An Assessment of Atlantic Bluefin Tuna

Committee to Review Atlantic Bluefin Tuna

Ocean Studies Board

Commission on Geosciences, Environment, and Resources

National Research Council

NATIONAL ACADEMY PRESS
Washington, D.C.
1994



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page R1
An Assessment of Atlantic Bluefin Tuna An Assessment of Atlantic Bluefin Tuna Committee to Review Atlantic Bluefin Tuna Ocean Studies Board Commission on Geosciences, Environment, and Resources National Research Council NATIONAL ACADEMY PRESS Washington, D.C. 1994

OCR for page R1
An Assessment of Atlantic Bluefin Tuna NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competencies and with regard for appropriate balance. This report has been reviewed by a group other than the authors according to procedures approved by a Report Review Committee consisting of members of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The National Academy of Sciences is a private, nonprofit, self-perpetuating society of distinguished scholars engaged in scientific and engineering research, dedicated to the furtherance of science and technology and to their use for the general welfare. Upon the authority of the charter granted to it by the Congress in 1863, the Academy has a mandate that requires it to advise the federal government on scientific and technical matters. Dr. Bruce Alberts is president of the National Academy of Sciences. The National Academy of Engineering was established in 1964, under the charter of the National Academy of Sciences, as a parallel organization of outstanding engineers. It is autonomous in its administration and in the selection of its members, sharing with the National Academy of Sciences the responsibility for advising the federal government. The National Academy of Engineering also sponsors engineering programs aimed at meeting national needs, encourages education and research, and recognizes the superior achievements of engineers. Dr. Robert M. White is president of the National Academy of Engineering. The Institute of Medicine was established in 1970 by the National Academy of Sciences to secure the services of eminent members of appropriate professions in the examination of policy matters pertaining to the health of the public. The Institute acts under the responsibility given to the National Academy of Sciences by its congressional charter to be an adviser to the federal government and, upon its own initiative, to identify issues of medical care, research, and education. Dr. Kenneth I. Shine is the president of the Institute of Medicine. The National Research Council was organized by the National Academy of Sciences in 1916 to associate the broad community of science and technology with the Academy’s purposes of furthering knowledge and advising the federal government. Functioning in accordance with general policies determined by the Academy, the Council has become the principal operating agency of both the National Academy of Sciences and the National Academy of Engineering in providing services to the government, the public, and the scientific and engineering communities. The Council is administered jointly by both Academies and the Institute of Medicine. Dr. Bruce Alberts and Dr. Robert M. White are chairman and vice chairman, respectively, of the National Research Council. Support for this project was provided by the U.S. Department of Commerce, NOAA Contract No. 50-DGNC-3-00016. Library of Congress Catalog Card Number 94-67949 International Standard Book Number 0-309-05181-9 Cover art by Ellen Hill-Godfrey. Ms. Hill-Godfrey received her master of fine arts degree from the University of North Carolina-Chapel Hill. Her paintings and prints have been exhibited in the Washington, DC, area and throughout the Mid-Atlantic and Southern regions. She has done illustrations for the University of Georgia Press and the University of North Carolina’s Endeavors magazine. She lives in Germantown, MD, and teaches at The Barnesville School. Copyright 1994 by the National Academy of Sciences. All rights reserved. Printed in the United States of America

OCR for page R1
An Assessment of Atlantic Bluefin Tuna COMMITTEE TO REVIEW ATLANTIC BLUEFIN TUNA John J. Magnuson, University of Wisconsin-Madison, Chairman Barbara A. Block, Stanford University Richard B. Deriso, Inter-American Tropical Tuna Commission John R. Gold, Texas A&M University William Stewart Grant, Wits University Terrance J. Quinn II, University of Alaska Saul B. Saila, University of Rhode Island Lynda Shapiro, University of Oregon E. Don Stevens, University of Guelph Staff Mary Hope Katsouros, Director Robin Peuser, Study Director Curtis Taylor, Project Assistant Paulette Salmon, Research Assistant

