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Bycatch governance and best practice mitigation technology in global tuna fisheries


  • Gilman, Eric L.


Overexploitation of bycatch and target species in marine capture fisheries is the most widespread and direct driver of change and loss of global marine biodiversity. Bycatch in purse seine and pelagic longline tuna fisheries, the two primary gear types for catching tunas, is a primary mortality source of some populations of seabirds, sea turtles, marine mammals and sharks. Bycatch of juvenile tunas and unmarketable species and sizes of other fish in purse seine fisheries, and juvenile swordfish in longline fisheries, contributes to the overexploitation of some stocks, and is an allocation issue. There has been substantial progress in identifying gear technology solutions to seabird and sea turtle bycatch on longlines and to direct dolphin mortality in purse seines. Given sufficient investment, gear technology solutions are probably feasible for the remaining bycatch problems. More comprehensive consideration across species groups is needed to identify conflicts as well as mutual benefits from mitigation methods. Fishery-specific bycatch assessments are necessary to determine the efficacy, economic viability, practicality and safety of alternative mitigation methods. While support for gear technology research and development has generally been strong, political will to achieve broad uptake of best practices has been lacking. The five Regional Fisheries Management Organizations have achieved mixed progress mitigating bycatch. Large gaps remain in both knowledge of ecological risks and governance of bycatch. Most binding conservation and management measures fall short of gear technology best practice. A lack of performance standards, in combination with an inadequate observer coverage for all but large Pacific purse seiners, and incomplete data collection, hinders assessing measures' efficacy. Compliance is probably low due to inadequate surveillance and enforcement. Illegal, unreported and unregulated tuna fishing hampers governance efforts. Replacing consensus-based decision-making and eliminating opt-out provisions would help. Instituting rights-based management measures could elicit improved bycatch mitigation practices. While gradual improvements in an international governance of bycatch can be expected, market-based mechanisms, including retailers and their suppliers working with fisheries to gradually improve practices and governance, promise to be expeditious and effective.

Suggested Citation

  • Gilman, Eric L., 2011. "Bycatch governance and best practice mitigation technology in global tuna fisheries," Marine Policy, Elsevier, vol. 35(5), pages 590-609, September.
  • Handle: RePEc:eee:marpol:v:35:y:2011:i:5:p:590-609

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    Cited by:

    1. Kirby, David Seán & Ward, Peter, 2014. "Standards for the effective management of fisheries bycatch," Marine Policy, Elsevier, vol. 44(C), pages 419-426.
    2. Chan, Valerie & Clarke, Raymond & Squires, Dale, 2014. "Full retention in tuna fisheries: Benefits, costs and unintended consequences," Marine Policy, Elsevier, vol. 45(C), pages 213-221.
    3. Curtis, K. Alexandra & Moore, Jeffrey E. & Boyd, Charlotte & Dillingham, Peter W. & Lewison, Rebecca L. & Taylor, Barbara L. & James, Kelsey C., 2015. "Managing catch of marine megafauna: Guidelines for setting limit reference points," Marine Policy, Elsevier, vol. 61(C), pages 249-263.
    4. Gilman, Eric & Owens, Matthew & Kraft, Thomas, 2014. "Ecological risk assessment of the Marshall Islands longline tuna fishery," Marine Policy, Elsevier, vol. 44(C), pages 239-255.
    5. Poisson, François & Séret, Bernard & Vernet, Anne-Lise & Goujon, Michel & Dagorn, Laurent, 2014. "Collaborative research: Development of a manual on elasmobranch handling and release best practices in tropical tuna purse-seine fisheries," Marine Policy, Elsevier, vol. 44(C), pages 312-320.
    6. Davies, Tim K. & Mees, Chris C. & Milner-Gulland, E.J., 2014. "The past, present and future use of drifting fish aggregating devices (FADs) in the Indian Ocean," Marine Policy, Elsevier, vol. 45(C), pages 163-170.
    7. Evans, K. & Young, J.W. & Nicol, S. & Kolody, D. & Allain, V. & Bell, J. & Brown, J.N. & Ganachaud, A. & Hobday, A.J. & Hunt, B. & Innes, J. & Gupta, A. Sen & van Sebille, E. & Kloser, R. & Patterson,, 2015. "Optimising fisheries management in relation to tuna catches in the western central Pacific Ocean: A review of research priorities and opportunities," Marine Policy, Elsevier, vol. 59(C), pages 94-104.
    8. Trenkel, Verena M. & Hintzen, Niels T. & Farnsworth, Keith D. & Olesen, Christian & Reid, David & Rindorf, Anna & Shephard, Samuel & Dickey-Collas, Mark, 2015. "Identifying marine pelagic ecosystem management objectives and indicators," Marine Policy, Elsevier, vol. 55(C), pages 23-32.
    9. Oliver, Shelby & Braccini, Matias & Newman, Stephen J. & Harvey, Euan S., 2015. "Global patterns in the bycatch of sharks and rays," Marine Policy, Elsevier, vol. 54(C), pages 86-97.
    10. Fauconnet, Laurence & Rochet, Marie-Joëlle, 2016. "Fishing selectivity as an instrument to reach management objectives in an ecosystem approach to fisheries," Marine Policy, Elsevier, vol. 64(C), pages 46-54.


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