Thousands of species in the Antarctic could be driven to extinction because of climate change, according to the latest polar research presented at a major science conference yesterday.
A change of two or three degrees in water temperatures would be enough to wipe out many of the specialised marine organisms off the Antarctic continent, researchers said at the British Association for the Advancement of Science's festival in Leicester.
The festival is Britain's oldest and largest science conference.
Researchers presented a bleak future for life in the waters off Antarctica. "Climate change is under way," said Dr Andrew Sugden of the journal, Science, which co-hosted a special session, "Frontiers in polar science", with the American Association for the Advancement of Science.
While the polar regions remained relatively untouched directly by human activity, some of the most damaging indirect effects could be seen there, harming everything from the fairy shrimp to the whale, he said.
Quite small water temperature changes could have a major impact on Antarctic marine species, said Prof Lloyd Peck of the British Antarctic Survey.
Local water temperatures ranged from one or two degrees below zero centigrade to one or two degrees above. At between five and 10 degrees centigrade, species such as the giant sea spider, many molluscs, isopods and sea gooseberries die outright. At between three and five degrees centigrade, they struggle to take in enough oxygen, but at just two or three degrees, many of these marine species can't move, forage or carry out normal activities, he said.
Most climate change predictions say this three-degree centigrade temperature will be reached during this century. "It looks like the prospect for the animals in the sea is they will face rising temperatures in the future," he added.
A number of species had been studied to see how they might cope with warmer waters and all tested so far were unable to survive. "Every species we have looked at so far falls into that category." The impact overall would be huge.
"We are talking about thousands of species," he said, not just the "loss of a mite on the end of an elk's nose." There were 750 species of amphipods in those waters alone, all of which would be under risk. In other habitats, species could migrate to remain within regions of suitable climate but in the Antarctic they would have nowhere to go, and these species have a limited capacity to adapt naturally, having slow rates of reproduction, he said.
Dr Andrew Brierley of the University of St Andrews, Scotland, described using a small automated submarine to probe 30 kilometres underneath floating sea ice which rims the Antarctic coastline. He was studying krill, four- to five-centimetre-long shrimp-like animals that are crucial to the Antarctic food chain.
These organisms are known to congregate in a narrow band along the edges of floating sea ice but climate change was significantly reducing this ice, he said. There had been reductions in sea ice of up to 25 per cent in the Waddell Sea off the Antarctic peninsula, he said, raising fears that this could threaten krill. Studies showed, however, that this reduction had caused only a 9 per cent fall in the amount of sea ice "edge" available to feeding and multiplying krill.