberty ranging from 22 

to 473 days. For vertebrae samples used in this study, shark size at release ranged from 90 to 

276 cm total length (TL). OTC marked vertebrae from at least 20 more sharks have been 

returned and will be processed to build upon this study. Results thus far from band counts of 

vertebrae distal to OTC marks indicate that a single band pair (1 translucent and 1 opaque) is 

formed per year for blue sharks of the size range examined. These preliminary results 

corroborate annual deposition rates found in the only other OTC validation study for blue sharks 

and should aid in future blue shark age and growth studies in the Pacific Ocean. 

Foraging Ecology of Pelagic Sharks 

The California Current is a productive eastern boundary current that is an important nursery and 

foraging ground for a number of highly migratory predator species. To better understand niche 

separation and the ecological role of these spatially overlapping species, stomach content 

analyses have been ongoing at the SWFSC since 1999. Stomachs are obtained primarily from 

the CADGN observer program. 

Stomach content analysis work has continued since the publication of Preti et al. 2012. 

From March 2012-March 2013 a total of 91 stomachs of several species of pelagic sharks have 

been analyzed from fishing seasons 2011 and 2012. Current levels of analysis have allowed us 

to identify some of the most frequently encountered prey species (F=Frequency of prey 

occurrence). Shortfin mako stomachs (n=30) contained market squid (Loligo opalescens) (F=8), 

Pacific saury (Cololabis saira) (F=8) and Pacific sardine (Sardinops sagax) (F=7). Blue shark 

stomachs (n=7) contained Octopus squid (Octopoteuthis sp.) (F=4), market squid (F=4), and 

Gonatus sp. squid (F=4). Common thresher shark stomachs (n=44) contained market squid 

(F=21), Pacific mackerel (Scomber japonicus) (F=11), and Pacific sardine (F=11). Salmon shark 

stomachs (n=6) contained Pacific mackerel, duckbill barracudina (Magnisudis atlantica), striped 

mullet (Mugil cephalus), unidentified rockfish, and market squid. Bigeye thresher stomachs 

(n=4) contained Pacific mackerel, market squid and tunicates. 

These very preliminary results already indicate a possible shift in feeding trends. In past 

seasons, jumbo squid (Dosidicus gigas) were frequently found in the stomachs of examined 

predators, especially shortfin mako and blue shark (Preti et al. 2012), whereas current data 

indicate a decrease in the importance of jumbo squid to the diets of these species. 

Data on shark foraging ecology were also used to develop a new approach for characterizing 

habitat use and improving our understanding of ecological interactions. We introduced a 

resampling method to indirectly estimate foraging habitat based on diet data and knowledge of 

prey habitat use. The method is unique in that (1) it is based on resampling by bootstrapping, 

and (2) it does not require quantitative prey distribution information. For this study, we 

combined diet data with qualitative prey distribution information for six different habitats 

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segregated by depth and distance from shore. The combined data were organized into various 

matrices and resampled by bootstrapping to create an estimate of predator distribution based on 

prey habitat occupancy. Our method indicates a significant difference in foraging habitat 

between predator species. Generally, blue sharks foraged more frequently in offshore habitats, 

threshers foraged mostly in nearshore epipelagic habitats, and shortfin makos foraged both nearand offshore in epi- and mesopelagic habitats. The flexibility of the new method should allow 

for wide application, adding to the suite of possible indirect techniques available to infer 

foraging habitat use. The results of this research are now under internal review. 

Algal Toxins in the Forage of Pelagic Sharks 

In 2011, a study of algal toxins (domoic acid) in sharks was started utilizing stomach contents as 

the basis for the study. Samples from several species have been examined. A blue shark 

contained 4172 ng/g of domoic acid in its stomach juices and its prey, a paper nautilus 

(Argonauta sp.), contained over 2000 ng/g. Three thresher shark stomachs with juices and prey 

also had high levels of the toxin, the highest being 1708 ng/g found in one thresher stomach with 

its prey of squid having a level exceeding 2000 ng/g. 

These results confirm that the toxin is present in the food chain and can be transferred from the 

bottom up. Further studies are needed to document domoic acid in muscle and the potential 

implications of measured concentrations for shark and human health. 

Basking Shark Research Program 

The eastern North Pacific basking shark population appears to have declined dramatically in the 

last 50 years with no evidence of recovery. Where hundreds to thousands of individuals were 

observed off the U.S. West Coast in the early to mid-1900s, sighting even a few individuals is 

now rare. Due to concern about basking shark populations along the west coast of North 

America, the basking shark was listed as endangered in Canada and as a Species of Concern in 

the U.S. in 2010. Given severe data gaps for this population, the SWFSC initiated a basking 

shark research program in 2010 to (1) mine existing data for additional biological information, 

(2) conduct an electronic tagging study, (3) improve international data collection, and (4) 

improve national sightings information by developing a sightings website and an education and 

outreach program centered around Monterey Bay, California. 

This research program has progressed at a number of different levels. A dedicated website 

(http://swfsc.noaa.gov/baskingshark/), email (basking.shark@noaa.gov), and hotline (858-334­

2884) have been established as a part of a sightings network. SWFSC also developed a trinational team with colleagues in Canada and Mexico to coordinate research efforts. 

During the past year the SWFSC continued to monitor for basking sharks in order to collect and 

analyze data on patterns of occurrence and potentially deploy more satellite tags. SWFSC did 

hear from a few constituents about basking shark sightings in the SCB during the spring and 

early summer of 2012, although reports were sparse and sporadic. A couple of failed attempts 

were made to find sharks for tagging based on some of the reports. Significant progress has been 

made on the quantitative modeling of historical basking shark records with environmental 

variables. 

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Data from the three sharks tagged with satellite tags in 2010 and 2011 have been analyzed and 

are being prepared for publication. The sharks showed impressive plasticity in vertical behaviors 

depending upon the region and distance from shore, as has been shown in the Atlantic. Dramatic 

shifts in behavior make estimating abundance based on aerial surveys and predicting overlap 

with fisheries challenging. Additional information on the patterns in vertical and horizontal 

movements is needed. 

Genetic Analysis of Pelagic Sharks 

An understanding of stock structure is important in order to make accurate assumptions 

concerning stock assessments and to develop effective management objectives that take the 

species range, distribution and life history into account. Various genetic analyses are useful to 

help identify differentiation between and within presumed stocks. 

Shortfin Mako Shark 

As part of his Ph.D. work at University of California Davis and San Diego State University in 

collaboration with the SWFSC, Dovi Kacev has developed a suite of 11 nuclear microsatellite 

markers and optimized an additional five to further refine the spatial and temporal resolution of 

shortfin mako stocks within the Pacific. In addition to studies of stock structure, these markers 

are being used to develop estimates of effective population size within the California Current 

region. Data analyses are ongoing and a manuscript is being drafted. These markers have also 

been shared with international collaborators and are currently being applied to global studies of 

shortfin makos. 

Common Thresher Shark 

Common threshers are regularly encountered in temperate coastal marine fisheries but little is 

known about regional connectivity. In recent years threshers have become part of an 

increasingly important recreational fishery in Southern California in addition to being a major 

component of local gillnet fisheries. In order to better understand population connectivity, Dovi 

Kacev has developed eight nuclear microsatellite markers for this species and successfully cross 

amplified three of the shortfin mako loci. These markers are being applied and data collection is 

ongoing. 

Silky Shark 

Silky sharks are the most abundant shark encountered by tropical tuna fisheries world-wide. In 

an effort to better inform the first stock assessment for this species in the EPO approximately 450 

samples were added to an earlier study to examine stock structure in the Pacific. These samples 

filled in areas of previous low sample size (i.e. Western Pacific) and areas for which there is 

specific EPO management concern (i.e. South Eastern Equatorial Pacific). The current dataset 

includes nuclear (9 microsatellite loci) and mitochondrial data (control region sequence) for 

approximately 730 animals, predominantly from the Pacific. These new data continue to support 

stock structure generally north and south of the equator with animals south of the Galapagos 

Islands in the Eastern Pacific more closely allied with the northern stock. This spillover of the 

northern stock south of the equator is likely seasonal and is concordant with regional 

oceanography and size composition data. 

Pelagic Thresher Shark 

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Pelagic thresher sharks are landed in high numbers by artisanal fisheries throughout the tropical 

Pacific and Indian Oceans. Due to past misidentification with other thresher species there is little 

known regarding the biology and life history of this species. Recent genetic work at the SWFSC, 

using both nuclear (5 microsatellite loci) and mitochondrial DNA data (cytochrome oxidase 

sequence), has revealed the presence of very strong stock structure between eastern and western 

Pacific populations. Interestingly, the central Pacific seems to be an area of overlap for these 

two populations. Additional samples and genetic data are being added this year in collaboration 

with colleagues in Columbia to better characterize the stock structure for this species. 

Shark Stock Assessments 

The SWSFC provides scientific advice on stock status of pelagic sharks to international and 

domestic regional fishery management organizations. Collaborative stock assessment work has 

begun on pelagic sharks through the Shark Working Group (SHARKWG) of the ISC, chaired by 

SWFSC scientist Dr. Suzanne Kohin, and through other multinational efforts. Starting in 2010, 

we began working with member nations of the ISC, as well as scientific partners in Mexico, of 

the IATTC, and the Secretariat of the Pacific Community (SPC) to begin the first formal 

assessments of common thresher, blue and shortfin mako sharks in the eastern Pacific and north 

Pacific basins. These sharks are both fishing targets and incidental bycatch in numerous 

fisheries throughout their range and their status requires long-term monitoring. 

In order to promote data collection in Mexico, the SWFSC and WCR began a multiyear effort 

with collaborators at CICESE, led by Dr. Oscar Sosa-Nishizaki, to coordinate artisanal fish camp 

monitoring and sampling in Baja California, Mexico and help advance cooperative stock 

assessment efforts with Mexico, U.S. and IATTC scientists. CICESE scientists are conducting 

data collection for blue, shortfin mako and thresher sharks at fish camps throughout Baja 

California. The 2012 sampling effort was completed in early 2013. The 2012 sampling was 

extensive and now supplements a time series begun as part of an earlier collaboration with 

investigators at Scripps Institution of Oceanography and CICESE. As a result of the new 

sampling program, fishery data for pelagic sharks now includes some size and sex sampling as 

well as several years of species specific catch information. The data collected thus far have 

already been used to develop historic and recent time series catch information for common 

thresher, blue and shortfin mako sharks. 

In 2012, shark assessment effort was focused on conducting the first ISC SHARKWG stock 

assessment of north Pacific blue shark. The assessment is on track to be completed in time for 

review by the ISC Plenary in July. The assessment is being conducted with a Bayesian Surplus 

Production model using compiled estimated catch data for most north Pacific nations including 

Canada, China, Chinese Taipei, Japan, Korea, Mexico, and USA, as well as some estimated 

catch contributed by IATTC for purse seine vessels operating in the IATTC Convention area, 

and non-ISC member longline catch in the WCPFC Convention area, contributed by SPC. 

Preliminary modeling with an age-structured model will also be conducted. For Mexico catch, 

the species composition data collected through the sampling program described above 

contributed to an analysis of estimated blue shark catch for use in the assessment (Sosa-Nishizaki 

2013). 

Northwest Fisheries Science Center (NWFSC) 

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Monitoring and Assessment Activities 

The NWFSC conducts and supports several activities addressing the monitoring and assessment 

of sharks along the West Coast of the United States and in Puget Sound. The PacFIN serves as a 

clearinghouse for commercial landings data, including sharks. In addition, the At-Sea Hake and 

West Coast Groundfish Observer Programs collect data on shark species caught on vessels 

selected for observer coverage. 

The NWFSC conducts annual trawl surveys of the West Coast, designed primarily to acquire 

abundance data for West Coast groundfish stocks. The tonnages of all shark species collected 

during these surveys are documented. In addition, the survey program has conducted numerous 

special projects in recent years to help researchers acquire data and samples necessary for 

research on various shark species. Since 2002, the survey has collected biological data and 

tissue samples from spiny dogfish, including dorsal spines, which can be used to age the fish. 

Biological data and tissue samples were also collected from leopard sharks and cat sharks during 

the bottom trawl surveys. 

In addition to these monitoring activities, the NWFSC conducted the first assessment for 

longnose skate in 2007. This assessment was reviewed during the 2007 stock assessment review 

(STAR) process, and was adopted by the PFMC for use in management. The NWFSC 

conducted an assessment of spiny dogfish along the Pacific coast of the United States in 2011 

(see section 2.3). 

