It is summer in this reindeer-herding village in northern Russia and with not an iceberg in sight, residents are acquiring a taste for bathing in the local river.

"We used to have ice on the river all year round. The warming process is speeding up," said the worried head of the state-controlled reindeer company at Kanchalan, Arkady Makhushkin.

"The reindeers' health is suffering. Their meat isn't so tasty," he said, explaining that the animals had to be herded greater distances to find cooler grazing grounds in upland areas.

As he tries to work out the effects of rising temperatures on his 32,000 reindeer, questions are being asked about global warming across northern Russia, from Chukotka region in the east, where Kanchalan is located, to Murmansk in the west.

While there are fears for wildlife, there is growing optimism about the Arctic maritime passage that runs across the top of Russia from the Bering Straits to the north Atlantic.

In May President Vladimir Putin called for greater attention to this passage, which is known as the Northern Sea Route and now operates only piecemeal. It could potentially cut thousands of kilometres (miles) off sea travel between Europe and Asia.

In an address on a nuclear ice-breaker in Murmansk, he urged more effort in the area to secure Russia's "strategic, economic, scientific and defence interests."

In Chukotka, regional governor Roman Abramovich, the oil tycoon and owner of Britain's Chelsea football club, has given at least symbolic backing to this goal.

He sponsored a successful search for the steamship Chelyuskin, which sank off Chukotka's coast in 1933 while trying to prove the viability of the Northern Sea Route. The operation rescued from the ice almost all those who were on board, and salvaged some items from the ship.

The administration now plans to build a floating nuclear power station off Chukotka's north coast as part of the bid to revive the region.

In addition, explorer and parliament member Artur Chilingarov is leading a survey of the Arctic seabed this summer, with a view to extending Moscow's territorial claims and developing new energy deposits.

Referring to prospects for the Northern Sea Route, Chilingarov told AFP: "No one except Russia can do this.... We have our own ice-breakers. We had a system in Soviet times. We need to restore it."

A British yachtsman, Adrian Flanagan, is due shortly to head off from Chukotka to attempt the first solo sail through the Northern Sea Route.

While one Chukotka port official described this as "kamikaze," Flanagan too is optimistic. Contacted by AFP he said that the ice looked set to recede at least as far as in 2005, which was a record year.

But while some see opportunities, others are already counting the costs of climate change.

In Kanchalan, some 70 kilometres (45 miles) northwest of the regional capital Anadyr, teachers at the local school blamed global warming for cracks that have appeared in the building due to melting of the permafrost below ground.

And while Makhushkin worries about his reindeer, receding ice is also proving troublesome for sea mammal hunters.

In coastal districts members of the Chukchi ethnic group are struggling to adapt as whales head for cooler waters even further north, says Eduard Zdor, secretary of Chukotka's Association of Traditional Marine Mammal Hunters.

Also along the coast there is growing conflict between people and polar bears.

The bears have been forced ashore as their normal habitat, the polar ice sheets, now recedes as much as 1,000 kilometres (620 miles) north of Chukotka in summer.

In the last five years two people have been killed and another maimed by polar bears in Chukotka as the animals have taken to approaching villages, desperate for food, says Anatoly Kochnev, a fisheries researcher with the agriculture ministry.

"Whereas before people wanted to feed them, tolerated them and considered them beautiful, now they are seen as enemies and are getting killed more and more," he said.

"We can't maintain nature in absolutely the same state but we need to reduce our influence on the animal world, not help them to die," he said.

There is little sign of environmental decline from the Anadyr seashore, where visitors can see fish jumping from the water and seals and white whales surfacing for air.

In Chukotka, where the 1991 collapse of the Soviet Union brought many people close to starvation, it may be the quality of government rather than climate change that will most preoccupy residents in coming years.

While the whales are retreating farther north, the longer summer fishing season is so far not having much effect on other sea life, said Anatoly Zaitsev, head of a local fishing team.

"As long there isn't over-fishing, we'll continue to have fish," he said as he breakfasted on salmon roe spread thickly on hunks of bread.