Susan Crockford: Ten Good Reasons Not To Worry About Polar Bears
This year marks the 40th anniversary of the signing of an international agreement to protect polar bears from commercial and unregulated sport hunting. The devastating decades of uncontrolled slaughter across the Arctic, including the Bering Sea, finally came to an end. And so in honor of International Polar Bear Day(Wed. February 27) – and because some activists are calling 2013 The Year of the Polar Bear – I’ve made a summary of reasons not to worry about polar bears, with links to supporting data. I hope you find it a useful resource for tuning out the cries of doom and gloom about the future of polar bears and celebrating their current success.
1) Polar bears are a conservation success story. Their numbers have rebounded remarkably since 1973 and we can say for sure that there are more polar bears now than there were 40 years ago. Although we cannot state the precise amount that populations have increased (which is true for many species – counts are usually undertaken only after a major decline is noticeable), polar bears join a long list of other marine mammals whose populations rebounded spectacularly after unregulated hunting stopped: sea otters, all eight species of fur seals, walrus, both species of elephant seal, and whales of all kinds (including grey, right, bowhead, humpback, sei, fin, blue and sperm whales). Once surveys have been completed for the four subpopulations of polar bears whose numbers are currently listed as zero (how about funding that, WWF?), the total world population will almost certainly rise to well above the current official estimate of 20,000-25,000 (perhaps to 27,000-32,000?).
2) The only polar bear subpopulation that has had a statistically significant decline in recent years is the one in Western Hudson Bay (WH)(Fig. 1). A few others have been presumed to be decreasing, based on suspicions of over-harvesting, assumed repercussions of reduced sea ice and/or statistically insignificant declines in body condition (see 3, below) – not actual population declines.
Figure 1. A map of the 19 polar bear subpopulations (courtesy the Polar Bear Specialist Group (PBSG), with a few additional labels).
3) Polar bears in the US portion of the Chukchi Sea are in good condition and reproducing well, while sea ice in the Bering Sea has rebounded from record lows over the last ten years – good reasons not to be worried about polar bears in the Chukchi. The Chukchi subpopulation (which includes bears in the Bering Sea) was formerly assumed to be decreasing due to suspected over-harvesting and past declines in sea ice – even though no population survey had ever been done (see 2, above) – but preliminary reports about a recent survey suggest that Chukchi polar bears are doing very well. While there is still no official population estimate for the Chukchi (currently listed as zero), sea ice coverage in the Bering Sea has been higher than averageover the last ten years and 2012 didn’t just break the satellite-era record set in 1999, it exceeded it by almost 100,000 square kilometers.
4) A survey by the Nunavut government in 2011 showed that polar bear numbers in Western Hudson Bay have not declined since 2004 as predicted and all available evidence indicates thatHudson Bay sea ice is not on a steadily precipitous decline – good reasons not to be worried about Hudson Bay bears.