Research on Bluntnose Sixgill Sharks (Hexanchus griseus) in Puget Sound 

The NWFSC, in collaboration with Washington Department of Fish and Wildlife (WDFW) and 

the Seattle Aquarium, has completed several studies estimating movement parameters of 34 

bluntnose sixgill sharks in Puget Sound from 2005 to 2009. Sharks were weighed, measured, 

sexed, surgically tagged with Vemco© ultrasonic tags, and released at their capture site. Tags 

transmitted a signal every few minutes containing a unique identification code and a depth 

estimate; these signals were detected when they were within the range of Vemco© receivers that 

were either deployed at fixed listening stations (passive tracking) or towed by a small boat 

(active tracking). 

Acoustic telemetry data allowed estimation of movement parameters (e.g., depth changes, move 

length, and turning angles) that allowed estimation of home range sizes (Andrews et al. 2007); 

daily, seasonal, and interannual movement patterns (Andrews et al. 2009, 2010, Levin et al. 

2012); and use of different habitat types (Andrews et al. 2009, 2010). The researchers found that 

Puget Sound is an important habitat for pupping and provides a nursery ground for the juveniles. 

The adults return to the coast after pupping, while the juveniles stay in Puget Sound for several 

years until they mature and then move out to the coast. The juveniles make regular diel vertical 

migrations, the rate and magnitude of which appear to be based on season, tide, and bathymetry; 

these migrations were most likely related to foraging. 

Biological data (e.g., genetic samples, blood samples, gut contents, and stable isotope ratios of 

tissues) were also collected. Genetic analysis indicated that the Puget Sound sixgill shark 

population has a high degree of relatedness and polyandry (i.e., multiple mates per litter for 

mature females) (Larson et al. 2011). Stable isotope data were consistent with large-scale 

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movement patterns of juveniles and females as determined by the tagging studies, and are being 

analyzed to estimate trophic position of juvenile sixgill sharks in the Puget Sound food web. 

Research on Broadnose Sevengill Sharks (Notorynchus cepedianus) along the West Coast 

The NWFSC, in collaboration with WDFW, examined the biology, distribution, and movements 

of broadnose sevengill sharks in coastal estuaries and shelf waters along the West Coast from 

2003 to 2006. All sevengill sharks were captured in Willapa Bay on the southern Washington 

coast. Sharks were weighed, measured, examined to determine sex and maturity, and then 

released. In addition, 32 individuals were surgically tagged with Vemco© ultrasonic tags. 

Sevengill sharks were found to make seasonal use of Willapa Bay and other coastal estuaries 

(G.D. Williams et al. 2012). During spring and summer months, individuals returned to Willapa 

Bay in consecutive years, showing site fidelity to specific areas within Willapa Bay. 

Spatiotemporal patterns of habitat use within the bay were size- and sex-dependent. Later in the 

year, sevengill sharks generally departed Willapa Bay for coastal waters ranging from Puget 

Sound to Southern California. Sevengill sharks fed on harbor seals (Phoca vitulina) while in 

Willapa Bay (G.D. Williams et al. 2011). 

Research on Spiny Dogfish (Squalus acanthias) Bioenergetics and Movements 

NWFSC researchers have studied spiny dogfish energy budget (bioenergetics) models and 

applied them to spiny dogfish populations along the West Coast and in Puget Sound waters, the 

latter in conjunction with movement studies. 

A basic spiny dogfish bioenergetics model was developed to estimate the effect of temperature 

variation on spiny dogfish in shelf waters of the West Coast (Harvey 2009). The study 

specifically examined how climate variability affected three important indicator metrics: prey 

consumption, age-1 size, and maturation rate of spiny dogfish, sablefish (Anoplopoma fimbria), 

and yellow eye rockfish (Sebastes ruberrimus). Spiny dogfish were highly sensitive to 

temperature variation in terms of age at maturity, and also responded strongly in terms of total 

prey consumption; thus, climate variability could potentially affect spiny dogfish demography 

and food web dynamics. 

Recently, NWFSC researchers have examined movements of northern spiny dogfish in Puget 

Sound, using acoustic telemetry methods similar to those outlined previously for sixgill and 

sevengill sharks. In a forthcoming manuscript, K. S. Andrews and C. J. Harvey describe how a 

large portion of the spiny dogfish population in Puget Sound emigrates from the system in the 

fall and moves into waters along the West Coast, remaining there until at least the following 

spring before returning. There is some evidence of interannual site fidelity by individuals 

returning to Puget Sound. Using the bioenergetics model described above, the researchers have 

concluded that the seasonal dogfish migration represents a major decrease in predation pressure 

in the Puget Sound ecosystem. 

Alaska Fishery Science Center (AFSC, Auke Bay Laboratory) 

Stock assessment and research efforts at the Alaska Fishery Science Center’s Auke Bay 

Laboratory are focused on: 

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•	 Improving stock assessments and collection of data to support stock assessments of shark 

species subject to incidental harvest in waters off Alaska. 

•	 Migration and habitat use of Pacific sleeper sharks. 

•	 Migration and habitat use of spiny dogfish. 

•	 Development and validation of improved ageing methods for spiny dogfish and Pacific 

sleeper sharks. 

•	 Investigations into life history characteristics and population demography. 

•	 Examination of spiny dogfish markets and modeling incidental catch. 

Stock Assessments of Shark Species Subject to Incidental Harvest in Alaskan Waters 

Species currently assessed in Alaskan waters include Pacific sleeper sharks (Somniosus 

pacificus), spiny dogfish (Squalus suckleyi, note that this was formerly referred to as S. 

acanthias; see Ebert et al. 2010 for details of the species redescription), and salmon sharks 

(Lamna ditropis). These are the shark species most commonly encountered as incidental catch in 

Alaskan waters. In both the Gulf of Alaska (GOA) and Bering Sea/Aleutian Islands (BSAI) 

fishery management plans, sharks are managed as a complex. There are no directed fisheries for 

sharks in either area and directed fishing for all sharks is prohibited. Most shark species are 

considered Tier 6, where annual catch limits are based on estimated historical incidental catch in 

the groundfish fisheries. In the GOA, spiny dogfish is currently Tier 5, with annual catch limits 

based on biomass and natural mortality. Biomass is currently estimated from the NMFS fisheryindependent bottom trawl survey; however, it is thought that other surveys may better reflect the 

populations. Efforts are underway to develop a model to estimate biomass for spiny dogfish that 

would include data such as the NMFS and International Pacific Halibut Commission (IPHC) 

annual longline surveys. Stock assessments are summarized annually in the North Pacific 

Fishery Management Council’s Stock Assessment and Fishery Evaluation Report (see Tribuzio 

et al. 2012a and 2012b). 

Catch of sharks in unobserved fisheries 

The fishing fleet targeting Pacific halibut (Hippoglossus stenelopus) was unobserved until 2013. 

Prior to that, catches of non-halibut species (bycatch) were not accounted for unless the bycatch 

was landed. State of Alaska and Federal fishery managers and scientists have long recognized 

the need for bycatch estimation in this fishery. At-sea data collection (i.e. observers) was not 

authorized until 2013 with the implementation of the Amendment 76 to the Fishery Management 

Plan for Groundfish Fisheries in the Gulf of Alaska and Amendment 86 to the Fishery 

Management Plan for Groundfish Fisheries in the Bering Sea/Aleutian Island Area. Accounting 

for bycatch in the Pacific halibut fishery is also a requirement under the guidelines to National 

Standard 1 of the Magnuson-Steven Fishery Management and Conservation Act. We examined 

six methods of estimating bycatch that combined data from the IPHC annual longline survey and 

commercial CPUE. Results suggest that proportionally weighting the survey data is the most 

appropriate method to treat the survey data to reflect commercial fishing and that using CPUE 

based on numbers of fish per hook is more appropriate than other methods proposed. However, 

all methods rely on the assumption that the catch characteristics of the IPHC survey are 

statistically similar to those occurring in the commercial fishery. The purpose of this project was 

not to determine how these catch estimates should be incorporated into the assessment and no 

management advice is provided in this document. There are a number of caveats to be 

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considered when using the catch estimates and assessment authors are recommended to be aware 

of those caveats prior to using the estimates. 

Trophic Ecology of Pacific Sleeper Sharks in the Eastern North Pacific Ocean 

Stable isotope ratios of nitrogen (δ15N) and lipid normalized carbon (δ13C’) were used to 

examine geographic and ontogenetic variability in the trophic ecology of Pacific sleeper sharks 

in the eastern North Pacific Ocean (Courtney and Foy 2012). Mean muscle tissue δ13C’ values 

of Pacific sleeper sharks differed significantly among geographic regions of the eastern North 

Pacific. Linear models identified significant ontogenetic and geographic variability in muscle 

tissue δ15N values. The trophic position of Pacific sleeper sharks in the eastern North Pacific 

estimated from previously published stomach content data was within the range of Pacific 

sleeper shark trophic position predicted from a linear model of muscle tissue δ15N (3.3–5.7) for 

sharks of the same mean total length (LT; 201.5 cm), but uncertainty in predicted trophic position 

was very high (95 percent prediction intervals ranged from 2.9–6.4). The relative trophic 

position of Pacific sleeper sharks determined from a literature review of δ15N by taxa in the 

eastern North Pacific was lower than would be expected based on stomach content data alone 

when compared to fish, squid, and filter feeding whales. Stable isotope analysis revealed wider 

variability in the feeding ecology of Pacific sleeper sharks in the eastern North Pacific than 

shown by diet data alone, and expanded previous conclusions drawn from analyses of stomach 

content data to regional and temporal scales meaningful for fisheries management. 

Migration and Habitat Use of Pacific Sleeper Sharks 

During the summers of 2003–2006, scientists from Auke Bay Laboratory deployed 138 

numerical Floy tags, 91 electronic archival tags, 24 electronic acoustic tags, and 17 electronic 

satellite popup tags on Pacific sleeper sharks in the upper Chatham Strait region of Southeast 

Alaska (Courtney and Hulbert 2007). Two numerical tags and 10 satellite tags have been 

recovered. The recovery of temperature, depth, and movement data from the electronic archival 

and acoustic tags will aid in the identification of Pacific sleeper shark habitat utilization and 

distribution in Southeast Alaska, and identify the potential for interactions between Pacific 

sleeper sharks and other species in this region. Analysis of tagging data is ongoing. 

Migration and Habitat Use of Spiny Dogfish in the Gulf of Alaska 

Since 2009 scientists from Auke Bay Laboratory have deployed 180 pop-off archival tags on 

spiny dogfish in the GOA, inside waters of Southeast Alaska, along the west coast of Vancouver 

Island (British Columbia) and in Puget Sound (Washington). Six tagged fish from Washington 

station were also double tagged with acoustic transmitting tags for a secondary project to validate 

the geolocation of the pop-off archival tags. Data have been successfully recovered from 140 

tags to date. Results will indicate habitat preference with respect to depth and temperature, 

which may play a role in examining the effects of climate changes in the North Pacific. Further, 

the geolocation data will elucidate the degree to which GOA spiny dogfish populations mix with 

those populations of British Columbia, Canada, and off the U.S. Pacific Coast. Preliminary 

results suggest a general westward movement from Yakutat Bay toward Cook Inlet and Kodiak 

Island between August and December, with some animals moving far south to waters off the 

coast of California. Further, these data are showing different daily behavior patterns depending 

on the migration path (i.e. those animals that stayed within the GOA or those that undertook 

larger migrations). 

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Age and Growth Methods 

Scientists at Auke Bay Laboratory and the NMFS AFSC Resource Ecology and Fisheries 

Management Division age and growth lab received funding from the North Pacific Research Board 

to expand on a pilot study that examined a potential new method for ageing of spiny dogfish. 

Traditional age determination methods used the dorsal fin spine, which can be worn or broken over 

time, thus introducing a source of uncertainty in the ageing estimation process (Tribuzio et al. 

2010). The new method, which uses the vertebrae and histological staining, has been applied to 

spiny dogfish from the U.S. East Coast in efforts to reduce the uncertainty of age estimates. This 

project will compare the results of both ageing methods to determine whether the vertebrae method 

is appropriate for GOA spiny dogfish. The second purpose of this study is to establish a method for 

ageing Pacific sleeper sharks, which have not been successfully aged. This histological method has 

been successful on deep sea Squaloid sharks in the North Atlantic, and there is some suggestion that 

it will work for Pacific sleeper sharks. Scientists at Auke Bay Laboratory are working to establish 

a captive population of spiny dogfish, which will be used to validate the histological aging methods. 

Captive sharks will be injected with oxytetracycline (OTC) on an annual basis for up to 5 years. 

OTC binds with calcium and leaves a distinct mark on the hard structures that are used for ageing. 

The improved age-at-length data will be used to re-estimate growth models used in stock 

assessments. 

