Harbor Seal

This species is also known as the common seal, because it is often seen in these surroundings, not infrequently venturing up into river estuaries, too.

The harbor seal is found along the northern coasts of North America, Europe and Asia, having a very similar range to that of the grey seal. The harbor seal has a dog-like face, with a more rounded snout than the Roman-style “nose” that typifies the grey seal. It is difficult to make accurate estimates of the size of the common seal population, because this species lives in small, widely distributed groups, and is highly mobile.

Harbor seals have large, sensitive eyes with specialized retinas, which allow them to see well underwater. However, sometimes the water is too murky for seals to hunt by sight, so they use their long, touch-sensitive whiskers to feel for prey in the gloom. Young seals eat shrimps and bottom-dwelling crustaceans. Older individuals take herring, salmon, anchovies, cod and other fish, as well as octopus. They can dive for up to 10 minutes but average dives last for three minutes.

The harbor seal's coloration is variable, but it generally consists of a grey or brownish-grey background speckled with darker spots. From a distance, the head of a common seal poking above the waves can closely resemble that of a human. As a result, these seals are sometimes mistaken for swimmers in trouble.

Young harbor seals can swim and dive soon after they are born. Females can therefore give birth in relative safety on sandbanks that are only evident during low tide. This species has the most extensive range of any pinniped, but serious outbreaks of disease have impacted its numbers locally. During 1988, over 17,000 harbor seals died in an epidemic caused by a new seal virus, which struck populations in the North sea. These seals are also at risk from pollution.

Distribution: Occurs in coastal areas through the northern hemisphere, present in both the North Atlantic and the North Pacific, as well as the North and Baltic seas.

Habitat: Sheltered coastal waters.

Weight: 45 - 170 kg (99 - 375 lb); males are heavier.

Length: 120 - 190 cm (47 - 75 in).

Maturity: Females 4 - 6 years; males 5 - 6 years.

Gestation Period: About 225 days; embryonic development only starts about 4.5 months after fertilization.

Breeding: 1; weaning occurs at around 28 days.

Diet: Feeds mainly on fish, including sand eels and herring, also crustaceans and  cephalopods such as squid.

Lifespan: 20 - 30 years; males typically have a shorter lifespan.

Status: Common.


Varies from shades of tan through brown to grey, with spots and rings evident on the upperparts.

Ear canal

This opening, on the side of the head behind the eye, is relatively large.

Hind flippers

As with other phocids, the rear flippers provide the thrust for swimming.

Front flippers

Harbor seals are quite clumsy on land, compared with other seals.


The flippers are flat and wide to aid swimming.


Adopting an upright position in the water affords good allround visibility and helps the mother to support her pup.