Harbour porpoises are the UK's most common cetacean but thousands are killed annually as bycatch in fishing gear — welfare science documents the suffering this causes and pingers are a proven solution.
Drowning in fishing nets causes acute suffocation. Porpoises are air-breathing mammals that drown within minutes when entangled underwater. The welfare impact is brief but extreme. Scale is the critical factor: thousands of individuals per year represent a significant population-level welfare problem. Pinger technology is proven, cheap, and easy to deploy. Mandatory pinger use in high-risk fisheries is a direct welfare intervention.