Antarctica reveals secrets as sea ice vanishes
By Charles Clover, Environment Editor
Last Updated: 2:49am GMT 26/02/2007
For the scientists of the sea it was a bitter-sweet dream come true.
A 10-week voyage exploring the untouched Antarctic waters exposed by the collapse of the Larsen A ice shelf in 1995 and the loss of Larsen B in 2002 offered an opportunity to discover up to 19 new marine species.
The collaspe of the Larsen B ice shelf exposed untouched waters
But the researchers know that, in an area that scientists say is warming faster than anywhere else on Earth, the whole ecosystem they have found may be in peril.
Among the new species is a shrimp like no other. At four inches long it is larger than many found in temperate climes – so big, in fact, that some may wonder at its right still to be called a shrimp.
The expedition, part of the global Census of Marine Life, explored an area a third the size of Belgium and found the remains of one of the most pristine ecosystems on the planet, where sparse numbers of deep-sea species have survived for thousands of years below the ice at relatively shallow depths.
It also found signs of rapid biological change since the shelves collapsed under the impact of warmer winds and currents. The ecosystem has been invaded by opportunistic species such as krill and minke whales which are now abundant.
There are no penguins, however, showing that it takes many more years for their rookeries to move and become established. Lots of fish, such as Antarctic herring, have also moved into the area.
On the sea bed, 52 scientists on the German research vessel Polarstern found fields of colonising gelatinous sea squirts and herds of sea cucumbers on the move.
Julian Gutt, of the Alfred Wegener Institute for Polar and Marine Research and chief scientist on the expedition, said: "Until now, scientists have glimpsed life under Antarctica's ice sheets only through drill holes. We were in the unique position of being able to sample wherever we wanted."
Scientists were intrigued to find abundant deep sea lilies, species normally living at depths of 2,000 metres, along with their relatives, sea cucumbers and sea urchins.
Among many hundreds of animal specimens collected on the voyage were 15 potentially new species of shrimp, including one of the largest found around Antarctica, and four new species of cnidarians – species related to coral, jelly fish and sea anemones.
There is concern about how further climate change will affect the shrimp-like krill which are the bottom rung of a marine food chain which sustains penguins, whales and seals.
Dr Michael Stoddart, the leader of the Antarctic census, said the slow decrease of sea ice and the planktonic algae that grows underneath it was expected to be an important consequence of more global warming. "Algae is a source of abundant winter food and is utterly central to the whole ecosystem," he said.
Biologist Gauthier Chapelle said: "This is virgin geography. If we don't find out what this area is like now … we won't have any basis to know in 20 years what has changed and how global warming has altered the marine ecosystem."
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