Dana Bergstrom of the Australian Antarctic Division, in a telephone interview with Reuters, said,
"Antarctica is the last bastion of a pristine environment compared to the rest of the world...It has been isolated by the southern ocean - people are starting to break that barrier,"
Among plants a type of European grass - agrostis stolonifera - may be among threats if the icy climate thaws.
"It's a species that gets everywhere, it's already on most of the Antarctic islands," said Dana Bergstrom who leads an international research project entitled "Aliens in Antarctica."
"It would just create lawns," she said
Elsewhere in Antarctica, grass was found growing under a Japanese research hut. Alien plants were found near a Russian station and a wide variety of new fungi near an Australian station.
New species are getting in partly because visitors' clothes often contain seeds, spores or insect eggs.
Invasive species have a long and disruptive history, from rabbits brought to Australia by European settlers to signal Crayfish decimating the UK’s native populations. Now the same threat faces the Antarctic.
So far, invaders have bridgeheads on Antarctic islands ringing the continent, which have been getting warmer in recent decades. Among the most damaging were reindeer on South Georgia and rats and cats on Macquarie Island, Bergstrom said.
The fear is that the rapidly warming climate will create conditions suitable for rats or mice in Antarctica, where currently the biggest land creature is a tiny flightless midge.