A group of isolated Antarctic islands have proved to be unexpectedly rich in life. The first comprehensive biodiversity survey of the South Orkney Islands, near the tip of the Antarctic Peninsula, has revealed that they are home to more species of sea and land animals than the Galapagos.
© UnknownEmperor penguins like these are the tallest and heaviest penguins alive today
The findings raise the issue of what sort of impact climate change - already hitting the Antarctic hard - will have on this rich biodiversity.
Researchers from the British Antarctic Survey and the University of Hamburg, Germany, carried out the survey using a combination of trawl nets, sampling as deep as 1500m, and scuba divers. The team found over 1200 species, a third of which were not thought to live in the region. They also identified five new species. The majority of animals were found in the sea, with most living on the seabed.
These findings go against the traditional view that biodiversity declines away from the tropics and towards the polar regions, says lead researcher David Barnes of the British Antarctic Survey.
"Our paper makes the point that if you go right the way across different animal groups rather than taking one specific animal group, which is what most biodiversity studies do, then you get a much better perspective of real biodiversity," he says. "This is the first place in either polar region, not just the Antarctic, where we've actually got a biodiversity across all groups."
Previous research has shown that Antarctic waters harbour a surprising diversity of plankton and larvae and that deep-sea life in the Southern Ocean is similarly rich. But the new study is the first to look at all animals on land as well as in the seas.
"As the sea gets warmer, then temperate species will move into Antarctica and Antarctic species will shift further south or into colder regions," says Barnes. "The South Orkney Islands is the one place where we have a real possibility of detecting new things arriving and things leaving."
Jon Copley, a marine ecologist at the University of Southampton, UK, agrees. "The starting point for any conservation strategy has got to be knowing what you've got to conserve," he says, "and this study provides a very valuable baseline in that regard."
While biodiversity in this region may not decrease as a result of the warming, says Barnes, it is likely that the changes in species composition will result in an overall loss in the Earth's biodiversity.
"All that it will take is for a few things to alter," says Barnes. "It is only a matter of time."
See a gallery
of South Orkney animals.
Journal reference: Journal of Biogeography
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