Canberra scientists have found worrying evidence that Antarctica is not as isolated from the rest of the world as previously believed, discovering proof that foreign species can travel to the icy continent.
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A research team led by the Australian National University has found that clumps of kelp, large algae seaweed not known to exist in icy waters, drifted more than 20,000 kilometres across the ocean to Antarctica in the longest biological rafting event ever recorded.
Lead researcher Dr Ceridwen Fraser said to get there, the kelp had to pass through barriers created by polar winds and currents that were, until now, believed to be impenetrable.
Dr Fraser said the kelp found in Antarctica was a large species that could grow up to 12 metres long, and which contained other species that had burrowed in.
"We’ve essentially shown in this research that plants and animals are able to reach Antarctica on their own, and we’re talking about plants and animals that wouldn’t normally be able to travel long distances," she said.
"When the kelp breaks off and drifts away across the ocean, it carries these communities with it, so you can have diverse invertebrate species, other algae ... all sorts of things living inside that kelp as they drift for thousands of kilometres across the ocean.
“... Our findings also indicate that plants and animals living on Antarctica could be more vulnerable to climate change than we had suspected.”
Scientists previously thought Antarctic plants and animals were distinct from others around the world because they were isolated, but the new research suggests that the differences are instead almost entirely down to environmental extremes.
Dr Fraser said this meant foreign marine creatures and insects could "surf" to Antarctica using kelp as a raft, opening the door for them to one day populate Antarctica, which had some of the fastest-warming regions on the planet.
Co-researcher Dr Adele Morrison said if global warming continued to moderate conditions on Antarctica, other species may eventually be able to not only travel there, but live there.
"If plants and animals get to Antarctica fairly frequently by floating across the ocean, they will be able to establish themselves as soon as the local environment becomes hospitable enough,” Dr Morrison said.
A DNA analysis on the kelp that washed up in Antarctica traced it back to the Kerguelen Islands, off the coast of Western Australia, and the South Georgia islands off Argentina.
