Harbour Porpoise Welfare and Gillnet Bycatch

Harbour porpoises are the UK's most common cetacean but face high mortality from gillnet bycatch, threatening some regional populations.

Key Facts

Harbour porpoises are the smallest cetacean in UK waters at around 1.5 metres
Gillnet bycatch mortality may exceed natural mortality in some North Sea populations
Pingers (acoustic deterrents) reduce bycatch by up to 90% when used correctly
UK law requires pinger use in certain fisheries but compliance monitoring is limited
Pollution and prey depletion add additional pressure to bycatch mortality

Welfare Considerations

Harbour porpoises caught in gillnets drown as air-breathing mammals unable to surface. Post-mortem examination of bycaught porpoises reveals lung haemorrhage from struggling while entangled. Animals that escape entanglement may have injuries impairing swimming and feeding. The bycatch mortality rate in some populations exceeds the rate at which they can reproduce, causing population decline with long-term welfare consequences. Pinger devices that reduce bycatch represent a practical welfare intervention available to fishing fleets.

What You Can Do

Support mandatory pinger use and compliance monitoring in gillnet fisheries
Choose seafood from fisheries certified with low cetacean bycatch
Donate to WDC campaigns for porpoise bycatch reduction
Advocate for expanded harbour porpoise protection in UK marine protected areas
Report injured or stranded porpoises to BDMLR immediately