69热视频

Antarctica is the coldest, driest, windiest place in the world, and is often considered the most isolated and pristine. But now, because of human impacts, the Earth鈥檚 southernmost continent is rapidly changing鈥攏ot least of all due to the alien species humans are unintentionally introducing, according to a study published today (March 5) in the Proceedings of the National Academy of Sciences.

鈥淎 risk assessment such as this one is long overdue,鈥� said Anthony Ricciardi, an invasive species biologist at 69热视频 in Canada, who was not involved in the research. Nearly 200 alien species are already established in the Antarctic region, primarily in the sub-Antarctic islands, and most of those invaders could not have arrived without human assistance, he said.

鈥淲e knew that Antarctica was invaded, but we had a very poor idea to what degree it was invaded,鈥� he said. The new study is a clear demonstration that 鈥渨hat was once considered to be an isolated biota is no longer isolated,鈥� he said.