Alien Species Invading Antarctica, Experts Warn

John Roach
for National Geographic News
July 6, 2006
Golf in Antarctica, anyone?

You can't set a tee time just yet, but a type of grass favored for putting greens—annual bluegrass—has taken root on King George Island, about 75 miles (120 kilometers) from the icy continent.

Scientists are not amused.

"Sooner or later, invasive species do become a big problem," said Maj de Poorter, an invasive-species researcher at Auckland University in New Zealand.

De Poorter is among a handful of scientists raising a call to arms to prevent the invaders from transforming Antarctica's unique ecosystems.

Annual bluegrass's recent arrival to King George Island signals a tough battle. The turf may have been transported there by a duffer on an adventure travel holiday.

And more tourists and researchers are going to Antarctica each year. For the 2006-2007 tourist season, the International Association of Antarctica Tour Operators expects at least 28,000 people will make the trek.

According to de Poorter, each season also sees as many as 10,000 scientists. This rise in human traffic means a greater likelihood that alien species will be introduced and take hold, she says.

"The more individuals of an alien species or nonnative species get there, the more likely something will be able to establish and live there," she said.

Another invader is the North Atlantic spider crab—males and females have been found in the waters near the Antarctic Peninsula. They likely stowed away in the ballast tanks of a ship, according to scientists.

Ships carry water in their tanks and cargo holds for stabilization at sea. Organisms that live in the water get transported to new environments when the water is dumped.

And while the invaders hitch passage to the continent on ships and planes, a warming climate is allowing more of them to survive once they arrive.

"That's also an issue," de Poorter said.

Microscopic Organisms

John Priscu is an environmental scientist at Montana State University in Bozeman who has spent 22 years studying microscopic organisms in the McMurdo Dry Valleys of Antarctica.

(See an interactive map and wallpaper photos of Antarctica.)

He says the climate there is actually cooling, but the contamination of the environment with human bacteria and bacteria from other regions of Antarctica is a real concern.

For example, he says, researchers have found seals and penguins infected with bacteria from the sewage at the McMurdo Station research base.

At the nearby Scott Base, seals are infected with canine distemper, a virus passed to them by researchers' dogs.

Priscu and his colleagues wear special suits whenever working in ice-covered lakes to prevent contamination. Researchers also follow strict protocols to make sure equipment used to explore one region does not transfer bacteria to another.

Priscu is also embroiled in a debate over whether humans should be allowed to drill for research purposes into the pristine waters of Lake Vostok, the largest ice-covered lake in Antarctica, and risk contamination with human-borne bacteria.

(Read "Under-Ice Lakes in Antarctica Linked by Buried Channels" [April 2006].)

"One group of people argues that it doesn't matter. What can live there?" he said.

Human bacteria thrive in an environment that is 98.6 degrees Fahrenheit (37 degrees Celsius). The lake is just above freezing, shielded from light, and poor in nutrients, the argument goes.

"The thing is, we're finding more and more extremophiles out there," Priscu said, referring to organisms that can survive in extreme environments such as Lake Vostok.

And in places like the Antarctic Peninsula, where newly exposed soils are hosting new exotic species such as turf grass, bacteria that used to have no means to survive might now thrive.

"Antarctica has a relatively nondiverse ecosystem compared to temperate ecosystems, but as it warms up the environment will start playing host to a broader range of organisms," Priscu said.

Raising Awareness

According to de Poorter, the alien invasion of Antarctica—at least on land—is not of "plague proportions" yet but is a sign of things to come.

"It's more a question of becoming very much aware of it and working on the prevention angle," she said.

In the water, the situation could be worse: Nobody has a good grasp on what organisms are there—native or invasive, she adds.

"I think awareness is growing," she said. "Part of that is awareness of very bad impacts elsewhere is starting to grow as well. It goes hand in hand."

The growing awareness of invasive species led to the adoption of new measures to reduce the risk from nonnative species at last month's Antarctic Treaty Consultative Meeting in Edinburgh, Scotland.

As a first step, visiting ships are being asked to dump their ballast water before arriving at the ocean that surrounds Antarctica.

Ultimately de Poorter hopes Antarctica will remain pristine, in part for philosophical reasons.

"It still sparks the imagination as the last place on Earth which is sort of like a symbol of how people and the environment can get along," she said.

"So I think it's good we have this chance to be very proactive and protect it better than we've managed to do with the rest of the world."

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