Report of the U.S. Longline 

Bycatch Reduction Assessment 

and Planning Workshop 

Seattle, Washington, USA 

18-20 September 2007 

Conveners: 

Office of Protected Resources 

National Marine Fisheries Service 

Silver Spring, MD 20910 

 

 U.S. Department of Commerce 

 National Oceanic and Atmospheric Administration 

 National Marine Fisheries Service 

 

 NOAA Technical Memorandum NMFS-OPR-41 

 September 2008 

Report of the U.S. Longline Bycatch Reduction 

Assessment and Planning Workshop 

Office of Protected Resources 

National Marine Fisheries Service 

Silver Spring, MD 20910 

NOAA Technical Memorandum NMFS-OPR-41 

September 2008 

U.S. Department of Commerce 

Carlos M. Gutiérrez, Secretary 

National Oceanic and Atmospheric Administration 

Vice Admiral Conrad C. Lautenbacher, Jr., USN (Ret.) 

Under Secretary for Oceans and Atmosphere 

National Marine Fisheries Service 

James W. Balsiger, Acting Assistant Administrator for Fisheries 
Suggested citation: 

National Marine Fisheries Service. 2008. Report of the U.S. Longline Bycatch Reduction 

Assessment and Planning Workshop. U.S. Dep. Commerce, NOAA Tech. Memo. NMFS-OPR41, 42 p. 

A copy of this report may be obtained from:

Office of Protected Resources 

NMFS, NOAA 

1315 East-West Highway, F/PR2 

Silver Spring, MD 20910 

Or online at: 

http://www.nmfs.noaa.gov/pr/publications/techmemos.htm 

Technical Memoranda are used for documentation and timely communication of preliminary 

results, interim reports, or special-purpose information and have not received complete review, 

editorial control, or detailed editing, however they are expected to reflect sound professional 

work. 
iii

TABLE OF CONTENTS 

EXECUTIVE SUMMARY ......................................................................................................... iv

PART I. WORKSHOP BACKGROUND AND INTRODUCTION ........................................ 1

PART II. SUMMARY OF WORKSHOP DELIBERATIONS AND OUTCOMES .............. 4

SECTION 1: OVERVIEW OF BYCATCH REDUCTION BY SPECIES GROUPS................................. 4 

Marine Turtles.............................................................................................................................4 

Seabirds.......................................................................................................................................10 

Marine Mammals.....................................................................................................................13 

Billfish..........................................................................................................................................16 

Sharks...........................................................................................................................................19 

SECTION 2: BREAKOUT SESSION DISCUSSION AND EVALUATION OF CURRENT BYCATCH 

REDUCTION EFFORTS........................................................................................... 19 

SECTION 3: PLENARY PRESENTATIONS AND DISCUSSIONS ON GLOBAL IMPLEMENTATION 

OF BYCATCH REDUCTION .................................................................................... 22 

SECTION 4: PLENARY DISCUSSION AND INITIAL PRIORITIZATION OF RESEARCH NEEDS .... 22 

PART III. BEST GEAR AND FISHING PRACTICES ......................................................... 24

PART IV. ACTION PLAN ........................................................................................................ 25

APPENDIX A: BEST GEAR AND FISHING PRACTICES ................................................. 27

APPENDIX B: TABLE OF NEAR-TERM ACTION PLAN ................................................. 29

APPENDIX C: WORKSHOP AGENDA ................................................................................. 31

APPENDIX D: LIST OF PARTICIPANTS............................................................................. 34

APPENDIX E: GROUND RULES............................................................................................ 37

APPENDIX F: RESULTS OF RESEARCH NEEDS PRIORITIZATION .......................... 39
iv

EXECUTIVE SUMMARY 

On September 18-20, 2007, NOAA’s National Marine Fisheries Service (NMFS), Office of 

Protected Resources, convened the U.S. Longline Bycatch Reduction Assessment and Planning 

Workshop (Workshop) in Seattle, Washington. 

The purpose of the Workshop was to review and assess the results of all U.S. longline bycatch 

reduction efforts to date, including the available information on the effects of circle hooks on 

bycatch species and target catch, and to use this information to (1) identify best gear and fishing 

practices and (2) develop an action plan to direct NMFS’ domestic and international marine 

turtle longline bycatch reduction efforts. The workshop focused primarily on marine turtle 

bycatch, while also considering bycatch of other species, including billfish, marine mammals, 

seabirds, and sharks. Twenty-six invited participants with expertise relevant to the issue of 

longline fishery bycatch participated in the Workshop. The majority of participants were NMFS 

staff; the remaining participants represented other federal agencies and intergovernmental and 

non-governmental organizations. 

During the workshop, federal participants identified best gear and fishing practices (see 

Appendix A) for each of five major categories of fisheries: swordfish (classic, shallow), bigeye 

(classic, deep), other pelagics (tunas, sharks, combination), mahi-mahi (artisanal), and demersal. 

Best gear and fishing practices were identified for the following categories: hook type/size, bait, 

gear configuration, light sources, set/haul time, fishing depth, and turtle avoidance tactics. For 

hook type, participants recommended circle hooks as a best gear type for all of the fishery 

categories, although recommended hook size varied for the different fisheries. For bait, 

participants recommended whole finfish, as large as practical, with the bait covering the point of 

the hook for all of the fishery categories. For gear configuration, light sources, set/haul time, 

fishing depth, and turtle avoidance tactics, best practice recommendations varied by fishery 

category. In some cases, there was insufficient information to make a recommendation. 

Drawing on discussions of best gear and fishing practices, global implementation and the 

implications of the Magnuson-Stevens Fishery Conservation and Management Reauthorization 

Act (MSRA), and research needs and priorities, federal participants also developed a concise 

near-term (1-3 years) action plan (see Appendix B) for guiding NMFS’ domestic and 

international efforts to implement best practices for reducing marine turtle bycatch in longline 

fisheries. Participants recommended one or more actions and an estimated timeline to complete 

the action for each of six identified focus areas. The six focus areas addressed: 

 Reducing domestic bycatch by modifying gear and fishing practices; 

 Reducing international bycatch by working within regional fishery management 

organizations, bilateral agreements, international turtle agreements, and international 

provisions in the Magnuson-Stevens Fishery Conservation and Management Act; 

 Refining safe handling and release practices; 

 Continuing gear research both domestically and internationally; 

 Increasing capacity building and outreach; and 

 Enhancing information dissemination and packaging. 
v

The workshop consisted of two sessions: an open session (Days 1-2), and a federal closed 

session (Day 3). The primary purpose of the open session was to inform Day-3 federal 

discussions on best gear and fishing practices and an action plan. The workshop also included a 

mix of plenary presentations and discussions and breakout session discussions. Key experts 

presented updates on bycatch in longline fisheries for different taxonomic groups, including 

marine turtles, billfish, marine mammals, and seabirds. Participants also participated in extended 

breakout sessions to discuss and evaluate current longline bycatch reduction efforts. Here, 

participants exchanged information and views on: recent efforts to reduce hooking (e.g., through 

the use of different hook designs, bait types, and light sources); recent efforts to reduce 

entanglement and the role played by hook design, gangion design, and use of leaded swivels; the 

effectiveness of current safe handling and release practices; and key issues affecting current 

experimental data and estimation methods. 

1

PART I. WORKSHOP BACKGROUND AND INTRODUCTION 

The NMFS U.S. Longline Bycatch Reduction Assessment and Planning Workshop took place on 

September 18-20, 2007 in Seattle, Washington. 

Workshop Purpose 

The purpose of the Workshop was to review and assess the results of all U.S. longline bycatch 

reduction efforts to date, including the available information on the effects of circle hooks on 

bycatch species and target catch, and to use this information to (1) identify best gear and fishing 

practices and (2) develop an action plan to direct NMFS’ domestic and international marine 

turtle longline bycatch reduction efforts. The Workshop focused primarily on marine turtle 

bycatch while also considering bycatch of other species, including billfish, marine mammals, 

seabirds, and sharks. 

The Workshop outcomes described below are intended to serve as guidance and 

recommendations for the agency. 

Workshop Organization 

The Workshop was organized into two parts, as follows: 

• Days 1-2 of the Workshop were open to invited federal and non-federal participants as 

well as public observers. The format included a mix of plenary presentations and 

discussions and breakout session activities. The primary purpose of this open session was 

to inform agency-only discussions on Day 3. In particular, Days 1-2 were designed to 

provide background and context to Workshop participants on the topics of longline 

bycatch reduction efforts for various taxonomic groups. Other topics discussed included 

research needs and global implementation of bycatch reduction. 

• Day 3 was a closed planning session in which only federal government officials 

participated. The primary purpose of the federal closed session was to develop Workshop 

recommendations on (1) best gear and fishing practices, and (2) an action plan for 

directing NMFS’ future domestic and international marine turtle longline bycatch 

reduction efforts. These topics are discussed in sections below. 

The agenda for the Workshop is provided in Appendix C. 

Discussions during Days 1-2 of the Workshop focused on the exchange of facts and information. 

The aim was to seek the ideas, views, and recommendations of individual Workshop 

participants; it was not to seek consensus advice on future federal government policies or actions 

from participants as a group. The information gathered during Days 1-2 was to inform the 

Federal planning session on Day 3. 
2

Participants, Roles, and Ground Rules 

Twenty-six invited participants with expertise relevant to the issue of longline fishery bycatch 

participated in the Workshop. Participants were recruited based upon their expertise in longline 

fishery bycatch of marine turtles, billfish, marine mammals, seabirds, and/or sharks. See 

appendix B for a list of participants. 

The majority of participants were NMFS staff, including individuals from Regional Offices and 

Science Centers as well as the Offices of Protected Resources, Sustainable Fisheries, and 

International Affairs. The other federal agency represented was the U.S. Department of State. 

Non-federal participants included representatives from intergovernmental and non-governmental 

organizations. One member of the public, representing a conservation organization, attended the 

workshop as an observer. 

NMFS Assistant Administrator Bill Hogarth participated and offered welcoming remarks. 

CONCUR, Inc—an environmental mediation firm specializing in marine and water resources 

issues—facilitated the Workshop. 

The primary role of invited participants was to provide expert input for NMFS’ consideration. In 

this role, participants were asked to share pertinent information, ask clarifying questions, and 

express professional views in both plenary and breakout sessions. Observers were invited to view 

and track the deliberations on Days 1-2 but not participate in the discussions. 

Workshop participants adopted a set of ground rules for the Workshop. The ground rules were 

intended to foster and reinforce constructive interaction and deliberation among the Workshop 

participants. They emphasized clear communication, respect for divergent views, creative 

thinking, and collaborative problem solving. The adopted ground rules for the Workshop are 

presented in Appendix D. 

Workshop Preparations 

Workshop preparations were guided by a steering committee consisting of both agency staff and 

non-agency participants. Steering committee members included: Chris Boggs, Alan Bolten 

Kristy Long, Pat Moran, Cheryl Ryder, Barbara Schroeder, Kim Rivera, Yonat Swimmer, and 

John Watson. The steering committee worked with the CONCUR facilitation team in the 

preparation of the Workshop. 

To help establish the context for the Workshop, Workshop conveners produced a Workshop 

reader synthesizing relevant information on longline bycatch reduction activities. This internal 

document, intended for Workshop participants only, represented the latest information on 

longline bycatch reduction efforts and research. The compiled reader included background 

information on the following topics: 

• Description of longline fishing gear 

• Overview of artisanal fisheries 
3

• Summary of marine turtle longline bycatch mitigation research (including research from 

the Pacific and Azores) 

• Summary of recent technical workshops on sea turtle bycatch reduction efforts and 

experiments 

• Summary of longline bycatch reduction activities from nations and regions 

• Summary of international tools and measures for reducing longline bycatch of marine 

turtles 

• Comparison of longline bycatch reduction outreach materials 

• Summary of bycatch reduction research for billfish, marine mammals, seabirds, and 

sharks 

• List of select longline bycatch reduction publications 

Workshop Facilitators 

Scott McCreary and Eric Poncelet of CONCUR, Inc. served as the facilitators for the Workshop. 

CONCUR also worked closely with the Steering Committee in preparation of the Workshop. 

Additionally, CONCUR drafted a Workshop summary, which served as the basis for this 

Technical Memorandum. 

Workshop Logo 

Christofer Boggs of the NMFS Pacific Islands Fisheries Science Center graciously created the 

artistic logo for the Workshop. 
4

PART II. SUMMARY OF WORKSHOP DISCUSSION AND OUTCOMES 

Open Session (Days 1-2) 

The public portion of the workshop was organized into 4 sections: 

1) Overview of bycatch reduction by species groups 

2) Breakout session discussion and evaluation of current bycatch reduction efforts 

3) Plenary presentations and discussions on global implementation of bycatch reduction 

4) Plenary discussion and initial prioritization of research needs 

Key outcomes of each of these sections are summarized below. 

