Polar bears can dive, but it can’t save them from climate change: biologist
“Increased diving ability cannot evolve rapidly enough to compensate for the increasing difficulty of hunting seals”
A three-minute dive of an old and hungry polar bear in the Svalbard Islands off Norway has drawn global attention from those who view this as a sign polar bears are doomed by global warming.
“Tragic” was the comment made Aug. 4 by a journalist in the Washington Post
That came in response to a widely-circulated paper in the most recent online edition of the journal Polar Biology attributed to climate change and hunger on the part of a polar bear spotted — and filmed — in a long dive in the Svalbard Islands off Norway.
The paper’s authors, polar bear biologist Ian Stiring and nature guide Rinie van Meurs, suggest, based on an observation of this polar bear, that “it is possible that the ability to hold its breath for so long may indicate the initial development of a significant adaptation for living and hunting in its marine environment.”
In other words, polar bears are learning to hold their breath to give them an edge on hunting in open water.
Previously, Stirling, now retired from the University of Alberta, warned that global warming and less ice has forced polar bears to spend more time on land where there is less food.
But even diving won’t save polar bears in a warmer Arctic, he said.
That’s because “increased diving ability cannot evolve rapidly enough to compensate for the increasing difficulty of hunting seals because of the rapidly declining availability of sea ice during the open-water period resulting from climate warming,” the most recent paper asserts.
Inuit say polar bears have always been able to swim and dive — and Inuit also speak of a special kind of polar bear, a “water bear,” one that lives almost exclusively in the water and is “noted for their HUGE size,” said Iqaluit’s former mayor Madeline Redfern in a recent tweet in response to the long polar bear-dive.
Stirling has said the longest dive by a polar bear he had ever seen until now took place in 1973 — so for him the 2014 dive can be interpreted as a sign of rapid adaptation and another sign that polar bears are in trouble due to global warming.