In fact, many creatures of the Arctic Ocean are already in trouble. The Arctic is changing faster than scientists can document. Until recently no one knew that there were many creatures of the Arctic Ocean. In the 1970s a Russian biologist named Melnikov discovered 200 species of tiny organisms, algae and zooplankton, hanging around ice floes in immense numbers, forming slime jungles on the bottoms of bergs and plankton clouds in every break of open water. Their carcasses fall to the bottom to nourish clams, which are eaten by walruses.
Arctic cod live on algae scraped off the ice.
The cod are eaten by seabirds, whales, and seals. The king of the food chain, hunting mainly seals, is the great white bear. That was the system until the ice started to thin. The ice was nearly gone. Many had just moved north, following the ice, but that means moving farther from land, with widening stretches of open water between.