Research Implications of Adopting the Precautionary Approach to Management of Tuna Fisheries

FAO Fisheries Circular No. 963
FIRM/C963

ISSN 0429-9329

International Commission for the Conservation of Atlantic Tunas
Inter-American Tropical Tuna Commission

Table of Contents

FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS
Rome, 2001

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© FAO 2001

Table of Contents

PREPARATION OF THIS DOCUMENT

ACKNOWLEDGEMENTS

EXECUTIVE SUMMARY

1 INTRODUCTION

1.1 Background
1.2 Proposed research or actions
1.3 Uncertainty expected in results of tuna research
1.4 Review of tuna biology

1.4.1 Characteristics of tropical and temperate tunas
1.4.2 Stock structure and mixing rates
1.4.3 Spatial distribution and movements
1.4.4 Biological parameters

1.5 Management-related issues

1.5.1 Mandates for criteria and/or management objectives for the CCSBT, IATTC, ICCAT, IOTC and SPC
1.5.2 Review of Precautionary Approaches in other bodies with respect to research implications
1.5.3 Definitions of concepts

1.6 Structure of this report

2 IMPLICATIONS FOR STOCK ASSESSMENT OF TUNAS AND ASSOCIATED SPECIES

2.1 Description of possible fishing management regimes and the implications for stock assessment research

2.1.1 Control rules
2.1.2 Recovery plans
2.1.3 Communication
2.1.4 Research links

2.2 Stock assessment models

2.2.1 Characteristics of tunas and tuna-like fishes as they relate to stock assessment models
2.2.2 Model types
2.2.3 Measures of abundance
2.2.4 Stock-recruitment relationships and projections
2.2.5 Empirical methods

2.3 Ecological and environmental issues in stock assessments

2.3.1 By-catches and stock assessment
2.3.2 Environmental issues in stock assessments

2.4 Uncertainty analysis

2.4.1 Sources of uncertainty
2.4.2 Data required to quantify and reduce uncertainty
2.4.3 Quantification of uncertainty

2.5 Alternative sources of information

2.5.1 Adaptive learning through probing
2.5.2 Industry participation

3 IMPLICATIONS FOR BIOLOGICAL AND ENVIRONMENTAL RESEARCH

3.1 Introduction
3.2 Pending problems and how they might be solved

3.2.1 Catch at age
3.2.2 Age-specific natural mortality
3.2.3 Variability in biological parameters in accordance with time and density
3.2.4 Stock structure, spatial heterogeneity and mixing rates
3.2.5 Genetic diversity

3.3 Impacts of environmental variability

3.3.1 Inter-annual variability
3.3.2 Decadal variability
3.3.3 Long-term changes
3.3.4 Different time scales and similar mechanisms

3.4 Catches of target and by-catch species by fisheries for tunas and tuna-like fishes

3.4.1 Definitions
3.4.2 Available data
3.4.3 Vulnerability
3.4.4 Challenge of developing indices of relative abundance for vulnerable species
3.4.5 Catches of target and by-catch species by major gear types
3.4.6 General recommendations on the problem of by-catches in tuna fisheries

3.5 Ecosystems and tuna fisheries: the Precautionary Approach

3.5.1 General considerations on ecosystems
3.5.2 Pelagic ecosystems and tunas
3.5.3 A suggested approach to pelagic ecosystem-fisheries modelling
3.5.4 Area-time closures as an approach for the management of tuna fisheries and pelagic ecosystems
3.5.5 Impacts of fisheries on ecosystem resiliency-a caveat

4 IMPLICATIONS FOR DATA COLLECTION AND STATISTICS

4.1 Data confidentiality
4.2 Principal fisheries

4.2.1 Purse-seine fisheries
4.2.2 Longline fisheries
4.2.3 Pole-and-line and gillnet fisheries
4.2.4 Artisanal and recreational fisheries

4.3 Other data

4.3.1 Biological data
4.3.2 Environmental data
4.3.3 Observer program data
4.3.4 Fleet data

4.4 Key problems in improving data quality and coverage

4.4.1 Data aggregation and sharing
4.4.2 Catch and landings data
4.4.3 Effort data
4.4.4 Incidental catch data
4.4.5 Vessel-monitoring and global-positioning systems
4.4.6 Biological data
4.4.7 Environmental data
4.4.8 Fleet data

5 CONCLUSIONS

APPENDIX 1 CONCEPTUAL AND PRACTICAL CONSIDERATIONS FOR THE QUANTIFICATION OF OVERALL UNCERTAINTY IN STOCK ASSESSMENTS

APPENDIX 2 GLOSSARY

APPENDIX 3 REPORT OF THE EXPERT CONSULTATION ON IMPLICATIONS OF THE PRECAUTIONARY APPROACH FOR TUNA BIOLOGICAL AND TECHNOLOGICAL RESEARCH