It’s Official: Polar Bear Numbers Continue To Grow
via The Global Warming Policy Forum (GWPF)http://www.thegwpf.com
Increased numbers of polar bears in Svalbard and Baffin Bay/Kane Basin are likely to increase the global estimate of polar bears to 23,000-33,000.
The 2016 Scientific Working Group report on Baffin Bay and Kane Basin polar bears was released online without fanfare last week, confirming what local Inuit have been saying for years: contrary to the assertions of Polar Bear Specialist Group scientists, Baffin Bay and Kane Basin subpopulations have not been declining but are stable.
Until recently, the Baffin Bay (BB) and Kane Basin (KB) polar bear subpopulations, that live between NW Greenland, and Baffin and Ellesmere Islands, were assessed with confidence by the IUCN Polar Bear Specialist Group (PBSG) to be declining due to suspected over-hunting (see 2016 Report, Ch. 1, pg. 4).
It turns out they were wrong.
NEW (2016) POLAR BEAR SUBPOPULATION ESTIMATES FOR BB AND KB:
Baffin Bay – 2,826 (95% CI = 2,059-3,593) at 2013
[vs. 1546 (95% CI = 690-2,402) expected 2004]
vs. 2,074 (95% CI = 1,553-2,595) in 1997
Kane Basin – 357 (95% CI: 221 – 493) at 2013
vs. 164 (95% CI: 94 – 234) in 1997
[1997 figures from 2015 IUCN Red List estimates, from Supplement, pg. 8); 2004 “expected” figure for Baffin Bay from 2016 SWG report, Ch. 1, pg. 4]
In 2014, Environment Canada’s assessments were ‘data deficient’ for Kane Basin and ‘likely declining’ for Baffin Bay (see map below):
However, the results of this new study (conducted 2011-2013) would likely make KB in the map above dark blue (‘stable’), and BB light blue (‘likely stable’), depending on how the new information is interpreted (given differences in methodology between the 1991-1997 and 2011-2013 counts). Note that a recent paper by Jordan York, Mitch Taylor and others (York et al. 2016) suggested this outcome for Baffin Bay was likely (i.e. ‘stable’) but thought that the status of Kane Basin would remain ‘declining.’
This new information leaves only the Southern Beaufort subpopulation (SB) in a ‘likely declining’ condition, but since that decline was due to thick spring ice conditions in 2004-2006 (Crockford 2017), it does not reflect a response to recent loss of summer sea ice. The new population estimates for Baffin Bay and Kane Basin also suggests that a revision needs to be made to the 2015 IUCN Red List assessment with respect to the global population estimate because polar bears are clearly more abundant in Baffin Bay and Kane Basin than previously thought.
The new BB and KB subpopulation estimates should increase the 2015 global population size estimate issued in 2015 by the IUCN Red List from 22,000-31,000 to 22,633-32,257 which would likely be rounded off to 22,500-32,000. But wait! That estimate does not include a reported 42% increase in the Svalbard portion of the Barents Sea subpopulation in late 2015 (975 bears counted, up 290 over the 2004 count of 685) that was not included in the Red List assessment of 2644 (95% CI: 1,899 – 3,592) based on 2004 data. Therefore, when the Svalbard increase and the Baffin Bay/Kane Basin increases are all added to the 2015 Red List estimate, it might give a revised 2015 global estimate of something like 23,000-33,000 depending on how all the results are interpreted.
via The Global Warming Policy Forum (GWPF) http://www.thegwpf.com
February 15, 2017 at 07:54PM
Iowa Climate Science Education 