OCR for page R1
An Assessment of Atlantic Bluefin Tuna OCEAN STUDIES BOARD William Merrell, Texas A&M University, Chairman Robert A. Berner, Yale University Donald F. Boesch, University of Maryland Kenneth Brink, Woods Hole Oceanographic Institution Gerald Cann, Independent Consultant Robert Cannon, Stanford University Biliana Cicin-Sain, University of Delaware William Curry, Woods Hole Oceanographic Institution Rana Fine, University of Miami John E. Flipse, Texas A&M University Michael Freilich, Oregon State University Gordon Greve, Amoco Production Company Robert Knox, Scripps Institution of Oceanography Arthur R. M. Nowell, University of Washington Peter Rhines, University of Washington Frank Richter, University of Chicago Brian Rothschild, University of Maryland Thomas Royer, University of Alaska Lynda Shapiro, University of Oregon Sharon Smith, University of Miami Paul Stoffa, University of Texas Staff Mary Hope Katsouros, Director Edward R. Urban, Jr., Staff Officer Robin Peuser, Research Associate Mary Pechacek, Administrative Associate LaVoncyé Mallory, Senior Secretary Curtis Taylor, Office Assistant Paulette Salmon, Research Assistant

OCR for page R1
An Assessment of Atlantic Bluefin Tuna COMMISSION ON GEOSCIENCES, ENVIRONMENT, AND RESOURCES M. Gordon Wolman, The Johns Hopkins University, Chairman Patrick R. Atkins, Aluminum Company of America Edith Brown-Weiss, Georgetown University Law Center Peter S. Eagleson, Massachusetts Institute of Technology Edward A. Frieman, Scripps Institution of Oceanography W. Barclay Kamb, California Institute of Technology Jack E. Oliver, Cornell University Frank L. Parker, Vanderbilt/Clemson University Raymond A. Price, Queen's University at Kingston Thomas A. Schelling, University of Maryland Larry L. Smarr, University of Illinois Steven M. Stanley, The Johns Hopkins University Victoria J. Tschinkel, Landers and Parsons Warren Washington, National Center for Atmospheric Research Staff Stephen Rattien, Executive Director Stephen D. Parker, Associate Executive Director Morgan Gopnik, Assistant Executive Director Jeanette Spoon, Administrative Officer Sandi Fitzpatrick, Administrative Associate Robin Allen, Senior Project Assistant

OCR for page R1
An Assessment of Atlantic Bluefin Tuna This page in the original is blank.

OCR for page R1
An Assessment of Atlantic Bluefin Tuna Preface Issues of stock structure and international management of Atlantic bluefin tuna have been contentious for a number of years. In 1993, management issues became particularly antagonistic when several nongovernmental conservation organizations in the United States tried to have Atlantic bluefin tuna listed as an endangered species under the Convention on International Trade in Endangered Species Treaty and thus subject to severe trade restrictions. In preparation for the 1994 annual management meeting of the International Commission for the Conservation of Atlantic Tunas (ICCAT), the U.S. Department of Commerce's National Oceanic and Atmospheric Administration (NOAA) asked the National Research Council (NRC) of the National Academies of Sciences and Engineering for independent advice on the scientific basis of management for Atlantic bluefin tuna. The NRC was asked to complete its work in six months so that this advice would be received in time to be useful for the ICCAT meeting. The NRC's Ocean Studies Board formed the Committee to Review Atlantic Bluefin Tuna. The committee's charge was to: Conduct a technical review and evaluation of the scientific basis of U.S. management of fisheries for Atlantic bluefin tuna, and address the following general questions: Are the current Standing Committees on Research and Statistics (SCRS) assessments of eastern and western Atlantic bluefin the most defensible interpretation of the available data?

OCR for page R1
An Assessment of Atlantic Bluefin Tuna Are uncertainties in the assessments dealt with adequately? What is the status of the Atlantic bluefin tuna relative to the convention's goal of managing tuna to achieve maximum sustainable yield? Does the available information support treating bluefin tuna as separate eastern and western management units (i.e., how much mixing is likely, and is it enough to invalidate two separate management units)? Recommend research. By August 30, 1994, produce for NOAA a report based on the committee's analysis of the technical information on the assessments of the status of eastern and western Atlantic bluefin tuna, including stock structure. Acknowledgements to the many who helped the committee develop and complete this technical report and reanalysis follow this preface. However, I extend my personal thanks to an unusually strong and responsive committee and NRC staff, who made it work. The full committee met twice to receive background presentations and draft its report. Several subgroup meetings also were held to work on the analyses and text of the report. The committee reviewed extensive background material,1 including public comments that were received. The committee intends this technical review to be of immediate use in management approaches and decisions by NOAA's National Marine Fisheries Service and ICCAT. Responding to the challenge implied by this scientific assessment will require a new view, attention to the best science, and a commitment to international cooperation. The committee dedicates this report to the giant bluefin tuna and to those who enjoy its majesty and value. John J. Magnuson, Chairman Committee to Review Atlantic Bluefin Tuna 1   The report refers to several SCRS and ICCAT documents. For information on how to obtain any of these documents, contact NOAA's Office of International Affairs (301 713-2276) located at 1335 East-West Highway, Silver Spring, Maryland, 20910.

