Opportunity to Leverage Tactics Used by Skilled Fishers to Address Persistent Bycatch Challenges

ABSTRACT Effective management of shark bycatch is urgently needed to reverse widespread population declines, especially in longline fisheries that are estimated to be responsible for half of global shark catch. Management of shark catch typically focuses on the safe release of landed sharks, with limited attention to reducing the initial catch. Where controls on fishing effort or catch do exist, management frameworks tend to treat fishing fleets as homogeneous units. The underlying assumption is that fishers have similar abilities to catch target species and avoid bycatch. We test this assumption by analysing variability in shark bycatch rates among individual vessels in an industrial tuna longline fleet operating in the Western Pacific. Controlling for factors such as geographic location, time of day and gear depth, we find that individual vessels drive highly variable bycatch rates of blue ( Prionace glauca ) and silky sharks ( Carcharhinus falciformis ) – two shark species with the highest global catch volumes. Additionally, we found that the operating company can influence fisher performance. As countries and regional organisations increasingly adopt shark conservation plans and make international conservation commitments, it is crucial to identify viable new strategies that do not unduly burden the industry or penalise good actors. Tailoring management actions to individual fishers and companies – holding high‐bycatch fishers accountable and incentivising low‐bycatch fishers to continuously improve – presents a crucial opportunity to address the overfishing of sharks and other global bycatch challenges.