Published on February 20th, 2013 | by James Ayre1
Polar Bears Populations Could Be Halved In Only One Year From Climate Change Caused Melting Events, Report Says
February 20th, 2013 by James Ayre
Polar bear populations could be more than cut in half in a single year with only one extreme melting event in the Arctic, according to a new repot from the University of Alberta. The report is strongly urging the relevant governments to actively begin planning for the conservation of the animal, specifically with regards to dealing with the very rapid changes in the Arctic that will occur in the coming years as a result of climate change.
The report, co-authored by U of A professor Andrew Derocher, clearly explains the reality that with just one unpredicted jump in Arctic melting polar bear populations would begin a very steep decline. One which would not be easy to recover from, and could bring them much closer to extinction.
Given that polar bears are one of the last remaining species of megafauna in the world, it does seem almost inevitable that they will follow after all the other now “mythic seeming” animals that were alive only a few thousand years ago, such as the Elasmotherium unicorn, the massive Northern American Lion, and the ‘dragon’ Megalania. It may seem hard to think that they could just completely disappear, but perhaps in a hundred years polar bears will seem as strange and distant as those animals do.
“It’s a fact that early sea ice breakup, late ice freeze-up and the overall reduction in ice pack are taking their toll,” said Derocher. “We want governments to be ready with conservation and management plans for polar bears when a worst-case climate change scenario happens.”
Climate change is causing very clear changes in the Arctic, and on polar bears. The effects have been seen in “both observational and modelling studies in many areas where the bears are found.” Previous studies done by Derocher and his fellow researchers have made it clear that with just one year of large ice-loss, there would be “hundreds of Hudson Bay polar bears stranded on land for an extended period. Such an event could erase half of a population in a single year,” Derocher said.
“The management options for northern communities like Churchill would range from doing nothing, to feeding the bears, moving them somewhere else or euthanizing them,” said Derocher.
The researchers make it clear that they aren’t trying to dictate government policies, but they do want those involved, the policy makers and wildlife managers, to really start looking at the likely future of the Arctic, and of polar bears, and make decisions based on that. Rather than just put it off into the future when their may be no longer be any ‘good’ options available.
“You’re going to make better decisions if you have time to think about it in advance; it’s a no-brainer,” said Derocher, noting that “consultation with northern residents takes time and the worst time to ask for input is during a crisis.”
One of the options available include what the researchers are calling the ‘wild bear park model’, which means “feeding and releasing the bears when freeze-ups allow the animals to get to their hunting grounds.” Ideas such as that have significant downsides though, being expensive and making the bears more or less human-reliant. The researchers correctly note that such programs would have significant ramifications on the animals long-term behavior. (Author’s note: I’m of the opinion that programs such as this should not be undertaken. If an animal is going extinct in its environment, it’s going extinct. Making the animals completely dependent upon humans, such as in this program, or in zoos, robs them of their good qualities and does not benefit them. The likely fate of polar bears, in my opinion, is a large loss of population numbers and subsequent hybridization with northern grizzly bear populations.)
The researchers also note, that as the Arctic ice disappears, more and more polar bears will be venturing near human settlements, potentially creating further dangers for the humans that live there. And if there were a large number of incidents involving polar bears killing humans, there would likely be a significant backlash against the animals from the local populations of humans.
“Around the world, polar bears are an iconic symbol, so any tragedy would produce massive attention,” said Derocher. “If the warming trend around Hudson Bay took an upward spike, the population of 900 to 1,000 bears in western Hudson Bay would be on the line, so there has to be a plan.”
The new paper Rapid Ecosystem Change and Polar Bear Conservation, was published January 25th in the journal Conservation Letters.
Some background on the beautiful animals:
“The polar bear (Ursus maritimus) is a bear native largely within the Arctic Circle encompassing the Arctic Ocean, its surrounding seas and surrounding land masses. It is the world’s largest land carnivore and also the largest bear, together with the omnivorous Kodiak Bear, which is approximately the same size. A boar (adult male) weighs around 350–700 kg (770–1,500 lb), while a sow (adult female) is about half that size. Although it is closely related to the brown bear, it has evolved to occupy a narrower ecological niche, with many body characteristics adapted for cold temperatures, for moving across snow, ice, and open water, and for hunting the seals which make up most of its diet. Although most polar bears are born on land, they spend most of their time at sea. Their scientific name means “maritime bear”, and derives from this fact. Polar bears can hunt their preferred food of seals from the edge of sea ice, often living off fat reserves when no sea ice is present.”
“The polar bear is classified as a vulnerable species, with eight of the nineteen polar bear subpopulations in decline. For decades, large scale hunting raised international concern for the future of the species but populations rebounded after controls and quotas began to take effect. For thousands of years, the polar bear has been a key figure in the material, spiritual, and cultural life of Arctic indigenous peoples, and polar bears remain important in their cultures.”
“The polar bear is found in the Arctic Circle and adjacent land masses as far south as Newfoundland Island. Due to the absence of human development in its remote habitat, it retains more of its original range than any other extant carnivore. While they are rare north of 88°, there is evidence that they range all the way across the Arctic, and as far south as James Bay in Canada. They can occasionally drift widely with the sea ice, and there have been anecdotal sightings as far south as Berlevåg on the Norwegian mainland and the Kuril Islands in the Sea of Okhotsk. It is difficult to estimate a global population of polar bears as much of the range has been poorly studied; however, biologists use a working estimate of about 20,000 to 25,000 polar bears worldwide.”
“There are 19 generally recognized, discrete subpopulations. The subpopulations display seasonal fidelity to particular areas, but DNA studies show that they are not reproductively isolated. The thirteen North American subpopulations range from the Beaufort Sea south to Hudson Bay and east to Baffin Bay in western Greenland and account for about 70% of the global population. The Eurasian population is broken up into the eastern Greenland, Barents Sea, Kara Sea, Laptev Sea, and Chukchi Sea subpopulations, though there is considerable uncertainty about the structure of these populations due to limited mark and recapture data.”
“Of the 19 recognized polar bear subpopulations, eight are declining, three are stable, one is increasing, and seven have insufficient data, as of 2009.”
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