The sea ice food web

Ice is of paramount importance for many Arctic species and multi-year sea-ice especially, supports complex and specialized communities of organisms that live in close association with it. At the edge of the ice and underneath it, the beginning of the spring melt season triggers a remarkable explosion of biological activity. Light penetrating the ice provides the energy for the growth of algae called phytoplankton. These tiny plants provide food for small undersea animals including single-celled protozoans, shrimps, and worms that are collectively known as zooplankton, and which, in turn provide the main food for many Arctic fish and diving birds as well as bowhead whales. One of the most important consumers of zooplankton is the Arctic cod, a small fish found throughout the Arctic. The most northerly of all marine fishes adapted only to cold polar waters the Arctic cod thrives even in waters below 0°C because of natural antifreeze proteins in its blood. With its fat-rich flesh is an important food source for many species especially narwhal, beluga, ringed seal and seabirds such as murres and guillemots. Warming waters and loss of ice directly threaten populations of Arctic cod – one of the vital links in the Arctic food web. Read more on Arctic wildlife and biodiversity.