OCR for page R1
An Assessment of Atlantic Bluefin Tuna Acknowledgments This study would not have been possible without the help and contributions of a number of individuals. The committee would especially like to thank Alejandro Anganuzzi, Richard Punsly, and Pat Tomlinson, who provided intensive technical support for the committee's analyses at the Inter-American Tropical Tuna Commission (IATTC) located in La Jolla, California. In addition, the committee thanks James Joseph of IATTC for allowing it to use the IATTC facilities and equipment for analyses and for hosting the final meeting in June. The committee extends its thanks to the other IATTC staff members who assisted in the June meeting, including Berta Juarez and Milton Lopez. Staff of the Southeast Fisheries Science Center of the National Oceanic and Atmospheric Administration's (NOAA) National Marine Fisheries Service (NMFS) assisted in providing data sets for the stock assessment analyses. In addition, they provided the most recent International Commission for the Conservation of Atlantic Tunas (ICCAT) tag and release data for review. For the committee to have enough time for analyses, quick responses to requests for information and data sets were essential. The committee is appreciative of the prompt attention to its requests by NMFS's Southeast Fisheries Science Center staff and NMFS staff in Washington, D.C. The committee also thanks Frank Hester and the East Coast Tuna Association for supplying the captains' logbook data that were analyzed in this report. In addition, the committee thanks Andre Punt for providing the software ADAPT used in the analyses for this report. The committee expresses its gratitude to those who provided written comments and who at their own expense attended the open sessions of the committee

OCR for page R1
An Assessment of Atlantic Bluefin Tuna meetings and provided oral comments. In particular, the committee thanks: Nelson Beideman, Gordon Broadhead, Paul Brouha, Philip G. Coates, Frank Cyganowski, John Mark Dean, Bill Degnan, Katsuma Hanafusa, Eric M. Hesse, Ken Hinman, John J. Hoey, Alexander Krause, Naozumi Miyabe, Thom Palchanes, Ellen M. Peel, Richard Ruais, Carl Safina, Stephen Sloan, Michael Sutton, Ziro Suzuki, Steve Weiner, and Peter Weiss.

OCR for page R1
An Assessment of Atlantic Bluefin Tuna Contents     LIST OF FIGURES AND TABLES   xv     SUMMARY   1 1   BACKGROUND   5     ICCAT Regulations for Atlantic Bluefin Tuna,   6     Issues in Atlantic Bluefin Tuna Management,   7     Purpose of This Study,   8 2   HISTORICAL EVIDENCE FOR STOCK STRUCTURE   9     Introduction,   9     Concept of Stocks,   9     History of Atlantic Bluefin Tuna Stock Designations,   11     Genetic Studies,   13     Genetic Variation in Tunas and Scombroid Fish,   15     Genetic Variation in Bluefin Tuna,   16     Conclusion,   17     Recommendation,   17     Life History Parameters,   18     Geographic Locality of Spawning Grounds,   18     Timing of Spawning,   19     Age at Sexual Maturity,   20     Larval Biology,   21     Physiological Ecology of Bluefin Tuna Movement Patterns,   21

OCR for page R1
An Assessment of Atlantic Bluefin Tuna     Giant Bluefin Tuna in Winter,   28     Movements of Age 0 Fish, Small Fish, and Medium Fish,   28     Giant Bluefin Tuna in New England,   29     Conclusions,   29     Recommendations,   29     Climate,   30     Climate and Evolutionary History,   30     Conclusion,   31     Fish Abundance and Climatic Changes,   31     Conclusion,   35     Recommendation,   35     Movement Based on Nongenetic Markers,   35     Parasite Markers,   35     Conclusion,   36     Recommendation,   36     Microconstituent Analysis,   36     Conclusions,   36     Recommendation,   37 3   TRANSATLANTIC MOVEMENT OF ATLANTIC BLUEFISH TUNA   39     Introduction,   39     Tag-Recapture Data,   39     West to East,   39     East to West,   41     Reanalysis of Tagging Data,   42     Methods,   42     Results,   45     Discussion,   76 4   FISH STOCK ASSESSMENT   79     Growth,   79     Standardization of Western Atlantic Bluefin Tuna Catch Rates (CPUEs),   80     Introduction,   80     Model Development,   80     Analyses,   83     Rod and Reel Indices for Small Fish,   83     Rod and Reel Indices for Giant Bluefun Tuna,   84     Captains' Logbook Data for Giant Bluefin Tuna,   86     Comparison of Captains' Logbook Data and Rod and Reel Survey for Giant Bluefin Tuna,   89     Trend Analysis,   91

