Scientists give Hudson Bay polar bears 30 years to live

Scientists are giving the population of polar bears that lives in the Hudson Bay area of Canada only 30 more years, saying climate change threatens to extinguish the group.

Three academics used a mathematical model to calculate how long the threatened Hudson Bay population of polar bears might have before facing extinction, and the conclusion is 30 years. Professor Andrew Derocher joined with Professor Mark Lewis and graduate student Peter Molnar, all who are with the University of Alberta. Their paper, Predicting survival, reproduction and abundance of polar bears under climate change was published in the journal Biological Conservation in April. The scientists created a mathematical model that predicts the future of the Hudson Bay polar bears. Simply put, the mathematical model figures global warming will endanger the Southern Hudson Bay population of polar bears by forcing them to undergo a longer period of time without food than they currently do, decreasing their ability to survive. There are approximately 900 bears currently in this group. Loss of sea ice will affect reproduction as well. Express News quoted Derocher as saying

"If the ice-free period extends to 180 days our modeling shows upward of half of those animals will die.”

Yale 360 explained the mathematical model:

"The calculation is not overly complex, since the health of polar bears is directly tied to the amount of time they spend on sea ice hunting seals.

The basic facts are as follows: The region’s polar bears have been forced to spend an extra week per decade onshore; the bears have been losing, on average, more than 20 pounds per decade; the body mass of the bears has been steadily declining; females have lost 10 percent of their body length; and the population has dropped from 1,200 to 900 in three decades, with much of the decline coming in the last 10 years.

Looking at projected sea ice declines, Derocher and his colleagues estimated in a recent paper in Biological Conservation that western Hudson Bay’s polar bear population could well die out in 25 to 30 years."

However, as Yale 360 learned during an exclusive interview with Derocher, it wouldn't take much to imperil this population of polar bears, and the bears could very quickly succumb to global warming phenomena.

"Derocher said that the population — one of 19 in the Arctic — could be gone within a decade. All it would take is several straight years of low sea ice conditions — such as the current year — which could force the bears onshore for more than five months a year, leading to a sharp decline in the bears' physical condition and the inability of females to gestate cubs. “One of the things we found was that the changes in this population could happen very dramatically,” says Derocher. “And a lot of the change could come within a single year if you just ended up with an earlier melt of sea ice.”"

Express News reported Derocher wanted the federal government of Canada to take the mathematical prediction and take steps to protect the bears.

“We have two thirds of the world’s polar bears and collectively scientists around the world and people are looking to Canada for leadership but we’ve been very slow to recognize polar bears as a threatened species. That has to change.”

Derocher told The Independent

"There's been a gradual decline in [the bears'] body condition that dates to the 1980s and we can now correlate that very nicely with the loss of sea ice in this ecosystem. And one of the things we found was that the changes that could come in this population could happen very dramatically, and a lot of the change could come within a single year, if you just ended up with an earlier melt of sea ice."

According to the World Wildlife Fund (WWF), in 2008 it was thought that 13 of the 19 populations of polar bears found in Canada live in Canada exclusively. The other six populations move between countries. There were thought to be 20,000 to 25,000 polar bears in 2008, but due to declines in populations, it is now thought there are only some 15,500 bears in Canada. The Southern Hudson Bay population has been in decline for the past few years. It is thought that two populations of polar bears are actually increasing said the Daily Mail. One group is found in Svalbard Norway, the other in Canada. A satirical piece in The Daily Shame reports polar bears have been "exaggerating the melting of the polar ice caps" and "putting on a bit of a show." The piece pokes fun at those who say global warming is a con-game, denying that polar bears need increased protection. The Government of Canada is one of the nay-sayers, Reuters reported in April. Polar bears aren't the only Arctic species that will suffer the consequences of global warming - research published in 2007, reported on by the Globe & Mail, demonstrated that the warming of the Arctic also affects Arctic-living marine mammals such as whales and narwhals.