Reproduction in salmon shark 

Little is known about the reproductive biology of the salmon shark, Lamna ditropis, from the 

eastern North Pacific Ocean. Female salmon shark specimens were collected from Alaska 

waters in the summer, autumn, and winter to examine reproductive timing, periodicity, and 

fecundity. Results suggest that female salmon sharks ovulate during the autumn months of 

September and October. Further, those animals captured in July were either in a resting or postpartum state indicating a short gestation time of nine to 10 months. The presence of two 

maturity stages in both the summer and autumn months indicates a resting period of at least 14 

months between parturition and ovulation. This study found mean fecundity was 3.88 (n = 8, SE 

= 0.13) with the majority of pregnant salmon sharks having a fecundity of four sharks per litter. 

These results provide new information on the reproductive biology of salmon sharks and will aid 

in the development of stock assessments for this species. 

Modeling Spiny Dogfish Distribution 

The spiny dogfish is a common incidental catch species in commercial longline fisheries in the 

GOA. This small shark is widely considered a nuisance and most dogfish catch is discarded. 

Their spatial distribution in the GOA is poorly understood. A better understanding of areas of 

high incidental catch would provide critical information to fishery managers, whether they seek 

to convert discards into valuable fishery landings or to manage fishing mortality on this longlived species. We analyzed the spatial distribution of the spiny dogfish from fishery-dependent 

and fishery-independent data collected between 1996 and 2008 using generalized additive and 

generalized linear modeling techniques. Modeling results showed that longline catches of spiny 

dogfish were concentrated east of Kodiak Island, Alaska, with increased spatial homogeneity of 

dogfish between the eastern and western GOA. The number of dogfish caught generally showed 

a decreasing trend with increasing depth and decreasing number of hooks. However, depths 

between 1 and 100 meters had the greatest positive influence on dogfish catch. Areas of high 

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dogfish incidental catch indicate core areas that may be important to future considerations of 

stock assessments, at-sea discard estimation, and fishery management. 

World Market Analysis of the Spiny Dogfish 

The spiny dogfish is a globally distributed shark species that is an important trade commodity for 

Europe and Asia. Dogfish have been overexploited in areas that are important for market supply, 

primarily U.S., Canadian, and European fisheries in the northern Atlantic Ocean. Market 

impacts from the decline of dogfish are poorly understood, but recent media campaigns by 

environmental groups discouraging consumption of dogfish may reduce product demand. Data 

on trade, capture, and informal interviews with dogfish suppliers were used to characterize 

market channels and sources of demand in Asia and Europe. Market trends in Europe show 

drastic reductions in demand for dogfish, while market patterns in Asia are less clear. 

Structurally, the markets are segmented, with European markets segmented into frozen and fresh 

products and Asian markets comprised of frozen dogfish and fins. Future increases in market 

share for dogfish will require differentiating the product from potential substitutes while using 

eco-labeling and marketing to inform consumers. 

Policy Perspective of the Spiny Dogfish Market in Alaska 

Spiny dogfish is a common species caught incidentally in Alaskan trawl, longline, and salmon 

fisheries. Markets for dogfish (mainly Squalus suckleyi and S. acanthias) exist in Europe and 

Asia. The purpose of this study is to describe historical dogfish harvests in Alaska and provide 

an analysis of potential harvest given the current and future regulatory environment, including 

suggestions for improving marketing efforts in Alaska. Regulations currently allow dogfish to 

be retained in proportion to the amount of target species retained in a directed fishery. This 

specification will not result in significant retention of dogfish unless ex-vessel prices 

dramatically increase relative to target species. Even with an increased ex-vessel value, few 

vessels may be able to capitalize on dogfish revenue due to restrictions on harvest of bycatch 

species and limited access programs for vessels focusing on other, more valuable target species. 

Substantial marketing efforts by the Alaska seafood industry are necessary to establish dogfish 

markets leading to increased ex-vessel prices. A robust dogfish market in Alaska is unlikely to 

occur unless management allows directed fishing. Such a management change may create 

incentives to use dogfish as a guise to harvest other, more valuable species under regulations for 

bycatch retention allowances. In developing management options, agencies must establish target 

and limit reference points for fishing mortality commensurate with the vulnerability of this 

species to overfishing. 

Northeast Fisheries Science Center (NEFSC) 

Fishery-Independent Surveys and Recreational Monitoring of Coastal and Pelagic Sharks 

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Fishery-Independent Coastal Shark Bottom Longline Survey 

The fishery-independent survey of Atlantic large and small coastal sharks is conducted biennially 

in U.S. waters, depending on funding. Its primary objective is to conduct a standardized, 

systematic survey of the shark populations off the U.S. Atlantic coast to provide unbiased indices 

of relative abundance for species inhabiting the waters from Florida to the Mid-Atlantic (see 

Figure A1.6). This survey also provides an opportunity to tag sharks with conventional and 

electronic tags as part of the NEFSC Cooperative Shark Tagging Program, inject with OTC for 

age validation studies, and collect biological 

samples and determine life history 

characteristics (age, growth, reproductive 

biology, trophic ecology, etc.). In addition, 

the collection of morphometric information 

provides data needed to calculate length-tolength and length-to-weight conversions. 

The time series of abundance indices from 

this survey is critical to the evaluation of 

coastal Atlantic shark species. Standardized 

indices of abundance from this survey for 

sandbar and dusky sharks were used in the 

2010 Southeast Data Assessment and 

Review (SEDAR) process (McCandless and 

Natanson 2010). The next survey is 

scheduled for spring 2012. 

Figure A1.6. Releasing a sandbar shark during the 

NEFSC Coastal Shark Bottom Longline Survey. 

Source: L.J. Natanson / NMFS photo. 

Fishery-Independent Pelagic Shark Longline Survey 

NMFS and its predecessor agencies, the Bureau of Commercial Fisheries and the Bureau of 

Sport Fish and Wildlife, conducted periodic longline surveys for swordfish, tunas, and sharks off 

the U.S. East Coast starting in the early 1950s. Surveys first targeted tunas and swordfish along 

the edge of the continental shelf, and subsequently focused on pelagic and coastal sharks over a 

variety of depths, including inshore bays and estuaries. The last large-scale pelagic fishing trip 

was conducted in 1985; however, the NEFSC Narragansett Laboratory completed a pilot survey 

in spring 2006 and conducted additional pelagic sets in 2007. The goal of this research is to 

initiate a standardized fishery-independent pelagic shark survey in order to conduct research and 

monitor shark abundance and distribution. 

Juvenile Shark Survey for Monitoring and Assessing Delaware Bay Sandbar Sharks (Carcharhinus 

plumbeus) 

The juvenile sandbar shark population in Delaware Bay is surveyed by NEFSC staff as part of the 

COASTSPAN program. A random stratified longline sampling plan, based on depth and 

geographic location, was developed in 2001 to assess and monitor the juvenile sandbar shark 

population during the nursery season. In 2011, a total of 286 sandbar sharks were caught and 

released with conventional tags. The mark-recapture data from this study has been used to examine 

the temporal and spatial relative abundance and distribution of sandbar sharks in Delaware Bay, and 

the juvenile index of abundance from this standardized survey has been used as an input into 

various stock assessment models in the SEDAR process. In the 2010 SEDAR(McCandless 2010), 

CPUE in number of sharks per 50-hook set per hour was used to examine the relative abundance 

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of young of the year, age 1+, and total juvenile sandbar sharks between the summer nursery 

seasons in Delaware Bay from 2001 to 2009. All three juvenile sandbar shark time series 

showed stability in relative abundance from 2001 to 2005 with only a brief decrease in 

abundance in 2002, which may be attributed to a large storm (associated with a hurricane 

offshore) that passed through the Bay that year. There was a subsequent decreasing trend from 

2005 to 2008 that ends with an increase in relative abundance in 2009. 

Delaware Bay Sand Tiger (Carcharias taurus) Survey 

A survey, initiated in 2006 targeting the sand tiger 

shark for identifying Essential Fish Habitat (EFH) 

and for future stock assessment purposes, 

continued in 2011(see Figure A1.7). This study 

incorporates historical NEFSC sampling stations 

to allow for comparison between historic and 

current abundances. This survey is also used to 

monitor the Delaware Bay sand tiger population 

and to evaluate long-term changes in abundance 

and size composition. In 2011, a total of 46 sand 

tigers were caught and released with conventional Figure A1.7. Measuring a sand tiger 

during the NEFSC Delaware Bay Sand tags, bringing the total since the beginning of the Tiger Survey. survey to 206 sand tigers. Source: Corey Eddy/NMFS photo. 

Collection of Recreational Shark Fishing Data and Samples 

Historically, species-specific landings data from recreational fisheries are lacking for sharks. In 

an effort to augment these data, the NEFSC has been attending recreational shark tournaments 

continuously since 1961 collecting data on species, sex, and size composition from individual 

events—in some cases, for nearly 50 years. In addition, these tournaments provide a source of 

samples for pelagic and some coastal sharks to aid in our biological research. Analysis of these 

tournament landings data was initiated by creating a database of historic information (1961–2011) 

and producing preliminary summaries of some long-term tournaments. These analyses have been 

used to provide advice on future minimum size catch requirements for these tournaments. The 

collection and analysis of these data are critical for input into species- and age-specific population 

and demographic models for shark management. In 2011, biological samples for life history studies 

and catch and morphometric data for more than 150 pelagic sharks were collected at nine 

recreational fishing tournaments in the northeastern United States. Participation at recreational 

shark tournaments and the resultant information is very valuable as a monitoring tool to provide 

long-term data that can detect trends in species and size composition, provide critical specimens and 

tissue for life history and genetic studies, provide outreach opportunities for recreational fishermen 

and the public, and to provide additional information on movements that complement the NMFS 

Cooperative Shark Tagging Program. 

NEFSC Historical Longline Survey Database 

The NEFSC recovered the shark species catch per set data from the exploratory shark longline 

surveys conducted by the Sandy Hook and Narragansett Laboratories from 1961 to 1991. In 

addition to the fishery-independent surveys conducted by the NEFSC, scientific staff has been 

working with the University of North Carolina (UNC) to electronically recover the data from an 

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ongoing coastal shark survey in Onslow Bay that began in 1972. These surveys provide a 

valuable historical perspective for evaluating the stock status of Atlantic sharks. This data 

recovery process is part of a larger, systematic effort to electronically recover and archive 

historical longline surveys and biological observations of large marine predators (swordfish, 

sharks, tunas, and billfishes) in the North Atlantic. When completed, these efforts will include 

reconstructing the historic catch, size composition, and biological sampling data into a 

standardized format for time series analysis of CPUE and size. Standardized indices of 

abundance developed for sharks caught during these longline surveys have been and will 

continue to be used in stock assessments as part of the SEDAR process. During the 2010 

SEDAR process, abundance indices were summarized for sandbar and dusky sharks caught 

during the NEFSC exploratory longline surveys (McCandless and Hoey 2010) and for blacknose, 

sandbar, and dusky sharks caught during the UNC shark survey (Schwartz et al. 2010). Work on 

the recovery of environmental data for both the NEFSC and the UNC time series, as well as the 

associated individual shark data, is ongoing to further refine these indices and to develop indices 

of abundance for other shark species, and for future use in shark EFH designations. Analyzing 

catch rates according to differences in time, space, or methods provides an opportunity to better 

understand seasonal distribution patterns and relative vulnerability of various species to different 

fishing practices. 

Southeast Data, Assessment, and Review (SEDAR) Process 

Staff participated in the SEDAR Data Workshop for the assessment of the blacknose, dusky, and 

sandbar sharks and contributed seven SEDAR working papers. These documents summarized 

blacknose, dusky, and sandbar shark mark-recapture data from the Cooperative Shark Tagging 

Program (Kohler and Turner 2010) and standardized indices of abundance for blacknose, dusky, 

and/or sandbar sharks from the NEFSC historical longline surveys (McCandless and Hoey 

2010), the NMFS Northeast shark longline surveys (McCandless and Natanson 2010), the 

University of North Carolina shark longline survey (Schwartz et al. 2010), and the 

COASTSPAN surveys in Delaware Bay (McCandless 2010), South Carolina (McCandless and 

Frazier 2010), and Georgia (McCandless and Belcher 2010). 

Deepwater Horizon C252 Pelagic Fish Sampling 

Staff biologists participated in a pelagic longline cruise inside and adjacent to the area closed to 

fishing due to the Deepwater Horizon C252 oil spill. The objectives of this cruise were to collect 

highly migratory fish for food quality studies in the vicinity of the oil spill resulting from the 

sinking of the Deepwater Horizon oil platform; to monitor the distribution and abundance of 

highly migratory species in the Gulf of Mexico with reference to the oil sheen; and to collect 

salinity and temperature profile data and water samples for hydrocarbon analysis. All 

commercially and recreationally valuable and legal-sized pelagics were saved for seafood sampling. 

