Pelagic longline fisheries targeting tuna and swordfish are among the largest sources of sea turtle bycatch globally, with gear modifications achieving significant reductions.
Sea turtles hooked on longlines face drowning if they cannot surface, or painful hook removal injuries if brought to the surface alive. Deeply swallowed hooks cause internal injury whether cut or left in place. Turtles that survive longline encounters often retain hooks that cause chronic injury or digestive obstruction. Circle hooks cause shallower hooking at the jaw rather than deep ingestion, significantly reducing injury severity in addition to capture frequency. The welfare case for circle hook mandates is compelling and the productivity impact on target species is minimal.