Section 1: Overview of Bycatch Reduction by Species Groups 

To set the context for the Workshop, key experts presented overviews on the bycatch species and 

bycatch reduction efforts in longline fisheries for several different taxonomic groups. The 

purpose of this discussion was to inform and update Workshop participants with regard to the 

latest in research and bycatch reduction efforts for the suite of taxonomic groups impacted by 

longline fisheries. Presentations included the following: 

Summary of Pelagic Longline Bycatch Mitigation Research Results 

John Watson, NMFS Southeast Fisheries Science Center 

Pelagic longline fishers and scientists in several countries have been developing, testing, and 

implementing fishing techniques and gear modifications to improve the selectivity and 

sustainability of pelagic longline fisheries and increase post-release survival of bycaught 

animals. This approach is an alternative to other management strategies that reduce available 

fishing grounds, such as time-area closures, which have historically predominated U.S. bycatch 

reduction measures, but which have been only rarely adopted by regional fisheries management 

organizations (RFMOs). 

Over the past decade, national governments, RFMOs, and longline industries have developed 

and tested numerous seabird mitigation methods in longline fisheries. Several methods nearly 

eliminate bird captures when correctly employed (Brothers et al. 1999). Methods that not only 

have the capacity to minimize bird capture, but are also practical and provide crew with 

incentives to employ them consistently and effectively, hold promise for minimizing seabird 

bycatch to negligible levels (Gilman, 2001). The methods include bird-scaring flag lines that 

stream behind the vessel (“tori lines”), line shooters, side setting, and weighted lines to rapidly 

sink the baits below the range of birds, and dyed bait to reduce visibility during deployment. 

Gilman and Moth-Poulsen, 2007, reviewed measures taken by intergovernmental organizations 

(IGOs) to address sea turtles and seabird interactions in marine capture fisheries. Several IGOs 

have begun to examine seabird or sea turtle interactions, several have adopted voluntary 

measures to address problematic interactions, and five RFMOs have legally binding measures 
5

requiring the employment of seabird avoidance methods in pelagic and demersal longline 

fisheries. Currently, there are no legally binding measures in place by an IGO to manage sea 

turtle-fishery interactions. 

In 1999, Hoey and Moore produced a comprehensive report on U.S. longline fishing gear 

operational characteristics. They concluded that geographic area, month, and time of set, gear 

soak time, surface temperature, fishing depth, bait size, bait type, baiting technique, hook size 

and hook type can have significant effects on the selectivity of pelagic longline gear. Beginning 

in 2000, several researchers began investigating mitigation measures designed to reduce bycatch 

in pelagic longline gear with emphasis on sea turtle bycatch. This research has resulted in the 

development of bycatch reduction strategies which include: safe handling and release gear and 

protocols, the use of circle hooks in place of traditional J-style hooks, the use of fish bait rather 

than squid and gear restrictions such as branch line lengths, limits on the length of mainline, and 

the use of non-stainless steel corrodible hooks. Much of this research has concentrated on the 

impact of changes in hook designs and bait type on bycatch and target species. In addition to 

hook and bait studies, research has been conducted on initiatives to reduce effort in shallow 

depths while refocusing effort in cooler strata associated with frontal systems or by fishing 

greater depths to reduce bycatch. One such technique has recently been developed to reduce 

shallow bycatch species and selectively target bigeye tuna by setting the gear to ensure all hooks 

are below 100m depth (Beverly, 2004). Other mitigation techniques being investigated include 

moving away from an immediate fishing area once an interaction has occurred and fostering 

vessel communications within the commercial fleet to avoid areas of high interaction. 

In 2007, the ICCAT sub-committee on ecosystems reviewed existing data on the effects of circle 

hooks and bait type on target and bycatch species compared to traditional J and tuna hooks in 

pelagic longline fisheries. The data reviewed included studies conducted in the Azores, U.S. 

Atlantic, Gulf of Mexico, and Pacific longline fisheries, Canadian North Atlantic, Eastern Pacific 

coastal longline fisheries, Japanese far seas fishery, Japanese Western North Pacific fishery, 

Korean Eastern Pacific fishery, Spanish Indian Ocean fishery, and Italian Mediterranean fishery. 

The results of this review indicated that the reported effect of circle hooks on target and bycatch 

species was dependent on the size of circle hooks relative to the size of traditional J and tuna 

hooks to which they were compared and, in some cases, was dependent on the bait type used in 

various fisheries. 

The available data include two published results of research and many research reports including 

preliminary reports on ongoing research. There are several caveats that should be considered 

when reviewing the available data: 

• The effect of circle hooks varies with hook size and shape and the size and shape of the 

hook to which it is being compared, and generalizations of the effect of circle hooks can 

be misleading and should be avoided. 

• Bait type and size can significantly alter the effect of circle hooks. 

• We must be very careful to draw conclusions from any study that does not include a 

complete description of the hooks and the bait type and size used in the study. 

• More rigorous studies are needed for some applications to determine the best circle hook 

size and shape and the bait type and size needed to achieve the desired result. 
6

Below is a summary of the effect of circle hooks and bait types by species on target and bycatch 

species. 

Swordfish 

Catch rates with circle hooks was dependent on bait type (U.S. North Atlantic and Eastern 

Pacific, Azores, Spanish Indian Ocean, Japan Far Seas Fishery). 

• 18/0 circle hook with squid bait compared to 9/0 J hooks with squid bait reduced 

swordfish catch between 21% and 33%. 

• 18/0 circle hook with large mackerel bait compared to 9/0 J hooks with squid bait 

increased swordfish catch between 5% and 30%. 

• 16/0 circle hook with squid bait reduced swordfish catch 31%. 

• 3.8 sun circle hook compared to 3.8 sun tuna hook: there was no substantial difference in 

swordfish catch rates. 

Bigeye Tuna 

Catch rates with circle hooks was dependent on bait type (U.S. North Atlantic and Eastern 

Pacific, Eastern Pacific Coastal, Japan Far Seas, Spanish Indian Ocean) 

• 18/0 circle hook with squid bait compared to 9/0 J hooks with squid bait increased bigeye 

tuna catch between 24% and 35%. 

• 18/0 circle hook with large mackerel bait compared to J hooks with squid bait decreased 

bigeye tuna catch between 50% and 83%. 

• 18/0 circle hook with small mackerel bait compared to 16 (?) J hook increased bigeye 

tuna catch 30%. 

• 3.8 sun circle hook compared to 3.8 sun J hook: there was no substantial difference in 

bigeye tuna catch. 

Yellowfin Tuna 

Catch rates with circle hooks was dependent on hook size (U.S. North Atlantic and Gulf of 

Mexico, Spanish Indian Ocean). 

• 18/0 circle hook with small fish bait compared to 16/0 circle hook with small fish bait 

reduced yellowfin tuna catch by 26% 

• 18/0 circle hook with squid bait compared to 16 (?) J hook increased yellowfin tuna catch 

6%

• 18/0 circle hook with small mackerel bait compared to 16 (?) J hook increased yellowfin 

tuna catch 46%

• 16/0 circle hook with mixed bait compared to J hooks increased yellowfin tuna catch by 

2.5 times 
7

Albacore Tuna

Catch rates with circle hooks was dependent on bait type (U.S. North Atlantic, Spanish Indian 

Ocean). 

• 18/0 circle hook with squid bait compared to 9/0 J hook with squid bait increased 

albacore tuna catch between 33% and 64%. 

• 18/0 circle hook with large mackerel bait compared to 9/0 J hook with squid bait reduced 

albacore tuna catch 85%. 

• 18/0 circle hook with squid bait compared to 16 (?) J hook increased albacore tuna catch 

16%. 

• 18/0 circle hook with small mackerel bait compared to 16 (?) J hook increased albacore 

tuna catch 56%. 

Mahi-mahi 

Large circle hooks consistently reduced catch of Mahi-mahi (U.S. North Atlantic and Eastern 

Pacific). 

• 18/0 circle hook with squid bait compared to 9/0 J hooks with squid bait decreased Mahimahi catch between 61% and 80%. 

• 18/0 circle hook with large mackerel bait compared to 9/0 J hooks with squid bait 

reduced Mahi-mahi catch between 34% and 85%. 

All Tuna Species Combined 

Studies that combined data for all tunas indicate that circle hook performance is dependent on 

hook size (U.S. Eastern Pacific, Eastern Pacific Coastal, Japan Far Seas, Korean Eastern Pacific). 

• 18/0 circle hook with large mackerel bait compared to J hooks reduced all tunas 

combined by 50%. 

• 16/0 circle hook with mixed bait compared to tuna and J hooks had similar catch rates for 

all tuna combined. 

• 18/0 circle hook with mixed bait compared to 4.0 tuna hook reduced all tuna combined by 

35%. 

• 15/0 circle hook with mixed bait compared to 4.0 tuna hook reduced all tuna combined by 

2%. 

Sharks 

Circle hook effect on shark catches was dependent on hook size and bait type (U.S. North 

Atlantic and Eastern Pacific, Japan Western North Pacific, Korean Eastern Pacific). 

• 18/0 circle hook with squid bait compared to 9/0 J hook increased blue shark catch rate 

by 9%. 

• 18/0 circle hook with large mackerel bait compared to 9/0 J hook decreased blue shark 

catch by 30%. 
8

• 18/0 circle hook with large mackerel bait decreased all sharks combined 34%. 

• 4.3 sun and 5.2 sun circle hooks with squid bait compared to 3.8 sun tuna hooks; there 

was no significant difference for blue shark catch. 

• 18/0 circle hooks with mixed baits compared to 4.0 tuna hooks reduced combined shark 

catch 57%. 

• 15/0 circle hooks with mixed baits compared to 4.0 tuna hooks reduced combined shark 

catch 52%. 

Billfish 

Circle hooks reduced billfish catch rates (Korean Eastern Pacific). 

• 18/0 circle hooks with mixed baits compared to 4.0 tuna hooks reduced billfish catch 

17%. 

• 15/0 circle hooks with mixed baits compared to 4.0 tuna hooks reduced billfish catch 

40%. 

Seabirds 

Observer data from the U.S. North Atlantic indicates six times lower seabird CPUE with circle 

hooks compared to J hooks. 

Loggerhead Sea Turtles 

Circle hook effect was dependent on circle hook size and bait type (U.S. North Atlantic and 

Eastern Pacific, Canadian North Atlantic, Azores, Eastern Pacific Coastal, Japan Far Seas, 

Korean Eastern Pacific, Italian Mediterranean). 

• 18/0 circle hook with squid bait compared to 9/0 J hook reduced loggerhead sea turtle 

catch between 77% and 85%. 

• 18/0 circle hook with large mackerel bait compared to 9/0 J hook reduced loggerhead sea 

turtle catch between 88% and 90%. 

• 18/0 circle hook with squid bait compared to 3.6mm tuna hook reduced loggerhead sea 

turtle catch 74%. 

• 16/0 circle hook with squid bait compared to 3.6mm tuna hook reduced loggerhead sea 

turtle catch 58%. 

• 16/0 circle hook with mixed bait compared to small (< 9/0) J hooks reduced hard shell sea 

turtle catch (loggerhead and olive ridley) between 40% and 60%. 

• 3.8 sun circle hook compared to 3.8 sun J hook not effective in reducing loggerhead turtle 

CPUE. 

• 4.3 sun and 5.2 sun circle hooks compared to 3.8 sun J hooks had potential to reduce 

hooking rates of loggerhead turtles. 

• 16/0 circle hook compared to J hook with same gape was effective in reducing 

loggerhead catch. 

• 16/0 circle hook compared to 4/0 J hook reduced loggerhead catch. 
9

• Squid Versus Fish Bait – 95.5% of hardshell turtles captured on sets using squid bait 

(Canada). Loggerhead turtle catch rate for squid was substantially higher than that for 

mackerel. 

Leatherback Sea Turtles 

Large circle hooks and large mackerel bait effective in reducing leatherback catch (most 

leatherback interactions are entanglement) (U.S. North Atlantic and Eastern Pacific and 

Canadian North Atlantic). 

• 18/0 circle hook with squid bait compared to 9/0 J hook reduced leatherback turtle catch 

between 50% and 75%. 

• 18/0 circle hook with large mackerel bait compared to 9/0 J hook reduced leatherback 

catch between 63% and 83%. 

• 16/0 circle hook compared with 9/0 J hook; leatherback turtle captures increased when J 

hooks were used. 

Hook Effects and Implications for Post-Release Mortality 

A much higher percentage of all bycatch species are hooked in the mouth with circle hooks than 

with J hooks, which more often are deeply swallowed (U.S. North Atlantic and Eastern Pacific, 

Azores, Eastern Pacific Coastal, Japan Far Seas). 

