May 7, 2009
IT’S CROWDED UNDER THE POLAR ICE
Just below the floating ice of Antarctica there are vast numbers of tiny sea creatures that play a key role in the food chain. PhD graduate Dr. Hauke Flores discovered that the density of the tiny crabs, fish and other organisms here is much higher than it is in open water.
For a long time, the life directly below the ice has been a hidden world. But Flores used a special fishing net to get access to the border where the Antarctic ice meets the sea water below it. He discovered that the underside of the ice forms the hub of the Antarctic food chain. ‘In and under the ice grow algae that determine the entire production of the ecosystem’, Flores explains. ‘Turn over an ice floe and you’ll see that the underside is completely green.’ Masses of small marine creatures such as krill and sea slugs feed on the algae and are in turn prey to larger animals such as whales, penguins and seals. ‘Like this, the small marine animals bring the energy that is laid down as biomass by the algae deeper into the water’, says Flores.
Biologists had already guessed that the underside of the ice played an important role in the biodiversity of the South Pole, but they lacked quantitative data. The results of this new research will make it easier to estimate the consequences of climate change for the Antarctic ecosystem. / Laurien Holtjer
Hauke Flores was awarded his PhD on 1 May by Professor Wim Wolff of the National University of Groningen. He carried out his research at Wageningen Imares.