Seals in Denmark

Marine mammals

Perfectly adapted to life at sea


Seals are marine mammals, just like whales. They have many features which make them ideally suited to living in water. However, unlike whales, seals sometimes move onto dry land. Therefore, they are also suited to living on land. For example, they feed their pups and moult on land. Even though they can sleep at sea, seals actually rest better on land.
Moving through water at speed is harder than moving through air. That is why the seal’s body is streamlined, to minimise the resistance of water. Seals have a thick layer of fat on their bodies; this is called blubber. The blubber insulates the seal’s body, but also helps to make it even and smooth. Actually, it is only the seal’s flippers that disturb the streamlined shape. In addition, both the common seals and the grey seals lack outer ears, and the male seal’s penis is only extended visibly during mating.
When seals swim, they move their back flippers from side to side, while they use their front flippers to steer with. When they swim fast, they keep their front flippers close to the body. Both species of seal can swim up to 17 kilometres an hour over short distances, but normally from two to nine kilometres an hour.



Can you tell the difference?

It can be difficult to tell the difference between the common seal and the grey seal, even though the grey seal is somewhat larger than the common seal. However, there are some distinguishing features you can look for. The grey seal has a cone-shaped head, while the common seal’s head is rounder and its muzzle is short. You can also examine their nostrils. The nostrils of the grey seal are parallel, whereas the common seal’s nostrils look like a ‘V’. If you look at their teeth, you will notice that the grey seal’s back teeth are cone-shaped, while the common seal’s back teeth are serrated.

In our Sealarium you can meet the two species of seal native to Denmark: the common seal and the grey seal. Most of the seals in Denmark are common seals. However, you could be lucky to see the grey seal, which, weighing in at an impressive 300 kg, is the biggest predator in Denmark. Actually, both common seals and grey seals are to be found on the sandbanks in the Wadden Sea directly opposite the Fisheries and Maritime Museum.

Read more about our seals here

Be a seal-friendly tourist

The Danish Environmental Protection Agency has set guidelines on how to be a seal-friendly tourist.

  • Pay close attention to the seals' behaviour when you approach - if they react to you, you're too close!
  • Never enter seal resting places from the water side.
  • Only visit the resting place in daylight.
  • Slow down to a maximum of 5 knots if approaching by boat.
  • Sail only alongside the group of resting seals - never against them.
  • Avoid loud and sudden noises around the animals.
  • Use boats and vehicles that make as little noise as possible.
  • Never feed the seals.
  • Do not touch the seals.
  • Leave your pets at home. Dogs in particular should be avoided near seals.
  • Never follow seals to swim with them.

Facts about seals

Facts about the common seal

Latin name: Phoca vitulina
Length: Male approx. 1.5 metres; female approx. 1.4 metres
Weight: Male 75-104 kg; female 67-83 kg
Age: Male over 30 years; female over 35 years

Facts about the grey seal

Latin name: Halichoerus grypus
Length: Male approx. 2 metres; female approx. 1.8 metres
Weight: Male 170-300 kg; female 100-190 kg
Age: Male over 20 years; female over 30 years


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