• For J hooks between 60% and 68.8% of loggerhead turtles caught swallowed the hooks 

compared to between 13% and 27.3% for circle hooks. 

• The 3.8, 4.3, and 5.2 sun circle hook reduced the proportion of turtles hooked in the 

throat and increased the proportion hooked in the mouth compared to the 3.8 sun tuna 

hook. 

• A significantly higher proportion of white marlin and blue marlin were released alive 

from circle hooks compared to J hooks. 

• Juvenile bluefin tuna release mortality was 4% for circle hooks compared to 28% for J 

hooks. 

Summary of research findings:

1. Circle hooks reduce the proportion of hooks that are swallowed by bycatch and target 

species compared to “J” hooks. 

2. Fish bait reduces the catch rate for sea turtles compared to squid bait. 

3. Reduction in bycatch species catch rates with circle hooks is dependent on the size of 

circle hooks relative to the “J” hooks to which they are compared and, in some cases, is 

bait dependent. 

4. The effect of circle hooks on target species is dependent on circle hook size and bait type 

and size. 

5. Research results must include hook specifications and bait type and size. 

6. There is a need to standardize hook measurement techniques and terminology. 

 
10

Recommendations:

1. Switch to fish bait from squid bait. 

2. Use 18/0 or 5.2 sun circle hooks in swordfish and bigeye tuna fisheries. 

3. Conduct additional research to determine most effective circle hooks size for other tuna 

and Mahi-mahi fisheries. 

NMFS National Seabird Program: Seabird Bycatch Reduction Efforts 

Kim Rivera, NMFS Alaska Fisheries Science Center

Increased concerns have arisen about the incidental capture of non-target species in various 

fisheries throughout the world. Incidental capture can be economically wasteful, it impacts living 

marine resources, and the accidental killing of non-harvested animals may be aesthetically 

averse. Incidental catch of non-target marine species such as marine mammals, sea turtles, and 

seabirds has generated growing concern over the long-term ecological effects of such bycatch in 

longline and other fisheries conducted in many areas of the world's oceans. 

In response to these concerns, the United Nations' Food and Agriculture Organization (FAO) 

called for an expert consultation on the issue of global seabird bycatch in longline fisheries. As a 

result of the consultation, the FAO adopted an International Plan of Action for Reducing the 

Incidental Catch of Seabirds in Longline Fisheries (IPOA-S) in 1999. The IPOA-S applies to 

"States" (hereafter Countries) in whose waters longline fishing is being conducted by their own 

or foreign vessels, and to Countries that conduct longline fishing on the high seas and in the 

exclusive economic zones (EEZs) of other Countries. The IPOA-S is a voluntary measure that 

calls on Countries to: (1) assess the degree of seabird bycatch in their longline fisheries; (2) 

develop individual national plans of action (NPOA-Seabirds) to reduce seabird bycatch in 

longline fisheries that have a seabird bycatch problem; and (3) develop a course of future 

research and action to reduce seabird bycatch. The NPOA-Seabirds is to be implemented 

consistent with the FAO Code of Conduct for Responsible Fisheries and all applicable rules of 

international law, and in conjunction with relevant international organizations. 

The FAO’s Committee on Fisheries (COFI) focused considerable attention at its 27th Meeting 

(COFI-27, March 2007) on the IPOAs for seabirds and sharks and the sea turtle guidelines. 

Several Members advised COFI on their progress to develop or implement their NPOA-Seabirds. 

Many Members were of the view that FAO, in collaboration with BirdLife International, should 

seek to strengthen the implementation of the IPOA-Seabirds by developing best practice 

technical guidelines to support the elaboration of NPOA-Seabirds. It was agreed that FAO 

should, in cooperation with relevant bodies, develop best practice guidelines to assist countries 

and Regional Fishery Management Organizations (RFMOs) in implementation of the IPOA–

Seabirds and that the best practice guidelines should be extended to other relevant fishing gears. 

Many Members expressed the view that the Commission for the Conservation of Antarctic 

Marine Living Resources (CCAMLR), the Agreement on the Conservation of Albatrosses and 

Petrels (ACAP) and BirdLife International were the most relevant bodies in that context. It is 

likely that an FAO expert consultation will be held in 2008 to develop these best practice 

guidelines. 
11

The United States developed its NPOA-Seabirds in 2001. Development of the NPOA was a 

collaborative effort between the NOAA's National Marine Fisheries Service (NMFS), the U.S. 

Fish and Wildlife Service (FWS) and the Department of State (DOS), carried out in large part by 

the Interagency Seabird Working Group (ISWG) consisting of representatives from those three 

agencies. This partnership approach recognizes the individual agency management authorities 

covering seabird interactions with longline fisheries. Also in 2001, NMFS appointed its National 

Seabird Coordinator to head up its NPOA implementation initiatives. This work requires 

maintenance of a national perspective through coordinated regional activities. 

NMFS manages U.S. fisheries under the authority of the Magnuson-Stevens Fishery 

Conservation and Management Act and the High Seas Fishing Compliance Act. FWS manages 

birds predominately under the authority of the Endangered Species Act and the Migratory Bird 

Treaty Act. In addition, DOS has the lead role in international negotiations on fisheries 

conservation and management issues that should help promote IPOA implementation by 

encouraging other nations to develop NPOAs. Given each agency's responsibilities, the NPOASeabirds was developed collaboratively by NMFS and FWS. This collaborative effort has 

increased communication between seabird specialists and fishery managers in FWS and NMFS. 

Maintaining this cooperation is a high priority for both agencies. 

NMFS’ role in reducing seabird bycatch in fisheries is guided by the following: 

9 Magnuson-Stevens Fishery Conservation & Management Act (as reauthorized in 2006) 

9 Endangered Species Act 

9 United States’ National Plan of Action for Reducing the Incidental Catch of Seabirds in 

Longline Fisheries (NPOA-Seabirds) 

9 NMFS National Bycatch Strategy and National Bycatch Report 

9 Executive Order (EO) 13186 “Responsibilities of Federal Agencies to Protect Migratory 

Birds” 

New language in the Magnuson-Stevens Act requires the Secretary, within 1 year, to establish 

regional bycatch reduction programs to develop technological devices designed to minimize 

bycatch and seabird interactions in Federally-managed fisheries. The language further authorizes 

the Secretary to coordinate with Interior to undertake projects to improve information and 

technology to reduce seabird bycatch, including outreach to industry on new technologies and 

methods, mitigation projects, and actions at international fishery organizations. The Act further 

directs us to transmit an annual report to Congressional committees describing the funding 

provided to implement this section, development in gear technology achieved under this section, 

and improvements and reduction in bycatch and seabird interactions associated with 

implementing this section, as well as proposals to address remaining bycatch or seabird 

interaction problems. 

NMFS has been implementing the NPOA-Seabirds since 2001 and numerous activities have 

been undertaken such as: seabird avoidance regulations (NMFS Regions in Alaska, Pacific 

Islands, and the Southwest), Fishery Management Plan (FMP) development addressing seabird 

mitigation (West Coast Highly Migratory Species FMP), cooperative mitigation research with 

the longline industry (Alaska, Hawaii), observer training, education and outreach materials for 

fishermen and the public (NMFS Regions or Science Centers in Alaska, Pacific Islands, 
12

Southwest, Northwest, Northeast, and Southeast), and international efforts at numerous regional 

fishery management organizations that have jurisdiction for management of fisheries on the high 

seas, bilateral government fishery meetings, fishers forum, fisheries observer conferences, 

albatross and seabird conferences, and ACAP. 

NMFS pursues effective and practicable solutions for seabird bycatch reduction in its fisheries 

through collaborations with fishing industry groups, gear technologists, scientists, seabird 

biologists, and environmental conservation groups. These collaborative approaches have 

resulted in successful outcomes as seen by seabird bycatch reductions in Alaska and Hawaii 

longline fisheries. Since paired streamer lines with performance standards were implemented by 

the Alaska demersal longline fleet beginning in 2002, total seabird mortality and seabird bycatch 

rates are down by 69% and 79% respectively, while fishing effort increased. Results from a 

cooperative research study in Hawaii showed that side-setting was the most effective method at 

reducing seabird captures in both tuna and swordfish pelagic longline gear, resulting in seabird 

capture rates of 0.002 and 0.01 captures/1000 hooks, respectively. In 2006, the estimated 

albatross interactions with the Hawaiian longline fleet were less than 100 birds (73 black-footed 

albatross Phoebastria nigripes, 15 Laysan albatross P. immutabilis). This compares to bycatch 

in 2000 when over 2,300 albatross were estimated taken (1,339 black-footed albatross, 1,094 

Laysan albatross). This order of magnitude reduction likely occurred as a result of required 

mitigation measures and a modified swordfish fishery. 

NMFS’ action on seabird bycatch reduction in longline fisheries has focused on Pacific fisheries, 

where seabird species that more commonly interact with longline gear occur (e.g., albatross). 

Observer data from the Atlantic pelagic longline fishery has also been analyzed and relatively 

few seabirds are taken. Only 113 seabirds were estimated to be taken from 1992 to 2004 and 

greater shearwaters (Puffinus gravis) accounted for the majority of the take. Preliminary results 

from this data analysis suggest that sets using circle hooks may catch fewer birds than those sets 

using J hooks. The study sample size is small though and requires further study to determine if 

hook type impacts the number of birds hooked. This type of study and information is critical and 

could lend additional justification for the use of circle hooks to reduce impacts on non-target 

species. 

International efforts are also critical to stem any fishery impacts on seabird species that have 

broad global distributions. Efforts have included support of binding seabird avoidance measures 

at RFMOs and participating as an observer at the meetings of ACAP. ACAP’s involvement at 

RFMOs has increased and its Seabird Bycatch Working Group has developed a mitigation 

research plan that identifies top priorities for research to address mitigation in pelagic longline 

fisheries that is most likely to be both effective at reducing bycatch and practicable for fishermen 

to use. Identified high priorities include: streamer lines, bait setting capsule, side-setting, 

weighted branchlines, bait pod/smart hook, and circle hooks. 

Summary: 

9 Seabird bycatch in US domestic longline fisheries off Alaska and Hawaii has been 

reduced through collaborative and cooperative approaches with industry, scientists, and 

environmental conservation groups; 

9 Seabird bycatch reduction solutions are science-based and focus on methods and gear that 

are practicable for use by fishermen and may be fishery-specific; 
13

9 This model for seabird bycatch reduction efforts in US fisheries can be applied to 

international fisheries; 

9 Methods used for the bycatch reduction of turtles (i.e., circle hooks) may also reduce 

bycatch of seabirds; 

9 Research testing the efficacy of circle hooks on non-seabird species must also measure 

whether bycatch of seabirds is reduced; 

9 Development of bycatch reduction methods for one taxa must consider potential impacts 

on other taxa; and 

9 Continued research on effective mitigation methods for seabird bycatch reduction is 

needed and has been prioritized. 

Marine Mammals 

Lance Garrison, NMFS Southeast Fisheries Science Center 

Interactions between longline fishing gear and marine mammals is a global problem. The 

primary factor driving these interactions appears to be “depredation” or the removal of catch and 

bait from longline fishing gear by marine mammals. This behavior results in two important 

management concerns. First, depredation by marine mammals results in a direct economic loss 

to fishermen. In many cases, marine mammals can remove significant amounts of commercially 

valuable catch from the longline. Second, marine mammals often are either hooked or become 

entangled in fishing gear resulting in serious injury or mortality. While the overall rate of such 

interactions is relatively low, the large amount of longline fishing effort may result in high total 

estimated mortality and represents a conservation concern. Thus, identifying mechanisms to 

reduce the rate of depredation on longline fishing gear, and thereby reduce the likelihood of 

incidental bycatch or mortality of marine mammals, is both a significant management and 

conservation issue. 

 

Interactions with marine mammals have been observed in both pelagic and bottom longline 

fisheries throughout the world’s oceans. For example, in the Southern Ocean surrounding 

Antarctica, interactions between bottom longlines in the Patagonian toothfish (Dissostichus 

eleginoides) fishery from both Orca whales (Orcinus orca) and Sperm whales (Physeter 

macrocephalus) were common, but variable, with up to 70% of observed trips including some 

degree of interaction with these two species (Kock et al., 2006). For both mammal species, 

observer reports in this region indicate that they may remove up to 80% of the catch from the 

line leaving only toothfish jaws or lips behind in trips where the mammals are present. 