Essential Fish Habitat 

Pelagic Nursery Grounds 

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Pelagic shark biology, movements, and abundance 

studies continued in 2011 with further 

investigations of pelagic nursery grounds in 

conjunction with the high seas commercial 

longline fleet. This collaborative work offers a 

unique opportunity to sample and tag blue sharks 

(Prionace glauca) and shortfin makos (Isurus 

oxyrinchus) in a potential nursery area on the 

Grand Banks, to collect length-frequency data and Figure A1.8. Shortfin mako brought aboard biological samples, and to conduct conventional during the NEFSC Pelagic Nursery Ground and electronic tagging of these species (see Figure cruise. 

A1.8). In 2007 and 2008, two real-time satellite Source: Lisa Natanson / NMFS photo. 

(SPOT) tags and five pop-up satellite archival 

tags (PSAT) tags were deployed on shortfin makos and one PSAT tag was deployed on a blue 

shark. A total of 500 blue sharks have been double-tagged using two different tag types to help 

evaluate tag-shedding rates used in sensitivity analyses for population estimates and to calculate 

fishing mortality and movement rates for this pelagic shark species. In 2011, an additional 250 

sharks were tagged, bringing the total to more than 2,750 with 190 recaptured. These fish were 

primarily blue sharks recovered by commercial fishermen working in the mid-Atlantic Ocean. This 

research was featured as part of the Discovery Channel’s “Swords: Life on the Line” series 

documenting the lives of commercial longline fishermen. 

Cooperative Atlantic States Shark Pupping and Nursery (COASTSPAN) Program 

The NEFSC manages and coordinates this program, which surveys Atlantic coastal waters from 

Florida to Massachusetts and in the U.S. Virgin Islands (USVI) by conducting cooperative, 

comprehensive, and standardized investigations of coastal shark nursery habitat. COASTSPAN 

surveys are used to describe habitat preferences and to determine the relative abundance, 

distribution, and migration of shark species through longline and gillnet sampling and markrecapture data (see FigureA1.9). In 2011, COASTSPAN participants were the Georgia 

Department of Natural Resources, South Carolina Department of Natural Resources, North 

Carolina Division of Marine Fisheries, and University of North Florida. The NEFSC staff 

conducts the survey in Narragansett and 

Delaware Bays and additional sampling in 

the USVI and Massachusetts in conjunction 

with the Massachusetts Division of Marine 

Fisheries (MDMF). Data from 

COASTSPAN surveys are used to update 

and refine EFH designations for multiple 

life stages of managed coastal shark 

Figure A1.9. Tagging a juvenile sandbar shark during species. Standardized indices of abundance 

the NEFSC COASTSPAN Program Survey. from COASTPAN surveys are used in the 

Source: W. David McElroy / NMFS photo. stock assessments for large and small 

coastal sharks. During the 2010 SEDAR 

process, three COASTSPAN documents 

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summarized abundance indices for sandbar sharks in Delaware Bay (McCandless 2010), 

blacknose and sandbar sharks in South Carolina waters (McCandless and Frazier 2010), and 

blacknose and sandbar sharks in Georgia waters (McCandless and Belcher 2010). 

MDMF and NMFS initiated a study in 2006 to investigate the spatial and temporal use of nursery 

habitat by neonatal blacktip (Carcharhinus limbatus) and lemon (Negaprion brevirostris) sharks 

in Fish Bay and Coral Bay on the island of St. John, U.S. Virgin Islands, using both active and 

passive acoustic telemetry. Acoustic transmitters were surgically implanted in blacktip and 

lemon sharks and their movements are currently being monitored using passive acoustic 

telemetry to determine site fidelity, residency, and migration patterns. Only 8 percent of lemon 

sharks and14.5 percent of blacktip sharks exhibited long-term residency (>180 days) within the 

bays, while most of the sharks moved out by the fall and early winter months. Although several 

sharks were detected outside of Fish and Coral Bays and a few (five blacktips) traveled between 

the two bays, each species exhibited strong site attachment to the bay in which they were tagged. 

Efforts to examine intra- and inter-specific patterns of habitat use as they relate to the biotic and 

abiotic characteristics of each embayment are ongoing. A presentation summarizing these 

results (Legare et al. 2011) was given at the 2011 American Elasmobranch Society Meeting. 

Habitat Utilization and Essential Fish Habitat of Sand Tiger Sharks 

Funding was received in 2006 through the NOAA Living Marine Resources Cooperative Science 

Center to support a multi-year cooperative research project with staff from Delaware State 

University and the University of Rhode Island on habitat use, depth selection, and the timing of 

residency for sand tigers in Delaware Bay. Sand tigers were implanted with standard acoustic or 

depth-sensing transmitters to monitor their movements and habitat use of Delaware Bay during 

the summer months. Sand tiger movements continue to be monitored using passive acoustic 

telemetry. 

Funding was received through the NMFS Species of Concern Grant Program to study the 

regional movements, habitat use, and site fidelity of sand tigers off the U.S. East Coast using 

satellite telemetry. PSATs were deployed on four sand tigers; two caught in Massachusetts State 

waters and two caught in Rhode Island State waters. Results from these tags will be examined to 

quantify large-scale three-dimensional movements of these fish as they relate to oceanographic 

features (e.g., temperature), time of year, essential fish habitat, size, age, and sex. 

Essential Fish Habitat (EFH) Designations 

NEFSC staff participates on a working group with others from the NMFS Highly Migratory Species 

Division and Southeast Fisheries Science Center to update and refine the EFH designations for 

managed shark species. This process was ongoing in 2011 and entailed providing summaries from 

COASTSPAN surveys to update EFH for coastal shark species and information for the EFH section 

of the annual Stock Assessment and Fisheries Evaluation Report. 

Elasmobranch Life History Studies 

NEFSC life history studies are conducted on Atlantic species of elasmobranchs to address 

priority knowledge gaps and focus on species with declines and management issues. Biological 

samples are obtained on research surveys and cruises, on commercial vessels, at recreational 

fishing tournaments, and opportunistically from standings. In recent years, studies have 

concentrated on a complete life history for a species to obtain a total picture for management. 

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This comprehensive life history approach encompasses studies on age and growth rates and 

validation, diet and trophic ecology, and reproductive biology essential to estimate parameters 

for demographic, fisheries, and ecosystem models. 

Atlantic Blue Shark (Prionace glauca) and Shortfin Mako (Isurus oxyrinchus) Life History and 

Assessment Studies 

Collaborative programs to examine the biology and 

population dynamics of the blue shark (Figure A1.10) and 

shortfin mako in the North Atlantic are ongoing. Fisheryindependent published research on blue shark 

demographics has allowed for the construction of an agestructured population model. This model confirms the 

importance of juvenile survival for population growth. In 

addition, a risk analysis is proposed as a supplement to 

the data-limited stock assessment to better evaluate the 

probability that a given management strategy will put 

the population at risk of decline. 

Figure A1.10. Blue shark ready to be 

tagged and released. 

Source: Lisa Natanson /NMFS photo. 

Shortfin mako survival was estimated from NMFS Cooperative Shark Tagging Program (CSTP) 

mark-recapture data. Estimates of survival (0.705–0.873 per year) were generated with the 

computer software MARK by analyzing tagged (n=6,309) and recaptured (n=730) animals. An 

estimate of survival is a key variable for stock assessments and subsequent demographic 

analyses, and is crucial when it comes to directly managing exploited or commercially viable 

species. 

From samples collected from recreational fishing tournaments and research cruises, a genetic 

approach for identifying pelagic shark tissues was streamlined by researchers at NOVA 

Southeastern University. The result is a rapid, accurate, and relatively inexpensive genetic assay 

for identifying tissues and body parts from the shortfin mako and four other shark species (silky, 

dusky, sandbar, and longfin mako). 

Regional sizes, sex ratios, maturation, and movement patterns were analyzed for 91,450 blue 

sharks tagged by CSTP in the North Atlantic Ocean from 1962 to 2000. Of these, 5,410 were 

recaptured for an overall recapture rate of 5.9 percent. Blue sharks made frequent trans-Atlantic 

crossings from the western to eastern regions, and were shown to move between most areas; the 

mean distance traveled was 857 km, and the mean time at liberty between tagging and recapture 

was 0.9 year. North Atlantic blue sharks are believed to constitute a single stock, and a better 

understanding of their complex movements, life history strategies, and population structure is 

needed to develop informed management of this open ocean species. 

Using this blue shark tag-recovery data from the NMFS CSTP (1965–2004), a spatially 

structured tagging model was used to estimate blue shark movement and fishing mortality rates 

in the North Atlantic Ocean (Aires-da-Silva et al. 2009). Four major geographical regions (two 

on each side of the ocean) were assumed with the blue shark fishing mortality rates (F) found to 

be heterogeneous across the four regions. While the estimates of F obtained for the western 

North Atlantic Ocean were historically lower than 0.1 year–1, the F estimates over the most 

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recent decade (1990s) in the eastern side of the ocean are rapidly approaching 0.2 year–1 . 

Because of the particular life history of the blue shark, these results suggest careful monitoring of 

the fishery, as the juvenile and pregnant female segments of the stock are highly vulnerable to 

exploitation in the eastern North Atlantic Ocean. 

The blue shark has been subject to bycatch fishing mortality for almost a half-century, and has 

even become the target species in pelagic longline fisheries in the North Atlantic Ocean. 

Nevertheless, stock status is ambiguous and improved input data are needed for stock 

assessments. It is particularly important to obtain reliable indices of abundance because of the 

uncertainty in estimates of bycatch. An index of relative abundance was developed for western 

North Atlantic blue sharks, starting from the mid-1950s, when industrial pelagic longline tuna 

fisheries began. Longline catch and effort records from recent observer programs (1980–1990s) 

were linked with longline survey records from both historical archives and recent cruises (1950– 

1990s). Generalized linear models were used to remove the effects of diverse fishing target 

practices, and geographical and seasonal variability that affect blue shark catch rates. The 

analysis revealed a decline in blue shark relative abundance of approximately 30 percent in the 

western North Atlantic from 1957 to 2000. The magnitude of this relative abundance decline 

was less than other recently published estimates and seems reasonable in light of the high 

productivity of the blue shark revealed by life history studies and preliminary stock assessments. 

Biology of the White Shark (Carcharodon carcharias) 

An update to an NEFSC western North Atlantic white shark distribution paper is being finalized 

for publication. This study is a joint effort with NMFS staff from the NEFSC, SEFSC, and the 

Greater Atlantic Regional Fisheries Office 13 (GARFO) and scientists from MDMF and the 

Florida Museum of Natural History. The update builds upon previously published data 

combined with recent unpublished records to presents a synthesis of over 550 confirmed white 

shark records compiled over a 210-year period (1800–2009) and is the largest white shark dataset 

yet compiled for the western North Atlantic. Descriptive statistics and GIS analyses are used to 

quantify the seasonal distribution and habitat use of various subcomponents of the population. In 

2011, relative indices of abundance from historical NEFSC surveys, NEFSC tournament data, 

the observer program for the directed shark longline fishery, and visual records of white sharks 

in New England waters were analyzed to determine temporal trends of white shark abundance in 

the northwest Atlantic. 

Researchers from Stony Brook University, Field Museum of Chicago, Nova Southeastern 

University, and NEFSC are employing a multi-analytical approach to test the hypothesis that 

northwest Atlantic white sharks have experienced a recent loss of genetic diversity due to a 

population bottleneck. Results show that contemporary northwest Atlantic white sharks are 

genetically distinct from other populations and comprise a demographically distinct unit. 

Ongoing work includes attempting to reconstruct the genetic diversity of white sharks in the 

1960s and 1970s using DNA recovered from archived vertebrae. Historical genetic diversity will 

be directly compared to contemporary genetic diversity in this study, which could serve as a 

model for similar studies of other elasmobranchs. 

13 In February 2014, the Northeast Regional Office was renamed the Greater Atlantic Regional Fisheries Office. 

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Biology of the Thresher Shark (Alopias vulpinus) 

Life history studies of the thresher shark in the western North Atlantic continued with analysis of 

age and reproductive parameters. Reproductive organs from 134 male and 257 female thresher 

sharks were examined to determine size at maturity and reproductive cycle. Males ranged in size 

from 78 to 237 cm FL and females ranged from 62 to 263 cm FL. Reproductive tissues were 

processed and sectioned using histological techniques. Age and growth estimates were 

generated using vertebral centra from 173 females, 135 males, and 11 individuals of unknown 

sex ranging in size from 56 to 264 centimeters fork length. These results will be combined with 

the morphological reproductive data to determine sexual sizes at maturity for this species. In 

2011, additional work on demography was initiated using the values from the reproduction and 

age and growth papers. Two papers will be submitted in tandem for publication. 

