Bycatch

Global estimates suggest that bycatch amounts to 40% of total marine catch — approximately 38 million tonnes annually — the majority of which is discarded dead. The most destructive bycatch interactions include longlines killing critically endangered seabirds (albatrosses) and sea turtles; drift gillnets drowning cetaceans; and bottom trawls destroying benthic habitat while capturing juvenile fish below legal size limits. Technical solutions include turtle excluder devices (TEDs) in shrimp trawls, circle hooks and bird-scaring 'tori lines' on longlines, and acoustic pingers on gillnets to deter dolphins. Bycatch reduction agreements are central to fisheries certification by the Marine Stewardship Council.