 

Similarly, depredation on demersal longlines by sperm whales has been documented in the 

Alaskan sablefish (Anoplopoma fimbria) fishery. These interactions have been studied through 

the “SEASWAP” program, which is a consortium of academic scientists, fishermen, and 

government scientists. In this fishery, a longer season with lower overall effort appears to have 

increased the opportunity for sperm whales to interact with fishing gear, and reports of 

depredation have increased rapidly in recent years. In an evaluation of 39 sets, sperm whale 

depredation was seen on 71% of sets when whales were present, and there was a significant loss 

of catch when whales were present. Sperm whales are frequently observed “waiting” near flag 

buoys for the gear to be hauled back and may be attracted to the acoustic signatures of the 

vessels during hauls (Jan Straley, University of Alaska, pers. comm.; reviewed in Donoghue et 
14

al., 2003). The SEASWAP program is continuing to investigate these interactions and the 

behavior of whales around fishing gear to identify potential mitigation approaches. 

Marine mammal interactions with pelagic longlines in tropical to temperate waters throughout 

the world’s oceans are also relatively common (reviewed in Donoghue et al., 2003). For the 

most part, these interactions are documented with smaller toothed whales described as 

“blackfish” such as Orca whales, false killer whales (Pseudorca crassidens), melon-headed 

whales (Peponocephala electra), pygmy killer whales (Feresa attenuata), or longfin or shortfin pilot 

whales (Globicephala sp.). For most of the international fleets, there is relatively little systematic 

observer coverage, and thus both the rates of interactions and the identification of species are 

uncertain. However, reports from fishermen indicate both that depredation is common and that 

cetaceans may be incidentally hooked or entangled in lines. Interviews with fishermen in the 

Taiwanese distant water longline fleet indicated that fishermen attempted to deter depredation by 

harpooning cetaceans or other forms of harassment, but that these efforts have limited effectiveness 

(reviewed in Donoghue et al., 2003). 

In U.S. waters, marine mammal interactions and incidental bycatch have been observed in the 

Hawaiian pelagic longline fishery with false killer whales and Risso’s dolphins (Grampus griseus) 

and in the East Coast pelagic longline fishery primarily with unidentified pilot whales and Risso’s 

dolphins (Grampus griseus). In the Hawaiian fisheries, there were a total of 84 documented cetacean 

takes from 1994-2006. The primary species interacting with this gear were false killer whales and 

Risso’s dolphins. For the most part, these interactions involved hooking in the mouth, and the 

animals were considered seriously injured (K. Forney, Southwest Fisheries Science Center, pers. 

comm.; Carretta et al., 2006). In 2004, regulations were implemented to mandate the use of larger, 

18/0 circle hooks. Preliminary analyses suggest a reduction in the overall rate of marine mammal 

interactions with longline gear associated with this change. However, analysis of these data is 

ongoing (K. Forney, Southwest Fisheries Science Center, pers. comm.). 

The east coast pelagic longline fishery has been the subject of a recent take reduction team mandated 

under the Marine Mammal Protection Act (MMPA) due to concerns over incidental serious injury 

and mortality of pilot whales in longline fishing operations in the mid-Atlantic Bight. The team met 

between June 2005 and April 2006 to evaluate patterns of incidental bycatch and develop approaches 

to reduce interactions. As with other pelagic longline fisheries, depredation, by pilot whales in 

particular, is a significant issue for fishermen, resulting in economic losses. Pilot whale bycatch in 

pelagic longline gear is concentrated primarily along the shelf-break between Cape Hatteras, North 

Carolina and New Jersey. Seasonally, the bycatch rates peaked during September through November 

as effort intensifies. The shelf break is particularly important since both longline effort and pilot 

whale spatial distribution is strongly correlated to this feature. This reflects oceanographic features 

that result in high densities of fish and squids, which in turn concentrates the large pelagic fish that 

are the target of the fishery along with marine mammals (Garrison, 2007). 

Approximately 50% of the pilot whales observed caught on pelagic fishing gear are entangled in the 

mainline or other portions of the gear while the remaining half are hooked in the mouth. In the case 

of animals that are entangled, but not hooked, fishermen generally work to free the animal and most 

are released without entangling gear. In the case of mouth-hooked animals, the gear is often cut or 

breaks and the animal is released with both a hook in the mouth and significant amounts of trailing 

monofilament line (Garrison, 2007). Under NMFS guidelines (Angliss and DeMaster, 1998), these 

animals are considered to be seriously injured and likely to die, and hence are counted against the 

potential biological removal (PBR) benchmark as mandated by the MMPA. The total estimated 
15

serious injury and mortality of pilot whales in the east coast longline fishery averaged 132 animals 

per year from 1999-2003. This accounts for 63% of the commercial fishery related mortality and 

serious injury of pilot whales on the east coast (Waring et al., 2006). 

Analyses conducted in support of the Pelagic Longline Take Reduction Team were used to identify 

environmental factors and fishing practices that were correlated with pilot whale and Risso’s dolphin 

bycatch. This analysis indicated that the probability of catching a marine mammal increased with 

increasing water temperature, decreasing distance from the shelf break, the presence of damage to 

swordfish catch, and the length of the mainline set (Garrison, 2007). The correlations with 

environmental features are consistent with the proposed mechanism of physical oceanographic 

features concentrating the prey of both large pelagic fish and marine mammals along the shelf break. 

In addition, the correlation with swordfish damage indicates the importance of depredation as a 

process related to incidental bycatch and serious injury. The observer data also indicate that bycatch 

of marine mammals was significantly reduced in sets with mainlines less than 20 nautical miles in 

length. It is hypothesized that shorter sets may be less attractive to marine mammals, are less 

detectable to marine mammals, and/or have shorter haulback times resulting in reduced opportunities 

for depredation, entanglements, and hooking (Garrison, 2007). This potential mitigation measure is 

currently being considered by NMFS within the framework of the developing Pelagic Longline Take 

Reduction Plan. 

The analyses described above encompass observer data collected from 1992-2004, and thus do not 

include data since the implementation of regulations mandating the use of circle hooks in the east 

coast longline fishery in late 2004. Thus, there is a possibility that these regulations to reduce turtle 

bycatch have implications for marine mammal bycatch. A thorough analysis of the available 

observer data did not suggest any correlation between hook size or type and marine mammal bycatch 

(Garrison, 2007). Further, the total estimated bycatch of pilot whales has been increasing in the 

pelagic longline fishery during the last five years while overall effort has been declining. 

Interestingly, the bycatch of Risso’s dolphins has been declining and was zero in 2006 (FairfieldWalsh and Garrison, 2007). After the implementation of the circle hook regulations, both bycatch 

rates and total estimated bycatch for pilot whales were slightly higher than those prior to the 

regulations (Fairfield-Walsh and Garrison, 2007). Thus, while the limited data available do not 

indicate that the recent regulations have significantly increased marine mammal bycatch, there is also 

no indication that they have significantly decreased bycatch. 

The strategies to reduce marine mammal bycatch are generally linked to the depredation issue. 

Mitigation strategies focus on reducing both the “attractiveness” and “predictability” of the fishing 

gear. For example, fishermen in Alaska have attempted to stop hauling while whales are in the area 

and wait to resume the haul until the animals have left. Some studies have also suggested that setting 

“dummy” surface buoys with no attached longlines may distract whales. Other suggested strategies 

include avoiding marine mammal “hotspots” if possible, moving and fishing in a different area if 

depredation is occurring, setting strings with no hooks on them in between regular sets, and working 

to reduce the amount of noise radiated into the water column during haulback (reviewed in 

Donoghue et al., 2003). For the Atlantic take reduction plan, a proposed reduction in mainline length 

to less than 20 nautical miles is predicted to reduce marine mammal bycatch by between 30-45% 

depending upon how fishermen compensate for the resulting reduction in effort (L. Garrison, 

unpublished analysis). Other research areas include improving methods to detect marine mammals 

near fishing gear using passive acoustic detection methods and improving the capability of fishermen 

to safely remove gear from marine mammals. It is likely that some combination of these methods 

will be required to reduce both economic losses due to depredation and the impacts of longline 

fishing on marine mammal populations. 
16

Billfish Longline Bycatch Reduction: A Summary of Hook Performance Research 

Joe Serafy, NMFS Southeast Fisheries Science Center 

Introduction

The billfishes (Family Istiophoridae) are apex predators that support recreational fisheries valued 

in the billions of dollars in subtropical and tropical pelagic waters. Despite their ecological and 

economic importance, little is known about their basic biology and ecology, especially their 

growth, reproduction and movement within a dynamic oceanic habitat. Most billfish research to 

date has focused on issues of stock structure, population abundance and fishing mortality as part 

of stock assessments. There is general consensus that the principal source of mortality on adult 

istiophorid billfishes is pelagic longline fisheries (Cramer 2004). For the most part, billfish are 

caught incidentally as bycatch in fleets primarily targeting tunas (Scombridae) and swordfish 

(Xiphias gladius). Therefore, understanding billfish bycatch in longline fisheries is key to 

reducing uncertainties in stock assessments, implementing appropriate management measures 

and developing new techniques to reduce incidental billfish capture, injury, and mortality. 

Empirical studies on the istiophirids (marlins, sailfish and swordfish) that have potential 

relevance to billfish bycatch reduction are relatively new, few and based primarily on research 

conducted in the northwestern Atlantic and/or the Caribbean Sea. Consequently, the focal 

species in this small body of literature are: blue marlin (Makaira nigricans), white marlin 

(Tetrapterus albicans) and sailfish (Istiophorus platypterus). Comparatively less data have been 

collected on Pacific sailfish and striped marlin (Tetrapterus audax). As is the case with virtually 

all aspects of spearfish ecology and population dynamics, there is virtually no information 

relevant to addressing bycatch reduction for the spearfishes (e.g., Tetrapterus pfluegeri, T. 

georgii, T. belone, T. angustirostris) in any of the world’s oceans. 

Hook Studies 

Nine empirical studies have compared the relative “performance” of circle hooks with respect to 

billfish catch, injury and/or mortality. Approximately half of these studies examined circle hook 

performance in recreational fisheries specifically targeting billfish (Prince et al. 2002; Domeier 

et al. 2003; Horodysky and Graves 2004; Prince et al. 2007), while the others were based on 

commercial longline fisheries where tuna and/or swordfish were targeted (Falterman and Graves 

2002; Kerstetter and Graves 2006a; Kerstetter and Graves 2006b; Kerstetter et al. 2006; Diaz 

2007; Rice et al. in prep.). Most information pertains to sailfish and white marlin and to a lesser 

extent blue marlin and striped marlin. As noted above, no quantitative hook evaluations relevant 

to spearfishes have been conducted. Numbers of individuals (interactions) per billfish species 

have ranged from 4 to 766. The most common hook evaluations relevant to billfish compare the 

performances of 0-degree offset circle hooks and 10-degree offset J hooks. Four studies directly 

compare the performance of circle hooks with different degrees of offset (Prince et al. 2002; 

Domeier et al. 2003; Prince et al. 2007; Rice et al. in prep.). In addition, samples sizes, hook 

sizes, other hook specifications, baits, baiting and fishing methods have not been uniform among 

studies. 

Recreational Fishing: Catch rates 

In a Pacific recreational trolling fishery for sailfish and blue marlin, Prince et al. (2002) found no 

catch rate differences between 5-degree offset circle hooks and 0-degree offset “J” hooks. 

Similarly, they detected no catch rate differences between 0-, 5- and 15-degree offset circle 

hooks in an Atlantic recreational fishery for sailfish. Examining a recreational fishery for striped 
17

marlin in eastern Pacific waters, Domeier et al. (2003) found almost identical catch rates for a J 

hook (10-degree offset) as compared to two circle hooks (with 0-degree and 10-degree offset). 

In a recent study on an Atlantic sailfish recreational fishery, Prince et al. (2007) evaluated 

changes with drop-back time in the performance of two types of circle hook (both with 0-degree 

offset) and one J hook (5-degree offset). At the greatest drop back interval (i.e., > 15 seconds) 

differences between circle and J-hooks were not significant. 

Longline Fishing: Catch Rates 

Working on a longline fishing vessel primarily in northwestern Atlantic waters, Kerstetter and 

Graves (2006a) compared the performance of circle hooks and “J” hooks with 0-degree and 10-

degree offset, respectively. They did not report significant catch rate differences for the sailfish 

or white marlin that were caught on the two hook types. Diaz (2007) compared circle and “J” 

hook catch rates in a commercial longline fishery in a Gulf of Mexico fishery targeting yellowfin 

tuna. He detected no significant catch rate differences for blue marlin or white marlin caught on 

0-degree offset circle hooks and 10-degree offset “J” hooks. Rice et al. (in prep) compared blue 

marlin, white marlin and sailfish catch rates between two circle hook types deployed on 

commercial longlines. They found a significantly higher catch rate for sailfish on 10-degree 

offset circle hooks than for 0-degree offset circle hooks; corresponding results for blue marlin 

and white marlin were not statistically significant. 

