WELLINGTON, Jan. 14 (Xinhua) -- Ecosystems in the Antarctic and sub-Antarctic islands are being irreversibly changed by alien plant and animal species introduced through human contact, a leading Antarctic researcher warned Tuesday.
British Antarctic Survey researcher Professor Pete Convey, a visiting academic at New Zealand's University of Canterbury, said the frozen continent had been protected from human contact until about 100 years ago, when humans deliberately and accidentally began introducing new organisms.
All of Antarctica had more than 200 documented examples of alien species, mostly on the sub-Antarctic islands, but around 10 percent were further south in the Antarctic proper.
"All known instances are most easily traced to national operations over the last 50 to 60 years, or the previous historical exploitation industries. Tourism is thus far a red herring here but all human movement to the continent carries a risk," Convey said in a statement.
"We think that human assistance is responsible for more than 100 times the number of establishment events over the history of our contact with Antarctica than those linked to natural dispersal and colonization."
Some sub-Antarctic islands had as many species of introduced plants and invertebrates as native ones, posing a threat to unique ecosystems that were often unable to tolerate new competition or predators.
"In parts of the Antarctic these numbers are now increasing more rapidly. In some parts this is compounded by climate change making conditions less extreme, meaning even more species could have the ability to transfer and survive," said Convey.
"A proportion of these invaders are likely to become ecosystem engineers, fundamentally or irreversibly changing the way that sub- Antarctic and Antarctic ecosystems work."
Effective biosecurity education and procedures were the last chance for protecting the Antarctic.
"This is the last chance we have to demonstrate that we can sensibly and effectively manage the threat of biological invasions at continental scale before they actually happen. This is now impossible with all other continents and significant landmasses globally."