Biology of the Galapagos Shark (Carcharhinusgalapagensis) 

The Galapagos shark is distributed worldwide in warm, temperate waters and is known to prefer 

oceanic islands. As such, it is the most common species in Bermuda, where commercial 

fishermen land approximately 200 sharks each year, primarily for their liver oil or as bait in 

lobster traps. Despite its ubiquitous presence, Bermuda's Department of Environmental 

Protection has only limited regulations in place to manage this species. This study was begun to 

investigate the life history and ecological role of these sharks. Size-at-maturity is being 

investigated by examining the reproductive system of sharks collected from landings of 

commercial fishermen. Size-at-age and age-at-maturity estimates will be derived from band 

pairs in the vertebral centra of these sharks. Elements of feeding ecology, such as trophic 

position and diet shifts, are being investigated via stable isotope analysis of muscle, liver, and 

vertebrae with stomach contents analysis to reinforce these results. This study is being done in 

conjunction with staff from the University of Massachusetts and Massachusetts Division of 

Marine Fisheries. A presentation summarizing these results (Eddy et al. 2011a) was given at the 

2011 American Elasmobranch Society Meeting. 

Biology of the Atlantic Torpedo (Torpedo nobiliana) 

A Master’s thesis was completed on the biology of the Atlantic torpedo (Mataronas 2010). This 

research is ongoing due to a lack of large females for reproductive analysis. Samples for age and 

growth, reproduction, and food habits were obtained from the bycatch of bottom trawl, trap net 

and gillnet fisheries operating primarily out of Point Judith, Rhode Island. Males mature 

between 79 and 86 cm TL (50 percent maturity was estimated to be 83.6 cm TL). Females 

mature between 113 and 123 cm TL (50 percent maturity was estimated to be 120.9 cm TL). 

The fecundity appears to be low, although it is higher than other torpedinid species, probably 

because it is the largest of the torpedo rays. Seasonality in the reproductive cycle could not be 

defined due to the inability to obtain rays during all months of the year. However, based on the 

observed reproductive condition of the females, data support a biennial reproductive cycle, with 

a fall mating season and parturition occurring the following spring. Size at birth was estimated 

to be 20–21 cm TL. The strong relationship of vertebral radius to total length suggests that 

vertebrae should be a useful ageing structure for this species. However, vertebral banding 

patterns vary widely among individuals; therefore, ageing has not been completed due to the 

inability to define a working criterion for the identification of band pairs. Work with researchers 

at other institutions is ongoing to determine whether it is possible to develop a criterion for band 

identification. There are approximately 21 validated species in the genus Torpedo, of which only 

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the Atlantic torpedo, Torpedo nobiliana, is believed to be found in the northwest Atlantic Ocean. 

The torpedo rays caught off New England were originally named T. occidentalis and were later 

synonymized as a junior synonymy of a Mediterranean species, Torpedo nobiliana. As a result 

of this study, the population of torpedo rays off the coast of Rhode Island is being more closely 

examined to determine whether the species is actually distinct and should revert to the name T. 

occidentalis. Currently, an effort is being made to obtain samples from the eastern North 

Atlantic to compare with the samples from this study to validate the species. 

Biology of the Smooth Skate (Malacoraja senta) 

The smooth skate is one of the smallest (<70 cm TL,<2.0 kg wet weight) species of skate 

endemic to the western North Atlantic and has a relatively broad geographic distribution, ranging 

from Newfoundland and the southern Gulf of St. Lawrence in Canada to New Jersey in the 

United States. Age and growth estimates for the smooth skate were derived from 306 vertebral 

centra from skates caught in the North Atlantic off the coast of New Hampshire and 

Massachusetts. Male and female growth diverged at both ends of the data range and the sexes 

required different growth functions to describe them. Males and females were aged to 15 and 14 

years, respectively. Age and size at sexual maturity was determined for 185 male and 96 female 

smooth skates (ranging in size from 370 to 680 mm total length), collected from the western Gulf 

of Maine (Sulikowski et al. 2009). Fifty percent maturity occurs between 9 and 10 years and 560 

mm LT for males, and occurs at age 9 years and 540 mm LT for females. 

Northeast Skate Complex 

Skates caught off Rhode Island for use in the lobster bait industry were sampled from January 

through September 2009 in response to the Northeastern Skate Fishery Management Plan 

objectives to collect information critical for improving knowledge of the identification of these 

species, monitoring their status, and improving management approaches. Data including date, 

catch location, species name, total length, disk width, and weight were collected from 2,213 

skates from boats out of Point Judith and Little Compton, Rhode Island. Of the skates sampled, 

2,024 were identified as little skate (Leucoraja erinacea) and 189 were identified as winter skate 

(Leucoraja ocellata). Length frequency graphs were produced for both species and weight-tolength conversion equations were calculated. Reproductive measurements and vertebrae were 

also collected from 39 individuals for future analysis. 

Atlantic Angel Shark (Squatina dumeril) 

The Atlantic angel shark is among 20 species of sharks prohibited from both commercial and 

recreational fisheries. However, off the northeast coast of the United States, this species is 

encountered in several commercial fisheries, including the bottom otter trawl and gillnet 

fisheries. The NEFSC Observer Program and survey vessels have collected 54 angel sharks to 

date. Dissections of these specimens have resulted in preliminary maturity estimates of greater 

than 1 m FL for both male and female angel sharks. Preliminary age determination estimates 

from the vertebrae are similar to results from angel sharks from the Gulf of Mexico and Pacific; 

there does not appear to be any correlation between band periodicity and time. Further work is 

required to determine band periodicity in this species. DNA samples have also been collected to 

examine the angel shark evolutionary history and population structure using mitochondrial DNA 

control region sequences. DNA from the northwest Atlantic and from western and eastern 

populations in the Gulf of Mexico will be compared. Results from this collaborative study 

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supports current U.S. fisheries management banning all landings of the Atlantic angel shark, with 

management and conservation units established for a single genetic stock until further genetics 

and tagging programs can be conducted. 

Smalltooth Sand Tiger (Odontaspis ferox) 

The smalltooth sand tiger, a large, deep-water shark species, has been reported as occurring in 

the western North Atlantic Ocean based on a single female caught off the North Carolina coast in 

September 1994 during a research vessel bottom trawl survey. Recently, certified NEFSC 

observers described and photographed two more captured specimens of this species during trawl 

trips targeting squid in waters off the eastern coast of the United States. The International Union 

for Conservation of Nature currently lists the smalltooth sand tiger as vulnerable for the 

following reasons: this species may be naturally rare, has an assumed low fecundity as seen in 

the closely related sand tiger shark, and developing deep-sea fisheries apply an increasing 

amount of pressure. However, as noted in previous accounts, it is only when an occasional 

individual of this deep water species comes onto the continental shelf that there is an opportunity 

for its capture; therefore the smalltooth sand tiger may be more common than suggested by the 

few documented captures. A presentation summarizing some results was given at the 2010 

American Elasmobranch Society Meeting. 

Dusky Shark (Carcharhinus obscurus) Genetics 

A collaborative study on the genetic stock structure of the dusky shark was conducted to 

delineate management units and monitor trade in sharks (Benavides et al. 2011). This is the first 

assessment of global stock structure of C. obscurus, and it was completed via analysis of the 

mitochondrial control region in 255 individuals sampled from eight geographically dispersed 

locations. These analyses suggest that replenishment of the collapsed U.S. Atlantic management 

unit via immigration of females from elsewhere is unlikely. In addition, these mitochondrial 

control region sequences can be used to reconstruct the relative contributions of U.S. Atlantic, 

South Africa, and Australia management units to the Asian fin trade. 

Age and Growth of Elasmobranchs 

Tiger Shark (Galeocerdo cuvier) 

Age and growth estimates for the tiger shark in the western North Atlantic were derived from 

band counts of 238 sectioned vertebral centra. Growth functions fit to length-at-age data 

demonstrated that growth rates were similar for males and females up to approximately 200 cm 

fork length, after which male growth slowed. Both sexes appear to reach maturity at age 10. 

Males and females were aged to 20 and 22 years, respectively, although longevity estimates 

predict maximum ages of 27 and 29 years, respectively. Bomb radiocarbon analysis of 10 band 

pairs extracted from four vertebral sections suggested that band pairs are deposited annually up 

to age 20. This study provides a rigorous description of tiger shark age and growth in the 

western North Atlantic and further demonstrates the utility of bomb radiocarbon as an age 

validation tool for elasmobranch fishes. 

Basking Shark (Cetorhinus maximus) 

Age and growth of the basking shark was examined using vertebral samples from 13 females 

(261 to 856 cm total length), 16 males (311 to 840 cm total length), and 11 specimens of 

unknown sex (376 to 853 cm total length). Vertebral samples were obtained worldwide from 

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museums and institutional and private collections. Examination of multiple vertebrae from along 

the vertebral column of 10 specimens indicated that vertebral morphology and band pair 

(alternating opaque and translucent bands) counts changed dramatically along an individual 

column. Smaller sharks had similar band pair counts along the length of the vertebral column, 

while large sharks had a difference of up to 24 band pairs between the highest and lowest count 

along the column. Evidence indicates that band pair deposition may be related to growth and not 

time in this species, and thus the basking shark cannot be directly aged using vertebral band pair 

counts. 

Dusky Shark (Carcharhinus obscurus) 

A revision of the age and growth of the dusky shark in the Northwestern Atlantic Ocean was 

initiated in conjunction with the SEFSC Shark Observer Program and staff of the NEFSC. 

Approximately 150 new vertebrae were examined for age determination, and preliminary growth 

curves were generated. Preliminary data indicated that the growth is similar to previous 

estimates; however, more analysis is needed to verify this finding and provide updated growth 

curves to the stock assessment. In addition, in conjunction with scientists from Woods Hole 

Oceanographic Institution, one vertebra is being processed for bomb carbon analysis in an 

attempt to validate the periodicity of band pair formation for this species. In 2011, preliminary 

results were obtained from this bomb carbon analysis that indicated band pair periodicity was not 

annual. In order to obtain a better picture of the periodicity we decided to process more samples. 

Results are still pending for these analyses. 

White Shark (Carcharodon carcharias) 

The white shark is well documented in the western North Atlantic from Newfoundland to the 

Gulf of Mexico, including the Bahamas and parts of the Caribbean. However, the species is 

relatively elusive in the western North Atlantic and efforts to study its life history and ecology 

have been hampered by the inability of researchers to predictably encounter these sharks. 

Vertebrae for age and growth have been collected by members of the Apex Predators Program 

since 1963. Because they are a prohibited species and new samples are not likely to be obtained 

in sufficient quantity, in 2011 an age study was undertaken with the archived samples in 

conjunction with MDMF. Vertebrae from 105 samples were processed and band pairs were 

counted. Preliminary data indicated higher counts than previously obtained for white sharks in 

other parts of the world. To validate these counts, samples from five specimens were processed 

for bomb carbon analysis in conjunction with researchers at Woods Hole Oceanographic 

Institution. In all but one case, these validated our age estimates. In the last case, the bomb 

carbon indicated a significant underestimation using band pair counts. Further testing is 

currently underway to fine-tune the analysis. Results are still pending. 

Bull Shark (Carcharhinus leucas) 

The bull shark is a common coastal carcharhinid that is widely distributed in tropical and 

subtropical areas of the world's oceans. Bull sharks can also travel into warm rivers and lagoons. 

In the western North Atlantic, the bull shark is distributed from Massachusetts to southern Brazil, 

including the Gulf of Mexico and Caribbean Sea and the Bahamas. It also occurs in the 

Mississippi and Atchafalaya Rivers in the southwestern United States. In 2011, in conjunction 

with Doug Adams of the Florida Fish and Wildlife Conservation Commission, vertebrae from 

124 bull sharks were collected and processed for age studies. The preliminary count was 

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accomplished by the primary reader. More counts need to be done and a secondary reader needs 

to be identified. 

Sandbar Shark (Carcharhinus plumbeus) 

In collaboration with PIFSC, a bomb radiocarbon and tag-recapture dating study was completed 

to determine valid age-estimation criteria and longevity estimates for the sandbar shark 

(Andrews et al. 2011). Results indicated that current age interpretations based on counts of 

growth bands in vertebrae are accurate to 10 or 12 years. Beyond these years, bomb radiocarbon 

and tag-recapture data indicated that large adult sharks were considerably older than the 

estimates derived from counts of growth bands. Three adult sandbar sharks were 20 to 26 years 

old based on bomb radiocarbon results—a 5- to 11-year increase over the previous age estimates 

for these sharks. The tag-recapture data provided results that were consistent with bomb 

radiocarbon dating and further supported a longevity that exceeds 30 years for this species. 