Recreational Fishing Injury/Bleeding 

Prince et al. 2002 found significantly more sailfish were “deep-hooked” with 0-degree offset “J” 

hooks (46%) than with 5-degree offset circle hooks (2%) in the Pacific recreational trolling 

fishery. In the same fishery, incidence and severity of bleeding was significantly higher for 

sailfish caught with the 0-degree offset “J” hooks than the circle hook. In their comparison of 0-, 

5- and 15-degree offset circle hooks in an Atlantic recreational trolling fishery for sailfish, Prince 

et al. (2002) found deep-hooking and bleeding both increased with increasing offset. Domeier et 

al. (2003) reported similar results in their comparison of circle (0- and 10-degree offset) versus J 

hooks in a Pacific recreational striped marlin fishery. Significantly more deep-hooking and 

bleeding was associated with fish caught on J hooks. Focusing on a recreational white marlin 

fishery in Western Atlantic waters, Horodysky and Graves (2006) recorded hook location on 

individuals that were subsequently released bearing pop-up satellite tags. They observed a 

tendency for more deep-hooking for white marlin with the 10-degree offset “J” hooks, but this 

difference was not statistically significant. Kerstetter and Graves (2006a) also examined 

hooking location and post-release mortality for white marlin using pop-up satellite tags, but with 

a focus on longline-caught individuals. Again, hook location differences were minor between 0-

degree offset circle hooks and 15-degree offset J hooks were minor. In the Prince et al. (2007) 

study, which compared circle hooks (0-degree offset) and J hooks (5-degree offset) in a 

recreational Atlantic sailfish fishery, incidence of bleeding was significantly higher in fish 

caught on J hooks than circle hooks. 

Longline Fishing: Injury/Bleeding 

Kerstetter et al. (2006) tested for hook location differences in sailfish caught in the Brazilian 

longline fishery. They found a significantly higher likelihood of deep-hooking with 10-degree 

offset “J” hooks versus 0-degree offset circle hooks. In the Kerstetter and Graves (2006b) 

longline study comparing 0-degree offset circle hooks with 10-degree offset J hooks, hooking 

location differences were not significant for white marlin and sailfish. Similarly, Rice et al. (in 
18

prep) detected no significant hook location differences for sailfish, white marlin or blue marlin 

caught on 0- versus 10-degree offset circle hooks deployed on longline gear. 

Recreational Fishing: Mortality 

In the striped marlin fishery study by Domeier et al. (2003), a subset of the fish caught on circle 

or J hooks were released bearing pop-up satellite tags to gain insight into post-release mortality. 

They reported: (1) identical mortality rates for striped marlin caught on 5-degree offset circle 

hooks versus 10-degree offset J hooks; and (2) a minor (i.e., not significant) difference in postrelease mortality between fish caught on 0-degree offset versus 5-degree offset circle hooks. The 

Horodysky and Graves (2006) study was similar to the Domeier et al. (2003) study in that popup satellite tags were deployed on recreationally-caught white marlin to reveal post-release 

mortality. However, they found significantly higher post-release mortality for white marlin 

caught on “J” hooks (10-degree offset) versus circle hooks (0-degree offset). 

Longline Fishing: Mortality 

In the Kerstetter et al. (2006) study of the Brazilian longline fishery, they found significantly 

greater mortality in sailfish caught with 10-degree offset “J “hooks relative to 0-degree offset 

circle hooks; however, corresponding mortality comparisons for blue and white marlin were not 

significant. Using pop-up satellite tags, Kerstetter and Graves (2006a), found significantly 

higher post-release mortality in white marlin caught with J hooks (15-degree offset) versus circle 

hooks (0-degree offset). In the Kerstetter and Graves (2006b) longline catch study, mortality 

differences were not significantly different between hook types for white marlin and sailfish. In 

the Diaz (2007) longline study in the Gulf of Mexico, blue marlin and white marlin mortality 

rates were significantly higher for J hooks (10-degree offset) versus circle hooks (0-degree 

offset). For longline-caught blue marlin and white marlin, Rice et al. (in prep.) found 

significantly higher mortality associated with circle hooks with 10-degree offset versus 0-degree 

offset. For sailfish, higher mortality was also associated with 10-degree offset circle hooks, but 

the difference was not statistically significant. 

Summary

Outlined above are the results of nine studies of potential relevance to billfish bycatch reduction 

during longline fishing via modification of hook type. Of these, four examine recreational 

fisheries that target billfish and five examine billfish as bycatch in commercial longline fisheries. 

Each study reports on some aspect of the relative “performance” of circle hooks with respect to 

billfish catch, injury and/or mortality (either at boatside or post-release as interpreted from popup satellite tag data). Focal species are blue marlin, white marlin, striped marlin and sailfish. No 

study found statistically significant catch rate differences for billfish between circle and J hooks. 

One study found significantly higher sailfish catch rates on 10-degree offset circle hooks as 

compared to 0-degree offset circle hooks. Of the eight studies examining billfish injury/bleeding 

associated with circle versus J hooks, four reported significantly more trauma associated with the 

latter hook type; the remainder did not detect significant differences. One of the three studies 

comparing billfish injury among different styles of circle hook found the incidence of deephooking increased with increasing degree of offset. In the six studies comparing billfish 

mortality in relation to circle and J hooks, four reported significantly higher mortality associated 

with J hooks than circle hooks. Of the three studies comparing billfish mortality rates between 

two types of circle hook, two reported no difference, whereas the second found the circle hook 

with greater offset (10-degree) resulted in higher (sailfish) mortality. Collectively, these studies 
19

support the notion that minimizing or eliminating the use J hooks has conservation benefits for 

billfishes. 

Sharks 

Workshop participants discussed the status of shark bycatch in longline fisheries, drawing on 

their own knowledge on this topic and articles included in the workshop reader. A formal 

presentation and summary document were not presented.

Section 2: Breakout Session Discussion and Evaluation of Current Bycatch Reduction 

Efforts 

Breakout session discussions took place during the afternoon of Day 1 and the morning of Day 2. 

The purpose of the breakout sessions was to provide participants with robust opportunities in 

small group settings to share current knowledge regarding bycatch reduction efforts. These 

discussions, in turn, were intended to inform Day 3 deliberations on best gear and fishing 

practices and development of an action plan for directing NMFS' future domestic and 

international sea turtle longline bycatch reduction efforts. 

The goal of the breakout sessions was to invite participants to discuss and evaluate current 

longline bycatch reduction efforts. The primary focus was on sea turtle bycatch in longline 

fisheries, although Workshop participants were also asked to bring in relevant information 

regarding bycatch of other species groups (i.e., seabirds, marine mammals, billfish, and sharks). 

Two parallel breakout groups1

 each addressed the same five topics. The breakout group 

instructions and discussion questions for each topic are listed below. 

These breakout session discussions and subsequent plenary discussions provided a useful starting 

point for the Day 3 deliberations, which culminated in the recommended best gear and fishing 

practices and action plan presented in this meeting summary. 

Discussion Topic 1: Global Longline Fishery Characterization 

The purpose of this discussion was to help ensure that workshop discussions and 

recommendations consider the effects of all relevant global longline fisheries. Participants were 

asked to review and discuss each fishery on the list below to determine whether it accurately 

encompasses and categorizes longline fisheries of concern. Participants were also asked to 

identify which bycatch species are of concern for each fishing category. 

• Classic pelagic swordfish – shallow set 

• Classic pelagic tuna – deep set 

• Artisanal mahi mahi 

• Artisanal tuna, billfish, shark 

• Other shallow set (Spain, Azores, Japan) 

 

1

 Breakout group composition was organized to ensure a broad range of expertise in each breakout group. 
20

Discussion Topic 2: Reducing Hooking 

The purpose of this discussion was to explore and assess recent strategies for reducing hooking 

of sea turtles and other bycatch species. Participants were asked to respond to a series of 

questions on the topics of: hook design, bait type, use of lightsticks, time of setting and hauling, 

and fishing depth (see questions below). 

1. Hook Design (type, size, offset): consider species and size class in discussions

• How important are the following hook design elements to sea turtle bycatch 

reduction?

x Hook size versus hook shape 

x Circle hook size and offset 

x Appendage and ring hooks and other adapted or non-circle hook designs 

• Is there any new information about circle hooks that could improve bycatch 

reduction?

• Should NMFS continuing further developing and refining circle hooks as the best 

hook design?

• What problems are associated with the lack of standardization in width measurement 

and hook design?

2. Bait

• How important are the following factors to sea turtle bycatch?

x Different bait types 

x Bait size 

x Baiting technique 

x Access to recommended baits 

• Is there sufficient information to develop “best practices” with regard to the use of 

bait?

3. Lightsticks 

• What are the impacts of lightsticks on sea turtle bycatch? 

• What new studies can best inform our understanding of this issue? 

4. Time of Setting and Hauling

• How important is the timing of setting and hauling to sea turtle bycatch?

• Is there sufficient information to develop “best practices” for sea turtles with regard 

to the timing of setting and hauling?

• If so, how would these practices vary by fishing category?
21

5. Fishing Depth

• What is the impact of fishing depth on sea turtle bycatch?

• Is there sufficient information to develop “best practices” with regard to fishing depth 

for sea turtles?

• How would these practices vary by fishery category? 

Discussion Topic 3: Reducing Entanglement 

The purpose of this discussion was to explore and assess recent strategies for reducing 

entanglement of sea turtles and other bycatch species. Participants were asked to address the 

following questions. 

• What do we know about the relative impacts of the following factors relative to 

reducing sea turtle entanglement? 

• Hook design 

• Hook placement relative to floats 

• Use of leaded swivels and their placement 

• Gangion design (material/stiffness/thickness) 

• Setting/hauling time 

• Fishing depth 

• Lightsticks 

• Bait type and size 

• Method of entanglement (e.g. foul hooked; foul hook location; entangled only) 

• Where on the gear entanglement occurs (e.g. gangion, mainline, floatline, 

combination) 

• Turtle species and size 

• What do we know from other gear types that can inform the issue of longline 

entanglement? 

• What studies are needed? 

Discussion Topic 4: Safe Handling and Release

The purpose of this discussion was to explore current problems with dehookers and other 

possible changes to existing requirements for safe handling and release tools and/or techniques. 

Participants were asked to address the following questions. 

• What are some of the problems with dehookers relative to certain hooks and how can 

they best be addressed? 

• Are any changes needed to the existing requirements for safe handling and release 

tools and/or techniques? 
22

Discussion Topic 5: Experimental Design

The purpose of this discussion was to explore key issues relative to current experimental data 

and estimation methods. Participants were asked to address the following questions. 

• What are the key issues relative to the analytical confidence and statistical inference 

of: 

• Our experimental data 

• Our estimation methods 

• What are the key issues relative to interpreting and standardizing research results? 

Section 3: Plenary Presentations and Discussions on Global Implementation of Bycatch 

Reduction 

Workshop participants received presentations and engaged in follow-up discussion on the topic 

of global implementation of bycatch reduction, especially as it relates to two key sections of the 

Magnuson-Stevens Fishery Conservation and Management Reauthorization Act (MSRA): 

• Section 103. Pat Moran provided an overview of international provisions in the MSRA 

and engaged the Workshop participants in a discussion of possible implications for 

reducing longline bycatch. Workshop participants discussed which specific countries 

and/or regional fishery management organizations (RFMOs) are the greatest concern for 

longline bycatch, how the U.S. is currently engaged with these entities, and how the U.S. 

can more effectively reach out to artisanal fleets and address artisanal bycatch issues. 

• Section 316. Lee Benaka provided an overview of the Bycatch Reduction Engineering 

Program (BREP) established by the MSRA. Workshop participants discussed possible 

ways that they BREP may contribute to ongoing longline bycatch reduction efforts and 

the role that the BREP might play in driving gear modifications and research. 

These discussions informed Day 3 development of an action plan for directing domestic and 

international longline bycatch reduction efforts. 

Section 4: Plenary Discussion and Initial Prioritization of Research Needs 

Throughout discussions on Day 1 and the morning of Day 2, any research needs identified were 

recorded for subsequent discussion. Then, during the afternoon of Day 2, participants reviewed 

and discussed the list of 34 research needs that emerged throughout the course of the prior 

breakout session and plenary discussions. The research needs were grouped under the following 

general categories: hook type/size; bait; light sources; species biology/behavior; fishing depth; 

gear and gear configurations; and fishing practices. 
23

Then, as a preparation step for the Day 3 deliberations, participants were asked to prioritize the 

list of research needs, applying their own professional judgment and interpretation to these 

guiding considerations: 

• Will the research provide the most significant conservation benefit for turtles, keeping in 

mind positive or neutral effects on other bycatch species? 

