A few days ago in a radio interview, a senior US Fish & Wildlife biologist repeated the tall tale that Southern Beaufort Sea polar bear numbers declined in recent years due to loss of summer sea ice. But restating this egregious misinformation does not make it true.
The Southern Beaufort population did decline between 2001 and 2006 but it was due to natural causes (thick ice in spring from 2004 to 2006) – it had nothing to do with recent summer sea ice loss and Eric Regehr knows it.
There is no evidence that the population decline continued after 2006, so it cannot be said to be still declining. Moreover, the situation in the Southern Beaufort does not support the predictions made by Regehr and his colleagues that polar bear populations will decline precipitously if summer sea ice declines further.
My recently published paper demolishes the message of doom for polar bears and the misinformation it’s based upon: it’s free and written in straight-forward scientific language.
Crockford, S.J. 2017. Testing the hypothesis that routine sea ice coverage of 3-5 mkm2 results in a greater than 30% decline in population size of polar bears (Ursus maritimus). PeerJ Preprints 19 January 2017. Doi: 10.7287/peerj.preprints.2737v1 Open access. https://peerj.com/preprints/2737/ (pdf here).
Here’s an excerpt of the nonsense broadcasted on KNOM Radio Alaska by Regehr and transcribed for their website (29 January 2017) [my bold]:
“If there’s a poster child for Arctic animals affected by climate change, it’s the polar bear.
“Putting together all available data, and making some informed projections on the basis of those data, do suggest that there is a high probability that the global population of polar bears could face reductions of up to one-third or greater in the next 35 to 40 years,” said Regehr.
One group that’s thriving is the Chukchi Sea subpopulation, which includes Western Alaska and the Russian coast across the water.
“The waters are shallow, they’re nutrient rich; there are a lot of seals, ringed seals and bearded seals, out there for the polar bears to eat,” said Regehr. “And so, other studies suggest that, despite the fact that the Chukchi Sea region has exhibited a loss of Arctic sea ice the bears in that region appear to be faring quite well, currently.”
But their neighbors to the East, the South Beaufort subpopulation, are declining in number.
“The continental shelf is much narrower, the region is less biologically productive,” said Regehr. “And scientific studies there suggest that the polar bears have been negatively affected by sea ice loss. So there is a lot of variation in their status across the Arctic.”
Despite this variation, Regehr says the decline in population numbers expected in the next few decades is likely to affect bears in all regions of the Arctic.”
Read the whole thing here.
As noted above, I addressed all of this rhetoric in my recently published paper that rejects the hypothesis that if sea ice declines, polar bear numbers will necessarily decline.
Or you could buy my recent-released polar bear science book, “Polar Bears: Outstanding Survivors of Climate Change.”