In the pristine frozen continent of Antarctica scientists fear an alien invasion — not from outer space, but carried in people's pockets and bags. Seeds and plants accidentally brought to Antarctica by tourists and scientists may introduce alien plant species which could threaten the survival of native plants in the finely balanced ecosystem. Invasive alien plants are amongst the most significant conservation threat to Antarctica, especially as climate change warms the ice continent, said a report in the Proceedings of the National Academy of Sciences Journal published Tuesday. More than 33,000 tourists and 7,000 scientists visit Antarctica each year by ship and aircraft, and a two month survey of visitors has found that many are carrying plant seeds picked up from other countries they have already visited. The study vacuumed travelers' pockets, trouser and sleeve cuffs, shoes and inside their bags, and used tweezers to pry out accidentally hidden seeds. On average each person checked had just 9.5 seeds in clothing and equipment. “The people that were carrying the most had lots and lots of seeds. They really were substantial threats,” said Dana Bergstrom, from the Australian Antarctic Division. “When we take things in through hitchhiking then we get species which are competitive. The plants and animals there are not necessarily competitive, so there's a good chance... we'd start losing various precious biodiversity on the (Antarctic) continent”, Bergstrom told Reuters. Amongst the alien species discovered were the Iceland Poppy, Tall Fescue Velvet grass and Annual Winter Grass — all from cold climates and capable of growing in Antarctica.
