Posted onOctober 7, 2021|Comments Off on Alaska polar bear researchers claim poor sea ice limited spring field work in 2021 more than 2019
According to an Inside Climate Newsreport, polar bear researchers at the US Geological Survey had trouble darting bears in the Southern Beaufort Sea in March-May of 2019 and 2021. They claim their research program was hampered by thinner-than-necessary ice for safely landing the nearly 4,000 lb. outfitted helicopter (with crew and gear) in 2019 but that conditions in 2021 were even worse (it is implied work proceeded in 2020 despite pandemic restrictions but no data for that year are discussed).
However, this claim of worse conditions in 2021 is not corroborated by reports from sea ice experts and ice charts for the Southern Beaufort this spring, where thick first year and multiyear ice was present from March through June. Ice didn’t begin to pull away from landfast ice to form patches of open water near the Canadian border until late April 2021 compared to early May in 2019 (as it did in 2016), as shown in the video and charts below. Moreover, the researchers oddly fail to mention that the presence of thin ice and open water in spring is essential for polar bear survival in the Southern Beaufort, a fact which has been documented and discussed in the scientific literature by their colleagues.
Posted onSeptember 27, 2018|Comments Off on Now at least 10 years with sea ice at 2050-like levels yet polar bears are still abundant
We’ve hit the seasonal Arctic sea ice minimum for this year, called this morning by US NSIDC for 19th and 23rd of Septmeber: 4.59 mkm2, the same extent as 2008 and 2010. This is not a “ho-hum” year for polar bears: it means that since 2007, they have triumphed through 10 or 11 years1 with summer ice coverage below 5.0 mkm2 — levels that in 2007were expected to cause catastrophic declines in numbers.
Summer sea ice below 5.0 mkm2 were not expected to occur until about 2050, according to 2005/2006 sea ice models and polar bear specialists at the US Geological Survey (USGS). Polar bear survival models predicted 2/3 of the world’s polar bears would disappear when ice levels reached this threshold for 8 out of 10 years (Amstrup et al. 2007, 2008; Hunter 2007) but polar bears have been more resilientthan expected (Crockford 2017, 2018; Crockford and Geist 2018). In fact, in many areas (like the Chukchi Sea, Barents Sea and Foxe Basin) polar bears are thriving despite dramatic declines in summer sea ice coverage (Aars et al. 2017; ACSWG 2018; Peacock et al. 2013; Regehr et al. 2016; Stapleton et al. 2016).
The sea ice models used to support the addition of polar bears to the US Endangered Species List as ‘threatened’ with extinction suggested sea ice levels from 3-5 mkm2 would not occur unti mid-century, yet they dropped before the ink was dry on the 2007 USGS Reports (ACIA 2005; Hassol 2004; Holland et al. 2006; Solomon et al. 2007; Zhang and Walsh 2006).
The ice extent charts from the University of Bremen (below) show ice that’s 50% concentration or greater at the date of the seasonal minimum (19th September): what polar bear specialists define as preferred habitat (Amstrup et al. 2007).
Compare the minimum shown above to the coverage predicted for 2050 and to coverage at the minimum in 2012 (the NSIDC image is here):
Posted onJuly 25, 2018|Comments Off on Tracking polar bears in the Beaufort Sea May and June updates
At the end of June, there were nine bears remaining from the original 14 that were tagged with glue-on ear transmittors in April 2018 near Kaktovik, Alaska by US Geological Survey biologists.
Below is the June 2018 tracking map (high resolution image is here):
Original caption: “Movements of 9 satellite-tagged polar bears for the month of June, 2018. These bears received satellite eartag transmitters in 2018 on the spring-time sea ice of the southern Beaufort Sea. Polar bear satellite telemetry data are shown with AMSR2 remotely-sensed ice coverage for 30 June, 2018.”
See the close-up for June 2018 below:
As ear tags are notoriously short-lived, there may not be any remaining by the end of July but if there are, I will post the tracks. The map for May 2018 is below. Continue reading
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Posted onMay 20, 2018|Comments Off on Tracking polar bears in the Beaufort Sea resumes after a one year hiatus
Fourteen bears tagged by the US Geological Survey (USGS) on or near the central Southern Beaufort Sea coast in April 2018 (near Kaktovik) will be tracked online over the coming months.
