Harbor Porpoise Bycatch: The Most Common Cetacean Bycatch Victim

Harbor porpoises are the most frequently bycaught cetacean in North Atlantic and North Sea fisheries. Acoustic deterrents called pingers have proven highly effective at reducing entanglement.

Key Facts

An estimated 5,000-10,000 harbor porpoises are killed annually in fishing nets in the North Sea and northeast Atlantic.
Harbor porpoises are the most common cetacean in European waters but are listed as Least Concern globally.
Gillnet entanglement is the primary cause of bycatch; porpoises fail to detect the nets with echolocation.
Acoustic deterrents (pingers) that emit sounds in the porpoise hearing range reduce bycatch by 70-90% when used correctly.
EU regulations require pinger use in some gillnet fisheries; compliance and enforcement remain inconsistent.
Porpoises caught in nets drown within minutes; the welfare harm is acute but brief.
Bycatch also causes significant sub-lethal harm: stress, injury, and behavioral disruption in animals that escape entanglement.

Welfare Considerations

Harbor porpoise bycatch represents one of the most technically solvable welfare problems in marine conservation. The solution — acoustic pingers attached to gillnets — is cheap, effective, and widely available. A single pinger costs a few dollars and reduces bycatch by up to 90% in well-designed trials. The welfare harm of gillnet drowning, while brief, is acute: entanglement causes panic, exhaustion, and eventual asphyxiation. Sub-lethal entanglement — where animals escape — causes injury, prolonged stress, and behavioral disruption. The primary barrier to widespread pinger adoption is not technical but regulatory: mandatory pinger requirements in gillnet fisheries are inconsistently enforced across European and North American jurisdictions. Consumer and policy pressure for universal pinger requirements in high-risk fisheries could protect thousands of cetaceans annually.

What You Can Do

Support mandatory pinger regulations for gillnet fisheries in North Atlantic and North Sea waters.
Choose seafood from fisheries with documented cetacean bycatch reduction programs.
Support organizations monitoring harbor porpoise bycatch and advocating for regulatory action.
Engage with retailers to require bycatch monitoring and pinger use in their gillnet seafood supply chains.
Donate to porpoise stranding networks that document bycatch and collect data supporting regulatory action.