Common Seal: Ecology and Welfare
The common seal (Phoca vitulina), also known as the harbour seal, is one of two seal species regularly found around British coasts, along with the larger grey seal. Common seals face significant conservation concerns, with populations in some areas in severe decline while others remain stable or increasing.
Ecology and Behaviour
Common seals are smaller and rounder-faced than grey seals, with characteristic V-shaped nostrils and spotted coats. They breed in June-July, pupping on sandy beaches, intertidal rocks, and sandbanks. Unusually, common seal pups can swim within hours of birth — a consequence of their intertidal breeding habitat where tidal flooding requires immediate swimming ability.
They feed primarily on fish (sand eels, herring, cod, flatfish) and some invertebrates, diving repeatedly to 30-70 metres depth. Their coastal habitat brings them into frequent contact with human activities — fishing, boat traffic, and coastal development.
Population Decline
Common seal populations around the Wash, East Anglia, and Scottish east coast have declined dramatically since the 1990s — by over 50% in some areas. The causes remain incompletely understood but likely include changes in prey availability (particularly sand eel decline), disease, predation by grey seals, and bycatch in fishing gear. The contrast with stable or increasing grey seal populations suggests species-specific factors at play.
Individual Welfare Concerns
Common seals are frequently entangled in fishing gear, marine debris (plastic, fishing line), and monofilament netting, causing lacerations, progressive constriction wounds, and death. Seals with neck or body constriction injuries require specialist wildlife rehabilitation — wound management and often extended care before release is possible.
Pup disturbance on pupping beaches — by dogs, walkers, and boat traffic — causes abandonment and welfare compromise. Maintaining distance from resting and pupping seals (minimum 100 metres) reduces disturbance impacts.
Rehabilitation and Release
British Divers Marine Life Rescue (BDMLR) coordinates seal rescue and rehabilitation training across Britain. Seal pups found alone should be monitored — many are simply resting between maternal visits. A pup that appears injured, is entangled, has obvious wounds, or is in an unsafe location should be reported to BDMLR via their hotline (01825 765546).