Wednesday 21 June is the longest day of the year: wear something white tomorrow to acknowledge and celebrate the success of polar bears despite such low summer sea ice since 2007 that 2/3 of them were predicted to disappear.
White tie, white shirt, white socks work too. Keep cool and signal to the world that you love outstanding survivors of climate change, fat though they may be.
Read here and here.
Global sea ice extent at 19 June 2018, well past the end of the intensive spring feeding period for polar bears:
Last week, the Norwegian Polar Institute updated their online data collected for the Svalbard area to include 2017 and 2018 — fall sea ice data and spring polar bear data. Older data for comparison go back to 1993 for polar bears and 1979 for sea ice, showing little to no impact of the reduced ice present since 2016 in late spring through fall.
Here’s what the introduction says, in part [my bold]:
“…The polar bear habitat is changing rapidly, and the Polar Basin could be ice-free in summer within a few years. Gaining access to preferred denning areas and their favourite prey, ringed seals, depends on good sea ice conditions at the right time and place. The population probably increased considerably during the years after hunting was banned in 1973, and new knowledge indicates that the population hasn’t been reduced the last 10-15 years, in spite of a large reduction in available sea ice in the same period.”
See Aars et al. 2017 for details on the 2015 Svalbard polar bear population count, keeping in mind that the subpopulation region is called “Barents Sea” for a reason: only a few hundred individuals currently stick close to Svalbard year round while most Barents Sea bears inhabit the pack ice around Franz Josef Land to the east (Aars et al. 2009; Crockford 2017, 2018).
Posted in Advocacy, Conservation Status, Sea ice habitat
Tagged Barents Sea, body condition, decline, denning, Derocher, Franz Josef Land, litter size, mothers with cubs, polar bear, population, sea ice, Svalbard
Polar bear season for St. Lunaire-Griquet Newfoundland ran from 6 March to 10 June this year — three long months when polar bears came to visit the community during the season when bears are usually occupied with feeding on young seals and mating.
Below is a map of the region: St. Lunaire-Griquet is at the tip of the Northern Peninsula of Newfoundland, just north of St. Anthony (where some of the action in my polar bear attack thriller, EATEN, takes place):
As of yesterday (June 10), when the last sighting of a fat and healthy polar bear took place, there was still quite a mass of thick first year ice (>1.2 m thick) off the northern peninsula of Newfoundland, amongst a field of icebergs:
The first sighting in the area this year was back in early March, which I blogged about here. Fortunately, the Davis Strait bears that occupy the East Coast pack ice are usually well feed at this time of year and seldom pose a serious threat to humans: the fact that visitors ashore are often easily pursuaded to leave (or do so on their own) suggests they are more curious than hungry.
Posted in Life History, Polar bear attacks, Sea ice habitat
Tagged ashore, East Coast, Eaten, harp seal, icebergs, Newfoundland, polar bear, sea ice, sightings, St. Anthony
Polar bear researchers have been doing capture/recapture studies in Western Hudson Bay for decades yet most of the data claimed to be critical for assessing effects of human-caused global warming on this species have not been published. I raised this point in one of my early blog posts (27 Sept 2012) but the situation has not changed in 6 years. Here’s an update.
Years ago now, in an oft-cited paper, Stirling and Derocher (2012) claimed to summarize the evidence that climate warming was negatively impacting polar bear health and survival. Several life history parameters were considered crucial, particularly body condition.
Despite almost a dozen papers (and perhaps more) on various aspects of WH polar bear health and life history studies based on capture/recapture data published since 2004 (e.g. Castro de la Guardia 2017; Lunn et al. 2016; Pilfold et al. 2017), none have reported the body condition data that supposedly support the claim that sea ice loss is having a severe impact — and the same is true for litter size, proportion of independent yearlings, and cub survival.1
Posted in Conservation Status, Life History, Population, Sea ice habitat
Tagged body condition, capture, Derocher, fat, field work, Lunn, mark-recapture, mass, polar bear, protocol, Sciullo, sea ice, Stirling, unpublished data, weight, western hudson bay
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.
The activist lawyer primarily responsible for polar bears being listed as ‘threatened’ on the US Endangered Species List (ESA) in 2008 is frustrated that those efforts have not generated her preferred political action. Kassie Siegel also claims in another 10 years it will be too late to save polar bears from extinction — despite clear evidence to the contrary.
In an emotional rant over at The Hill with a predictably hysterical headline, Siegel perhaps reveals more than she should about her motivation (“Keeping fossil fuels in the ground is the only way to save polar bears ravaged by climate change,” 26 May 2018).
Posted in Advocacy, Conservation Status, Population, Sea ice habitat
Tagged activists, anniversary, CBD, climate change, ESA, global warming, polar bear, politics, sea ice, walrus