Marine Mammal Bycatch: Dolphins, Porpoises, and Fishing Gear Solutions

Hundreds of thousands of dolphins, porpoises, and seals are caught and killed as bycatch in fishing gear annually. Technical and regulatory solutions are reducing but not eliminating this harm.

Key Facts

The vaquita porpoise faces extinction largely due to bycatch in gillnets in the Gulf of California
Baltic harbour porpoise populations have declined severely due to gillnet bycatch
Pingers — acoustic devices attached to nets — can reduce cetacean bycatch significantly
Turtle excluder devices and circle hooks reduce sea turtle bycatch in longline fisheries
The EU requires pinger use in some gillnet fisheries, but compliance monitoring is inconsistent

Welfare Considerations

Marine mammals caught in fishing gear experience severe welfare harms. Entanglement in nets causes drowning, exhaustion, injury from struggling, and prolonged suffering before death. Animals may also be dragged at depth or dragged along the seafloor. Bycatch reduction technology including acoustic deterrents, modified gear, and observer programs is available and effective, but adoption is inconsistent. Stronger regulations, better compliance monitoring, and consumer choices favouring certified sustainable seafood all drive improvements. Some species are so depleted by bycatch that population viability rather than individual welfare is the primary conservation concern.

What You Can Do

Choose seafood certified by schemes with bycatch reduction standards (MSC, Dolphin Safe)
Advocate for mandatory pinger use and gear modification requirements in high-risk fisheries
Support marine mammal conservation organisations working on bycatch solutions
Reduce seafood consumption to lower overall fishing pressure on marine ecosystems