The Arctic Ocean was once full of life

The Arctic Ocean is home to very few types of life. There are some plankton and algae, which provide the food for small fish, worms, crustaceans and molluscs, which in turn are eaten by cod. The cod are eaten by seals and the seals are eaten by polar bears. Of course, it is all a bit more complicated than that but there are not many different varieties of life in the Arctic Ocean because the fact that the ocean is mostly frozen tends to limit the size of the food chain.