Last fall, there were persistent alarms raised about low levels of sea ice in the Chukchi Sea that were echoed this spring. But these low ice levels are not really a serious concern for these polar bears: a 2018 assessment found the bears were in excellent health with no declines in cub production or survival. Funny how little we hear about that.
From “Military bases to open on Wrangel Island and Chukotka” 22 October 2015.
See a photo essay of Wrangel Island here and of the islands polar bears here and here.
You also don’t hear about the fact that sea ice has declined by about the same amount in the Chukchi Sea as in Western Hudson Bay. Since 1979, sea ice in the Chukchi Sea has declined at a rate similar to Western Hudson Bay (-0.90 days per year vs. -0.86 days per year, respectively), see graphs below from Regehr et al. (2016, Fig. 2):
While Western Hudson Bay bear numbers have declined slightly in number (by a non-statistically significant amount) and appear to have suffered some recent declines in cub survival (Dyck et al. 2017) (with unsubstantiated claims of declines in adult body condition), Chukchi Sea bears have not (Rode and Regehr 2010; Rode et al. 2013, 2014, 2018).
The fact that Chukchi bears are thriving while Western Hudson Bay bears appear to be struggling, given almost identical trends in sea ice decline, is a connundrum that polar bear specialist are loath to explain.
Only last week, it was announced that the quota for subsistence hunting of Chukchi Sea polar bears had been raised from 58 to 85 due to the excellent status of the population. Polar bear biologist Eric 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.”
So, despite warnings from the polar bear and sea ice “experts” that Chukchi Sea bears may be in dire straits due to recent sea ice declines (see below), it appears that the bears themselves are more resilient to changing conditions than the experts give them credit.
NSIDC sea ice experts cruising the Chukchi Sea took this photo of a polar bear in excellent condition a couple of weeks ago (early August 2018, A. Khan), despite the scary-looking melt ponds:
Posted in Conservation Status, Population, Sea ice habitat
Tagged body condition, Chukchi Sea, cub survival, fat bears, polar bear, Regehr, sea ice, western hudson bay, Wrangel Island
Tales of doom and gloom about polar bears reflect what some people think might happen in the future, not what is happening right now. Currently, polar bears are doing just fine despite the low summer sea ice coverage they’ve experienced since 2007 (Crockford 2017a; York et al. 2016). In other words, there has been no global population decline as predicted: officially, the numbers were 22,000-31,000 (or 26,500 average) in 2015 (Wiig et al. 2015) but about 28,500 when estimates published since then are included (Aars et al. 2017; Dyck et al. 2017; Matishov et al. 2014; SWG 2016), up from about 22,500 in 2005).
This increase might not be statistically significant but it is most assuredly not the decrease in abundance that was predicted by ‘experts’ such as Steve Amstrup and colleagues (Amstrup et al. 2007), making it hard to take subsequent predictions of impending catastrophe seriously (e.g. Atwood et al. 2016; Regehr et al. 2016; Wiig et al. 2015).
The doomsayers can’t stand to have someone provide the public with unbiased evidence of this failure so they attack my scientific integrity with an academically weak and aggressively vindictive ‘peer-reviewed’ paper (Harvey et al. 2017, in press) that you’ll hear more about in the new year.
Bottom line: 2017 saw abundant good news stories about polar bears, which I’ve summarized below. See also Crockford 2017b: Twenty reasons not to worry about polar bears, the 2017 update and my 2017 block-buster video, Polar Bear Scare Unmasked: The Saga of a Toppled Global Warming Icon:
Posted in Conservation Status, Population, Sea ice habitat, Summary
Tagged advocacy, BioScience, Chukchi Sea, failed predictions, good news, personal attack, science, sea ice, summary, Wrangel Island
Are the hundreds of polar bears spending the summer on Wrangel Island in the Chukchi Sea starving and desperate for any scrap of food? Hardly! Photos taken by Russian tourists on a cruise ship (19 September 2017) show a huge number of already-fat, healthy bears converging on a dead bowhead whale washed up on a beach. Most of these bears would have been without food since at least early August, when the last sea ice disappeared around the island, and will return to the ice by November.
This is what The Sun reported (29 September), based on a Siberian Times story (my bold):
The extraordinary sight was witnessed by tourists on an Arctic cruise aboard the Finnish-built MV Akademik Shokalskiy.
A source at Wrangel Island Nature Reserve said: “There were at least 230 polar bears, including single males, single females, mothers with cubs and even two mothers with four cubs each.”
Experts called the sight of so many polar bears together “unique”.
The huge number could in fact amount to as much one per cent of the entire world’s population of the creatures.
Tourists initially thought the bears were a flock of sheep after viewing them from a distance, The Siberian Times reports.
But as the boat drew closer, the lucky holidaymakers realised what they were witnessing.
Fat cubs of the year are seen in the photo below, from the Siberian Times story:
A self-proclaimed science-based news site (LiveScience, 29 September) that picked up the story of this unique event had the temerity to suggest the bears might have been “hungrier than usual” due to global warming.
