The Arctic Ocean is the world’s smallest ocean. The average thickness of the Arctic ice is around 3 metres, although there are some areas as thick as 20 metres or more. Holes in the ice are vital so that mammals, like seals and walruses, can breathe.
In the northern Arctic, the frozen water is home to the world’s largest carnivore; the polar bear. Polar bears are incredible swimmers and they’re experts at sniffling out seals. Polar bears can smell seals from many kilometres away and even detect their movements under more than 1 metre of ice. They have transparent fur (which looks white) and black skin underneath, which absorbs heat from the sun. They are perfectly adapted for life in such a harsh environment and they hibernate in dens during the winter.
Female bears give birth to twin cubs in these snow dens in November or December. Each cub is born the size of a guinea pig. They stay in the safety of the den for up to five months and then follow their mother for the next two years, learning all the skills and survival techniques for life on the ice.