The break in published USGS tagging data from March 2017 to April 2018 was the first since the project began in December 2009 but no explanation for the hiatus has been provided. It is therefore unclear whether no tagging occurred in spring 2017 or data was simply not published online. The last bears followed were tagged in March 2016.
In contrast to previous years, this spring all fourteen of the bears have glue-on ear transmitters, which means they are either adult males or juvenile bears rather than females (which are fitted with satellite collars):
“In collaboration with the U.S. Fish and Wildlife Service we are also experimenting with glue-on and ear tag satellite transmitters, which can be deployed on adult male bears and younger, still-growing bears.”
Posted onMarch 11, 2018|Comments Off on Amstrup & colleages can’t refute my critique of their 2007 polar bear survival model, Part 1
It’s been more than a year since I first published my scientific manuscript at PeerJ Preprints (a legitimate scientific forum) on the failure of Amstrup’s 2007 USGS polar bear survival model (Crockford 2017), a year waiting in vain for the polar bear community to comment. They either couldn’t be bothered or knew they couldn’t refute it – I haven’t known for sure which. But I do now.
Polar bear specialists didn’t comment because they couldn’t refute it in the scholarly manner required by PeerJ: all they could do is tear it down with derision, misdirection and strawman arguments.
I know this because the damage control team for the polar-bears-are-all-going-to-die-unless-we-stop-using-fossil-fuels message wasn’t activated over my fully-referenced State of the Polar Bear Report for 2017 (Crockford 2018) released on International Polar Bear Daylast month, but for a widely-read opinion piece I’d written for the Financial Post published the same day (based on the Report) that generated three follow-up radio interviews.
By choosing to respond to my op-ed rather than the Report or my 2017 paper, biologists Andrew Derocher and Steven Amstrup, on behalf of their polar bear specialist colleagues1, display a perverse desire to control the public narrative rather than ensure sound science prevails. Their scientifically weak “analysis” of my op-ed (2 March 2018), published by Climate Feedback (self-proclaimed “fact checkers”), attempts damage control for their message and makes attacks on my integrity. However, a scientific refutation of the premise of my 2017 paper, or The State of the Polar Bear Report 2017, it is not (Crockford 2017, 2018).
Derocher further embarrasses himself by repeating the ridiculous claim that global polar bear population estimates were never meant for scientific use, then reiterates the message with added emphasis on twitter:
Just as the badly written Harvey et al. (2017) Bioscience paper said more about the naked desperation of the authors than it did about me or my fellow bloggers, this attempt by the polar bear community’s loudest bulldogs to discredit me and my work reveals their frustration at being unable to refute my scientifically supported conclusion that Amstrup’s 2007 polar bear survival model has failed miserably (Crockford 2017).
Part 1 of my detailed, fully referenced responses to their “analysis” of my op-ed are below. Part 2 to follow [here]. Continue reading
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Posted onMarch 4, 2018|Comments Off on Archive of 2007 USGS reports supporting 2008 ESA listing for the polar bear
The administrative reports used in 2007 to support the decision to list polar bears as ‘threatened’ under the US Endangered Species Act (ESA) in 2008 disappeared from the US Geological Survey website several years ago. I have archived them here in pdf format to make them easy to find for anyone wishing to access the accuracy of the models, data, and assumptions made in 2007.
Steven Amstrup in 2005, then lead USGS polar bear biologist, with triplet cubs, Prudhoe Bay, AK.
This is a housekeeping post meant for future reference. I’ve included citations for the relevant sea ice projection papers used in the models presented in the 2007 documents and a few other related reports from the same time period. Continue reading
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Posted onFebruary 1, 2018|Comments Off on Polar bear specialists double-down on message of future starving bears
The really significant content of a new paper being heavily-hyped by the media1 is what wasn’t said rather than what the authors discovered about metabolic rates and weight maintenance of a small sample of nine Southern Beaufort Sea bears in 2014 to 2016 (Pagano et al. 2018; Whiteman 2018).
