Melting ice reveals unknown species in Antarctica
Global warming a bonanza for marine research
mongabay.com
February 26, 2007




An expedition to an area of seabed recently exposed by melting ice in Antarctica has discovered several previously unknown species of marine life, including deep sea lilies, gelatinous sea squirts, glass sponges, amphipod crustaceans, and orange starfish. The findings were announced Sunday by the Census of Antarctic Marine Life, a 10-year effort to map the biodiversity of the world's oceans.

"The breakup of these ice shelves opened up huge, near pristine portions of the ocean floor, sealed off from above for at least 5,000 years, and possibly up to 12,000 years in the case of Larsen B," said Julian Gutt, a marine ecologist at Germany's Alfred Wegener Institute for Polar and Marine Research and chief scientist on the Polarstern expedition.



First observation of the living color pattern of the recently described Antarctic sea anemone Stephanthus antarcticus (Rodriguez, Lopez-Gonzalez, 2003). © P. Lopez, University of Sevilla, 2007.



Antarctic octopus (Paraledone turqueti). © E. Jorgensen, NOAA 2007.



Antarctic Ice Fish. As an adaptation to low temperatures, the Antarctic ice fish has no red blood pigments (haemoglobine) and no red blood cells. Thus the blood is more fluid and the animals save energy otherwise needed to pump blood through their body. Interestingly the brittle stars are overgrown by a yellow sponge. © J. Gutt, Alfred-Wegener-Institute 2007.



A new giant Antarctic amphipod crustacean, nearly 100 mm long, belonging to the genus Eusirus sampled by baited traps off the Antarctic Penisula during the RV Polarstern expedition ANTXXIII/8 in the Weddell Sea 2006/07. © C. d'Udekem, Royal Belgium Institute for Natural Sciences, 2007.



A new species of Shackletonia, an amphipod crustacean sampled near Elephant Island, Antarctic Peninsula, during the RV Polarstern expedition ANTXXIII/8 in the Weddell Sea 2006/07. © C. d'Udekem, Royal Belgium Institute for Natural Sciences, 2007.



Glass Sponge (Larsen A). Different to Larsen B, Larsen A was probably not permanently covered by ice shelf since the last glaciation period. Here, at Larsen A, the expedition found large glass sponges, which are extremely slow-growing and, as a consequence, must have already existed before the recent disintegration of the ice shelf. © J. Gutt, Alfred-Wegener-Institute 2007.
"The collapse of the Larsen shelves may tell us about impacts of climate-induced changes on marine biodiversity and the functioning of the ecosystem. Until now, scientists have glimpsed life under Antarctica's ice shelves only through drill holes. We were in the unique position to sample wherever we wanted in a marine ecosystem considered one of the least disturbed by humankind anywhere on the planet."

"This knowledge of biodiversity is fundamental to understanding ecosystem functioning. The results of our efforts will advance our ability to predict the future of our biosphere in a changing environment," Gutt added.

The expedition found evidence of rapid colonization of the newly exposed sea beds, discovering deep sea lilies, sea cucumbers and sea urchins thriving in the shallow waters of the Larsen zone. They also found dense patches of sea squirts and slow-growing animals known as glass sponges. In total, the scientists collected around 1000 species, some of which may be new to science.

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

"Predicting the future of higher levels in the food chain, e.g. animals living at the sea-floor or fish, is very difficult. It is for example clear that in the Larsen zone a major biodiversity shift will happen and the unique under-ice shelf system will disappear in this limited area, but we have to analyze carefully our raw data to provide, as a first step, a basis for such predictions. Besides modeling, further observations and ecological field studies are necessary."

"This is virgin geography. 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," said Gauthier Chapelle, a biologist at the Brussels based International Polar Foundation.

"The Southern Ocean spans 35 million square km — 10% of Earth's ocean surface, and ice shelves cover 1.5 million square km of it," added Tarik Chekchak, Program Manager of the Cousteau Society. "When Captain Cousteau explored Antarctica aboard the Calypso in 1972-73, the Larsen B ice shelf was 3,250 square km bigger and krill abundance in the Peninsula was much higher than today. The annual local temperature has risen 2.5 °C since the 1940's."

"Impacts of these changes on the Southern Ocean ecosystem are substantial. Interplay between ocean circulation, sea ice extent, ice shelf cover and the iceberg's mechanical action on the sea bed seem to determine the characteristics of some key planktonic and benthic communities. 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," Chekchak concluded.





This article is based on a news release from COML.


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CITATION:
mongabay.com (February 26, 2007).

Melting ice reveals unknown species in Antarctica.

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