OCR for page R1
An Assessment of Atlantic Bluefin Tuna     Recommendations,   92     Quality Control,   92     Methods,   93     Population Assessment,   94     SCRS Base Case,   94     The Role of Indices,   95     Is the SCRS Base Case Reasonable?,   96     Are Uncertainties Adequately Incorporated into the SCRS Assessment?,   97     The Two-Area Mixed-Stock Case,   97     Discussion,   106     Conclusions—Standardization,   107     Recommendations—Standardization,   107     Conclusions—Population Assessment,   107     Recommendations—Population Assessment,   108 5   CONCLUSIONS AND RECOMMENDATIONS   109     General Recommendations,   109     Research Recommendations,   110     REFERENCES   113     APPENDIXES         A. Biographical Sketches of Committee Members   121     B. Bibliography   123     C. Genetic Variation in Other Tunas and Related Fish   127     D. Archival Tag Technology   135     E. Evidence for Mixing Based on Parasites   139     F. Microconstituent Analysis   147

OCR for page R1
An Assessment of Atlantic Bluefin Tuna This page in the original is blank.

OCR for page R1
An Assessment of Atlantic Bluefin Tuna List of Figures and Tables FIGURES 2-1.   General distribution of bluefin tuna in the Atlantic Ocean.   12 2-2.   Landings of giant Atlantic bluefin tuna in Canadian waters.   26 2-3.   Map showing the localities of the Canadian catches from the Gulf of St. Lawrence and surrounding Atlantic Ocean regions.   27 2-4.   Barometric shifts and wind patterns driving the Russell Cycle.   32 3-1.   Proportion of tagged bluefin tuna in area 2 (eastern Atlantic Ocean) that were originally released in area 1 (western Atlantic Ocean) for a hypothetical population.   77 4-1.   Western Atlantic Ocean small bluefin tuna indices.   86 4-2.   Western Atlantic Ocean giant bluefin tuna indices.   89 4-3.   Observed and predicted values of indices for case 1.   103 4-4.   Comparison of the long-term trends in spawning stock biomass for cases 1, 2, and 7.   105 E-1.   The increase in size of Nasicola with host size in Atlantic bluefin tuna   141 E-2.   Prevalence of parasites as a function of host age and locale of capture (A, Nasicola; B, Elytrophora).   143

OCR for page R1
An Assessment of Atlantic Bluefin Tuna TABLES 2-1.   Migration speed of Atlantic bluefin tuna calculated from tag-recovery data.   21 2-2.   Landings of giant Atlantic bluefin tuna from Canadian fisheries by province from 1960 to 1989.   24 3-1.   Synopsis of release and recapture (tagging experiments) of western Atlantic bluefin tuna.   40 3-2.   Synopsis of release and recapture (tagging experiments) of eastern Atlantic/Mediterranean bluefin tuna.   42 3-3.   Spanish tagging data for Atlantic bluefin tuna in the Cantabrian Sea (Bay of Biscay) from 1976 to 1991.   44 3-4.   Atlantic bluefin tuna release and recovery data from the United States tagging program in the western Atlantic Ocean. Tag returns are by year tagged and years out for all tag types.   46 3-5.   Atlantic bluefin tuna release and recovery data from the U.S. tagging program in the western Atlantic Ocean. Tag returns are by year tagged and years out for fish tagged with a single tag.   48 3-6.   Atlantic bluefin tuna release and recovery data from the U.S. tagging program in the western Atlantic Ocean. Tag returns are by year tagged and years out for fish tagged with two or more tags.   50 3-7.   Atlantic bluefin tuna tagged in the eastern Atlantic Ocean from 1976 to 1991. Month of tagging versus month of recapture, all types of tags.   52 3-8.   Atlantic bluefin tuna tagged in the western Atlantic Ocean from 1954 to 1990. Month of tagging versus month of recapture.   53 3-9.   Atlantic bluefin tuna release and recovery data from the U.S. tagging program in the western Atlantic Ocean. Tag returns are by year tagged and years out for single tags, double tags recovered with two tags, and double tags recovered with single tags.   54 3-10.   Atlantic bluefin tuna release and recovery data from the U.S. tagging program in the western Atlantic Ocean. Tag returns are by year tagged and quarters out for fish tagged with a single tag, tagged with two tags and recovered with two tags, and tagged with two tags and returned with one tag.   56 3-11.   Atlantic bluefin tuna tagged in the western Atlantic Ocean from 1971 to 1978. Estimates of annual instantaneous shedding rates using observed catches are shown in A, while B shows the observed catches increased by 20% for nonreporting.   58

