Over the weekend in Canada, the CBC ran a polar bear news feature that is now available online (“Polar bears in peril: the bleak future of Churchill bears,” The National, CBC, 3 December 2018). It gave polar bear biologist Nick Lunn of Environment Canada free rein to spread unsubstantiated claims and outright falsehoods about the status of Western Hudson Bay polar bears and sea ice. Apparently, he and the CBC learned nothing from National Geographic‘s fiasco over their ‘starving’ polar bear video last year: they still think the public will be swayed to “act” on human-caused global warming if a persuasive expert tells them that polar bears are on their way to extinction. I expect many were convinced otherwise, since the facts are available for all to see.
No triplet litters born since 1996? Nonsense, as the photo below (from 2017) shows.
The CBC video is described this way:
“They are a majestic icon of Canada’s North, but polar bears have also come to symbolize climate change. And scientists say the future for one particular population of polar bears in northern Manitoba is dire.“
Posted in Advocacy, Conservation Status, Population, Sea ice habitat
Tagged breakup, CBC, Churchill, declining population, fat, freeze-up, Hudson Bay, Nick Lunn, polar bear, sea ice, triplets, weight
There’s almost more blue in the Canadian Ice Service “departure from normal” charts for this week than red, which means more sea ice than usual, especially in the eastern half of the bay and northern Labrador. Eventually, the melting ice will force polar bears ashore where they will fast for 4-5 months, living off the fat they’ve put on over the spring feeding season.
Despite pronouncements from one polar bear specialist that “ice in Hudson Bay is in rapid retreat” a look back in time shows that there is more thick first year ice over the Bay this year for the week of the summer solstice than there was in 2004 – and much less open water than 1998.
Below, 2018, June 18 (the week of the summer solstice):
Compare the above to the same week coverage chart for 2004, below:
Ice coverage for some other recent years are shown below compared to 1998, the year the ice breakup pattern on Hudson Bay changed. Speed and melt sequences vary according to the amount of thick first year ice present, discussed previously here.
PS. If you’re wearing white today, flaunt it! Tell your friends and colleagues that you’re celebrating the success of polar bears despite such low summer sea ice since 2007 that 2/3 of them were predicted to disappear.
Posted in Sea ice habitat
Tagged breakup, decline, freeze-up, Hudson Bay, melt, observations, polar bear, retreat, sea ice, solstice, thick first year ice
A newly-published paper by Martyn Obbard and colleagues in the journal Arctic Science claims a 17% decline in abundance of polar bears in the Southern Hudson Bay region after years of reduced sea ice and declining body condition (Obbard et al. 2018). The decline in numbers was not statistically significant but an additional statistical analysis (“Monte Carlo simulation”) not applied to any other estimate in recent years suggested the decline could be real, so a real decline is what was reported to the press.
Only one Canadian Press story has so far been circulated amongst outlets in the media (published hours after the paper appeared online, not at the same time), suggesting there was no press release issued for this study. Odd, that — especially if the decline is as real and significant as the authors suggest.
While no evidence was provided for a correlation of this decline in numbers to recent (2012-2016) sea ice decline, previous evidence from the region (Obbard et al. 2016) showed a decline in body condition was correlated only with much later than usual freeze-up, a situation that did not occur from 2012 to 2015 (freeze-up was late in the fall of 2016 but occurred months after the Obbard et al. (2018) survey was completed).
Moreover, the paper reports that a decline in survival of yearling cubs (from 12% of the population in 2011 to 5% in 2016) was not associated with especially poor sea ice conditions in spring. We are likely to see a follow-up paper next year reporting the body condition and sea ice data from this study (as for the previous survey: Obbard et al. 2015, 2016), but there is no suggestion in this paper that body condition declined further from 2011/2012 levels or that sea ice conditions deteriorated markedly enough after 2012 to precipitate a population decline.
UPDATE 11 June 2018: See below, more recent versions of population and status assessment maps has been issued by Environment Canada that conclude Southern Hudson Bay is “likely declined.”
Following up on my previous post, it appears sea ice conditions on Hudson Bay this year might be headed for a late breakup due to the dominance of thick first year ice. That would mean a relatively longer on-ice season for polar bears in Western and Southern Hudson Bay.
As of the 1st week in May 2018, most of Hudson Bay, Foxe Basin and Hudson Strait were covered with thick 1st year ice (dark green, >1.2 m thick):
Compare that to the 1st week of May 2016, which had much less thick first year ice than 2018 and more medium first year ice (70-120cm, bright green):
To update the situation, at the end of May this year (week of 28 May), thick first year ice covered even more of the bay with a large patch of open water in the NW corner:
Thick first year ice does not melt as quickly as medium or thin first year ice (lime green) under most conditions, so the amount of thick first year ice present in May strongly affects the rate of breakup of the ice over the summer (temperature and wind also contribute). Here are some charts of ice melt sequences from the past (2016 and a couple others) that give a hint at what might be in store for Hudson Bay polar bears this year.
Just out from the City of Churchill: few polar bears reported onshore for the week of 17-23 July 2017 (week 2) but those seen “appear to be in great shape.”
Update 24 July 2017 12:20 PM: Just spotted this blog report from “Churchill Polar Bears” that I somehow missed last week, which includes what seems to be the first polar bear photo’s of the season (of a sow and two chubby cubs) that are also in fine condition.
The photos were taken by Churchill photographer and guide Alex De Vries on Thursday 13 July and I hope he doesn’t mind my including one of those here as documentary evidence of the good body condition of this mother and both her cubs — see more photos at the Churchill Polar Bears blog post dated 14 July here.
Compare last week’s PB Alert report above to last year’s (below):
Today, polar bear biologist Andrew Derocher posted a progress report via twitter on the annual journey ashore of the Western Hudson Bay bears tagged by his University of Alberta research team that shows virtually all of the bears are still out on the sea ice.
After months of gloomy reports on the state of the Hudson Bay sea ice, it’s clear from the map Derocher posted (below) that only one bear out of 12 still transmitting has come ashore so far, although he comments that “some tags haven’t reported lately” (the purple icons are ear tags put on males &/or young bears while the blue icons are collars put on adult females):
Oddly, the same comment was made almost a month ago about these same bears and the suggestion was made that these animals “may be swimming to shore”:
Money quote: Today Derocher remarked that “bears may be shifting behaviour to stay out on less ice” to explain why the tagged bears have still not come ashore as he expects them to do.
Perhaps if he used a different ice chart, it might make more sense (see below). However, the same thing has been happening year after year: WHB polar bears stay on the ice much longer than Derocher predicts but he does not change his expectations or the type of ice chart he uses to track the bears.
As I’ve pointed out before (because this is what field researchers have stated), polar bears have a tough time catching seals after about mid-June or so but they may still prefer to be on the sea ice than on land, even if it’s low concentration ice.