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Antarctic mission


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POSTED: Friday, April 16, 2010

Climate warming has heavily affected the ecosystems and diversity of marine life in the Antarctic Peninsula region, University of Hawaii oceanographers found during a two-month expedition.

Craig Smith, UH professor of oceanography, and Laura Grange, postdoctoral oceanographic researcher, had hoped to get into the area where the Larsen B ice shelf broke away in February and March 2002.

The mass of ice was more than 700 feet thick and has been breaking since 1995, Smith said. The last large chunk to break was the size of Rhode Island. It released 720 billion tons of ice, according to NASA's Earth Observatory.

The LARISSA (LARsen Ice Shelf System Antarctica) project funded by the National Science Foundation from Dec. 27 to March 9 was an interdisciplinary program to look at “;rapid and fundamental changes”; occurring in the Antarctic Peninsula region following the Larsen B collapse.

Smith said he and Grange wanted to look at sea floor ecosystems where breakage of the thick ice had exposed the area to sunlight and photoplankton in areas where nothing previously lived.

But the research vessel Nathaniel B. Palmer was unable to get to their primary site, which was “;jammed full of ice,”; Smith said. Though that was disappointing, he said, “;What we found was really remarkable.”;

The vessel went to the other side of the peninsula, where Smith and Grange studied four fjord systems.

In Andvord Bay and other fjords, the researchers documented huge numbers of giant marine worms—”;4 inches long and 1 inch in diameter and stuffed to the bursting point with eggs and sperm,”; Smith said.

Another surprising discovery, made with a remotely operated vehicle, was a large number of invasive king crabs moving up from deep water in a 4,752-foot-deep basin off Anvers Island, Smith said.

King crabs had been absent from cold Antarctic ecosystems for possibly millions of years, but with climate warming they are living about 990 feet shallower than ever recorded, he said. “;They're wiping out most fauna in the system.”;

All the fjord systems visited had high biomass, abundance and diversity of animals, including many ready to reproduce, he said. The high production of animals, he said, “;may be important for the whole Antarctic region”; as they could be providing larvae to seed sea floor populations beyond far beyond the fjords.

Smith said they were surprised to find more polar or subpolar conditions than in fjord systems elsewhere. “;What we think is going on is these fjords are in a colder stage than those in the Northern Hemisphere, so the amount of glacial sediments and melt water going in is quite limited.”;

But he said, “;Climate warming in Antarctica is faster than anywhere on the globe.”; Productivity and abundance of animals might decline as a result of warming, and “;unique communities may change,”; he said. “;Species may be lost.”;

This was Smith's third major expedition to Antarctica. “;A little-known fact is Hawaii is closer to the Antarctic than any other point in the United States,”; he said.

Smith hopes to schedule another cruise next year to study the fjord systems in more detail.

Given his interests in extreme environments, biodiversity and effects of climate change, he says, Antarctica “;is a natural place to work and also really beautiful. ... But it is painful to see how it's changing, and it is changing at an alarming rate.”;

In one area where they saw 9,000 mating pairs of Adelie penguins in 1999, there are now fewer than 2,000, he said. “;They require sea ice, and the sea ice is moving southward with the warming trend.”;