The common dolphin is the most numerous cetacean in UK waters, but bycatch mortality in fishing gear remains a significant welfare and conservation problem.
Common dolphins entangled in fishing gear drown slowly over a period of minutes, experiencing panic and hypoxia before death. Strandings resulting from non-lethal gear interactions show traumatic injuries consistent with entanglement and propeller strikes. Dolphins with sublethal bycatch injuries may strand repeatedly before death. The welfare toll of bycatch on common dolphins is enormous and largely invisible to the fishing industry and public. Mitigation measures including acoustic deterrents and modified gear types can substantially reduce bycatch rates, but compliance and maintenance standards vary widely.