Wild Porpoise Welfare in Coastal Waters

Harbor porpoises and other small cetaceans face welfare challenges from entanglement in coastal fishing gear, noise pollution, and prey depletion in heavily modified coastal waters.

Key Facts

Harbor porpoise (Phocoena phocoena) is the most common cetacean in European coastal waters; populations are declining in some areas
Gill net bycatch kills an estimated 5,000-7,000 harbor porpoises annually in European waters alone
Porpoises rely entirely on echolocation for navigation and prey detection; underwater noise impairs these critical functions
Construction of offshore wind farms generates noise levels harmful to porpoise at distances of several kilometers
Military sonar exercises have caused mass strandings of beaked whales and disorientation in porpoises
Porpoises have extremely fast digestive rates; they must consume approximately 10% of body weight daily and cannot fast without rapid body condition loss
Acoustic deterrents (pingers) on gill nets reduce porpoise bycatch by 70-90% in controlled trials
The ASCOBANS agreement coordinates porpoise conservation across European signatory states

Welfare Considerations

Porpoise welfare reflects the cumulative impacts of heavily modified coastal marine environments on animals whose survival depends on acoustic clarity and abundant, reliably located prey. A harbor porpoise in a noisy coastal environment with frequent vessel traffic, gill nets, and prey populations depleted by commercial fishing is navigating constant physiological stress: impaired echolocation, entanglement risk, and the energetic demands of compensating for reduced foraging efficiency. Drowning in gill nets is the most acute welfare harm — rapid asphyxiation over minutes — and is preventable with pinger deployment. Reducing underwater noise and maintaining prey fish populations are longer-term welfare interventions that require broader fisheries and marine spatial planning approaches.

What You Can Do

Support advocacy for mandatory pinger deployment on gill nets in porpoise habitat areas
Advocate for marine protected areas that reduce gill net pressure in key porpoise feeding and breeding areas
Support research into porpoise acoustic ecology to better understand noise impact thresholds
Choose certified sustainable seafood that avoids fishing methods with documented cetacean bycatch