Ice-loving boffins and tourists are wrecking the Antarctic by effectively busing in lifeforms alien to the cold continent, according to a new study.
Scientists who journey to the ice-bound land for research purposes, and the growing number of sightseers heading for the South Pole, are carrying with them seeds of foreign plants that are taking root in the once pristine landscape.
As the coldest and driest continent on the planet, Antarctica has a unique ecosystem, which could now be under threat from this alien invasion.
Eco-boffin Steven Chown, from the University of Stellenbosch in South Africa, led the study, which hoovered the clothes, shoes, bags and other gear of 853 people who went to the continent during the Antarctic summer of 2007 to 2008.
These folks represent about two per cent of the total number of visitors, but at least 2,600 seeds and other plant bits were found to have hitched a ride to the ice-free landing spots where they rocked up in Antarctica.
Scientists carried more seeds than tourists, averaging six each, but although globetrotters are only giving a lift to two to three seeds each, there are far more of them than the boffins. Annually there are about 33,000 holidaymakers hitting the Antarctic peninsula, compared to roughly 7,000 scientists.
Since the tourists and researchers generally had to come through other cold parts of the world to get to Antarctica, half of these seeds and plant bits on their clothes were capable of surviving in extreme climates, a situation Prof Chown described as "worrying".
As the seeds are already adapted to cold weather and with the expected effects of climate change on the region over the next century, as projected by the Intergovernmental Panel on Climate Change, the chance that these plants will take root is rising.
"With climate change, areas such as the Antarctic Peninsula, Ross Sea and the East Antarctic coastal regions will become high-risk areas because it is easier for plants to survive and establish on ice-free ground in these sectors,” Prof Chown said.
Several invasive species have already started growing on the Western Antarctic Peninsula, including Poa annua aka annual bluegrass.
"We are convinced that this study will provide the explicit evidence required for future management decisions aimed at conserving Antarctica,” he added.
“As it is an increasingly popular tourist destination and a place to undertake research, we need more stringent measures to reduce the risk of seeds from all over the world being transported to the area and ultimately becoming invasive.”
The study, published in the Proceedings of the National Academy of Sciences journal here [PDF], notes: "Invasive alien species are among the primary causes of biodiversity change globally, with the risks thereof broadly understood for most regions of the world. They are similarly thought to be among the most significant conservation threats to Antarctica, especially as climate change proceeds in the region." ®