06 September 2005

Study finds Arctic depths teeming with life

The remotest depths of the Arctic ocean are surprisingly full of life, including previously unknown species of jellyfish and worms, according to a scientific team that just finished exploring the area.

The scientists, led by the University of Alaska, used robot submarines and sonar to probe an isolated 3,800-metre basin off Canada's Arctic coast where they fear species could be at risk from global warming.

"We were surprised by the abundance and the diversity of life in this environment," said Rolf Gradinger of the University of Alaska, the chief scientist on the voyage.

"Even at a depth of 3,000 metres we found animals on the sea floor, we found sea cucumbers ... and all kinds of jellyfish and crustaceans.

"Some of the species that we saw are completely new to science. They have not been described in any area of the earth so far."

The new species are a jellyfish and three kinds of benthic bristle worms.

The team also found unexpectedly high numbers of cod as well as the first squid, octopus and flea-like crustaceans seen in an icy environment.

Global census
Scientists from the United States, Canada, Russia and China spent 30 days on the US icebreaker Healy as part of a $US1 billion, 10-year global Census of Marine Life funded by governments, companies and private donors.

The Healy returned on Tuesday with thousands of specimens from the Chukchi and Beaufort Seas and the Canada Basin, a vast bowl walled by steep ridges and covered with ice.

The team said the data would help measure the impact of climate change and, should polar caps continue receding, the damage done by increased energy exploitation, fishing and shipping.

"This is a benchmark and we hope that in the next 10, 20 or 30 years these kinds of studies will be repeated to see whether any kinds of changes have occurred in the composition and the abundance of animal life," Mr Gradinger said.

United Nations studies say the Arctic could be largely ice-free in summer by 2100 because of global warming, blamed mostly on gas emissions from cars, power plants and factories.

The scientists say that if the northern polar cap melts, more southerly species could enter Arctic waters and disrupt the ecology.

The team also said explorers would carry out similar studies in the Southern Ocean around the Antarctic, where conditions are much less settled than in the Canada Basin.

"Scientists now theorise the swirling Southern Ocean current is an evolutionary cauldron, upwelling Antarctic nutrients and mixing life forms from the Pacific, Indian and Atlantic oceans, returning them in centrifuge-like fashion," the team said in a statement.

Australian team
The Australian Antarctic Division in Hobart will lead the project from December 2007 to March 2008.

It will involve up to 200 scientists from 30 countries and take samples from as deep as 5,000 metres.

"Because the Southern Ocean appears to be so critical to the biology of the global ocean system, scientists are eager to understand how continued climate change, if realised, will affect it and the other oceans in turn," the team said.

Some of the exotic life forms the researchers have found in the Arctic can be seen at: http://www.coml.org/medres/iceocean/iceocean.htm

Source: www.abc.net.au


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