Polar cod fulfil a key role in the Arctic food web, as they are a major source of food for seals, whales and seabirds alike. But the polar cod themselves might soon be the hungry ones. Under the ice of the central Arctic, the juvenile fish are indirectly but heavily dependent on ice algae. As a result, retreating sea ice could have far-reaching impacts on the food web. Though researchers have long since suspected this relation existed, an international team of researchers led by the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), have now successfully confirmed it.