[LINK] "Alien Species Invading Antarctica via Tourists, Scientists"

[rfmcdonald]

The colonization of Antarctica is unlikely to happen. Notwithstanding all that real estate--admittedly real estate that's habitable in comparison to Mars, and real estate kept off-bounds by international treaty--even Argentina's territorial claims in the South Atlantic are unlikely to come to much in the medium term. Antarctica is just too remote, too hostile, too fragile. No one really wants to live in this frontier.

One might have thought that would have kept Antarctica safe, but no: ironically, non-permanent migration in the form of tourism may change the continent radically. Charles Q. Choi at National Geographic News describes how even short-term visitors may be changing the continent's environment through accidentally importing invasive species, including cold-tolerant species from the north polar region.

Foreign plants such as annual bluegrass are establishing themselves on Antarctica, whose status as the coldest and driest continent had long made it one of the most pristine environments on Earth.

But a boom in tourism and research activities to the Antarctic Peninsula may be threatening the continent's unique ecosystems, scientists say.

For the study, ecologist Steven Chown at the University of Stellenbosch in South Africa and colleagues vacuumed the clothes, footwear, bags, and gear of approximately 2 percent of people who visited during the Antarctic summer from late 2007 to early 2008. That amounted to 853 scientists, tourists, and accompanying support workers and ships' crew members.

"Endless hours were spent vacuum-cleaning clothes and gear. ... If one is doing so on a ship underway on a rough ocean, it can take a strong stomach," Chown recalled.

The results revealed more than 2,600 seeds and other detachable plant structures, or propagules, had hitched a ride to Antarctica on these visitors.

On average, tourists each carried two to three seeds, while scientists each carried six. However, the annual number of tourists now far outnumbers that of scientists—about 33,000 tourists to about 7,000 scientists in the 2007-2008 Antarctic summer. As a result, tourists and scientists likely pose similar risks overall to Antarctica, Chown said.

Disturbingly, the scientists said, 49 to 61 percent of the foreign plant material that reaches Antarctica are cold-adapted species that can withstand and colonize in extreme conditions.

The plants likely get stuck to cold-weather gear that travelers had used in other frigid climes prior to arriving to Antarctica.

For instance, Arctic species such as chickweed and yellow bog sedge have been found in Antarctica, according to the study, published March 5 in the journal Proceedings of the National Academy of Sciences.

Based on the nature of these foreign species and the present climate of Antarctica, the areas at highest risk are the Antarctic Peninsula coast and surrounding islands, the study said.