Seabird bycatch from longline fishing kills hundreds of thousands of birds annually, with proven mitigation measures available that remain inconsistently adopted across global fleets.
Seabird bycatch from longlines causes welfare harm that is large in scale but highly preventable — the gap between current bycatch rates and what could be achieved with universal mitigation adoption is enormous. The South African tuna fishery demonstrates that 99% reduction is achievable within years when political will and proper enforcement exist. The barrier is not technical but institutional — ensuring that mitigation measures are required on all vessels in all fisheries interacting with seabirds requires international cooperation and enforcement that remains incomplete. Each seabird killed by an unmitigated longline represents preventable welfare harm that effective advocacy and improved fisheries governance could eliminate.