This paper does not document starving or dying bears but merely found some (5/9) that lost weight when they should have been gaining, given that early April is the start of the ringed seal pupping season (Smith 1987) and the intensive spring feeding period for polar bears (Stirling et al. 1981).
The question is, why were Southern Beaufort Sea polar bears off Prudhoe Bay (see map of the study area below), still hunting and capturing only adult and subadult ringed seals from sea ice leads when newborn ringed seal pups and their mothers should have been plentiful and relatively easily available in theirbirth lairson the sea ice (see below)?
“Using video collar data, we documented bears’ hunting behavior and foraging success. Bears used sit-and-wait tactics to hunt seals 90% of the time, and stalking comprised the remaining 10% of hunts (movies S1 to S4) (19). Bears that successfully killed and ate adult or subadult ringed seals either gained or maintained body mass, whereas bears that only scavenged or showed no evidence of eating lost mass.”
There was no discussion in the paper of ringed seal birth lairs, or sea ice conditions at the time of the study, but several mentions about what might happen in the future to sea ice and potential consequences for polar bears. The press releasedid the same.
However, as you’ll see by the sea ice thickness maps below, there may be good reason for the lack of ringed seal lairs, and a general lack of seals except at the nearshore lead that forms because of tidal action: the ice just a bit further offshore ice looks too thick for a good crop of ringed seals in all three years of the study. This is reminiscent of conditions that occurred with devastating results in the mid-1970s and mid-2000s (Burns et al. 1975; Cherry et al. 2009; Harwood et al. 2012, 2015; Pilfold et al. 2012; Stirling 2002, Stirling et al. 1987). Those events affected primarily bears in the eastern half of the Southern Beaufort and were almost certainly responsible for the recorded decline in SB bear numbers in the 2001-2010 survey (Bromaghin et al. 2015; Crockford 2017; Crockford and Geist 2018).
It seems very odd to me that Pagano and colleagues suggested no reasons for the unexpectedly poor showing of polar bear hunting success during their study except a bit of hand-waving about higher-than-we-thought metabolic rates in the bears. For years, I’ve worried that the inevitable next episodes of thick Southern Beaufort spring ice would cause problems for polar bears and seals but we wouldn’t know it because whatever effects were documented would be blamed on reduced summer ice: I suspect that time may have come.
Figure 1 from Pagano et al. 2018 cropped to show only the study area off Alaska.
Posted onDecember 5, 2017|Comments Off on Retraction request to Bioscience: FOIA emails document another harsh criticism of Amstrup’s 2007 polar bear model
Today I sent a letter to the editors of the journal Bioscience requesting retraction of the shoddy and malicious paper by Harvey et al. (Internet blogs, polar bears, and climate-change denial by proxy) published online last week.
The letter reveals information about the workings of the polar bear expert inner circle not known before now, so grab your popcorn.
I have copied the letter below, which contains emails obtained via FOIA requests to the US Geological Survey and the US Fish and Wildlife Service by the Energy and Environment Legal Institute, E&E Legal, and the Free Market Environmental Law Clinic (USFWS request; USGS request) and sent to me by lawyer Chris Horner in 2014, unsolicited. I reveal some of them now, with his permission (most of the emails are boring, involving mostly technical topics not relevant to anything, as might be expected).
The emails in question, sent in 2014, pertain to preparations by three members of the Polar Bear Specialist Group for the IUCN Red List assessment due in 2015 (Kristin Laidre, University of Washington, Eric Regehr, US Fish and Wildlife Service, and Østein Wiig, Museum of Natural History, University of Olso), and Steven Amstrup (formerly head of the polar bear research at the US Geological Survey, now “head scientist” for conservation organization Polar Bears International.
They include frank discussions about a harsh critique of Amstrup et al.’s 2007 report and 2008 paper used to support listing polar bears as ‘threatened’ on the US Endangered Species List. The criticisms come from modeling expert and chair of the IUCN Red List Standards and Petitions Subcommittee (which develops guidelines for threatened and endangered species assessments, and evaluates petitions against the red-listing of these species), H. Resit Akçakaya. The IUCN is the world’s leading conservation organization, of which the PBSG is a part.