OCR for page R1
An Assessment of Atlantic Bluefin Tuna 3-12.   Atlantic bluefin tuna tagged with a single tag from 1971 to 1978. VPA analysis on the reported catches in number of fish, by time before recapture stratified by quarter-year intervals.   59 3-13.   Atlantic bluefin tuna tagged with two or more tags from 1971 to 1978. VPA analysis on the reported catches, with two tags remaining, in number of fish by time before recapture stratified by quarter-year intervals.   60 3-14.   Atlantic bluefin tuna tagged with a single tag from 1971 to 1978. VPA analysis on the reported catches in number of fish, increased by 20% to account for assumed non-reporting of tags, by time before recapture stratified by quarter-year intervals.   61 3-15.   Atlantic bluefin tuna tagged with a two or more tags from 1971 to 1978. VPA analysis on the reported catches in number of fish with two tags remaining, increased by 20% to account for assumed non-reporting of tags, by time before recapture stratified by quarter-year intervals.   62 3-16.   Atlantic bluefin tuna tagged in the western Atlantic Ocean with single, double, and multiple tags.   63 3-17.   Atlantic bluefin tuna tagged in the western Atlantic Ocean with a single tag.   63 3-18.   Atlantic bluefin tuna tagged with a single tag in the western Atlantic Ocean and recovered from the western Atlantic Ocean by year and by number of quarters out.   64 3-19.   Atlantic bluefin tuna tagged with a single tag in the western Atlantic Ocean and recovered from the eastern Atlantic Ocean by year and by number of quarters out.   66 3-20.   Atlantic bluefin tuna tagged in the eastern Atlantic Ocean and recovered in the eastern Atlantic Ocean versus time before recapture and a regression analysis of the natural logarithm of catch number against years out.   68 3-21.   Atlantic bluefin tuna tagged in the western Atlantic Ocean from 1960 to 1981 with a single tag and recovered in the western Atlantic Ocean vs. years before recapture and a regression analysis of the natural logarithm of catch number against years out.   69 3-22.   Atlantic bluefin tuna. VPA analysis on fish tagged in the eastern Atlantic Ocean from 1976 to 1991.   70 3-23.   Atlantic bluefin tuna. VPA analysis on fish tagged in the western Atlantic Ocean from 1960 to 1981.   72 3-24.   Estimates of transfer rates from east to west in the Atlantic Ocean, using tagging data.   74

OCR for page R1
An Assessment of Atlantic Bluefin Tuna 3-25.   Estimates of transfer rates from west to east in the Atlantic Ocean, using tagging data.   75 4-1.   Estimates of small bluefin tuna CPUE from rod and reel and handline.   84 4-2.   Relative abundance of small bluefin tuna from effort-weighted nonlinear least-squares regression.   85 4-3.   Estimates of giant bluefin tuna CPUE from rod and reel and handline.   87 4-4.   Relative abundance of giant bluefin tuna from effort-weighted nonlinear least-squares analysis.   88 4-5.   Estimates of relative CPUE of giant bluefin tuna from captains' logbook data.   90 4-6.   Trend analysis of abundance indices for western Atlantic bluefin tuna.   91 4-7.   Trend analysis results for CPUE indices of Tables 1-5.   93 4-8.   Spawning stock abundance and biomass ratios (1993/1988 and 1993/1975) for the western component of the Atlantic bluefin tuna.   99 4-9.   Estimated exploitation rates by age in 1992 for the different cases.   100 4-10.   Instantaneous fishing mortality rates as estimated for the different cases considered in the VPA.   101 4-11   Contribution of each index and total weighted sum of squared residuals for each of the cases considered in the VPA.   102 E-1.   Prevalence of Nasicola sp. parasites in bluefin tuna related to age of the host and to locale.   142 E-2.   Prevalence of Elytrophora sp. parasites in bluefin tuna related to age of the host and to the locale of host capture.   144 E-3.   Prevalence of Nasicola sp., Elytrophora sp., and both parasites in the same host for western Atlantic bluefin tuna age 2 to 6.   144 F-1.   Estimates of mixing between the two stocks based on discriminant function analysis using jackknife probabilities of group membership of adult bluefin tuna sampled from a variety of locations and at different times.   148