Ice Shelf Collapses Reveal New Species, Ecosystem Changes

February 27, 2007

Even before the global launch of International Polar Year this Thursday, scientists are announcing some unusual discoveries from the cold waters off the Antarctic Peninsula.

The collapse of two massive ice shelves in the past 12 years has opened a window onto a pristine—but rapidly changing—underwater world, an expedition team reported on Sunday.

In the first comprehensive survey of the region, 52 explorers aboard the research vessel Polarstern captured a glimpse of about a thousand rarely seen species of marine wildlife.

Several of the creatures may prove to be new to science, including a 1-inch-long (2.5-centimeter-long) shrimplike crustacean and a giant Antarctic barnacle (see photos of some of the species revealed by the Antarctic expedition).

The team also found a potentially new sea anemone that lives on the back of a snail.

The venomous anemone, the scientists said, helps protect the snail from predators while the snail transports the anemone to new food sources.

The scientists hope their work will help create a baseline for understanding what types of creatures existed under the ice shelves before they disintegrated.

"This is virgin geography," Gauthier Chapelle, outreach officer for the expedition and biologist at the Brussels-based International Polar Foundation, said in a media statement.

"If we don't find out what this area is like now, following the collapse of the ice shelf, and what species are there, we won't have any basis to know in 20 years' time what has changed and how global warming has altered the marine ecosystem."

Uncapped Sea

The Larsen A and B ice shelves once covered 3,900 square miles (10,000 square kilometers) of the Weddell Sea off the coast of Antarctica, shielding the seabed for at least 5,000 years (interactive map of Antarctica).

The Larsen A ice shelf broke apart in 1995, and the nearby Larsen B ice shelf followed in 2002.

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