Pelagic longline fisheries targeting tuna and swordfish kill hundreds of thousands of seabirds and sea turtles annually as bycatch, with proven mitigation measures reducing bycatch by 80-95% when properly implemented.
Longline bycatch welfare harms are acute and measurable. Seabirds hooked on longlines may drown immediately or survive hookings that cause injuries preventing normal feeding and flight. Sea turtles can survive initial hookings but suffer from hook wounds, internal injuries, and forced ascent barotrauma. The scale - hundreds of thousands of individual animals annually experiencing these welfare harms - is enormous. The mitigation technologies are proven and relatively inexpensive to implement; the challenge is compliance and enforcement across fleets operating in international waters with limited oversight. Consumer choice of MSC-certified products and advocacy for RFMO enforcement create market and regulatory pressure for bycatch reduction implementation.