These records are a damning indictment that the “best available science” was not used to assess conservation status of polar bears under the ESA in 2008 and 2014 and show that I am not the only scientist who thinks Amstrup’s model is fatally flawed. The letter is copied in full below, the emails are copied at the end. A file of all of the entire pertinent email thread is available as a pdf below. Here’s a sample:
Posted onJune 11, 2017|Comments Off on USGS ‘treadmill’ paper repeats bogus claim that ice loss harmed polar bears
The newest polar bear science paper making the rounds courtesy the US Geological Survey, is a perfect example of a statistically-significant result with no biological significance. While the results are rather lame, the paper is dangerous because it repeats the disingenuous claim (see Crockford 2017) that Southern Beaufort Sea polar bear numbers declined in recent years due to summer sea ice loss.
The USGS authors (Durner et al. 2017) know this harm-from-summer-ice-loss assertion is not true for the Southern Beaufort subpopulation but the more papers they can get into print that say so, the more likely it will be believed — and the less likely readers will check older literature that documents the recent decline in polar bear numbers was due to a three year period (2004-2006) when thick ice conditions in spring made seal hunting a challenge, a repeat of a well-known phenomenon (e.g. Stirling et al. 1980; Stirling 2002) unique to this region that has been documented since the 1960s.
The Durner paper (USGS press release “Increased Sea Ice Drift Puts Polar Bears on Faster Moving Treadmill” published online 6 June ahead of print) spins the research results as potentially significant bad news but in so doing reveals how desperate they have become to make the public and their biology colleagues believe that Southern Beaufort polar bears, among others,are being negatively affected by summer sea ice loss (as per Stirling and Derocher 2012).
Durner, G.M., Douglas, D.C., Albeke, S.E., Whiteman, J.P., Amstrup, S.C., Richardson, E., Wilson, R.R. and Ben-David, M. 2017. Increased Arctic sea ice drift alters adult female polar bear movements and energetics. Global Change Biology. DOI: 10.1111/gcb.13746 http://onlinelibrary.wiley.com/doi/10.1111/gcb.13746/abstract [paywalled]
In fact, the Durner et al. paper does not document any harm to polar bears from the proposed ‘treadmill’ effect of more rapidly moving ice for the period 1999-2013 compared to 1987-1998, but instead uses models to suggest bears might have to eat one to three more seals per year to compensate for the extra energy needed to walk against the moving ice. That’s right: perhaps only 1 more seal per year out of the 50 or so they would usually consume (see Stirling and Øritsland 1995). In my opinion, that’s a pretty lame result for what one of the co-authors described as an immense amount of work.
News outlets have essentially used the USGS press release as a click-bait lede for another round of Trump-bashing with respect to the Paris climate change agreement, see here andhere: the stories are hardly about polar bears at all. And predictably, polar bear activist and co-author Steven Amstrup (paid spokesperson for Polar Bears International, famous for their “Save Our Sea Ice” campaign) appears to be using the same approach: an up-coming call-in talk radio program at NPR’s Anchorage affiliate KSKA for Tuesday 13 June at 10:00 (Alaska time, see “Talk of Alaska”) is being billed as a discussion of “polar bears, climate change, and the Paris Accord” (h/t AK geologist). Continue reading
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Posted onApril 12, 2017|Comments Off on Global polar bear population size is about 28,500 when updates are included
Polar bear numbers have risen since 2005, no matter how you look at it:
USGS estimated 24,500 (average) polar bears in 2005.
IUCN estimated 26,500 (average of 22,000-31,000) in 2015
(assessment completed in July, released in November).
Subpopulation surveys completed or reported after July 2015 (Baffin Bay, Kane Basin, Barents Sea) added ~2,000 bears.
This brings the adjusted average total at 2015 to ~28,500.
This may not be a statistically significant increase but it is also not the catastrophic decline that was predicted to occur in association with the abrupt drop of summer sea ice in 2007 to a new average of about 3-5 mkm2 [updated 1 June 2017].
Explained in full in this published paper, pgs 20-21:
Crockford, S.J. 2017 V3. 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 2 March 2017. Doi: 10.7287/peerj.preprints.2737v3 Open access. https://doi.org/10.7287/peerj.preprints.2737v3
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