Only half or less of the estimated 2.6% loss per decade of March sea ice extent since 1979 (Fig. 1, below) represents a decline in polar habitat. That’s because several regions with sea ice that are not home to polar bears, like the Sea of Okhotsk, are included in Arctic sea ice totals.
Figure 1. Average monthly Arctic sea ice extent for March 1979-2015 (which includes ice in the Sea of Okhotsk, the Sea of Japan, and the Baltic, where polar bears do not live), shows a decline of 2.6% per decade. NSIDC, March summary 2015.
Both the Sea of Okhotsk and northern Sea of Japan (Fig. 2) have sea ice in winter (which is included in total Arctic sea ice records) but they are not truly “Arctic” – neither is connected to the Arctic by continuous ice, even when the ice is at its maximum extent (nor is the Baltic Sea — in contrast to Hudson Bay and the east coast of North America, which are connected to the Arctic by continuous ice).
Figure 2. Location of the Sea of Okhotsk and Sea of Japan. Insert ice map for March 1979 from NSIDC shows it’s position relative to the Arctic proper.
That lack of connection to Arctic pack ice is probably the main reason that polar bears never colonized the Sea of Okhotsk, even though western Arctic seal species (ringed, bearded, spotted, and ribbon) and Arctic whales (bowhead and beluga) live there. Polar bears don’t currently live in the Sea of Okhotsk and all evidence suggests they never have.
Sea ice maps show that about half of the total ice extent difference between March 1979 and March 2015 was due to a relatively large decline in sea ice cover for Sea of Okhotsk and northern Sea of Japan — regions without polar bears. Surely no reputable scientist or journalist would suggest that the “record low” maximum ice extent for 2015 has any relevance for polar bear health and survival? [or for Northwest Passage travel, for that matter] Sadly, they would.
Posted in Conservation Status, Sea ice habitat
Tagged Arctic, declining sea ice, Derocher, habitat, lost ice, lowest maximum extent, March, misinformation, NSIDC, polar bear, record low, sea ice, sea ice extent, sea ice maximum, Sea of Okhotsk, spring, variation
A new paper by polar bear biologists (Rode et al. 2015) argues that terrestrial (land-based) foods are not important to polar bears now and will not be in the future – a conclusion I totally agree with – but they miss the point entirely regarding the importance of this issue.
Whatever food polar bears consume in the summer – whether they are on land or on the ice – doesn’t really matter. What matters is how many fat-rich seals they can consume between March and June each year. The fat put on in late winter/spring from gorging on baby seals carries polar bears over the summer, no matter where they spend it.
USGS polar bear biologist Karyn Rode and colleagues (press release here) have tried to frame this issue as one about future survival of polar bears in the face of declining sea ice. However, the fact that polar bears in the Chukchi Sea and Southern Davis Strait are thriving despite dramatic declines in summer sea ice (aka an extended open-water season), proves my point and disproves their premise. Bears in these regions are doing extremely well – contrary to all predictions – because they have had abundant baby seals to eat during the spring (see here and here).
Posted in Advocacy, Conservation Status, Life History
Tagged Amstrup, Arctic, bird colonies, caribou, Chukchi Sea, climate change, Davis Strait, East Greenland, geese, global warming, goose eggs, habitat, InsideScience, polar bear, red herring, Rode, sea ice, sea ice loss, seabird eggs, Svalbard, terrestrial foods, us geological survey, USGS
More bad science: US biologists successfully used a scientifically flawed model to get polar bears listed as ‘threatened’ and thus emboldened, went on to do the same for walrus.
The intricate US Geological Survey model of ‘expert opinion’ that was used to support the listing of polar bears as ‘threatened’ under the US Endangered Species Act (ESA) has been soundly rejected by the world’s leading conservation organization, the IUCN,1 which has has tightened its rules for using “future conditions” (e.g., effects of global warming) in generating Red List assessments. That IUCN condemnation means the USGS model was never “the best available science” for evaluating the status of polar bears ̶ it was (and still is) substandard, inadequate science that makes a mockery of serious conservation efforts.
However, not only has this flawed model continued to be used by the USGS for polar bears, it has also been used to assess the conservation status of Pacific walrus, which are now officially “candidates” for being listed as ‘threatened’ (US Fish and Wildlife Service 2011).2
Posted in Advocacy, Conservation Status, Sea ice habitat
Tagged Amstrup, Bayesian Networks, best available science, conservation, endangered, ESA, IUCN, model, polar bear, threatened, US Fish and Wildlife Service, USGS, walrus
My request to Environment Canada in early December 2014 for the documents supporting their polar bear status maps has finally generated results.
