The Chukchi Sea finally has a polar bear population estimate! According to survey results from 2016 only recently made public, about 2937 bears (1522-5944) currently inhabit the region, making this the largest subpopulation in the Arctic. This is exciting news — and a huge accomplishment — but the US Fish and Wildlife Service responsible for the work has been oddly mum on the topic.
Not only that, but an extrapolation of that estimate calculated by USFWS researchers for Chukchi plus Alaska (the US portion of the Southern Beaufort Sea subpopulation) was estimated at 4437 (2283-9527), although with “significant uncertainty.” Nevertheless, it means the 2016 estimate for Alaska could be roughly three times what it was in 2010: a whopping 1500 or so, up from about 450 (or about 225-650) for the same area estimated during the last survey (Bromaghin et al. 2015: Fig. 5a).
Even if the real number for Alaska is only twice as large (~1000), that’s still a huge improvement. It would eliminate the Southern Beaufort as the only polar bear subpopulation in the Arctic to have shown a significant decline blamed on human-caused global warming (Crockford 2018). If the recovery is real, it means the 2004-2006 decline was a temporary fluctuation after all, just like previous declines in the region. I expect, however, that it will take a dedicated SB population survey for officials to concede that point.
not yet now a detailed report to cite (Regehr et al. 2018 in prep, see update below), but the numbers were announced at the 10th meeting of the Russian-American Commission on Polar Bears held at the end of July this year (AC SWG 2018) by Eric Regehr (formerly of the US Fish & Wildlife Service, as of 2017 at the University of Washington). [h/t to G.H.] This was the same report that raised the quota for subsistence hunting in the Chukchi from 58 to 85, based on these new figures, as I discussed last week.
From “Military bases to open on Wrangel Island and Chukotka” 22 October 2015.
Regehr was quoted as saying:
“Chukchi bears remain larger and fatter and have not seen downward trends in cub production and survival, according to new preliminary information on the health and numbers of bears.”
UPDATE 15 November 2018: The scientific paper describing the entirely new method (yes, yet another one: see Bromaghin et al. 2015) used to estimate the size of the Chukchi Sea population is now available (University of Washington press release here), in an open-access paper: Regher et al. 2018. News reports (see one here) spin the positive outcome as something that researchers expected all along but that’s simply not true. They expected Chukchi Sea bears and Southern Beaufort Sea bears to respond similarly to reduced amounts of summer sea ice, as explained here and in Crockford 2017).
Posted in Conservation Status, Population
Tagged Alaska, body condition, Chukchi Sea, cub survival, fat bears, guesstimate, healthy, increase, polar bear, population, Regehr, sea ice, Southern Beaufort, thriving, triplets
In the news today: “Nunavut Draft Plan Says There Are Actually Too Many Polar Bears In Territory” (CTV News via The Canadian Press, Bob Weber, 12 November 2018).
Polar bear eating seaweed near Churchill, Manitoba (November 2012). Lorraine Brandson photo.
From the Canadian Press story:
“There are too many polar bears in parts of Nunavut and climate change hasn’t yet affected any of them, says a draft management plan from the territorial government that contradicts much of conventional scientific thinking.
The proposed plan — which is to go to public hearings in Iqaluit on Tuesday — says that growing bear numbers are increasingly jeopardizing public safety and it’s time Inuit knowledge drove management policy.
“Inuit believe there are now so many bears that public safety has become a major concern,” says the document, the result of four years of study and public consultation.”
I’ve noted previously that there were two fatal polar bear attacks in Hudson Bay this summer. Both of them happened outside local communities and both happened early during the ice-free period (when bears would have been onshore for only a few weeks). Neither incident can be reasonably blamed on lack of sea ice, an extended ice-free period, or lack of management of problem polar bears within or near communities. The bears involved in the August attack were described as being in good condition.
Update 13 November 2018: See The Guardian‘s take on this story, by a different writer. Despite potential to talk to other polar bear specialists about this issue, only Derocher is quoted. Is no one else talking? “Polar bear numbers in Canadian Arctic pose threat to Inuit, controversial report says” (The Guardian, 13 November 2018).
Update 14 November 2018: See a new CBC story on Inuit perspectives on this issue. “Nunavut community says Inuit lives need to be protected over polar bear population” (CBC News, 14 November 2018).
Posted in Conservation Status, Polar bear attacks, Population, Sea ice habitat
Tagged attacks, climate change, Derocher, Foxe Basin, Hudson Bay, hunting, Inuit, management, polar bear, problems, sea ice, too many bears
This is the second year in a row that freeze-up of Western Hudson Bay ice has come earlier than average. Movement of tagged bears and reports by folks on the ground in WH show some polar bears are starting to hunt seals on the sea ice that’s developing along the shore. It’s unlikely that a strong wind will again blow the newly-formed ice offshore (as happened earlier this year) because the ice is more extensive. It seems polar bear viewing season in Churchill will be ending early this year, just like it did last year.