Elasmobranch Feeding Ecology 

Scalloped Hammerhead (Sphryna lewini) 

Scalloped hammerheads are apex predators with circumglobal distribution in tropical and warm 

temperate waters. Their role in the western North Atlantic ecosystem was explored by 

examining indices of standardized diet composition derived from stomach contents of sharks 

caught from research and commercial vessels, and in recreational tournaments. Impacts on the 

diet caused by biotic and abiotic factors were evaluated. Sample location had the strongest 

influence on diet, with sharks occurring in inshore waters feeding primarily on inactive demersal 

fish and secondarily on pelagic fish. Cephalopods were by far the largest food group found in 

sharks caught offshore. There were fewer empty stomachs found in the offshore sample (33 

percent) than in the inshore sample (45 percent), but the volume of stomach contents in those 

with food was higher inshore (0.6 percent body weight (BW) versus 0.4 percent BW). Season 

also played a significant role in the diet. The lowest percentage empty (9.6 percent), the largest 

average stomach content volume (0.8 percent BW), and the largest number of prey items per 

stomach (8.1) occurred in the summer. The summer sample also had the largest number of 

different prey types (1.8), although this was not statistically different from the other seasons. 

Most of these seasonal differences were found in sharks caught both inshore and offshore. Shark 

sex, state of maturity, decade caught, and gear type or source had little or no significant influence 

on diet. 

Shortfin Mako (Isurus oxyrinchus) 

The diet and daily ration of the shortfin mako in the inshore waters of the western North Atlantic 

were re-examined to determine whether fluctuations in prey abundance and availability are 

reflected in these two biological variables. During the summers of 2001 and 2002, stomach 

content data were collected from fishing tournaments along the northeast coast of the United 

States. These data were quantified by using four diet indices and were compared to index 

calculations from historical diet data collected from 1972 through 1983. Bluefish (Pomatomus 

saltatrix) were the predominant prey in the 1972–1983 and 2001–2002 diets, accounting for 92.6 

percent of the current diet by weight and 86.9 percent of the historical diet by volume. From the 

2001– 2002 diet data, daily ration was estimated and it indicated that shortfin makos must 

consume roughly 4.6 percent of their body weight per day to fulfill energetic demands. The 

daily energetic requirement was broken down by using calculated energy content for the current 

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diet of 4,909 KJ/kg. Based on the proportional energy of bluefish in the diet by weight, an 

average shortfin mako could consume roughly 500 kg of bluefish per year off the northeast coast 

of the United States. 

Sandbar Shark (Carcharhinusplumbeus) 

Non-lethal diet sampling of juvenile sandbar sharks 

(Figure A1.11) was conducted during summer months in 

Delaware Bay, one of the largest nurseries for the species 

in the western North Atlantic. Overall, sandbar sharks 

had a pattern characterized by a diverse diet, intermittent 

feeding, and occasional consumption of large meals. 

Significant ontogenetic changes in diet to progressively 

higher trophic-level prey were discovered. Sharks fed 

principally on teleosts, with crustaceans important to 

young sharks, and elasmobranchs an increasing dietary 

component for large juveniles. Small teleost prey was 

consumed more frequently by small sharks; whereas large 

teleosts became more common in big sharks. Significant 

monthly changes in feeding patterns were exhibited by 

young of the year, where June young of the year contained 

less total prey, ate smaller meals, and consumed 

predominantly less mobile species. August young of the 

year diet was similar in composition to small juvenile diet 

from June and July, and small juvenile diet in August was more consistent with the diet of large 

juvenile sharks. The dramatic monthly changes in feeding by young of the year suggested 

improvement in hunting capability by late summer, with some shifts to larger or more mobile 

prey continuing in juveniles. Overall, monthly peaks in consumption of some prey were 

consistent with reported times of peak abundance for those species, and this suggested a 

generally opportunistic strategy of feeding on abundant species. 

Results from non-lethal stomach eversion technique for sandbar sharks show great promise for 

trophic ecology studies. The technique involves inserting PVC pipe appropriately sized to the
 

mouth and pharynx into the throat and the stomach past the cardiac sphincter. The pipe is slowly
 

removed generating negative pressure, which draws the stomach into the pipe and down into the
 

mouth. In most cases, the stomach returned to its natural position when the shark was held 

upright; otherwise forceps were used. Only four sharks could not be everted and had to be
 

sacrificed; all contained extremely large meals (>3.3 %BM) of either teleost or elasmobranch
 

prey in the earliest stages of digestion. This technique was considered effective at limiting
 

sampling mortality, as 19 (1.8 percent) of 1,051 tagged and everted sharks were recaptured to 

date. Time at liberty (3–1,732 days) and straight line distance traveled (0–506 km) varied, 

though 68 percent of sharks were recaptured in Delaware Bay. The tag return rate and
 

movements were similar to other studies on C. plumbeus in the region. In addition, sharks kept
 

in tanks for feeding experiments survived multiple eversions.
 

Smooth Dogfish (Mustelus canis)
 

Quantitative ontogenetic, sexual, and monthly differences in food habits and feeding patterns of
 

Figure A1.11. Juvenile sandbar 

shark on NEFSC COASTSPAN 

Survey bottom longline. 

Source: NMFS photo. 

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smooth dogfish were examined in Delaware Bay, with 98 percent of the stomachs containing 

food with an average of 8 prey items in various digestive states per stomach, indicating a 

continuous feeding pattern. This shark species fed upon an array of invertebrate prey with 

significant ontogenetic shifts in prey composition. Young of the year consumed smaller and less 

mobile invertebrates; larger sharks had a diet of predominantly benthic macro-invertebrates, 

including most common large crab species, several gastropods, and a few teleosts. Differences 

in meal size, diet diversity, prey number, and total biomass among size classes were limited, 

indicating limited ontogenetic changes in foraging patterns. Some changes in diet composition 

between months occurred but likely reflected shifts in prey availability or habitat usage. The 

continuous feeding pattern of this species may help compensate for the lower energetic value of 

many of the prey. The large number and mass of prey items per stomach, as well as the 

abundance of this species, indicate that this species plays an important role in the trophic 

relationships of the macro-invertebrate community in the bay. 

In collaboration with the MDMF, NEFSC staff is also working to examine the feeding ecology 

of smooth dogfish in Massachusetts waters. This study was designed to characterize the diet of 

smooth dogfish where there is significant overlap with higher densities of American lobster 

(Homarus americanus). Consumption of lobster by predators such as smooth dogfish is thought 

to be extensive in this area, and may have led to the drastic decline in local abundance of the 

lobster over the past decade. Preliminary analysis found CPUE was greatest in the earlier 

months of the survey largely because of the abundance of male smooth dogfish. The sex ratio 

was dominated by males in May and June and then shifted toward females in the summer 

months. A dramatic decrease in the number of males occurred in July, which coincided with 

peak water temperatures within the bay during the same period. Stomach contents of all dogfish 

were everted and analyzed. The diet of the smooth dogfish consisted mostly of crustaceans, with 

lobster, rock crab, common spider crab, and mantis shrimp among the most common prey items. 

Preliminary analyses suggest that smooth dogfish may be an underestimated predator of the 

American lobster population in Buzzards Bay, but the extent to which they impact the lobster 

population remains to be determined. 

Resource Partitioning Between Shark Species 

Comparative feeding ecology and size-specific resource partitioning was examined between two 

abundant shark species in Delaware Bay, the sandbar shark and smooth dogfish. Foraging 

patterns differed distinctly; the smooth dogfish exhibited continuous feeding with numerous 

small meals, whereas the sandbar shark consumed larger, less frequent meals. Diet overlap 

between the species was restricted to adult smooth dogfish and young of the year sandbar shark, 

which exhibited differences in temporal and spatial distribution within the Bay. Adult smooth 

dogfish were captured in deeper regions, especially after June, more often than young of the year 

sandbar shark, which were principally captured in very shallow regions, particularly early in the 

summer. Thus, these two shark species partition resources by a combination of ontogenetic and 

monthly differences in diet and habitat use. 

Temporal Changes in Diet Between Shark Species 

Using the food habits data collected by the NEFSC Apex Predators Program over the past 38 

years, we examined temporal changes in prey species, taxonomic and ecological prey groups, 

and overall trophic levels for the blue shark and the shortfin mako. Indices of standardized diet 

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composition were analyzed to identify changes in the prey species consumed, and then related to 

temporal changes in the distribution and abundance of these prey items. The two shark species 

have dissimilar feeding strategies and respond differently to environmental changes and 

fluctuations in prey availability. The blue shark has a generalized diet and easily switches 

between prey types. Over the 4-decade period, some prey categories showed dramatic increases 

in the diet (spiny dogfish, marine mammals), others declined (cephalopods, flatfishes, hakes), 

and others fluctuated (bluefish, herrings, mackerels). The shortfin mako is more specialized, 

consuming mainly bluefish, and appears resistant to dietary change when its preferred prey 

becomes less abundant. A presentation summarizing some results was given at the 2010 

American Elasmobranch Society Meeting. 

Basking Shark Isotope Analysis 

Researchers at the Woods Hole Oceanographic Institution, MDMF, and NEFSC are using 

isotopic analysis on vertebrae to determine the trophic position of the basking shark as well as to 

learn more about their migratory behavior and ocean connectivity. This type of retrospective 

trophic-level reconstruction has broad applications in future studies on the ecology of this shark 

species to determine lifelong feeding and migratory patterns and to augment electronic tag data. 

Sable Island Seal Predation 

An investigation into shark predation on five species of seals on Sable Island, Nova Scotia, was 

completed in conjunction with Sable Island researcher Zoe Lucas (Lucas and Natanson 2010). 

Between 1993 and 2001, 4,906 seal corpses bearing wounds likely inflicted by sharks were 

examined on Sable Island. Five seal species were involved: grey (Halichoerus grypus), harp 

(Pagophilus groenlandica), harbor (Phoca vitulina), hooded (Cystophora cristata), and ringed 

(Phoca hispida) seals. Flesh wounds on seal corpses indicated that two or more shark species 

prey on seals in waters around Sable Island. Wounds were categorized as either slash or 

corkscrew, with different predators identified for each type. Wound patterns, tooth fragments, 

and marks on bones indicated that white sharks (Carcharodon carcharias) were involved in the 

slash wounds, which comprised a small proportion of attacks. Ninety-eight percent of seal 

corpses, however, bore the corkscrew wounds that could not be attributed to shark species 

identified in attacks on pinnipeds in other regions, and these wounds are previously unreported in 

the literature. Circumstantial evidence indicates that attacks by Greenland sharks (Somniosus 

microcephalus) were responsible for the clean-edged encircling corkscrew wounds seen on seal 

corpses washed ashore on Sable Island. This research was the basis of an episode of National 

Geographic Predator CSI, “Corkscrew killer.” 

Movements and Migrations Using Conventional and Electronic Tag Technology 

Cooperative Shark Tagging Program (CSTP) 

The CSTP provides information on distribution, movements, and essential fish habitat for shark 

species in U.S. Atlantic and Gulf of Mexico waters. This program has involved more than 7,000 

volunteer recreational and commercial fishermen, scientists, and fisheries observers since 1962. 

In 2011, information was received on 7,300 tagged and 415 recaptured fish, bringing the total 

numbers tagged to 230,000 sharks of more than 50 species and 13,600 sharks recaptured of 33 

species. To improve the quality of data collected through the CSTP, the Guide to Sharks, Tunas, 

& Billfishes of the U.S. Atlantic and Gulf of Mexico has been reprinted and made available to 

recreational and commercial fishermen through the Rhode Island Sea Grant. In addition, 

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identification placards for coastal and pelagic shark species were distributed. A toll-free number 

has been established, as well as online reporting to collect information on recaptures for all 

species. 

Alternative tag testing is underway utilizing recreational tag and release tournaments, the most 

recent in February 2009. These events offer an opportunity to investigate the use of two new 

dart tags on coastal and pelagic sharks. Many of these events have 100 percent observer 

coverage on the recreational boats, with observers alternatively using each tag type and recording 

tag data, release condition, and total catch and effort. This will allow an initial evaluation of 

these tags by getting feedback from the participants on how easy each tag is to handle, how well 

they stay on the tagging needle, and how easily the dart head penetrates the shark skin. This 

feedback on tag use and subsequent recaptures will enable us to begin to evaluate these tag types 

for future use. 