• Will the research provide information urgently needed to motivate conservation actions 

in international longline fisheries, especially where we have limited or no success or 

progress? 

• Will the outcomes (results) from the research answer key outstanding questions without 

which we are currently hampered or prevented from moving forward with sea turtle 

bycatch reduction? 

The results of the informal ranking exercise are presented in Appendix D. The top four issues 

included: 

1) Assess the effect of circle hook size on target catch retention. 

2) Develop fisheries specific experimental designs to evaluate circle hooks for HMS species 

in the Atlantic, Pacific, and Indian Oceans. 

3) Evaluate the effect of circle hooks (size and shape) on seabirds, billfish, marine 

mammals, and sharks. 

4) Investigate the type and frequency of hooking location and injuries by type and size of 

hook. 

During the plenary discussion that followed, participants recognized that the list of research 

needs flowed directly from the plenary and breakout session topics discussed on Days 1-2, and 

does not represent the complete universe of research priorities related to longline bycatch 

reduction. Participants also noted that many of the research needs identified were stated as broad 

needs rather than as specific research projects. As such, participants acknowledged that the 

research needs discussed do not constitute a comprehensive list of specific research topics on 

longline bycatch reduction. 

Closed Federal Session (Day 3) 

The primary purposes of the closed federal session on Day 3 were to develop two important 

products: 1) a list of best gear and fishing practices, 2) an action plan to guide U.S. efforts to 

reduce marine turtle bycatch in both domestic and international longline fisheries. As part of the 

second item, participants also intended to initiate planning for a possible follow-up international 

workshop on circle hooks. 

Key outcomes from these federal discussions are highlighted in parts III and IV below. 
24

PART III. BEST GEAR AND FISHING PRACTICES 

On the morning of Day 3, the federal closed session, agency participants drew on the 

presentations and discussions from Days 1-2 as well as the information presented in the 

workshop reader to develop recommendations on best gear and fishing practices to reduce 

marine turtle bycatch in longline fisheries. Participants identified best gear and fishing practices 

for each of five major categories of fisheries: swordfish (classic, shallow), bigeye (classic, deep), 

other pelagics (tunas, sharks, combination), mahi-mahi (artisanal), and demersal. Best gear and 

fishing practice sub-categories discussed included: hook type/size, bait, gear configuration, light 

sources, set/haul time, fishing depth, and turtle avoidance tactics. The results of this exercise are 

presented in Appendix A. 

In the plenary discussion, participants made the following additional key comments and 

suggestions for further developing best gear and fishing practices: 

• Develop introductory text that addresses the following: 

• Clarify that while the above-recommended best practices focus specifically on 

marine turtles, consideration should also be given to the potential impacts on 

other bycatch species. 

• Discuss the lack of standardized criteria for defining “circle hook” and measuring 

hook size. Some participants noted they define a large circle hook as a circle 

hook with a “minimum width” of no less than 4.9 cm. Workshop participants 

used a “minimum width” definition during discussions on hook type and size. For 

this purpose, "minimum width" is defined as the shortest distance across the 

outside perimeter of the hook, while substituting the concavity in that perimeter 

by a straight line. This is the minimum dimension obtained by constraining the 

hook between a draftsman's parallel rules, or similar parallel surfaces, such as the 

walls of a cylinder. The logic of this dimension is that it represents the diameter 

of the narrowest tube through which a hook could pass, which is thought to be 

relevant to ingestion by sea turtles. Note that generally size "18/0" or larger circle 

hooks, or size "5.2 sun" or larger circle hooks, meet or exceed this minimum 

width dimension, but those size terms refer to the length of steel that is bent to 

manufacture the hook, not to its width. It is possible to manufacture those sizes of 

hooks with a minimum width that is less than 4.9 cm, such as by making the 

shank longer or the profile more oval. 

• Insert links between the best practices identified in the table and data/information (e.g., 

journal articles, published reports) that support these best practices. This will be 

important for exporting these best practices to non-U.S. fisheries. 

• Treat the best practices document as a “living document.” 

• Post the best gear and practices on relevant NMFS websites. 
25

PART IV. ACTION PLAN 

Development of an Action Plan 

On the afternoon of Day 3, federal participants were asked to contribute to the development of a 

near-term (1-3 years) action plan for guiding NMFS' domestic and international efforts to 

implement best practices to reduce marine turtle bycatch in longline fisheries. 

This discussion was informed by Day 1-2 discussions on best gear and fishing practices, global 

implementation and the implications of MSRA, and research needs and priorities. 

Based on the guidance of the Steering Committee, the workshop participants prepared a concise 

action plan, organized as a table with the following headings: domestic bycatch reduction, 

international bycatch reduction, safe handling and release practices, gear research, capacity 

building and outreach, and information dissemination and packaging. 

The recommended action plan is provided in Appendix B. 

In the plenary discussion, participants made the following additional key comments and 

suggestions related to developing the action plan. 

• Develop introductory text for the action plan to address the following: 

• Clarify that while the action plan focuses primarily on marine turtles, 

consideration was also given to the potential impacts on other bycatch species. 

• As appropriate, actions in the plan should be considered within the context of 

MSRA. 

• The plan was not intended to include every possible action and does not preclude, 

for example, taking opportunistic or other actions that are likely to result in 

conservation benefits. 

• NMFS needs to clearly identify gaps where the U.S. has not addressed domestic bycatch 

issues. 

• Insert links between the action items and data/information (e.g., journal articles, 

published reports) that support these actions. This will be important to persuade other 

countries to pursue similar actions. 

• The “gear research” action items reflect tailored research projects that were based on the 

top ranking gear research needs identified during the research prioritization exercise on 

Day 2. 

• The Workshop participants did not fully complete the sections on the plan identifying 

timeline and responsible party. As a key next step, Workshop conveners completed this 

section and sent the updated action plan to all workshop participants for review. 
26

Advice for Convening a Follow-Up International Meeting on Circle Hooks 

In his welcoming remarks, NMFS Assistant Administrator Bill Hogarth described the need to 

expand the workshop’s discussions to the international community. He indicated his aspiration to 

convene an international meeting on circle hooks in 2008 although funding would need to be 

secured*

. 

On Day 3, workshop participants discussed how to leverage the workshop’s accomplishments. 

They also discussed preliminary planning for an international meeting on circle hooks, including 

possible scope, format, and participants for such a meeting. Key points raised included the 

following: 

• Effects of circle hooks on both target and bycatch species should be considered at such a 

workshop. 

• Recognize that the meeting has two potential audiences: technical experts, and policy 

decision makers. Some workshop participants suggested approaching the meeting as a 

two-step process. The first step would be to convene the technical experts, who need to 

review the demonstrated benefits of circle hooks. The second step would involve policy 

decision makers, who are ultimately responsible for implementing changes to gear and 

fishing practices. These participants noted, however, that a multi-step process would cost 

more money and take more time. 

• One potential approach to save costs would be to convene the meeting in conjunction 

with the September 2008 American Fisheries Society annual meeting in Canada. 

• Efforts should be made, if possible, to extend invitations beyond the commercial fishing 

sector to also include representatives of recreational longline fishing and private fisheries 

organizations. 

*At the time this technical memorandum was printed, the proposed international circle hook workshop had not been 

scheduled pending resolution of funding issues.
27

APPENDIX A: BEST GEAR AND FISHING PRACTICES (See page 24 for discussion)

Best Gear and Fishing Practices to Reduce Marine Turtle Bycatch in Longline 

Fisheries 

Type of Fishery 

Swordfish 

(classic, 

shallow) 

Bigeye 

(classic, 

deep) 

Other pelagics 

(tunas, 

sharks, 

combination) 

Mahi 

(Artisanal) Demersal 

Hook 

Type Circle Circle Circle Circle Circle

Minimum outer width 

(size) 

> = 49 mm 

(e.g., 18/0)

> = 49 mm 

(e.g., 18/0)

> = 42 mm 

(e.g., 16/0), 

prefer larger if 

practical 

> = X (e.g., 

14/0), prefer 

larger if 

practical 

insufficient 

info; larger is 

best

Offset 

prefer nonoffset, not > 

10 degree 

offset

prefer nonoffset, not > 

10 degree 

offset

prefer nonoffset, not > 10 

degree offset

prefer nonoffset, not > 

10 degree 

offset 

prefer nonoffset, not > 

10 degree 

offset

Bait 

Type Whole fish Whole fish Whole fish Whole fish Whole fish

Size 

As large as 

practical

As large as 

practical

As large as 

practical

As large as 

practical 

As large as 

practical

Baiting Technique 

Cover the 

point of hook

Cover the 

point of hook

Cover the point 

of hook

Cover the 

point of hook 

Cover the 

point of hook

Gear Configuration 

Float line length 

insufficient 

info

see Fishing 

Depth insufficient info

At least 2 m 

long n/a

Branchline length 

length of 

branchline 

exceeds 

length of 

floatline by at 

least 10% n/a

length of 

branchline 

exceeds length 

of floatline by at 

least 10% in 

shallow set 

fisheries

length of 

branchline 

exceeds 

length of 

floatline by at 

least 10% n/a

Mainline and 

branchline type mono

mono or 

tarred rope

mono or tarred 

rope

mono, at 

minimum 1 m 

of mono on 

either side of 

float and 

mono float 

line 

insufficient 

info

Weights/leaded 

swivels 

minimum 

weight 45 g 

within 1 m of 

the hook

minimum 

weight 45 g 

within 1 m of 

the hook

minimum 

weight 45 g 

within 1 m of 

the hook n/a n/a

Light Sources 

insufficient 

info

Should not 

use Should not use

Should not 

use 

Should not 

use
28

APPENDIX A: BEST GEAR AND FISHING PRACTICES (Continued)

Type of Fishery 

Swordfish 

(classic, 

shallow) 

Bigeye 

(classic, 

deep) 

Other pelagics 

(tunas, 

sharks, 

combination) 

Mahi 

(Artisanal) Demersal 

Set / Haul Time 

Minimize time 

gear is in the 

water during 

daylight 

hours 

Set Time Set after dark 

insufficient 

info insufficient info 

insufficient 

info 

insufficient 

info 

Haul Time 

Begin haul 

before 

daylight 

insufficient 

info insufficient info 

insufficient 

info 

insufficient 

info 

Fishing Depth n/a 

all hooks 

>100 m in 

depth n/a n/a 

insufficient 

info; fishing 

below 100 m 

probably 

better 

Turtle Avoidance 

Tactics 

Move out of 

area and 

share turtle 

bycatch 

information 

with nearby 

vessels 

Move out of 

area and 

share turtle 

bycatch 

information 

with nearby 

vessels 

Move out of 

area and share 

turtle bycatch 

information with 

nearby vessels 

Prohibit 

fishing off 

nesting 

beaches, in 

internesting 

habitats, and 

hotspot 

foraging 

habitats; 

move out of 

area and 

share turtle 

bycatch 

information 

with nearby 

vessels 

Prohibit 

fishing off 

nesting 

beaches, in 

internesting 

habitats, and 

hotspot 

foraging 

habitats; 

move out of 

area and 

share turtle 

bycatch 

information 

with nearby 

vessels 

 

Note where combinations of gear are needed to achieve conservation 

benefits. 