The 9 November map Andrew Derocher (University of Albera) published on twitter showing tagged and collared polar bear movements on Hudson Bay makes it look like almost no ice is present:
However, the Canadian Ice Service chart for 10 November shows the ice very clearly:
UPDATE 13 November 2018: See more recent ice charts and the latest (November 4-11, week 19) report from the Polar Bear Alert Program in Churchill that confirms the bears are moving offshore.
Posted in Conservation Status, Life History, Sea ice habitat
Tagged alert, charts, Churchill, concentration, freeze-up, Hudson Bay, hunting, polar bear, problem bears, sea ice, seals
Ryrkaypiy on the Chukotka coast of Russia is similar to Churchill, Manitoba: both human settlements are of similar size and are close to where polar bears wait for sea ice to form in the fall and where some pregnant females make their maternity dens in preparation for the birth of cubs over the winter (Durner et al. 2018:xxii). Sea ice advances from the west along the Chukotka shore and bears cannot move offshore to resume hunting until the sea ice reaches the village of Ryrkaypiy. According to the Siberian Times, the village is again having problems with local polar bears, as they have for the last several years (including 2013).
“At least twelve polar bears are inside the village, with some of them paying daily visits.
The rest are within three kilometres away.
‘We have to constantly scare the bears away with signal rockets, so far thanks to efforts of the Bear Patrol we manage well’, said acting head of Ryrkaypiy Yevgenia Malakhova.
The large group of bears started to form a month ago when they came close to Cape Kozhevnikov.
‘Now the bears moved close to the village, they also walk back and forth all along the shore line. The animals are irritated because they are ready to leave the area and start hunting in the deep sea, but ice is too thin’, said Malakhova.
All 760 locals are aware of the dangerous situation and take extreme care when moving around the place.”
More below, including map and ice chart.
Posted in Life History, Polar bear attacks, Sea ice habitat
Tagged attractants, carcasses, Chukchi Sea, Chukotka, Churchill, polar bear, problem bears, Russian, sea ice, Wrangel Island
What a difference two weeks make! When the seasonal minimum Arctic sea ice extent occurs in September, polar bear doom-mongers always forget to tell you that within two months, sea ice will return to virtually all regions where polar bears have spent the summer on land, including Hudson Bay. Just as it did in 2007, when polar bears did not die by the thousands due to lack of fall sea ice, polar bear habitat is reforming.
This year, the seasonal minimum came on 23 September. Despite the fact that the US National Snow and Ice Data Center proclaimed that “unusual warmth” in the Arctic continued during October, over the last two weeks sea ice expanded from 6 mkm2 to 9 mkm2. At the current rate of ice growth documented by sea ice charts (see below), Arctic sea ice will be wide-spread by 23 November.
Churchill, Manitoba is proud of its management of problem polar bears and rightly so. But it took time and money to implement the solutions that allowed Churchill to function as it does today, and that should be a lesson for other Arctic communities that have only really started to have problems with polar bears in recent years.
For those who want to understand the problems facing other communities, including Arviat (formerly “Eskimo Point”), a town 260 km north of Churchill. Arviat has a population more than three times the size of Churchill and has been having significant problems with bears since about 2007. I’ve made an excerpt of an excellent paper written by Ian Stirling and colleagues that was published back in 1977 (Stirling et al. 1977).
It describes in detail the problems Churchill had with polar bears in the 1960s and 70s when bear numbers were on the rise — and the various steps that were taken to try and resolve them (even by the time the paper was written, not all of them had been adequately resolved, see Kearney 1989). It’s a fascinating read — see it here.
What’s a good analogy for sea ice as essential polar bear habitat? Biologist Andrew Derocher claims that the soil in a forest is appropriate, because without the soil you can’t have the forest ecosystem. However, that’s a specious comparison because the amount of soil in a forest does not change markedly with the seasons the way that Arctic sea ice does.
A much better analogy is a big pond that dries up a bit every summer. The amount of habitat available to sustain aquatic plants, amphibians and insects is reduced in the dry season but many species have special adaptations for surviving reduced water availability. For the rest of the year, however, the pond provides an abundant and non-limiting habitat for all the creatures and plants that live there.
Posted in Advocacy, Life History, Sea ice habitat
Tagged analogy, ecosystem, extinction, forest, habitat, Interglacials, polar bears, resilience, sea ice, wetlands