Harbour Seal Welfare and Haul-Out Disturbance

Harbour seals rely on haul-out sites for rest, thermoregulation, pupping, and moulting. Human disturbance at these sites causes significant welfare harm and has contributed to population declines in some regions.

Key Facts

Harbour seals (Phoca vitulina) are the most widely distributed of all pinnipeds, found across the North Atlantic and Pacific
UK harbour seal populations have declined by over 30% in some regions since the 1990s, particularly around Orkney and Shetland
Haul-out sites are critical for rest, thermoregulation, moulting, pupping, and nursing
Disturbance from boats, kayaks, dogs, and pedestrians causes seals to flush into the sea, disrupting vital rest and nursing behaviour
Pup mortality increases when mothers are repeatedly disturbed during the lactation period
Seals moult annually and cannot thermoregulate effectively in water during this vulnerable period
Phocine distemper virus causes periodic mass mortality events; stressed seals with compromised immunity are more vulnerable
Marine pollution, prey depletion, and boat strikes also contribute to mortality and poor body condition

Welfare Considerations

Haul-out disturbance directly impairs welfare by denying seals the rest, thermoregulation, and nursing opportunities they require. Repeated flushing events cause chronic stress, elevated cortisol levels, and energy expenditure that cannot be replaced if prey availability is already reduced. Nursing pups that are separated from mothers prematurely have reduced survival rates. During moult, seals that are forced into cold water cannot regulate body temperature effectively, causing significant physiological stress. The cumulative effect of disturbance throughout the season - from increasing recreational water users - is population-level welfare harm that contributes to the documented declines in vulnerable regions.

What You Can Do

Maintain a minimum distance of 100 metres from haul-out sites when approaching by boat or kayak
Keep dogs on leads and away from beaches where seals are resting or pupping
Report disturbance of seal haul-out sites to British Divers Marine Life Rescue (BDMLR) and local wildlife trusts
Support the SMRU (Sea Mammal Research Unit) in their population monitoring and research work
Follow Seal Alliance guidance on responsible seal watching - never attempt to approach or touch wild seals
Advocate for haul-out sites to receive statutory protection with clear exclusion zones during pupping season