Read out

Again and again, huge icebergs dissolve in the Antarctic. They break off and fall into the sea. These icebergs can disturb the marine fauna and change the Antarctic ecosystem. This is what American researchers at Stanford University have found. They had analyzed satellite images of the Ross Sea and the Ross Ice Shelf, where in the spring of 2000, the 10000 square kilometer iceberg B-15 had solved. Within a few months, the huge mountain fell into several smaller parts that formed a dam off the Antarctic coast. As a result, less pack ice could drain into the Ross Sea than usual - usually free sea areas remained ice-covered. Therefore, the following spring, the important algal blooms of phytoplankton were much weaker than in normal years. Phytoplankton is at the beginning of the Antarctic food chain and needs open water for its development. Since this condition was not given, its stocks went back by 40 per cent. Phytoplankton serves the krill as food. These crustaceans are eaten by fish, sea lions, whales and penguins. For the penguins, the absence of algae had dramatic consequences: as they had to go further afield to find food, they could no longer focus on nest care. Many eggs were not hatched - and when the offspring hatched, the cubs mostly died of hunger and hypothermia.

Hans Groth

© science.de

Recommended Editor'S Choice