Considerations should be given to the potential impacts on other bycatch species 

(e.g., seabirds, marine mammals, billfish, sharks). 
29

APPENDIX B: TABLE OF NEAR-TERM ACTION PLAN (See page 25 for discussion)

Near-Term (1-3 Years) Action Plan for Guiding NMFS Domestic and International 

Efforts to Implement Best Practices to Reduce Marine Turtle Bycatch in 

Longline Fisheries 

FOCUS 

AREAS ACTIONS ESTIMATED TIMELINE 

Evaluate domestic longline fisheries using current data and 

recommended best practices and modify regulations accordingly. 2008-2010 

Modify HMS bait requirements (e.g., prohibit squid) in the Atlantic 

and Gulf based on current data. 2009-2010 

Require circle hooks in all U.S. longline fisheries with documented 

sea turtle bycatch. 2009-2010 

Domestic 

Bycatch 

Reduction 

Examine applicability of longline recommended best gear and 

practices to other hook and line fisheries. 2008-2009 

Compare and harmonize sea turtle resolutions in 

various RFMOs. By 2009 

Establish or strengthen observer programs in RFMOs 

with regard to sea turtle and other bycatch data 

collection. By 2009 

RFMOs / 

IGOs 

Pursue binding measures in appropriate RFMOs 

based on recommended best gear and practices. Ongoing 

ICCAT 

Pursue binding circle hook measure at November 

2007 meeting Nov 2007 

IATTC 

Pursue binding circle hook measure at June 2008 

meeting. June 2008 

WCPFC 

Propose mandatory sea turtle bycatch mitigation 

measure at WCPFC 4. Dec 2007 

IOTC 

Evaluate current measures and work with member 

nations to adopt FAO guidelines and recommended 

best gear and practices. By 2009 

Connect FAO guidelines and technical advice with 

recommended best gear and practices and 

recommend revising as needed. COFI 2009 

Evaluate whether converting current FAO guidelines 

into CCRF technical guidelines is needed. COFI 2009 

International 

Bycatch 

Reduction 

FAO 

Seek incorporation of longline recommended best 

gear and practices into FAO technology, transfer, and 

training programs. COFI 2009 

Spain 

Convene a technical bilateral with Spain, with sea 

turtle bycatch reduction in longline fisheries as one of 

the primary agenda items. 2008 

Japan 

Challenge Japan to provide ideas, data, and proposed 

mandatory management measures for bycatch 

reduction. May 2008 

Bilaterals 

Taiwan 

Work closely with Taiwan to capitalize on the 

commitments they've made to the U.S. on bycatch 

reduction. Ongoing 
30

APPENDIX B: TABLE OF NEAR-TERM ACTION PLAN (Continued)

FOCUS 

AREAS ACTIONS ESTIMATED TIMELINE 

Re-evaluate results of Korean circle hook experiment. Oct 2007 

Korea Convene a bilateral with Korea, with sea turtle bycatch 

reduction in longline fisheries as one of the primary 

agenda items. July 2008 Bilaterals 

(Continued)

China 

Convene a bilateral with China, with sea turtle bycatch 

reduction in longline fisheries as one of the primary 

agenda items. 2008 

IAC Pursue fisheries specific conservation measures. 2009-2010 Turtle 

Agreements IOSEA Examine potential avenues for sea turtle longline 

bycatch reduction under MOU. 2008 

Use recommended best gear and practices to guide implementation 

of MSRA. Ongoing 

MSRA Leverage MSRA as a tool (including positive recognition for reducing 

bycatch) to achieve bycatch reduction and ensure staff with sea 

turtle expertise are engaged in MSRA implementation. Ongoing 

Examine whether existing guidelines can be simplified for broader 

use domestically and internationally. 2008 

Review needs for additional translation of guidelines. 2008 

Safe Handling 

and Release 

Practices Review Atlantic and Pacific guidelines and certifications for 

consistency. 2008 

Conduct experiment (similar in rigor and analysis to NED 

experiment) on the effects of light sources on leatherback bycatch in 

cooperation with Canada. 2008-2009 

Conduct experiment (similar in rigor and analysis to NED study) on 

circle hooks and bigeye catch retention in cooperation with Spain to 

corroborate U.S. results. 2008-2009 

Develop USG-wide coordinated and prioritized research plan for 

longline sea turtle bycatch reduction. By 2009 

Mine and analyze current observer and experimental data sets for all 

relevant information on other bycatch species to assess impacts of 

circle hooks, and ensure these data are collected in all future 

research. 2008 

Gear Research 

Develop template for reporting research results from bycatch 

reduction experiments. June 2008 

Capacity 

Building / 

Outreach 

Encourage international training in safe handling and release 

protocols. Ongoing 

Convene an international workshop on circle hooks. 2008-2009 

Develop website on recommended best gear and practices with links 

to supporting data, research, regulations, etc. 2008 

Information 

Dissemination 

/ Packaging Develop customized information package for particular longline 

fisheries or fleets for targeted dissemination where necessary for 

reducing bycatch reduction. Ongoing 
31

APPENDIX C: WORKSHOP AGENDA 

 

TUESDAY, SEPTEMBER 18, 2007 (8:00AM – 6:00PM) – WALLINGFORD & FREMONT ROOMS

8:00 – 8:45 Welcome and Opening Comments – Barbara Schroeder 

 Introduction of Participants 

8:45 – 9:00 Overview of Agenda, Ground Rules, and Workshop Format – 

CONCUR, Inc. 

Morning Session: Overview of Bycatch Species Groups 

9:00 – 9:40 Marine Turtles – John Watson

9:40 – 10:00 Seabirds – Kim Rivera

10:00 – 10:30 Coffee Break 

10:30 – 10:50 Marine Mammals – Lance Garrison

10:50 – 11:10 Billfish – Joe Serafy

11:10 – 11:30 Sharks – Group Discussion 

11:30 – 12:00 Working Group Guidance and Assignments for Afternoon Session – 

CONCUR, Inc.

12:00 -1:00 Lunch 

Afternoon Session: Working Groups to Discuss and Evaluate Current Bycatch Reduction 

Efforts 

1:00 – 1:30 Discussion Topic I: Global Longline Fishery Characterization 

1:30 – 3:00 Discussion Topic II: Reducing Hooking 

3:00 – 3:30 Coffee Break 

3:30 – 5:30 Discussion Topic II: Reducing Hooking (continued) 

5:30 – 6:00 Report Back from Working Groups in Plenary 
32

APPENDIX C: WORKSHOP AGENDA (Continued)

WEDNESDAY, SEPTEMBER 19, 2007 (8:30AM – 5:30PM) – WALLINGFORD & FREMONT ROOMS

8:30 – 8:45 Opening Remarks – Bill Hogarth, NMFS Assistant Administrator 

Morning Session: Working Groups to Discuss and Evaluate Current Bycatch Reduction 

Efforts (continued) 

8:45 – 10:00 Discussion Topic III: Reducing Entanglement 

10:00 – 10:30 Coffee Break 

10:30 – 11:00 Discussion Topic IV: Safe Handling and Release 

11:00 – 12:00 Discussion Topic V: Experimental Design 

 12:00 -1:00 Lunch 

Afternoon Session: Plenary Reports, Global Implementation, and Future Research 

1:00 – 1:30 Report Back from Working Groups in Plenary 

1:30 – 3:00 Global Implementation of Bycatch Reduction and MSRA Section 103 – 

Pat Moran 

3:00 – 3:30 Coffee Break 

3:30 – 4:00 Global Implementation of Bycatch Reduction and MSRA Section 316 – 

Lee Benaka 

4:00 – 5:30 Future Research Discussion and Prioritization 
33

APPENDIX C: WORKSHOP AGENDA (Continued)

 

THURSDAY, SEPTEMBER 20, 2007 (8:30AM – 5:00PM) – WALLINGFORD ROOM

Federal Government Planning Session (federal participants only) 

8:30 – 9:00 Planning Session Overview and Guidance – CONCUR 

9:00 – 10:00 “Best Gear and Fishing Practices” - develop updated recommendations for 

 reducing sea turtle bycatch in longline fisheries, while considering effects on all 

 bycatch species 

10:00 – 10:30 Coffee Break 

11:00 – 12:00 “Best Gear and Fishing Practices” (continued) 

12:00 – 1:00 Lunch 

1:00 – 3:00 Develop Action Plan for Directing Domestic and International Marine Turtle 

 Longline Bycatch Reduction 

3:00 – 3:30 Coffee Break 

3:30 – 4:30 Develop Action Plan (continued) 

4:30 - 5:00 Next Steps and Closing Remarks 

5:00 Meeting Adjourns 
34

APPENDIX D: LIST OF PARTICIPANTS 

 

Lee Benaka 

National Marine Fisheries Service 

Office of Sustainable Fisheries 

1315 East-West Highway, 

Silver Spring, MD 20910 

Phone: 301-713-2341 x138 

Fax: 301-713-1193 

lee.benaka@noaa.gov

Charlie Bergmann 

National Marine Fisheries Service 

Southeast Fisheries Science Center 

Pascagoula Laboratory 

P.O. Box Drawer 1207 

Pascagoula, MS 39567 

Phone: 228-762-4591 

Fax: 228-769-8699 

charles.bergmann@noaa.gov

Chris Boggs 

National Marine Fisheries Service 

Pacific Islands Fisheries Science Center 

2570 Dole St. 

Honolulu, HI 96822 

Phone: 808-893-5370 

Fax: 808-983-2902 

christofer.boggs@noaa.gov

David Cottingham 

National Marine Fisheries Service 

Office of Protected Resources 

1315 East-West Highway 

Silver Spring, MD 20910 

Phone: 301-713-2322 

Fax: 301-427-2522 

david.cottingham@noaa.gov

Kelly Denit 

National Marine Fisheries Service 

Office of International Affairs 

1315 East-West Highway 

Silver Spring, MD 20910 

Phone: 301-713-2276 x 202 

kelly.denit@noaa.gov

Joe Desfosse 

National Marine Fisheries Service 

Office of Sustainable Fisheries 

1315 East-West Highway, 

Silver Spring, MD 20910 

Phone: 301-713-2347 

Fax: 301-713-1917 

joseph.desfosse@noaa.gov

Russell Dunn 

National Marine Fisheries Service 

Office of Sustainable Fisheries 

263 13th Avenue South 

St. Petersburg, FL 33701 

Phone: 727-824-5399 

Fax: 727-824-5398 

russell.dunn@noaa.gov

Peter Dutton 

National Marine Fisheries Service 

Southwest Fisheries Science Center 

8604 La Jolla Shores Drive 

La Jolla, CA 92038 

Phone: 858-546-5636 

Fax: 858-546-7003 

peter.dutton@noaa.gov
35

Tina Fahy 

National Marine Fisheries Service 

Southwest Regional Office 

501 W. Ocean Boulevard 

Suite 4200 

Long Beach, CA 90802 

Phone: 562- 980-4023 

Fax: 562-980-4027 

christina.fahy@noaa.gov

Shannon Fitzgerald 

National Marine Fisheries Service 

7600 Sand Point Way NE 

Building 4 

Seattle, WA 98115 

Phone: 206-526-4553 

Fax: 206-526-4004 

shannon.fitzgerald@noaa.gov

Dan Foster 

National Marine Fisheries Service 

Southeast Fisheries Science Center 

Pascagoula Laboratory 

P.O. Box Drawer 1207 

Pascagoula, MS 39567 

Phone: 228-762-4591 x262 

Fax: 228-769-8699 

dan.foster@noaa.gov

Karen Frutchey 

National Marine Fisheries Service 

Pacific Islands Regional Office 

1601 Kapiolani Blvd., Suite 1110 

Honolulu, HI 96814 

Phone: 808-944-2227 

Fax: 808-973-2941 

karen.frutchey@noaa.gov

Lance Garrison 

National Marine Fisheries Service 

Southeast Fisheries Science Center 

75 Virginia Beach Dr. 

Miami, FL 33149 

Phone: 305-361-4488 x488 

lance.garrison@noaa.gov

Brandee Gerke 

National Marine Fisheries Service 

Pacific Islands Regional Office 

1601 Kapiolani Boulevard 

Suite 1110 

Honolulu, HI 96814 

Phone: 808-944-2227 

Fax: 808-973-2941 

brandee.gerke@noaa.gov

Martin Hall 

Inter-American Tropical Tuna Commission 

8604 La Jolla Shores Drive 

La Jolla, CA 92037 

Phone: 858-546-7046 

Fax: 858-546-7133 

mhall@iattc.org

David Hogan 

U.S. Department of State 

2201 C Street NW 

Washington, DC 20520 

Phone: 202-647-2335 

Fax: 202-736-7350 

hogandf@state.gov

Dennis Klemm 

National Marine Fisheries Service 

Southeast Regional Office 

263 13th Avenue South 

St. Petersburg, FL 33701 

Phone: 727-824-5312 

Fax: 727-824-5309 

dennis.klemm@noaa.gov

Jennifer Lee 

National Marine Fisheries Service 

Southeast Regional Office 

263 13th Avenue South 

St. Petersburg, FL 33701 

Phone: 727-824-5312 

Fax: 727-824-5309 

jennifer.lee@noaa.gov
36

Kristy Long 

National Marine Fisheries Service 

Office of Protected Resources 

1315 East-West Highway 

Silver Spring, MD 20910 

Phone: 301-713-2322 

Fax: 301-427-2522 

kristy.long@noaa.gov

Pat Moran 

National Marine Fisheries Service 

Office of International Affairs 

1315 East-West Highway 

Silver Spring, MD 20910 

Phone: 301-713-2276 x 202 

pat.moran@noaa.gov

Moises Mug 

World Wildlife Fund 

Apartado postal 629-2350 

San Francisco de Dos Ríos 

San José, Costa Rica 

Phone: 506-234-8434 

Fax: 506-253-4927 

moisesmug@wwfca.org

Kim Rivera 

National Marine Fisheries Service 

Alaska Regional Office 

P.O. Box 21668 

Juneau, AK 99802 

Phone: 907-586-7424 

Fax: 907-586-7012 

kim.rivera@noaa.gov

Barbara Schroeder 

National Marine Fisheries Service 

Office of Protected Resources 

1315 East-West Highway 

Silver Spring, MD 20910 

Phone: 301-713-2322 

Fax: 301-427-2522 

barbara.schroeder@noaa.gov

Joe Serafy 

National Marine Fisheries Service 

Southeast Fisheries Science Center 

75 Virginia Beach Dr. 

Miami, FL 33149 

Phone: 305-361-4255 

Fax: 305-361-4562 

joe.serafy@noaa.gov

Yonat Swimmer 

National Marine Fisheries Center 

Pacific Islands Fisheries Science Center 

c/o Southwest Regional Office 

501 W. Ocean Blvd. 

Suite 4200 

Long Beach, CA 90802 

Phone: 310- 450-7470 

Fax: 562-980-4027 

yonat.swimmer@noaa.gov

John Watson 

National Marine Fisheries Service 

Southeast Fisheries Science Center 

Pascagoula Laboratory 

P.O. Box Drawer 1207 

Pascagoula, MS 39567 

Phone: 228-762-4591 x262 

Fax: 228-769-8699 

john.watson@noaa.gov

Workshop Facilitators: 

Scott McCreary 

Eric Poncelet 

CONCUR, Inc. 

