Crab invasion in Antarctica highlights biosecurity crisis

Scientists are calling for action to prevent foreign species from taking hold in Antarctica and wrecking the continent's unique ecosystems.

"I think we can say with some confidence that the (Antarctic Treaty Consultative) meeting has recognised this as a really important issue, that there is a need for research," Neil Gilbert, environmental manager at Antarctica New Zealand, told BBC News.

A paper on the issue tabled at this week's Antarctic Treaty Consultative meeting in Edinburgh met with "good agreement".

"We don't know much about what species are in the marine environment around Antarctica. We've got to get a better handle on what is there, so that we know what is native and non-native.

"Secondly, we need to know what are the vectors by which all this material is being brought in."

Despite Antarctica's inhospitable environment, non-native species introduced by tourists, scientists and explorers were gaining a foothold, he said. Species could hitch a ride on ships and planes carrying visitors and supplies.

Male and female North Atlantic spider crabs have been found in waters off the Antarctic Peninsula. Mr Gilbert said the species could not have migrated such a great distance by its own accord.

In addition, a cosmopolitan species of grass is surviving on King George Island, north of the Antarctic Peninsula.

According to Dr Gilbert, two principal factors are facilitating colonisation of Antarctic habitats by foreign species: the increased numbers of people travelling to the continent and climate change.

"There are more and more people going to Antarctica and we know that people and ships and planes carry plant seeds and other non-native species," Dr Gilbert told the BBC.

"The Antarctic Peninsula region is warming more quickly than anywhere else on the planet. Those species capable of surviving in polar climates are more likely to survive in a less harsh climate." More than 26,000 international tourists visit Antarctica each year and numbers grow by the thousand each season.

Scientists and bureaucrats behind the motion presented at the Antarctic meeting are to work on developing a code of conduct related to the introduction of foreign species -- a set of minimum standards to which Antarctic visitors should abide.

However, there is still no consensus on what to do with non-native species that have already arrived and those that could arrive in future.

"It's a challenging question. In some cases, management - trying to contain them - may be the best option. The chances are that the North Atlantic spider crab is already established," Dr Gilbert said.

"It costs thousands and sometimes millions of dollars to try to get rid of something. One of the things we have been pressing at this meeting is that prevention is better than a cure."

The Antarctic Treaty's Committee for Environmental Protection has agreed to make the issue of invasive species a standing item on its agenda and to consider management options at its next meeting, which will be held in India in April 2007.

- NZPA