Study suggests numbers could fall by as much as 30% in a year
Shrinking sea ice responsible
The analysis takes into consideration how long an adult polar bear can survive without food and has found that instead of a gradual drop off in polar bear numbers the population may fall by as much as 20-30% in a year as a result of the effects of climate change.
“You can go a reasonable period of time without seeing major effects. But once you look at the data, you start to see sudden, dramatic changes.” said Dr. Andrew Derocher, one of the world’s leading experts on polar bears and co-author of the study.
Shrinking sea ice will be the main factor determining the fate of polar bears. The animals rely on the ice as a means of moving between different areas in order to hunt seals. Polar bears often travel long distances in order to get enough food to prepare themselves for the mating season and then their long hibernation. A decrease in sea ice means less available food and has a knock on effect with fewer successful matings, less robust cubs and more adolescent bears “wandering around trying to find something to eat”.
Scientists calculate that whilst 3-6% of polar bears in the surveyed Western Hudson Bay area presently die during the 120 day summer fast, in the future, 28-48% of the bears would die should the period increase to 180 days as is expected. The amount of time polar bears have had to spend fasting has increased by 7 days per decade and is expected to continue to increase in the future.
Canadian Government yet to recognise threat
Currently Canada does not offer any significant protection to its polar bears, 900 of which are found in the Western Hudson Bay. In the US the polar bear is listed as threatened and thus receives extra protective meaures. The government advisory group Committee of the Status of Endangered Wildlife in Canada has labelled the polar bear only as of “special concern”. It is likely that the government will not change its position unless recommended to do so by this group.
The committee defends its controversial rating by citing evidence that the polar bear population in 2008 was the greatest it had been for over 50 years, and argue that the effect of climate change on the bears is not yet apparent.
“A major conservation failure”
Derocher has branded the committee’s recommendations “A major conservation failure”.
“We are past the point where we can couch this in cautious terms,” he said “Canada doesn’t take the threat of climate change seriously.”
Derocher admits that he didn’t foresee the deadly results of climate change to take place in his lifetime when he first started writing about arctic warming and its threat to the polar bear in 1993.
“I thought this was something for the generation coming after me. Now I’m very certain we’re going to see very serious changes in the near future.”