1832 Second Street 

Berkeley, CA 94710 

Phone: 510-649-8008 

scott@concurinc.net

 

 
37

APPENDIX E: GROUND RULES 

 

The purpose of this workshop is to develop a framework for an Agency action plan to guide U.S. 

efforts to reduce marine turtle bycatch in both domestic and international longline fisheries. To 

inform the plan, workshop participants will review and discuss the results of all U.S. longline 

bycatch reduction efforts to date, fully assess the available information on the effects of these 

efforts on key bycatch species and target catch, and identify gaps in our knowledge. The 

following ground rules are intended to foster and reinforce constructive interaction and 

deliberation among the workshop participants. They emphasize clear communication, respect for 

divergent views, creative thinking and collaborative problem solving. To that end: 

1. Workshop organization. Days 1-2 of the workshop are open to invited federal and nonfederal participants as well as public observers. Day 3 will be a closed planning session in 

which only Federal Government officials will participate. 

This workshop is not chartered under the Federal Advisory Committed Act; nor is it noticed 

in the Federal Register. For these reasons, discussions during Days 1-2 of the workshop will 

focus on exchanges of facts and information. The aim is not to seek consensus advice on 

future Federal Government policies or actions from participants as a group. Any 

information, ideas, recommendations, or advice provided to NMFS will reflect the views of 

individual workshop participants. All of this information will be considered in the Federal 

planning session on Day 3. 

2. Participation and Roles. Participants have been invited based upon their expertise in 

longline fishery bycatch issues. 

• Role of Participants: In their role of providing expert input for NMFS’ consideration, 

participants are responsible for sharing pertinent information, asking clarifying questions, 

and expressing professional views in both plenary and breakout sessions. Everyone will 

participate; no one will dominate. Everyone will help stay on track. 

• Role of Observers: Observers may view and track the deliberations on Days 1-2. They 

may be called upon by the workshop conveners or facilitators to help clarify an 

unresolved point of discussion based on their expertise. 

3. Respectful interaction. Participants will respect each other’s personal integrity, values, and 

legitimacy of interests. This includes avoiding personal attacks and stereotyping. Comments 

will be made and taken in a constructive manner. 

4. Integration. All participants will strive to integrate participants’ various ideas and 

perspectives into the discussions. Disagreements will be regarded as problems to be solved 

rather than battles to be won. 
38

5. Prioritization of future research needs. During discussions focused on prioritizing future 

research needs, participants are encouraged to consider their own interests as well as those of 

other participants. Federal participants will consider the outcomes of the prioritization 

activity on Day 3 of the workshop. 
39

APPENDIX F: RESULTS OF RESEARCH NEEDS PRIORITIZATION 

Research Item Score 

Assess the effect of circle hook size on target catch retention. 25 

Develop fisheries specific experimental designs to evaluate circle hooks for HMS species 

in the Atlantic, Pacific, and Indian Oceans. 

24 

Evaluate the effect of circle hooks (size and shape) on seabirds, billfish, marine 

mammals, and sharks. 

23 

Investigate the type and frequency of hooking location and injuries by type and size of 

hook. 

23 

Evaluate post-hooking mortality. 22 

Evaluate the effects of light sticks or other light sources on leatherback bycatch and 

target catch. As a first step, compare Canadian and Japanese longline data to U.S. data. 

18 

Investigate increasing line stiffness and the effects on bycatch rates. 18 

Develop a hook catalog. 17 

Study effects of wire size and bend strength for target catch, marine mammals, sharks, 

and billfish. 

14 

Investigate what is attracting different leatherbacks to gear (light source investigations 

needed, see above) and characterize that interaction. 

14 

Compile an inventory of longline fishing fleets, including vessel characteristics, to 

inform where bycatch reduction measures might apply or be needed. 

13 

Evaluate actual fishing depth of individual gear configurations, such as with hook 

temperature and depth recorders. 

12 

Evaluate effects of appendage hooks on bycatch and target catch. 11 

Conduct full factorial (2x2, hook type and bait type) studies. 11 

Test live bait in the Gulf of Mexico to determine effects on bycatch rates and elsewhere 

for seabirds. 

11 

Test different types of circle hooks against each other. 9 

Study turtles’ vertical movements, especially relative to the thermocline, other 

oceanographic features, different life history stages, etc. 

9 

Investigate what is attracting other bycatch species to gear and characterize that 

interaction. Investigate reducing the visibility of gear (some in progress) making 

attractants invisible and scare items visible (artisanal). 

9 

Conduct research regarding tournaments and recreational fisheries in relation to circle 

hooks. 

8 

Examine role of the hook size and shape in reducing entanglement. 7 

Explore light sources with variable brightness, blinking lights, wavelengths, etc. for 

different life stages and species. 

6 

Investigate interaction rates relative to hook/float placement as well as lead swivels. 6 

Investigate seabird interaction rates with weighted branch lines or lead swivels. 6 
40

APPENDIX F: RESULTS OF RESEARCH NEEDS PRIORITIZATION (Continued)

Research Item Score 

Evaluate hauling and setting effects on bycatch (e.g., evaluate current bycatch data for 

deep set fisheries; if there is high bycatch of hard shelled turtles, there is a high 

likelihood they are being caught during setting or hauling). Consider entanglement and 

hooking. 

6 

Document and conduct research on the nature of marine mammal entanglement. 

Quantify hookings, nature of entanglements, and species involved. 

5 

Evaluate the effects of ringed hooks on sea turtles and target catch. 4 

Evaluate fishing below 100 meters in areas where shallow set fishing has high turtle 

bycatch rates. 

4 

Investigate measuring sink rates with a line setter as a seabird mitigation strategy. 4 

Examine 10 degree or less offset versus non-offset hooks relative to entanglement of 

turtles. 

3 

Study variable bait sizes with constant hook type keeping in mind regulatory constraints. 3 

Explore shaded light sources that direct light downward. 3 

Explore the effect of other hook designs (e.g., hybrid between J and circle hook) on 

bycatch and target catch. 

2 

Conduct experiment that adds light sources in fisheries not currently using them and 

removing from fisheries that do currently employ light sources to evaluate leatherback 

bycatch rates. 

2 

Re-examine data for association with float and increasing hooking/entanglement in epipelagic animals. 2 
41

APPENDIX G: LITERATURE CITED

Angliss, R. P., and D. P. DeMaster. 1998. Differentiating serious and non-serious injury 

of marine mammals taken incidental to commercial fishing operations: Report of the 

serious injury workshop 1-2 April, 1997, Silver Spring, Maryland. NOAA Tech. Memo. 

NMFS-OPR-13, 48 p. 

Beverly, S. 2004. New deep setting technique tested Moolooba, Australia. SPC Fisheries 

Newsletter. 109:20-27. Secretariat of the Pacific Community, New Caledonia. 

Brothers, N.P., J. Cooper, and S. Lokkeborg. 1999. The incidental catch of seabirds by longline 

fisheries: worldwide review and technical guidelines for mitigation. FAO Fisheries 

Circular No: 937. 

Carretta, J.V., Forney, K.A., Muto, M.M., Barlow, J., Baker, J., Hanson, B., and M.S. 

Lowery. 2006. U.S. Pacific Marine Mammal Stock Assessments: 2005. NOAA Tech. 

Memo. NMFS-SWFSC-388, 325 p. 

Cramer, J. 2004. Life after catch and release. Marine Fisheries Review 66: 27-30. 

Domeier, M.L., and H. Dewar. 2003. Mortality rate of striped marlin (Tetrapturas audax) caught 

with recreational tackle. Mar. Freshwater Res. 54(4):435–445. 

Donoghue, M., R. R. Reeves, and G. S. Stone. 2003. Report on the workshop on 

interactions between cetaceans and longline fisheries. Apia, Samoa: November 2002. 

New England Aquarium Aquatic Forum Series Report 03-1. New England Aquarium 

Press, Boston, MA. 

Fairfield-Walsh, C. and L.P. Garrison. 2007. Estimated Bycatch of Marine Mammals 

and Turtles in the U.S. Atlantic Pelagic Longline Fleet During 2006. NOAA Technical 

Memorandum NOAA NMFS-SEFSC-560: 58 p. 

Falterman, B., and J.E. Graves. 2002. A comparison of the relative mortality and hooking 

efficiency of circle and straight shank ("J") hooks used in the pelagic longline industry. In 

J. A. Lucy and A. L. Studholme (Editors), Catch and release in marine recreational 

fisheries, p. 80–87, Am. Fish. Soc. Symp. 30, Bethesda, MD. 

Garrison, L.P. 2007. Interactions between marine mammals and pelagic longline fishing 

gear in the U.S. Atlantic Ocean between 1992-2004. Fishery Bulletin 105: 408-417.. 

Gilman, E. 2001. References on seabird bycatch in longline fisheries. Western Pacific Fisheries 

Regional Management Council. 
42

APPENDIX G: LITERATURE CITED (Continued)

Gilman, E. and T. Moth-Poulsen. 2007. Review of measures taken by intergovernmental 

organizations to address sea turtle and seabird interactions in marine capture fisheries. 

FAO Fisheries Circular No. 1025. Rome, Italy. 34 p. 

Hoey, J. and N. Moore. 1999. Captain's report: Multi-species catch characteristics for the U.S. 

Atlantic pelagic longline fishery. August 1999. 78 pp. 

Horodysky, A.Z., and J.E. Graves. 2005. Application of pop-up satellite archival tag technology 

to estimate postrelease survival of white marlin (Tetrapturus albidus) caught on circle 

and straight-shank ("J") hooks in the western North Atlantic recreational fishery. Fishery 

Bulletin 103: 84-96. 

Kerstetter, D.W., and J.E. Graves. 2006a. Survival of white marlin (Tetrapturus albidus) released 

from commercial pelagic longline gear in the western North Atlantic. Fish. Bull. 104: 

434-444. 

Kerstetter, D.W., and J.E. Graves. 2006b. Effects of size 16/0 circle versus size 9/0 J-style hooks 

on target and non-target species in a pelagic longline fishery. Fisheries Research, 80:239-

250. 

Kerstetter D.W., J.C. Pacheco, F.H. Hazin, P.E. Travassos, and J.E. Graves. Preliminary results 

of circle and J-style hook comparisons in the Brazilian pelagic longline fishery. Int. 

Comm. Cons. Atl. Tunas (ICCAT). SCRS/2006/150. 7 p. 

Kock, K.-H., M. G. Purves, and G. Duhamel. 2006. Interactions between cetaceans and 

fisheries in the Southern Ocean. Pol. Biol. 29: 379-388. 

Prince, E. D., M. Ortiz, and A. Venizelos. 2002. A comparison of circle hook and “J” hook 

performance in recreational catch-and-release fisheries for billfish. In J. A. Lucy and A. 

L. Studholme (Editors), Catch and release in marine recreational fisheries, p. 66–79, Am. 

Fish. Soc. Symp. 30, Bethesda, MD. 

Prince, E.D, D.J.C. Snodgrass, E.S. Orbesen, J.E. Serafy, and J.E. Schratwieser. 2007. Circle 

hooks, “J” hooks and “drop-back” time: a hook performance study of the South Florida 

recreational live bait fishery for sailfish (Istiophorus platypterus). Fisheries Management 

and Ecology 14: 173-182. 

Rice et al. (in prep). Billfish bycatch, injury and mortality: performance of two circle hooks (0- 

and 10-degree offset) deployed on commercial longline gear. 

Waring, G. T., E. Josephson, C. P. Fairfield, and K. M. Foley. 2006. U.S. Atlantic and 

Gulf of Mexico Marine Mammal Stock Assessments – 2005. NOAA Tech. Memo. 

NMFS-NE-194, 352 p.