Here is a quick compare and contrast of sea ice habitat for polar bears in Canada and the Southern Beaufort region of eastern Alaska near the end of June, 2012-2020.
Similarities between Hudson Bay ice/open water in the sea ice charts below are striking. Ice cover at the end of June shown in these charts since 2012 reinforces the fact, documented in the peer-reviewed literature, that there has been no continued declining trend in dates of sea ice breakup for Western and Southern Hudson Bay since 1998 at least (Castro de la Guardia et al. 2017; Lunn et al. 2016). WH bears are still on the ice.
As a consequence, recent declarations of impending doom for Hudson Bay polar bears, based on claims of reduced population size and health of these subpopulations – which in any case are statistically insignificant for WH and SH (Obbard et al. 2018; Dyck et al. 2017) – must be due to some other cause (Crockford 2020).
In all areas, winds rather than melt due to increased temperatures drive much of the expansion of open water at this time of year.
Posted in Conservation Status, Population, Sea ice habitat
Tagged Alaska, Beaufort, breakup, Canada, cause and effect, Hudson Bay, melt, polar bear, population decline, sea ice, western hudson bay
A few days ago I had the pleasure of talking with Anthony Watts from WUWT as part of his new podcast series. Listen to it here.
Below, I’ve copied a post from earlier this year that summarizes some misconceptions about polar bear conservation status and population size. I reiterate here (with links added for convenience) what I said last month:
The polar bear data are contradictory: contrary to predictions, several polar bear subpopulations (at least four of them) are indeed thriving despite much reduced summer sea ice [Chukchi Sea, Barents Sea, Kane Basin, M’Clintock Channel, as well as Foxe Basin and Davis Strait]. I have chosen to emphasis that good news, while Stirling and Derocher choose to emphasize the data that seem to fit their predictions [Western Hudson Bay and Southern Hudson Bay]. This is a classic conflict that happens all the time in science but presents no proof that I’m wrong or that the PragerU video is inherently ‘false’.
Note that Western Hudson Bay bears were last counted in 2016 but have had five good sea ice seasons in a row now, including this year by the look of it, so if ‘lack of sea ice’ is really the cause of the statistically-insignificant decline, then population numbers should be back up. And here is my video about the National Geographic video of the starving polar bear blamed on climate change mentioned by Anthony in the interview:
Posted in academic freedom, Advocacy, Conservation Status, Sea ice habitat, Summary
Tagged academic freedom, conservation, follow the money, podcast, polar bear, population, sea ice
No early breakup of Hudson Bay sea ice again this year: there is still extensive thick first year ice over most of Hudson Bay and all female polar bears fitted with tracking collars in Western Hudson Bay are still on the ice:
W Hudson Bay polar bears still out on the ice that’s packed together by winds. AE Derocher, 12 June 2020
Breakup of Hudson Bay sea ice as it relates to polar bear movement to land has been about the same since 1999 (about 2 weeks earlier than in the 1980s) and this year is shaping up to be no different: there is still no declining trend in date of sea ice breakup in Western Hudson Bay despite repeated predictions of imminent doom. An especially ‘early’ breakup year would have bears ashore before 15 June. Last year (2019) the first WH bear onshore was caught on film 5 July and problem bears were not recorded onshore in Churchill until the 2nd week of July.
Posted in Conservation Status, Life History, Sea ice habitat
Tagged breakup dates, declining population, early breakup, Hudson Bay, polar bear, sea ice, threatened, trends, western hudson bay
Here are ice conditions at the end of May, which signals the near-end of the critical spring feeding period for polar bears. This is because young-of-the-year seals take to the water to feed themselves, leaving only predator-savvy adults and subadults on the ice from some time in June onward (depending on the region).
Spring is the critical feeding period for polar bears (Crockford 2019, 2020; Lippold et al. 2020; Obbard et al. 2016):
“Unexpectedly, body condition of female polar bears from the Barents Sea has increased after 2005, although sea ice has retreated by ∼50% since the late 1990s in the area, and the length of the ice-free season has increased by over 20 weeks between 1979 and 2013. These changes are also accompanied by winter sea ice retreat that is especially pronounced in the Barents Sea compared to other Arctic areas. Despite the declining sea ice in the Barents Sea, polar bears are likely not lacking food as long as sea ice is present during their peak feeding period. Polar bears feed extensively from April to June when ringed seals have pups and are particularly vulnerable to predation, whereas the predation rate during the rest of the year is likely low.“ [Lippold et al. 2019:988]
Posted in Life History, Sea ice habitat
Tagged Beaufort, Chukchi, feeding, Hudson Bay, open water, polar bear, polynya, sea ice, seals, spring, summer
In case you missed it buried in the details of my rebuttal two weeks ago about Facebook labelling a short PragerU polar bear video as “false information”, in his review of the video (18 May 2020) Canadian polar bear biologist Ian Stirling revealed that a recent survey of M’Clintock Channel polar bears documented a population increase. The problem is we have no scientific details about the survey – apparently completed four years ago, in 2016 – because the final report has not been made public (COSEWIC 2018, pp. 42-43; Crockford 2020).
