A major food reserve hidden under Antarctic sea ice has been discovered by a robot submarine. The expedition in the Southern Ocean found that stocks of krill under the ice were five times more concentrated than those in open waters. The shrimp-like species is a key food for penguins, whales and fish. The importance of sea ice as a nursery for krill has long been suspected. However, these findings are the first large-scale measurements of the breeding ground's existence. Source