Are polar bears an endangered species?

Scientists disagree on whether or not polar bears are an endangered species. Reg Sherren digs into the disagreement in a new documentary.

Duelling scientific theories explored in The Politics of Polar Bears

"The Politics of Polar Bears" airs Saturday, August 30, at 7 p.m. on CBC Manitoba. (CBC)

Which of the following statements do you think is true?

  • Polar bear populations have been in decline for some time.
  • Polar bear populations are healthy.

The answer may surprise you. 

Reg Sherren examines the facts behind both statements in a new documentary called The Politics of Polar Bears.

For some time now the suggestion has been that polar bears are in trouble and that many sub-populations of ursus maritimus have been decreasing.

Scientist Andrew Derocher has spent his career studying polar bears. He's a longstanding member and past chair of the Polar Bear Specialist Group, composed of researchers from the five circumpolar nations  Canada, Greenland/Denmark, Norway, Russia, and the United States.

Derocher is a professor of biological science at the University of Alberta, and he has been more outspoken than most about the peril Churchill's big bears are facing.

"They could be gone in a couple of years," he says. "Our estimations are, if we had a very early melt, and a very late freeze, we could see up to 50 per cent mortality in a single year. You put a couple of years like that back-to-back, and things could happen very quickly."

But not everyone agrees with that statement. 

In fact, just last year Environment Canada reported that, "The polar bear does not have a small wild population, it does not have a restricted area of distribution and no marked decline has been observed." 

Biologist Markus Dyck works in Nunavut and says while climatic changes are real and observed, only one or two populations appear to be declining slightly due to changes in sea ice.

In The Politics of Polar Bears, Sherren will pick his way through the message track to help you decide what is really happening with the largest land carnivore on the planet.

The Politics of Polar Bears airs Saturday, August 30 at 7 p.m. on CBC Television in Manitoba.