Mission to depths of endangered Arctic Ocean hopes to discover thousands of new species

An international project to explore the Arctic Ocean is expected to discover thousands of new species of marine animals that have been cut off from the rest of the world for millions of years.

An international project to explore the Arctic Ocean is expected to discover thousands of new species of marine animals that have been cut off from the rest of the world for millions of years.

Scientists said yesterday that the exploration of the Arctic Ocean - perhaps the least understood body of salt water on earth - is urgent because of the threat posed by global warming to its unique marine life.

A particular focus of the census will be the Canada Basin, a huge and largely ice-covered underwater hole 3,800 metres (12,500ft) deep where life in its icy depths has remained practically isolated for millennia.

The Arctic exploration project is part of the $1bn (£660m) Census of Marine Life, an unprecedented collaboration of more than 300 marine scientists from 53 countries with the aim of addressing our ignorance of what lives in the sea.

Since the census began four years ago, more than 500 new species of fish have been identified but scientists believe there could be at least 10 times as many yet to be discovered.

Ron O'Dor, chief scientist for the global census, said that the exploration of the Arctic Ocean would be undertaken with robot submersibles and modern sonar equipment along with more traditional collection techniques deployed from ice-breaking research ships.

"The programme will almost certainly double the number of species known in the Arctic. There could be living fossils way down at 3,000 metres that have never been seen before," Dr O'Dor said.

The Arctic Ocean is unusual because much of it is permanently capped with ice and it is surrounded virtually on all sides by land which reduces the sea's contact with other oceans.

"The entire Arctic Ocean is like an enclosed box with a lid of ice on top. There's no other place in the world like it," he said. The Canada Basin, a huge region north of the Yukon and Alaska, is a prime target for the exploration programme because so little is known about what lives in its isolated depths, said the Arctic scientists Rolf Gradinger, Russ Hopcroft and Bodil Bluhm of the University of Alaska in Fairbanks.

"The shelf breaks and the deep-sea basins of the Arctic Ocean are poorly studied for all taxonomic groups, with the deep Canada Basin being the least known of all.

"Given the Canada Basin's long-time separation with little exchange to other deep-sea basins, it will be a particularly interesting area," they added.

A crucial feature of the entire Arctic region is the sea ice that covers much of the surface for most of the year. A warmer climate has, however, already set in motion a change in the thickness of the Arctic ice cap and the area of the sea that is permanently covered by ice.

Sonar instruments on board American and British nuclear-powered submarines have measured a 40 per cent average thinning of the sea ice over the past 30 to 40 years. Satellites show that the Arctic ice cover has shrunk by about 4 per cent per decade. Based on such observations, climatologists estimate that the Arctic summer - when more ice melts than freezes - has been extended by an extra five days every decade. The result, they said, was that the annual ebb and flow of ice coverage in the Arctic Ocean has led to a persistent shrinkage with scientists estimating a totally ice-free Arctic summer as soon as 2080.

A lack of thick ice is already having an impact on local wildlife. Polar bears, for instance, are being starved as a result of having to swim longer distances between ice floes when they go hunting for seals in spring and summer. Other marine animals unique to the Arctic could also be affected by global warming. These include the narwhal, with its long, unicorn-like tooth, the whiskered walrus, the white beluga whale and rare birds such as auks and ivory gulls.

Dr Hopcroft said that new species of jellyfish discovered in the Arctic Ocean have shown that the richness of this form of marine wildlife is on a par with the biodiversity found in warmer oceans.

"The Arctic Ocean is certainly not the desert people thought it to be. The basic biodiversity of all these gelatinous animals is grossly underestimated in polar waters."