In an email dated 2 March 2015, I received the document produced by the EC Polar Bear Technical Committee (PBTC). I waited to see if it would be appended to the webpage where the maps were posted last year (reported here and here). However, as of today, that has not happened, so I am posting it here. There are some rather striking differences that may surprise you.
UPDATE 22 March 2015: A copy of the letter from the Director General of the Canadian Wildlife Service that accompanied the document below, which I forgot to include, is here. It states that the once a new status table has been compiled (provided below), “it is reviewed by the Polar Bear Administrative Committee and then becomes a public document.” The implication is that the reviewed document has not yet been produced.
Posted in Conservation Status, Population
Tagged baffin bay, Canada, declining population, Environment Canada, IUCN Polar Bear Specialist Group, Northern Beaufort Sea, PBTC, polar bear, Polar Bear Technical Committee, population estimates, sea ice, Southern Beaufort Sea, USGS
In late January, the IUCN PBSG made significant changes to its polar bear status table but did not think it was worth bringing to the public’s attention via a tweet, press release or note on their web site’s home page.
What changes? Well, while the group did not see fit to agree with all of Environment Canada’s assessments (e.g. listing Davis Strait bears as “likely increasing” compared to the PBSG’s “stable”, see full list here), it did upgrade their status of Western Hudson Bay bears to ‘stable’ (which EC did back in June 2014).
More significantly, however, they also added two metrics of sea ice change to their assessment table, presumably because alongside ‘human-caused removals’ (which they also track in their tables)1, sea ice changes are supposedly critical ‘threats’ to polar bear health and survival.
So critical, in fact, that they’ve only just now gotten around to measuring it consistently across polar bear territory. Funny thing is, they cite no document that shows the sea ice change calculations for each subpopulation region, nor who generated them.
Let me be clear: no one has ever generated such a sea ice metric before – it is a unique PBSG construct that you will find nowhere else. By providing no documentation that lays out the calculations for inspection, the PBSG are simply insisting the public accept their unpublished, non-peer-reviewed work on faith. Details below.
Posted in Conservation Status, Sea ice habitat
Tagged definition of summer, East Greenland, IUCN Polar Bear Specialist Group, loss of summer ice, PBSG, polar bear, satellite data, sea ice, sea ice metric, spring sea ice, western hudson bay
Today’s the day to celebrate the resilience and adaptability of polar bears.
Not only did the record-breaking sea ice low of 2012 have virtually no effect on the bears but in 2014, only two subpopulations were classified as “declining” or “likely declining” – down from seven in 2010 and four in 2013 (see map below).
See my recent “Twenty good reasons not to worry about polar bears.”
[GWPF Briefing Paper version (pdf), just out today, here]
POLAR BEARS IN THE NEWS…
Kudos to the CBC for producing a propaganda-free polar bear “Fun Facts” page for kids that won’t give them nightmares – have a look.
Other news: Polar bears come early to Black Tickle, Labrador this year, a new population count is planned for the Barents Sea subpopulation, and The Times (UK) publishes some good news about polar bears. Details below.
UPDATE February 27, 2015. I’ve added another news item I missed below.
UPDATE APRIL 7, 2015. Correction to the February 27 update below.
Posted in Conservation Status, Population, Summary
Tagged Barents Sea, Black Tickle, briefing paper, conservation success, extralimital sighting, good news, Gulf of St. Lawrence, Labrador, polar bear, population estimate, sea ice
Here’s a new resource for cooling the polar bear spin, all in one place. I’ve updated and expanded my previous summary of reasons not to worry about polar bears, which is now two years old. In it, you’ll find links to supporting information (including previous blog posts of mine that provide background, maps and extensive references), although some of the most important graphs and maps have been copied into the summary. I hope you find it a useful resource for refuting the spin and tuning out the cries of doom and gloom about the future of polar bears — please feel free to share. Pdf here of the text below.
This is the 1st anniversary of Canada providing population estimates and trends independent of the pessimistic prognostications of the IUCN/SSC Polar Bear Specialist Group (PBSG) — so let’s celebrate the recent triumphs and resilience of polar bears to their ever-changing Arctic environment.
Posted in Advocacy, Conservation Status, Summary
Tagged arctic sea ice, cannibalism, conservation, den collapse, Environment Canada, IUCN, polar bear, Polar Bear Specialist Group, polar bear status, population, Red list, spin, starving, status, summary, threatened, vulnerable