Wild Fish Bycatch and Welfare: The Unseen Suffering of Non-Target Species

Bycatch — the incidental capture of non-target species in commercial fishing — causes the deaths of millions of animals annually, including seabirds, sea turtles, marine mammals, and fish.

Key Facts

Global bycatch is estimated at 9–40% of total catch by weight, representing tens of millions of tonnes of non-target species discarded annually
Longline fishing catches an estimated 300,000 seabirds annually as bycatch, including albatrosses and petrels, many of which are threatened
Sea turtle bycatch in shrimp trawls and longlines has caused significant population declines across multiple species
Porpoise and dolphin bycatch in gill nets and purse seines remains a major conservation and welfare concern globally
Fish discarded as bycatch may be returned to the sea dead, dying, or severely injured — the EU's landing obligation aims to reduce high-grading but has implementation challenges
Bycatch mitigation technologies include turtle excluder devices (TEDs), acoustic pingers to deter cetaceans from nets, and bird scaring lines on longliners
The Marine Stewardship Council (MSC) certification requires fisheries to demonstrate low bycatch impacts as a condition of certification
Ghost fishing — entanglement in lost or abandoned fishing gear — continues to catch and kill marine animals long after the original fishing operation

Welfare Considerations

Wild fish bycatch welfare encompasses both the suffering of fish and non-fish species incidentally caught in commercial fishing. For seabirds, entanglement in longlines causes drowning — a prolonged death as the bird is dragged underwater by the line. Sea turtles caught in nets face similar drowning deaths or prolonged exhaustion and injury. Marine mammals entangled in gill nets may struggle for hours before dying. Discarded fish returned to the sea may survive if handled carefully and quickly, but are often suffocated, crushed, or returned with swim bladder injuries incompatible with survival. Ghost gear — fishing equipment lost at sea — continues causing deaths for decades. Bycatch reduction has a dual justification: conservation of threatened populations and reduction of individual animal suffering. Effective interventions include: gear modifications (circle hooks rather than J-hooks on longlines reduce turtle catch while maintaining target catch efficiency), spatial and temporal fishing restrictions in high-sensitivity areas, and economic incentives for bycatch reduction through certification and labelling schemes.

What You Can Do

Choose seafood certified by the Marine Stewardship Council, which requires bycatch assessment and management
Support organisations working on bycatch reduction technology including TEDs, acoustic pingers, and circle hooks
Advocate for mandatory use of bycatch reduction devices in high-impact fisheries in your country
Raise awareness of bycatch as a welfare issue — the suffering of seabirds, turtles, and marine mammals in fishing gear is real
Support ghost gear clean-up programmes that remove abandoned fishing equipment from marine environments
Engage with fisheries management authorities about bycatch reduction requirements in national fishing policy