Time for a re-post

Thursday, March 30, 2006

Polar bears drown as ice shelf melts

Copyright © 2003 Donald Bradshaw

Will Iredale

SCIENTISTS have for the first time found evidence that polar bears are drowning because climate change is melting the Arctic ice shelf.
The researchers were startled to find bears having to swim up to 60 miles across open sea to find food. They are being forced into the long voyages because the ice floes from which they feed are melting, becoming smaller and drifting farther apart.

Although polar bears are strong swimmers, they are adapted for swimming close to the shore. Their sea journeys leave them them vulnerable to exhaustion, hypothermia or being swamped by waves.

According to the new research, four bear carcases were found floating in one month in a single patch of sea off the north coast of Alaska, where average summer temperatures have increased by 2-3C degrees since 1950s.

The scientists believe such drownings are becoming widespread across the Arctic, an inevitable consequence of the doubling in the past 20 years of the proportion of polar bears having to swim in open seas.

“Mortalities due to offshore swimming may be a relatively important and unaccounted source of natural mortality given the energetic demands placed on individual bears engaged in long-distance swimming,” says the research led by Dr Charles Monnett, marine ecologist at the American government’s Minerals Management Service. “Drowning-related deaths of polar bears may increase in the future if the observed trend of regression of pack ice continues.”

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Hat tip to The O C