NEWS

CHILE’S MELTING ICE CAPS DRAW NEW SPECIES TO ANTARCTIC

03/07/2007

CHILE’S MELTING ICE CAPS DRAW NEW SPECIES TO ANTARCTIC

Larsen Split Reveals Virgin Seabed And Provokes New Climate-Change Concerns

SANTIAGO TIMES

(March 7, 2007) Scientists have discovered a multitude of new species inhabiting Antarctica’s icy waters. The collapse of the Larsen icecaps – once in 1995 and then again in 2002 – allowed an international scientific team access to the previously ice-covered seabed 850 meters off the Antarctic Peninsula. The team’s star find was a 10- centimeter-long shrimp, but their search revealed worrying changes caused by global warming.

The new discoveries are the work of 52 scientists from 14 different countries who, during December 2006 and January 2007, boarded the German research ship Polarstern to carry out the Census of Antarctic Marine Life (CAML) project.

The collapse of the Larsen icecaps (Larsen A and Larsen B) was the largest ice shelf collapse ever observed by man. The size of Larsen B alone is the size of the state of Rhode Island. The weakened ice split due to global warming, which is affecting parts of Antarctica more rapidly than anywhere else in the world.

According to marine ecologist Julian Gutt, the opening of the sea bed revealed area sealed off for at least 5,000, maybe up to 12,000 years.

“The collapse of the Larsen shelves may tell us about the impacts of climate-induced changes on marine biodiversity and the functioning of the ecosystem,” he said. “Until now, scientists have glimpsed life under Antarctica’s ice shelves only through drill holes.”

The scientists found an abundance of deep sea lilies (from the crinoid family), sea cucumbers and sea urchins living on sea floor sediments that varied from bedrock to pure mud. Slow-growing glass sponges were found around Larsen A, where the creatures have had seven years to re-colonize since the icecap split. There is evidence that they are now also colonizing around Larsen B.

The team recorded the presence of species previously unknown to the area, such as the fast-growing gelatinous sea squirts. These were found in high densities and probably moved into the area only after the second ice shelf broke in 2002.

Alongside the giant shrimp, were 14 other new amphipod species. There were also four new species of cnidarians (simple animals, such as jelly fish, sea anemones and coral). Over the coming months scientists will examine these specimens in labs to confirm whether they are indeed new discoveries.

The polar team also had the pleasure of locating Minke whales and a very rare species of beaked whale near Elephant Island.

“It was surprising how fast such a new habitat was used and colonized by Minke whales in considerable densities,” said Dr. Meike Scheidat. “They indicate that the ecosystem in the water column changed considerably.”

A worrying impact of these changes is a decrease in krill – small, shrimp-like creatures at the bottom of the food chain. Krill feed on algae that grow under sea ice, but as the sea ice disappears, so do the krill. Krill form the basis of many sea creatures’ diets. A decrease in the small crustacean would have consequences affecting penguins, seals and whales. An adult blue whale alone eats about 4 million krill per day.

“Algae is a source of abundant, high quality winter food and is utterly central to the health of the whole ecosystem,” said CAML leader, Dr. Michael Stoddart.

The annual local temperature in Antarctica has risen 2.5 degrees Centigrade since 1940 and the Larsen B ice shelf has shrunk 3,250 kilometers since 1972. These climate change trends show no sign of subsiding without human action to reduce carbon emissions. Scientists warn that global warming in the southern ocean – which spans 35 million km² - will have major domino effects world-wide.

“Impacts of these changes on the southern ocean ecosystem are substantial,” said Tarik Chekchack, program manager of the Costeau Society. “In a changing environment, the results of the CAML efforts are key to advancing our ability to understand our biosphere, inform public debate and allow decision-makers to lead us into a more sustainable future.”

CAML is just one initiative happening during International Polar Year, which was launched in Paris on March 1.