Integrated Mark-Recapture Database Management System (I-MARK) 

The NEFSC I-MARK system provides a platform to keep multispecies tagging program data in a 

common format for management and analysis. Initiated by the Cooperative Research Program, 

the database design and application were developed collaboratively by the shark, yellowtail 

flounder, black sea bass, and scup tagging programs, and Data Management Systems. A web 

application is used for data input and quality control. I-MARK was designed to track fish and 

tags independently. It consists of several web application modules including inventory of tags, 

initial release events, subsequent recapture events, bulk data entry of cruise releases, contact 

name and address information, map display, reports, and statistical queries. Fate of animal, fate 

of tag, double tags, and multiple recaptures can be accommodated within the database. 

Extensive quality control is achieved using the web application to enter and maintain the IMARK data. These audits can be applied to data for all fisheries or a specific fishery and 

encompass standard audits such as checking data type, land locations, and allowable values, as 

well as more complex validations that check relationships between the fate of animal, fate of tag, 

and event type. A constituent release recapture letter is generated by the web application with a 

map and information on size, location, time at liberty, and distance traveled. In 2011, all 

scanned tag card images from the CSTP were linked to the existing I-MARK system. 

Porbeagle (Lamna nasus) Movement Patterns 

A study on the movement patterns, habitat utilization, and post-release survivorship of 

porbeagles captured on longline gear in the North Atlantic is being completed in conjunction 

with scientists from MDMF and the University of Massachusetts. The primary objective of this 

research is to deploy PSAT tags to examine the migratory routes, potential nursery areas, 

swimming behavior, and environmental associations that characterize habitat utilization by 

porbeagles. Information will be obtained to validate the assessment of the physiological effects 

of capture stress and post-release recovery in longline-captured porbeagles. These efforts will 

potentially allow the quantification of the stress cascade for this shark species captured using 

commercial gear, thereby providing fishery managers with data showing the minimum standards 

for capturing (e.g., longline soak time) and releasing these fishes to ensure post-release survival. 

Based on known and derived geopositions, the porbeagles exhibited broad seasonally dependent 

horizontal (77–870 km) and vertical (surface to 1,300 m) movements. All of the sharks 

remained in the western North Atlantic from the Gulf of St. Lawrence and the coast of Nova 

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Scotia to Georges Bank and oceanic and shelf waters south to North Carolina. In general, the 

population appears to contract during the summer and fall with more expansive radiation in the 

winter and spring. Although sharks moved through temperatures ranging from 2–26°C, the bulk 

of their time was spent in water ranging from 8–16°C. In the spring and summer months, the 

sharks remained epipelagic in the upper 200 m of the water column. In the late fall and winter 

months, some of the porbeagles moved to mesopelagic depths (200–1,000 m). Temperature 

records indicate that these fish were likely associated with the Gulf Stream. Additional analyses, 

which include the integration of these data with those from the long-term conventional tagrecapture database, are ongoing. Since none of these fish moved to the northeast Atlantic, this 

work also supports the two stock hypotheses for the North Atlantic. 

Spiny Dogfish (Squalus acanthias) Tagging Study 

The NEFSC Apex Predators and Cooperative Research Programs have joined forces to conduct a 

spiny dogfish tagging study to better assess stock structure, movement patterns, and life history 

for this species. The goal of this study is to tag spiny dogfish in two consecutive years during the 

winter and summer months in each of three designated regions: Southern New England, Gulf of 

Maine, and Georges Bank. In 2011, nine cruises were conducted, one in each area during the 

months of February, July, and late November/early December, with 16,034 spiny dogfish tagged 

and released during these cruises. 

Blacktip Shark (Carcharhinus limbatus) Movement Patterns 

Mark/recapture data from the NMFS CSTP were summarized for the blacktip shark in the Gulf 

of Mexico from 1964 through 2011 (Swinsburg et al. 2012). Data on FL, life stage, movement, 

time at large, and displacement was provided. No blacktip sharks in this study moved between 

the Gulf of Mexico and the Atlantic or Caribbean. 

Similarly, there was no evidence of exchange 

between the eastern and western Gulf of Mexico. 

Blacktip sharks were distributed strictly within the 

200 m depth contour. Some (n=33) of these sharks 

migrated from the United States to Mexican waters 

within a time period of less than one year. These 

data were pivotal in determining the need for 

Figure A1.12. Tagged blacktip shark on 

NEFSC Coastal Shark Bottom 

Longline Survey. 

Source: NMFS photo. 

multiple (Gulf of Mexico and U.S. Atlantic) stock 

assessments for this species. Additional tagging of 

blacktip sharks in Mexico is necessary to further 

elucidate these exchange patterns. 

Scalloped Hammerhead Shark (Sphyrna lewini) 

Movement Patterns 

The scalloped hammerhead shark is found circumglobally in temperate to tropical seas and range 

from shallow coastal waters to the continental shelf and beyond. In the northwest Atlantic 

Ocean, this species is found from New York to the Caribbean Sea, and throughout the Gulf of 

Mexico. Despite their worldwide range and encounters with both benthic and pelagic fisheries, 

very little is known of this species' habitat preferences or movement patterns. The objective of 

this study is to analyze mark/recapture data from the CSTP and to investigate movement patterns 

and habitat selection as well as the possible role that gender and age may play in determining 

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these characteristics. A poster summarizing these results (Eddy et al. 2011b) was given at the 

2011 American Elasmobranch Society Meeting. 

Southeast Fisheries Science Center (SEFSC) 

Stock Assessments of Large Coastal, Small Coastal, Pelagic, and Prohibited Sharks 

Following a Data Preparatory Meeting held in 2011, the SCRS conducted a stock assessment of 

the shortfin mako in 2012. Although the conclusion for both the North Atlantic and South 

Atlantic stocks of shortfin mako was that the stock was not overfished and overfishing was not 

occurring, the Committee stressed that there was a high degree of uncertainty in the results of the 

stock assessment. During 2012, the Shark Working Group also completed an updated and 

extended Ecological Risk Assessment of 15 Atlantic pelagic sharks and one ray species (20 

stocks in total) which found that the five stocks with lowest productivity were the bigeye 

thresher, sandbar, longfin mako, night, and South Atlantic silky shark, whereas the highest 

susceptibility (to pelagic longline fisheries) corresponded to shortfin mako, North and South 

Atlantic blue sharks, porbeagle, and bigeye thresher. Based on one of the indices used, the 

bigeye thresher, longfin and shortfin makos, porbeagle, and night sharks were classified as the 

most vulnerable (a combination of low productivity and high susceptibility) stocks. 

In 2012, SEFSC staff completed the Gulf of Mexico blacktip shark stock assessment (SEDAR 

29). The assessment generally provided a consistent picture of stock status wherein the stock 

was determined to not be overfished (spawning stock fecundity was 2-2.6 times the MSY level) 

and overfishing was not occurring (fishing mortality was only 7-27 percent the level of F 

resulting in MSY), although one of the reviewers expressed concern about the reliability of the 

overfishing conclusion. 

Observer Programs 

Shark Longline Program 

This program is designed to meet the intent of the ESA and the Consolidated Atlantic HMS 

Fishery Management Plan (FMP). It was created to obtain better data on catch, bycatch, and 

discards in the shark bottom longline fishery. While on board the vessel, the observer records 

information on gear characteristics and all species caught, condition of the catch (e.g., alive, 

dead, damaged, or unknown), and the final disposition of the catch (e.g., kept, released, finned, 

etc.). Recent amendments to the Consolidated Atlantic HMS FMP based on updated stock 

assessments have significantly modified the major directed shark fishery in the U.S. Atlantic. 

The amendments implement a shark research fishery, which allows NMFS to select a limited 

number of commercial shark vessels on an annual basis to collect life history data and catch data 

for future stock assessments. Furthermore, the revised measures drastically reduce quotas and 

retention limits, and modify the authorized species in commercial shark fisheries. Specifically, 

commercial shark fishers not participating in the research fishery are no longer allowed to land 

sandbar sharks (Carcharhinus plumbeus), which have been the main target species. Outside the 

research fishery, fishers are permitted to land 36 non-sandbar large coastal sharks. In 2008, 

NMFS announced its request for applications for the shark research fishery from commercial 

shark fishers with a directed or incidental permit. Based on the temporal and spatial needs of the 

research objectives, and the available quota, 11 qualified applicants were selected for observer 

coverage in 2008, seven in 2009, nine in 2010 and 2011. These vessels carried observers on 100 

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percent of trips. Outside the research fishery, vessels targeting shark and possessing current 

valid directed shark fishing permits were randomly selected for coverage with a target coverage 

level of 4 to 6 percent. 

Shark Gillnet Program 

Since 1993, an observer program has been underway to estimate catch and bycatch in the 

directed shark gillnet fisheries along the southeastern U.S. Atlantic coast. This program was 

designed to meet the intent of the Marine Mammal Protection Act, the ESA, and the 1999 

revised FMP for HMS. It was also created to obtain better data on catch, bycatch, and discards 

in the shark fishery. Historically, the Atlantic Large Whale Take Reduction Plan and the 

Biological Opinion issued under Section 7 of the Endangered Species Act mandated 100 percent 

observer coverage during the right whale calving season (November 15 to April 1). Outside the 

right whale calving season, observer coverage equivalent to 38 percent of all trips was 

maintained. In 2007, the regulations implementing the Atlantic Large Whale Take Reduction 

Plan were amended and included the removal of the mandatory 100 percent observer coverage 

for drift gillnet vessels during the right whale calving season, but now prohibit all gillnets in an 

expanded southeast United States restricted area that covers an area from Cape Canaveral, 

Florida, to the North Carolina-South Carolina border, from November 15 through April 15. The 

rule has limited exemptions, only in waters south of 29 degrees N latitude, for shark strike net 

fishing14 during this same period, and for Spanish mackerel gillnet fishing in December and 

March. Based on these regulations and on current funding levels, the shark gillnet observer 

program now covers a portion of all anchored (sink, stab, set), strike, or drift gillnet fishing by 

vessels that fish from Florida to the North Carolina year-round. All observers must record 

information on all gear characteristics, species caught, condition of the catch, and the final 

disposition of the catch. Two vessels were observed fishing with drift gillnets totaling 10 sets on 

5 trips in 2012, along with 5 vessels observed making 6 strike gillnet sets on 6 trips. Eighteen 

vessels were observed making 300 sink gillnet sets on 62 trips in 2012. Trips were made 

targeting one or more of the following: mixed shark species, king mackerel (Scomberomorus 

cavalla), smooth dogfish (Mustelus canis), Spanish mackerel (Scomberomorus maculates), 

southern kingfish (Menticirrhus americanus), and mixed teleosts (including Atlantic croaker 

(Micropogonias undulates), bluefish (Pomatomus saltatrix), and mixed teleost species). 

Determination of critical habitat for the conservation of dusky shark (Carcharhinus obscurus) 

using satellite archival tags 

In an attempt to improve the conservation status of dusky shark, NMFS established a time-area 

closure off North Carolina from January to July to reduce bycatch of neonate and juvenile dusky 

sharks. To better evaluate the closed area and determine critical habitat of dusky shark, we are 

deploying PSATs. Based on geolocation data, sharks generally traveled about 10 km per day 

with an average of 691 km in total. Overall, mean proportions of time at depth revealed dusky 

sharks spent the majority of their time in waters 20–40 m deep but did dive to depths of 400 m. 

Tagged sharks had varied movement patterns. One shark that was tagged off Key Largo, 

Florida, in January moved north along the east coast of the United States to the North 

Carolina/Virginia border in June. A second shark also tagged off Key Largo in March traveled 

14 When a vessel fishes for sharks with strike nets, the vessel encircles a school of sharks with a gillnet. This is 

usually done during daylight hours, to allow visual observation of schooling sharks from the vessel or by using a 

spotter plane. 

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south toward Cuba. The third shark, tagged off North Carolina in March, moved little from 

where it was initially tagged but problems with estimating the geolocation precluded fully 

determining its movement patterns in and around the closed area. Three dusky sharks were 

tagged in 2012; one animal died, one tag did not report, and the third animal traveled 723 km 

north of where it was initially tagged. 

Elasmobranch Feeding Ecology 

The current Consolidated Atlantic HMS FMP gives little consideration to ecosystem function 

because there are little quantitative species-specific data on diet, competition, predator-prey 

interactions, and habitat requirements of sharks. Therefore, several studies are currently 

underway describing the diet and foraging ecology, habitat use, and predator-prey interactions of 

elasmobranchs in various communities. 

