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September 06, 2008
Polar Bears Move When Climate Changes: A Note from Nichole Hoskin
Posted by jennifer, at 05:50 PM
Thirty years ago polar bear experts were discussing “climatic fluctuations” rather than climate change, and the effect this can have on polar bear distribution in the Arctic. In fact Christian Vibe, the Greenland representative on the Polar Bear Specialist Group, was more focused on how climatic fluctuations affected distribution, than abundance.
The observations of Dr Vibe back then, for example polar bears drowning in scattered drift ice, are similar to what is being observed now, but back then Dr Vibe did not consider such incidences as unusual or causing long term decline in polar bear numbers.
At the 2nd Working Meeting of the Polar Bear Specialist Group, in 1970, he said:
“The ecological conditions of the Arctic have changed as a result of this alteration of the climate. Some high Arctic regions get colder winters and less open water in summer. The productivity of the sea decreases in the Arctic and in regions nearer the Atlantic. The ringed seal moves to the areas of higher productivity, and the polar bear follows the seal.
This is the situation today in Northwest as well as in Northeast and Southeast Greenland. All other animals in Greenland, in the sea as well as on land, are affected by the same climatical fluctuations, which are reflected in a regular shift between Arctic and Atlantic conditions (or Continental and Atlantic) over a period of 56 to 66 years; they are more marked every second time the period culminates. The climatic situation of today, with intense movements in the drift ice in summer, is very similar to that 110-120 years ago. For the polar bear, especially in East Greenland, that means unstable living conditions, more roaming, and probably greater loss of animals by drowning in scattered drift ice off South Greenland.
Under the Atlantic conditions of forty years ago, the drift ice from the Polar Basin kept moving throughout the winter and melted at high latitudes in summer. The situation for the polar bear was quite the opposite to that today. It then had to go ashore early in summer at high latitudes –and fewer got lost.
Alternatively, we could say that the polar bear probably was more numerous 30-40 years ago - as all Arctic animals were - but the Arctic-Continental climate of today has forced it south to regions with unstable drift ice conditions and within the range of man.” (at pp 20-21)
In this extract from Dr Vibe wriiten in 1970, he notes the negative effects of colder Arctic winters and less open water in summer. He explains that polar bears in the late 1960s were moving southwards to unstable sea conditions, with the possibility that more polar bears were dying.
However, Dr Vibe also noted that polar bears adapt to climatic fluctuations in the Arctic by moving to the areas with more of their primary prey, ringed seals, as ringed seals move to more suitable habitats.
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I recently purchased a copy of Christian Vibe’s 1967 monograph ‘Arctic Animals in Relation to Climatic Fluctuation’, Meddelelser om Grønland (1967) 170(5), pp 1-227.
I have started putting direct quotes from this data-rich research on the Environment Wiki that is linked to this blog:
http://www.jennifermarohasy.com/wiki/Effects_of_Climatic_Fluctuations_on_Polar_Bears_in_Greenland
I purchased the book from Abebooks at:
http://www.abebooks.com/servlet/SearchResults?tn=Arctic+Animals+Relation+Climatic+Fluctuations
This blog is a gathering place for people with a common interest in politics and the environment. I strive for tolerance and respect. I don’t always agree with what I publish, but I believe in giving people an opportunity to be heard. I take no responsibility for comments and hyperlinks that follow each blog post and some content may be considered offensive by some people.
Posted by jennifer at September 6, 2008 05:50 PM
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