Aquatic Mammals in UK Waters: Seals, Dolphins and Welfare Threats

UK waters support populations of grey and common seals, bottle-nosed dolphins and harbour porpoises — all facing welfare threats from fishing, pollution and human disturbance.

Key Facts

The UK has approximately 40% of the global grey seal population — a major international responsibility
Seal pupping season runs October-January; disturbance during this period causes mothers to abandon pups
Common dolphins and harbour porpoises are regularly bycaught in static gear fisheries around the UK
Bottlenose dolphins around Cardigan Bay and Moray Firth face persistent vessel disturbance during tourist season
Microplastic ingestion and organochlorine accumulation affect the health and reproductive success of UK marine mammals

Welfare Considerations

Marine mammals in UK waters face a complex of welfare threats that no single intervention can address. Seal pups abandoned after disturbance face starvation; dolphins entangled in ghost gear drown; harbour porpoises accumulate organochlorine levels that impair reproduction. The cumulative welfare impact across individual animals is large, though largely invisible to coastal communities. British Divers Marine Life Rescue responds to individual stranding and entanglement cases, but the underlying welfare threats require policy-level responses: bycatch mitigation, disturbance exclusion zones, and chemical pollution reduction.

What You Can Do

Maintain a minimum 100m distance from seals, dolphins and porpoises when boating or kayaking near them
Report seal pup disturbance during pupping season to the BDMLR rather than approaching the pup yourself
Support BDMLR financially — their marine mammal rescue work is entirely donation-funded
Advocate for bycatch mitigation requirements on all static gear fisheries operating in UK waters
Reduce single-use plastic to lower the microplastic burden accumulating in marine mammal feeding habitats