No reason to be alarmed about the fate of the polar bear
To the Expositor:
Until very recently, the polar bear has been extensively used as a symbol in the climate debate. Projected warming in the Artic and summer sea ice loss have been cited as two major reasons why the species are in peril. Is this in fact the case and is the bear population in decline? The answer to the question would seen to be no!
In 2005 a Monnett/Gleason paper was published entitled, ‘Observations of Mortality Associated with Extended Open-Water Swimming by Polar Bears in the Beaufort Sea.’ The pair were part of a team conducting an aerial survey of bears in the area. Four bear carcasses were seen floating in open water. They assumed that the bears drowned in search of pack ice since the average distance from land to pack ice was about 180 kilometers. At the time no one had any idea of the swimming capabilities of the bears. Al Gore used this study as support for his animated clip of bears in the film, ‘An Inconvenient Truth.’ In 2008, a radio collared female bear was recorded making a continuous swim of 687 km and then intermittently swam and walked on the sea ice an additional 1,800km!
In any event, the film launched the polar bear into stardom as the icon for global warming and the bear is included in the IUCN (International Union for the Conservation of Nature) Red List of Threatened Species. There are four threatened categories including vulnerable, endangered, critically endangered and extinct in the wild. The bears rate as vulnerable. There are several ways to make the vulnerable list. Two of them are related to actual population reductions and the third way is projected population reduction. The bears got on the list based on the third: projected population reduction.
The bear population estimates have been on models that have been developed by various individuals and organizations. It has become increasingly obvious that the models are wrong. One of the basic assumptions included in the models is that summer sea ice extent will have a profound effect on polar bear survival. Eighty percent of most polar bear’s annual stored fat is accumulated during the ringed seal pupping season that usually extends from late March to the first week in May. In addition, heavy springtime ice is likely the greatest cause of bear nutritional deprivations since the adult seals cannot find suitable denning in the heavy ice conditions. Not one USGS model includes sea ice conditions in determining polar bear survival.
So what is the polar bear population and is it stable? Estimates vary but the count has increased since 1960 when the number was about 10,000. It is now estimated at about 25,000. There is no evidence of population decline in any of the sub-populations and polar bear body condition also looks encouraging.
Another interesting development is the Inuit are now calling the present period ‘The Time of the Most Polar Bears.’
In short, the bears seem to be doing fine, the population is stable and healthy and there is no reason to date to be concerned.