The most common seal species seen around the Cornish coast is the grey seal (Halichoerus grypus).

Atlantic grey seal  (Halichoerus grypus)

Grey seals live in the North Atlantic with their population centred around the British Isles.

When born, the pups have a white coat and are unable to swim. The mothers suckle the pups for only a couple of weeks after which the pups must fend for themselves. This is a very difficult and dangerous time for the pups and many can be lost to malnutrition, fishing activities and severe weather.

Within a month they shed the pup fur and grow the dense waterproof adult fur and leave for the sea to learn to fish for themselves.

In the UK there have also been calls for a cull from some fishermen, claiming that stocks have declined due to the seals. A recent paper, however, from the Seal Mammal Research Unit (SMRU) at St Andrews University clarifies that seals take less than 1% of the total stock biomass in the North Sea. The real problem is over fishing.

The grey seal is the largest native mammal in the British Isles, with the bulls reaching 2.5–3.3 m long and weighing up to 300 kg. The cows are much smaller, typically 1.6–2.0 m long and 100–150 kg in weight.