Cooperative Gulf of Mexico States Shark Pupping and Nursery Survey (GULFSPAN) and 

Tagging Database 

The SEFSC Panama City Shark Population Assessment Group manages and coordinates a survey 

of coastal bays and estuaries from Cedar Key, Florida, to Terrebonne Bay, Louisiana. Surveys 

identify the presence or absence of neonate (newborn) and juvenile sharks and attempt to 

quantify the relative importance of each area as it pertains to EFH. The Group initiated a 

juvenile shark abundance index survey in 1996. The index is based on random, depth-stratified 

gillnet sets conducted throughout coastal bays and estuaries in coastal areas of the Gulf of 

Mexico from April to October. The species targeted in the index of abundance survey are 

juvenile sharks in the large and small coastal management groups. This index has been used as 

an input to various stock assessment models. A database containing tag and recapture 

information on elasmobranchs tagged by GULFSPAN participants and NMFS Mississippi 

Laboratories currently includes over 8,000 tagged animals and 155 recaptured animals from 

1993 to present for both the Gulf of Mexico and U.S. southeast Atlantic Ocean. This fully 

searchable database is current through spring 2013 with hopes to have it online and searchable 

by all participants in FY 2014. 

Monitoring the Recovery of Smalltooth Sawfish (Pristis pectinata) 

The smalltooth sawfish was listed as endangered under the ESA in 2003. Smalltooth sawfish are 

the first marine fish and first elasmobranch listed under the ESA. Smalltooth sawfish were once 

common in the Gulf of Mexico and off the southeast coast of the United States. Decades of 

fishing pressure, both commercial and recreational, and habitat loss caused the population to 

decline by up to 95 percent during the second half of the twentieth century. Today they exist 

mostly in southern Florida. 

The completion of the Smalltooth Sawfish Recovery Plan in early 2009 brought about a new 

phase of research and management for the U.S. population of smalltooth sawfish. Research and 

monitoring priorities identified in the Recovery Plan are now being implemented. Field work is 

underway to gather information on determining critical habitat and monitoring the population. 

This information will evaluate the effectiveness of protective and recovery measures and help 

determine if the population is rebounding or, at the very least, stabilizing. 

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One of the high-priority research areas is monitoring of the number of juvenile sawfish in 

various regions throughout Florida to provide a baseline and time series of abundance. One of 

the more important regions for smalltooth sawfish identified in previous research is the section of 

coast from Marco Island to Florida Bay, Florida. This region encompasses the coast of the Ten 

Thousand Islands National Wildlife Refuge and Everglades National Park. Scientists from the 

Panama City Laboratory conduct monthly surveys in southwest Florida to capture, collect 

biological information, tag, and then release smalltooth sawfish. Preliminary results indicate that 

juvenile sawfish exhibit a high degree of site fidelity. Genetic identification of recaptured 

individuals indicates that sawfish caught on the same mudflat, for example, are siblings and a 

single adult female sawfish may give birth on that same mudflat year after year. Determination 

of critical habitat and movement and migration corridors for larger juvenile and adult sawfish is 

being undertaken using PSAT and SPOT tags. Preliminary results indicate sawfish are found at 

greater depths than originally anticipated and may be found in offshore aggregations in specific 

areas of the Gulf of Mexico. 

Life History Studies of Elasmobranchs 

Biological samples are obtained through research surveys and cruises, recreational and 

commercial fishermen, and collection by onboard observers on commercial fishing vessels. Age 

and growth rates and other life-history aspects of selected species are processed and analyzed 

following standard methodology. This information is vital as input to population models used to 

predict the productivity of the stocks and to ensure they are harvested at sustainable levels. 

Reproduction of the Blacktip Shark in the Gulf of Mexico 

Reproductive and age data were collected for blacktip sharks Carcharhinus limbatus in the Gulf 

of Mexico from fishery-dependent and -independent sources from 2006 to 2011 for stock 

assessment. A total of 757 blacktip sharks were sampled for reproductive analysis (399 females, 

358 males), of which 741 were aged. Additional length and age data from a previous age and 

growth study on blacktip sharks in the Gulf of Mexico (207 females, 161 males) were 

incorporated into the size- and age-at-maturity analyses. The results indicated that blacktip 

sharks in the Gulf of Mexico have a synchronous, seasonal reproductive cycle and that females 

exhibit a biennial ovarian cycle. Male and female mating and parturition peaked from March to 

May. Length at 50 percent maturity was estimated to be 105.8 and 119.2 cm FL for males and 

females, respectively, and age at 50 percent maturity was calculated as 4.8 and 6.3 years. Nearterm pups averaged 38 cm FL, and gestation was approximately 12 months. Litter size was 4.5 

pups per female, and fecundity was found to increase with both maternal size and age. Maternal 

body size—but not age—had a positive influence on offspring fitness. This represents the first 

comprehensive reproductive study of blacktip sharks in the Gulf of Mexico. 

Maximum Age and Missing Time in the Vertebrae of Sand Tiger Sharks (Carcharias taurus): 

Validated Lifespan From Bomb Radiocarbon Dating in the Western North Atlantic and 

Southwestern Indian Oceans 

Bomb radiocarbon analysis of vertebral growth bands was used to validate lifespan for sand tiger 

sharks, Carcharias taurus, from the western North Atlantic and southwestern Indian Oceans. 

Visual counts of vertebral growth bands were used to assign age and estimate year of formation 

for sampled growth bands in eight sharks from the western North Atlantic and two sharks from 

the southwestern Indian Ocean. Carbon-14 results were plotted relative to year of formation for 

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comparison with regional Δ14C reference chronologies to assess accuracy of age estimates. 

Results from the western North Atlantic validated vertebral age estimates up to 12 years, but 

indicated ages of large adult sharks were underestimated by 11-12 years. Age was also 

underestimated in adult sharks from the southwestern Indian Ocean by 14-18 years. Validated 

lifespan for C. taurus individuals in this study reached at least 40 years for females and 34 years 

for males. Findings indicate the current age-reading methodology is not suitable for estimating 

the age of C. taurus beyond approximately 12 years. Future work should investigate whether 

vertebrae of C. taurus record age throughout ontogeny, or cease to be a reliable indicator at some 

point in time. 

Age and Growth of Endangered Smalltooth Sawfish (Pristis pectinata) Verified with LA-ICPMS Analysis of Vertebrae 

Endangered smalltooth sawfish (Pristis pectinata) were opportunistically sampled in south 

Florida and aged by counting opaque bands in sectioned vertebrae (n = 15). Small sample size 

precluded traditional age verification, but fish collected in spring and summer had translucent 

vertebral margins, while fish collected in winter had opaque margins. Trends in strontium to 

calcium rations measured across vertebrae with laser ablation-inductively coupled plasma-mass 

spectrometry corresponded well to annual salinity trends observed in sawfish estuarine nursery 

habitats in south Florida, thus serve as a chemical marker verifying annual formation of opaque 

bands. Based on that finding and assumptions about mean birth date and timing of opaque band 

formation, estimated age ranged from 0.4 y for a 0.60 m TL male to 14.0 y for a 4.35 m TL 

female. Von Bertalanffy growth parameters computed from size at age data were 4.48 m for L‘, 

0.219 y21for k, and 20.81 y for t0. Results of this study have important implications for sawfish 

conservation as well as for inferring habitat residency of euryhaline elasmobranchs via chemical 

analysis of vertebrae. 

Cooperative Research-Visual identification guide for the fins of coastal elasmobranchs in the 

U.S. Atlantic Ocean. 

SEFSC and Stony Brook University completed a visual key (Abercrombie et al. 2013) for field 

identification of fins from shark species caught in fisheries in the Atlantic Ocean that are 

important to the global fin trade. Specifically, fisheries agents and customs inspectors will be 

able, with minimal training, to identify fins from CITES-listed species among groups of fins. 

The format of the guide is designed for rapid and, for many species, unambiguous identification 

using key characteristics of the fin, such as shape, color and texture. A photograph of a dorsal 

fin for 19 species and paired pectoral fins for 20 species has been included in this guide, along 

with a general distribution, a brief fin description and a list of similar species (if applicable) that 

may be confused for fins of the species in question. 

Cooperative Research—Brazil-U.S. pelagic shark research project 

Brazil (Universidade Federal Rural de Pernambuco) and the United States (NMFS SEFSC 

Panama City Laboratory and the University of Florida’s Florida Museum of Natural History) 

initiated a cooperative shark research project in 2007. The main goal of this cooperative project 

was to conduct simultaneous research on pelagic sharks in the North and South Atlantic Ocean. 

Central to conducting the research is development of fisheries research capacity in Brazil 

through graduate student training and stronger scientific cooperation between the United States 

and Brazil. Electronic equipment (hook-timer recorders and temperature and depth recorders) 

was sent from the United States to Brazil for deployment aboard commercial longline fishing 

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vessels to investigate preferential feeding times of pelagic sharks and associated fishing depths 

and temperatures for potential use in habitat-based models and estimation of catchability. 

Catches in longlines employing circle hooks (15/0 and 17/0) and 10/0 "J"- hooks were compared 

with the use of hook timers to measure differences in fishing mortality associated with time fish 

are hooked and on the line and hook type in the southwest Atlantic Ocean off the coast of Brazil. 

A total of 431 hook timers were activated, showing a clear increase in the mortality rate of fish 

caught with increasing time between capture and boarding; however, some species endured long 

capture periods surviving until the time of boarding. Swordfish had high mortality rates, unlike 

blue sharks, which had low mortality rates regardless of hook type and the location in which the 

hook was set. The species of tuna and billfish examined in this study showed a strong 

association between hook location and the animal’s release condition, with reduced mortality in 

individuals hooked externally. A trend of increased survival with increased individual fish 

length was observed for most species. However, in sharks, increased survival with increased 

individual fish length was only observed for the blue shark, while other shark species showed an 

opposite pattern, although the difference was only statistically significant for crocodile sharks. 

Results suggest that knowledge of factors affecting the survival of pelagic fish caught in longline 

fisheries may enable the development and adoption of fishing methods to reduce mortality of 

longline bycatch. 

In addition, the use of PSATs on blue, shortfin mako, and other pelagic sharks is intended to 

provide critical knowledge on daily horizontal and vertical movement patterns, depth 

distribution, and effects of oceanographic conditions on the vulnerability of these pelagic sharks 

to pelagic longline fishing gear. Six PSATs have been deployed to date (two oceanic whitetip 

sharks, three bigeye threshers and one longfin mako) in U.S. Atlantic waters. Archival satellite 

pop-up tags were also attached to three female blue sharks and two female shortfin mako sharks 

by pelagic longline fishing vessels in the southwestern Atlantic Ocean. Data collected by these 

tags are still being analyzed. 

Cooperative Research—Uruguay-U.S. pelagic shark research project 

The SEFSC is collaborating with Uruguay’s fisheries agency (DINARA) to advance knowledge 

on the productivity and susceptibility of pelagic sharks to longline fisheries in the western South 

Atlantic Ocean; aspects of which are largely unknown for pelagic sharks in the southern 

hemisphere. To that end, ten satellite tags have been deployed on blue sharks to date. Five tags 

are providing real time data, which along with data for ERA are used as outreach to promote the 

collaboration between NOAA and DINARA (http://cicmar.org/en/projects-developed-bycicmar/tiburuy-project-research-and-conservation-of-sharks-in-uruguay/blue-shark-satellitetracking). Staff from DINARA and the SEFSC also worked cooperatively on the creation of an 

identification guide for carcharhinid sharks of the Atlantic Ocean for ICCAT (ICCAT 2012). 

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Shark Assessment Research Surveys 

The SEFSC Mississippi Laboratories have 

conducted bottom longline surveys in the Gulf of 

Mexico (see Figure A1.13), Caribbean, and 

Southern North Atlantic since 1995 (30 surveys 

have been completed through 2012). The 

primary objective is assessment of the 

distribution and abundance of large and small 

coastal sharks across their known ranges in order 

to develop a time series for trend analysis. The 

surveys, which are conducted at depths between 

5 and 200 fathoms, were designed to satisfy five 

important assessment principles: stock wide 

survey, synopticity, well-defined sampling 

universe, controlled biases, and useful precision. 

The bottom longline surveys are the only long-term, nearly stock-wide, fishery-independent 

surveys of western North Atlantic Ocean sharks conducted in U.S. waters and neighboring 

waters. Recently, survey effort has been extended into depths shallower than 5 fathoms (9.1 

meters) to examine seasonality and abundance of sharks in inshore waters of the northern Gulf of 

Mexico and to determine what species and size classes are outside of the range of the sampling 

regime of the long-term survey. This work is being done in cooperation with the Dauphin Island 

Sea Lab and Gulf Coast Research Laboratory. For all surveys, ancillary objectives are to collect 

biological and environmental data, and to tag and release sharks. The surveys continue to 

address expanding fisheries management requirements for both elasmobranchs and teleosts. 

Figure A1.13. Scalloped hammerhead 

captured in the Gulf of Mexico during a 

bottom longline survey. 

Source: NMFS Mississippi Laboratories, 

Shark Team 

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