http://news.bbc.co.uk/2/hi/science/nature/2642773.stm
Thursday, 9 January,
2003, 16:38 GMT
Polar bear 'extinct within 100 years'
By Helen Briggs
BBC News Online science reporter
QUOTE:
"As the sea ice disappears, so will the polar bears"
Prof Andrew Derocher
CAPTION:
"The bears face pollution and climate threats"
The polar bear
could be driven to extinction by global warming
within 100 years, warns an ecology expert.
The animal, which relies
on sea ice to catch seals, is already
starting to suffer the effects of climate changes in areas such
as Hudson Bay in Canada.
Scientists say Arctic
sea ice is melting at a rate of up to
9% per decade. Arctic summers could be ice-free by mid-century.
Dr Andrew Derocher,
of the University of Alberta, Edmonton,
has used the data to assess the impact on the Arctic's top
predator.
Top carnivore
He believes the polar
bear could disappear in the wild
by the end of the century unless the pace of global warming
slows.
He told BBC News Online:
"Polar bears are a species whose
whole life history is dependent on having sea ice.
As the sea ice changes
in distribution and pattern we can
expect this to have fundamental changes on the ecology of
polar bears.
"As the sea ice
disappears, so will the polar bears."
Polar bears are uniquely
adapted to survival in the Arctic.
They are the world's largest land predator, feeding mainly
on seals.
They use the sea ice
as a floating platform to catch prey
and they travel across it on their way to their dens.
British polar expert
Dr Peter Wadhams of the University
of Cambridge says the bear faces a gloomy future unless
it is able to change its habits.
"It could be that
a polar bear could adapt to a new habitat
and adopt habits like the brown bear in Alaska which hunts
salmon in streams and other small animals on land," he said.
Fragile ecology
Scientists believe
that Ursus maritimus, the "sea bear",
evolved about 200,000 years ago from brown bear ancestors.
Whether it can "change
its spots" and behave more like a
brown bear is another matter.
Lynn Rosentrater, climate
scientist in the WWF International
Arctic Programme, thinks it unlikely.
There have been cases
of polar bears scavenging in bins for
food in summer, she said, but the animals need seal fat to
get through the winter.
"In the absence
of sea ice the whole basis of polar bear
ecology ceases to exist," she explained.
Polar bears are currently
found in Arctic regions of
Alaska, Canada, Russia, Greenland and Norway.
Populations in southern
limits such as Hudson Bay are
at most risk of dying out.
Bears stand most chance
of surviving, in isolated groups,
in the western Arctic or the Canadian archipelago.
Photos courtesy of
Andrew Derocher.
###