It deliberately conflates predictions of future starving bears due to low sea ice levels with this observation of many obviously not-starving bears checking out an attractive food source (my bold):
“It’s unclear, however, whether climate change had made these particular bears hungrier than usual. The frequency of starving polar bears is expected to increase as the climate warms and sea ice declines — not just because of climate change directly, but because ice loss is taking away seals, their main food source, Steven Amstrup, chief scientist at Polar Bears International, a nonprofit research organization dedicated to studying polar bears, told Live Science in 2015.”
Except that there is no evidence that ice loss is “taking seals away” — certainly not in the Chukchi Sea. Chukchi Sea seals have been found to be doing better with less ice than they were when there was more ice in the 1980s.
More below, including the location of Wrangel Island and sea ice maps.
UPDATE 2 October 2017: Sea ice in the Chukchi Sea has been lower this summer than over the last few years but the polar bears spending the ice-free season on Wrangel Island are still in good to excellent condition:
Posted in Conservation Status, Life History, Sea ice habitat
Tagged Arctic, Chukchi Sea, fat, ice-free season, onshore, polar bears, Russia, Siberia, summer, whale, Wrangel Island
You may or may not have noticed that even though Chukchi Sea ice coverage has been way below average this melt season, there has been no hue-and-cry about poor suffering Chukchi polar bears. That’s because polar bear biologist’s own research has shown that the health and survival of these bears has not been negatively impacted by low summer sea ice. There may be threats from poaching in Russia, but not lack of summer sea ice.
As of this date, developing sea ice is only just approaching Wrangel Island, a major polar bear denning region in the Chukchi Sea, see maps below (Ovsyanikov 2006).
Yet, polar bear specialists insist that neighbouring Beaufort Sea bears – who endure a much shorter open-water season – are in peril of extinction because of scarce summer sea ice.
I’ve written a briefing paper for the GWPF refuting claims that huge herds of Pacific walruses hauled out on land are a sign of global warming.
Here’s the GWPF press release:
London, 20 October: A briefing paper published today by the Global Warming Policy Foundation refutes claims that Arctic walruses are in distress and danger due to global warming.
The paper, written by Canadian zoologist Dr Susan Crockford, assesses the recent mass haulouts of walrus females and calves on the beaches of Alaska and Russia bordering the Chukchi Sea. The events have been blamed by US government biologists and WWF activists on lack of summer sea ice, amplified into alarming scare stories by news media around the world.
Such claims ignore previous haulouts that suggest a different cause. Scientific reports about large walrus haulouts that have occurred repeatedly over the last 45 years show that they are not new phenomena for this region.
At least two documented incidents of similar magnitude have occurred in the recent past: one in 1978, on eastern St. Lawrence Island and the other in 1972, on the western end of Wrangel Island. The 1978 event involved an estimated total of almost 150,000 walrus hauled out within in a small geographic area.
Moreover, sea ice maps for the months when known mass haulouts occurred, compared to years when they did not, suggest no strong correlation with low sea ice levels.
“The WWF and American walrus biologists have categorically linked the Point Lay mass haulout event to global warming, but available evidence suggests that’s alarmist nonsense,” Dr Crockford said.
“Blaming lack of sea ice for recent events ignores the documented factor – large population size – that drove walruses onto beaches en masse in the past, when plenty of ice was available. Conservation measures have almost certainly led to a spectacular recovery of walrus numbers over the last few years. This suggests that recent mass haulouts are more an indicator that Chukchi walrus are nearing maximum capacity than a sign of impending global warming catastrophe,” Dr Crockford added.
Here’s the paper. [Link fixed, h/t HO]
Posted in Advocacy, Sea ice habitat, Summary, walrus
Tagged briefing paper, Chukchi Sea, global warming, Global Warming Policy Foundation, GWPF, haulouts, minimum ice extent, on the beach, population size, sea ice, St. Lawrence Island, Susan Crockford, US Fish and Wildlife Service, USGS, walrus, Wrangel Island, WWF
Walruses as polar bear prey and sea ice were on my mind last night and I remembered that we DO have detailed sea ice information for 1978 and 1972 – from the sea ice atlas put together by University of Alaska Fairbanks (UAF), which has ice concentration maps for Alaska going back to 1850 — and for every year up to 2013 (reported previously here).
Chukchi Sea walrus, June 2014. US Fish and Wildlife Service.
I’ve copied some of the ice maps below.
It is clear that ice was available close to Wrangel Island in 1972 when walruses chose to haul out on the island in huge numbers. And in 1978, there was ice present to the north of the walrus herd, but they had moved away from the ice to get to St. Lawrence Island, where they hauled out in large numbers.
This means it is more likely that food resources were the issue, not sea ice.
UPDATE OCTOBER 3 2014:
See another interesting follow-up elsewhere: Walrus inconsistencies
Posted in Life History, Sea ice habitat, walrus
Tagged Chukchi Sea, climate change, Fay, global warming, ice levels, Kelly, mass mortality, Point Lay, sea ice atlas, sea ice declines, sea ice maps, St. Lawrence Island, stampede, UAF, walus, Wrangel Island, WWF