Wild Common Seal Welfare and Population Monitoring

Common (harbour) seals have declined significantly in several Scottish regions; understanding the welfare pressures driving decline informs conservation responses.

Key Facts

Common seal populations in Shetland declined by approximately 75% between 1994 and 2011
Orkney populations declined by about 40% over a similar period
Causes of decline are not fully understood but disease, prey availability and disturbance are implicated
Phocine distemper virus (PDV) caused mass mortality events in 1988 and 2002
Common seals haul out at traditional sites for pupping, moult and rest
Pup welfare is critical - pups are born able to swim but are vulnerable to separation and predation
Disturbance at haul-out sites causes pup abandonment and adult stress responses
Foraging success depends on prey availability - declining sandeels affect common seal condition

Welfare Considerations

Common seals face welfare threats from disease, disturbance at haul-out sites and food web changes affecting prey availability. PDV outbreaks cause mass mortality with significant individual suffering. Haul-out disturbance by boats, kayaks and walkers flushes seals into the water, disrupting pupping, moult and rest. Pup abandonment from disturbance causes starvation and death in vulnerable animals. Maintaining appropriate distances from haul-out sites and supporting prey fish ecosystem health are the most impactful welfare interventions for this species.

What You Can Do

Maintain at least 100 metres from seal haul-out sites and avoid flushing animals into the water
Support SNH and Marine Scotland monitoring of common seal populations in Scotland
Report injured or sick seals to BDMLR on 01825 765546
Advocate for haul-out site designations that restrict disturbance during pupping and moult seasons
Support ecosystem-level conservation that maintains sandeel and other prey populations