Bycatch of marine mammals including dolphins, porpoises, and seals in commercial fishing gear causes significant welfare harm and conservation concern. Effective mitigation tools exist but are inconsistently deployed.
Marine mammal bycatch welfare involves some of the most severe acute welfare events in fisheries: an entangled dolphin drowning in a gillnet experiences a prolonged, distressing death. The scale - hundreds of thousands of cetaceans annually - makes this one of the most significant acute welfare emergencies in the ocean. Effective solutions exist: pingers that deter cetaceans from nets have been demonstrated to reduce bycatch substantially without significantly affecting target species catch. The implementation gap is the key problem: regulatory requirements for pingers exist in some fisheries but not others, and enforcement is variable. Consumer pressure through certified seafood choices and advocacy for stronger bycatch regulations are the most direct levers available.