They can come on a ship or hop on a plane. Whatever the means of transportation non-native species are arriving in Antarctica as tourism and climate increase.

"Antarctica has long been considered as an isolated continent with a harsh environment. So the general perception has been that we don't have to worry about non-native species. We know better now," said Dr. Neil Gilbert, environmental manager of Antarctica New Zealand.

The matter of different species invading the continent, which scientists say are wrecking its eco-system, was reportedly tabled by the Antarctic Treaty Consultive Meeting. But scientists are calling for action, according to reports.

According to BBC reports, North Atlantic Spider Crabs were found in the water off the continent and a cosmopolitan species of grass was found growing on King George Island.

Officials plan to work on a code of conduct for future visitors to the continent--which has increased to 26,000 each year and growing. In the meantime officials are trying to figure out what to do with the non-native species already on the continent. Removing them can cost millions of dollars but scientist remain concerned with Antarctica's fragile eco-systems, reports say.