Fisheries bycatch contributes to population declines in seabirds, particularly albatrosses and petrels. While there are examples of successful mitigation, bycatch of seabirds remains a problem in many fisheries globally. International and national interventions within existing management frameworks have been set up to better address seabird bycatch but with varying success. The objective of this thesis is to review best-practice approaches to managing fisheries bycatch of seabirds and other marine vertebrates. These best practice approaches can then be used to develop adaptive management frameworks for evaluating the sustainability of fishing operations on seabirds.

Chapter 1 provides a general introduction on the current situation with respect to managing seabird bycatch and the objectives of the thesis. Chapter 2 includes a review of National Plans of Action for seabirds to identify best practices in identifying seabird bycatch as a problem and setting objectives and thresholds. Chapter 3 consists of application of the Productivity Susceptibility Analysis (PSA), a widely used risk assessment methodology, in two seabird case studies to evaluate its appropriateness and level of precaution when compared to other approaches. Chapter 4 includes a wider review of the PSA for marine vertebrates, and, through a robust evaluation process, a revised taxa-specific PSA is developed for seabirds, marine mammals and marine reptiles. Chapter 5 provides a review of global best practices in identifying bycatch problems and setting population and minimisation objectives for Endangered, Threatened and Protected species. The Marine Stewardship Council’s Fisheries Standard, used to assess sustainability of fisheries as part of the world’s largest wild capture seafood ecolabelling scheme, was revised to reflect these best practices.

The lessons learned from Chapters 2-5 are synthesised in Chapter 6. Recommendations on development and implementation of an adaptive management approach to address seabird bycatch are provided, particularly on methods to identify bycatch problems, evaluate their risk and set objectives to address them, noting that these are also relevant for managing bycatch of other marine vertebrates. Recommendations are made for action at different levels, managers of specific fleets, and regional or international management bodies.