Common seal  (Phoca vitulina)

The population of common seals in the UK cannot be estimated very accurately but humans have historically hunted the common seal in great numbers. The Seal Conservation Act of 1970 gives a degree of protection as shooting is outlawed during the breeding season, however if a seal is deemed to be interfering with fishing nets, it can legally be shot at any time under the 'Fisheries Defence Clause' (5). In 1988 a disease caused by the newly emerged phocine distemper virus killed about 3,000 of the UK's common seals. Such drastic population crashes seem to be a natural occurrence, and little can be done to prevent them (3). Common seals are also susceptible to oil and chemical pollutants (3).

A number of key UK pupping and haul-out sites have been suggested as candidate Special Areas of Conservation (9). It has been recommended that human access to breeding sites could be restricted to reduce disturbance. Guidance notes on monitoring techniques for this species have been produced by the Joint Nature Conservation Committee, the Government's wildlife advisor (9).