Seal ID guide


There are two species of seals resident in the UK, the harbour seal, also known as the common seal, (Phoca vitulina), and the grey seal (Halichoerus grypus).The UK harbour seal population is estimated at 37,400 individuals and the UK grey seal population is estimated at 112,300 individuals (research completed by the Sea Mammal Research Unit).

Find out the differences between the two species:


Harbour Seal

Grey Seal


Adult: 1.3-1.7m

Adult: 1.8-2.1m


Adult: 80-100kg

Adult Female: 150-200kg

Male: up to 300kg


20-30 yrs

20-30 yrs


Varies between dark bro

wn, pale grey and even chestnut red. Lighter colouring on stomach and chest than back. Often have mottled coats.

Varies from near black to creamy white, adult males often darker than females. Both sexes have lighter colouring on stomach than back. Pups have white fur when born.

Head Shape

Pronounced forehead, stout nose, eyes near front of head

Long flat nose, eyes mounted midway between nose and back of head

Haul out behaviour

Often spread out when on land and will venture further offshore to find haul out sites

Tend to stay in groups when on land and remain near shore


Wide variety of fish such as sandeels and cod. Also eat cephalopods such as squid

Forage to depth of continental shelf for sandeels, cod and plaice along with many other fish species


Northern France to Western Iceland

North Atlantic, Barents Sea and Baltic Sea


37,000 in the UK- 30% of the European harbour seal population

112,000 in the UK- 38% of global grey population


harbour seal
Harbour seal. Copyright: Lorraine Conterio











Grey seal
Grey seal. Copyright: Richard Spink