Using a new net, marine biologists from the Alfred Wegener Institute have, for the first time, been able to catch polar cod directly beneath the Arctic sea ice with a trawl, allowing them to determine their large-scale distribution and origin. This information is of fundamental importance, as polar cod are a major source of food for seals, whales and seabirds in the Arctic. The study, which was recently published in the journal Polar Biology, shows that only juvenile fish are found under the ice, a habitat the researchers fear could disappear as a result of climate change.