Posted in Conservation Status, Population, Sea ice habitat
Tagged Climate Feedback, Facebook, fact check, good news, M'Clintock Channel, numbers, polar bear, PragerU, science, sea ice, video
Facebook has labelled a recent short PragerU polar bear video as “false information” based on a ClimateFeedback review featuring statements by Andrew Derocher and Ian Stirling published 18 May 2020.
The video, posted on Facebook 5 May 2020, is also available here and here. Also here on the PragerU website.
I was approached yesterday by Nick Coltrain, a reporter for the Des Moines Register and USA Today, asking for a statement about the accuracy of the PragerU video, which cites me as a source for two of their three ‘inconvenient facts.’
My comments are below but I reminded Nick that what is going on is a classic conflict that happens all the time in science: it presents no proof that I’m wrong or that the PragerU video is ‘false information’. Climate Feedback is not ‘factchecking’: it is presenting its preferred side of a disputed science issue.
Posted in Advocacy, Conservation Status, Population, Sea ice habitat, Summary
Tagged censor, Climate Feedback, disputed science, Facebook, fact check, false information, good news, polar bear, PragerU, sea ice, video
It’s very open drift ice (1-4/10th concentration) but still: Bear Island (Bjørnøya) in the southern Barents Sea was still surrounded by pack ice at 15 May 2020. As far as I can tell from the Norwegian Ice Service archived ice charts, this hasn’t happened since 2003.
And last week, the island was surrounded by heavy drift ice, which hadn’t happened on 8 May since 1977.
The report on the latest population estimate for harp seals off the east coast of North America was released in late March without fanfare and therefore no media attention. This was one of the missing scientific reports mentioned in my State of the Polar Bear Report 2019 released in February (Crockford 2020): results of surveys promised for months or years by early 2020 but not delivered.
Not surprisingly then, we find the report has good news: the population estimate of harp seals in the NW Atlantic has risen to about 7.6 million (range 6.55-8.82) animals (DFO 2020), up from 7.4 million in 2014 (DFO 2014).
Note that the survey was done in March 2017, a low ice year for the Gulf of St. Lawrence (see discussion below) and while this may have resulted in some increased mortality for pups born there, it is also known that many ‘Gulf’ pregnant females will instead have given birth off Newfoundland and Labrador in a whelping region called ‘The Front’. Apparently, these factors were accounted for in the population model.
Harp seal pups born at the Front are an important food for Davis Strait polar bears. This increase in the prey base for Davis Strait polar bears suggests the bear population may have grown substantially since the last survey in 2007 (Peacock et al. 2013; Rode et al. 2012). Davis Strai is the only subpopulation of polar bears officially considered to have ‘likely increased’ at 2018 by Environment Canada. A new Davis Strait population size survey was apparently completed in 2018 but the results are not yet available (Crockford 2020).
Highlights, quotes, and figures from the harp seal report below. Continue reading
The chart below shows what sea ice thickness over Hudson Bay was like at the first week of May in a so-called a ‘good year’ (2019) – when polar bears came off the ice in excellent condition late in the summer and left early in the fall (‘thick first year ice’ is dark green and indicates ice greater than 1.2m thick):
Hudson Bay ice conditions this year appear to be shaping up to be as good or better than last year for polar bears yet specialist researchers and their cheerleaders have still been claiming that bears in this region – Western and Southern Hudson Bay – are doomed because of poor ice conditions. It’s no wonder they still haven’t published the data they’ve been collecting on polar bear body condition and cub survival over the last 15 years or so (Crockford 2020). With most field work cancelled for this year, what’s their excuse for not getting that done?
A recent paper that attempted to correlate pollution levels and body condition in Barents Sea polar bears reports it found body condition of female bears had increased between 2004 and 2017 despite a pronounced decline in summer and winter sea ice extent.
“Unexpectedly, body condition of female polar bears from the Barents Sea has increased after 2005, although sea ice has retreated by ∼50% since the late 1990s in the area, and the length of the ice-free season has increased by over 20 weeks between 1979 and 2013. These changes are also accompanied by winter sea ice retreat that is especially pronounced in the Barents Sea compared to other Arctic areas” [Lippold et al. 2019:988]
Posted in academic freedom, Conservation Status, Life History, Population, Sea ice habitat
Tagged Barents Sea, body condition, denier, deplatformed, ice-free season, polar bear, sea ice, summer, Svalbard, threatened, vulnerable