Study: Beaufort Sea polar bear numbers declined 40 per cent over 10 years

Monday, November 17, 2014, 1:51 PM - Grim news for the Arctic's top land predator.

Researchers in Canada and the U.S. found polar bear numbers in the southern Beaufort sea declined by as much as 40 per cent in the first decade of the 21st Century.

The findings, published Monday in the journal Ecological Applications, show survival rates were at their worst between 2004 and 2007.

"Of the 80 cubs observed in Alaska from 2004 to 2007, only two are known to have survived," Jeff Bromaghin, the study's lead author, said in a release by the United States Geological Survey.

The researchers say the sharp decline was likely due to unfavourable ice conditions making it harder for the bears to hunt their prey, although they also acknowledge low prey numbers may also have been a factor.

Beaufort Sea polar bear numbers stabilized at around 900 individuals in 2010. The researchers say it's not clear by survival rates saw an uptick after 2007, but add: "The survival of subadult bears declined throughout the entire period."

The International Union for the Conservation of Nature lists polar bears as a vulnerable species, one level below endangered. In Canada, it is listed as a species of "Special Concern."

There are an estimated 25,000 polar bears Arctic-wide. Of 19 subpopulations studied by the IUCN, four are listed as being in decline, five are stable, one is increasing. The remainder do not have enough data to make a determination.

READ MORE: Read our full feature on the threats faced by this Canadian icon.