An article by CBC News today (3 March 2020) is a surprisingly well-balanced report on a recently published paper by Kristin Laidre and colleagues on their work on the Baffin Bay polar bears that I discussed last month.
It presents the Inuit perspective that polar bears are currently abundant in the area and the population stable despite less summer sea ice and some documented declines in body weight and at least one scientist conceded this is indeed true.
However, the CBC writer still left out the most critical caveat included in the paper about the study: that factors other than changes in sea ice could have affected the body condition and litter size data that the authors documented but they didn’t look at anything except sea ice.
This automatically means the conclusions are scientifically inconclusive.
See some quotes below from the CBC article and the caveat from the paper.
‘It’s no surprise for Inuit — Baffin Bay polar bears defy past assumptions with stable population’ (Walter Strong, CBC News, 3 March 2020) [my bold]:
“But for now, researchers say the Baffin Bay polar bear population is relatively abundant, something that comes as no surprise to Inuit in the region who have lived with the bears for thousands of years.
The Baffin Bay polar bears inhabit approximately one million square kilometres of land and sea encompassing Baffin Bay, and portions of Baffin Island, all of Bylot Sound, and parts of west and northwest Greenland.
Their population is stable at about 2,800 animals, and appears to have been stable for a while. This population estimate was not a direct result of Laidre’s study, but was included in the report’s research.
Previous estimates of the Baffin Bay population pegged it at about 2,100 animals.
Inuit in the region have long argued that the Baffin Bay polar bear population was healthy, and maybe even growing. They have been making that argument, based on their observations, against the science of the day for at least 10 years.
Stephen Atkinson, one of the study’s co-authors, and now a contract wildlife biologist who has spent close to 30 years studying polar bears, cautioned against comparing the latest population estimate with the earlier. The two studies were designed differently, he said.
But he said the latest findings do back up what many Inuit were saying all along — that the population has not declined below what it was thought to be earlier.
“The findings were quite consistent with what people were seeing on the ground in Baffin Bay,” he said.”
My blog post on this study, with references: New paper says Baffin Bay polar bears may have been affected by less summer sea ice (5 February 2020).
The author’s caveat (2nd last sentence of their paper) is critical, so I’ve repeated it here:
“We note, however, that the functional and temporal relationships between declines in body condition and recruitment, and declines in subpopulation size, are poorly understood and that the trend of the BB subpopulation is currently unknown (SWG 2016).”
Laidre, K.L, Atkinson, S., Regehr, E.V., Stern, H.L, Born, E.W., Wiig, Ø., Lunn, N.J. and Dyck, M. 2020 in press. Interrelated ecological impacts of climate change on an apex predator. Ecological Applications https://doi.org/10.1002/eap.2071 [open access]
Dr. Susan Crockford is a zoologist (former adjunct professor, University of Victoria) specializing in Holocene mammals, including polar bears and walruses. Her new book is called The Polar Bear Catastrophe That Never Happened (Amazon).
Read more at Polar Bear Science
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