Harbour seal

Light grey or brownish-grey fur with dark patches

The harbour seal has a ‘turned-up nose’ in profile, a thick layer of blubber and light grey or brownish-grey fur with dark patches. With its extremely sensitive whiskers, the harbour seal can sense vibrations from fish movements, allowing it to hunt and catch fish even in the dark or when the water is murky. The harbour seal can detect a herring up to 180 metres away!

A harbour seal can dive to a depth of 200 metres and stay underwater for up to 45 minutes to hunt, but it usually stays underwater for five to ten minutes. Its pulse rate drops to around 20 beats per minute during prolonged dives, compared to a normal rate of 150 beats. It can also shut off much of its blood flow while diving to conserve blood oxygen.

Prefers sheltered sandbanks and rocky islets

The harbour seal prefers sheltered sandbanks and rocky islets where it can lie and rest. It often swims up rivers, and copes well in freshwater. The harbour seal is not usually seen more than a couple of dozen kilometres from the coast. The harbour seal is a congregatory creature, but does not live in dense colonies like many other species. They are hunted by polar bears, killer whales and larger sea lions. The pups are also sometimes caught by foxes and large birds of prey.

Harbour seals hunt alone in the water, but on the land they are often seen in small groups. They do not socialise with each other there, but react aggressively when they are disturbed by another animal.

Eats three to five kilos of fish a day

Adult harbour seals feed almost exclusively on fish, and on Sweden’s west coast 80 percent of their diet consists of cod. An adult eats three to five kilos of fish per day. The pups also eat shellfish and molluscs.

Pregnant for about a year

Mating takes place in the water, and after 8–12 months of gestation the female gives birth to a single pup. When it is born, the pup weighs about 9 kg and is about 85 cm long. It suckles for just under five weeks, after which it has to fend for itself.

Sensitive to viruses and environmental toxins

Harbour seals are found in Swedish waters along the entire west coast, in the Øresund Sound and in the southern Baltic Sea as far as just north of the Kalmar Sound. Evidence suggests that the Baltic Sea population has been isolated from other harbour seal populations for at least 6,000 years. This population is red-listed, i.e. it is classified as ‘Vulnerable’, with around 1,400 individuals. Numbers on the west coast and in the North Sea have now recovered to a population of around 15,000.

Internationally, however, the harbour seal is classified as ‘Least Concern’. Worldwide, the population has been estimated at 400,000–500,000 individuals. The species has a circumpolar distribution in the temperate regions of the northern hemisphere.

Harbour seals are vulnerable. In 1988, more than half of all individuals in Kattegat and Skagerrak died from a viral disease. The virus struck again in 2002, and once again about half of all harbour seals along the Swedish coast died. Other threats include toxic substances that enter the sea in the form of pollution, and fishing – sometimes harbour seals get caught in fishing nets and die.

Humans have hunted harbour seals since ancient times – partly for their meat, and partly for their fur and seal oil. It was not until the 1970s that protective measures were introduced.

Our seals here at Skansen eat good quality fish that is MSC-certified. This means that the fish is caught with care for the marine environment. Find out more about Skansen’s environmental work.

The harbour seal is classified as ‘Least Concern’ according to the Swedish Species Information Centre’s red list