In recent years, sea ice loss over Hudson Bay has begun with open water in the NW corner (which is just as likely due to prevailing offshore winds as ice melt) rather than along the east coast but this year that patch of ice is smaller than its been for the last two years. In addition, despite two patches of open water at either end of the Beaufort Sea, most of the coast of Alaska is still covered in thick ice — much more than existed last year, yet masses of polar bears did not die as far as I know (actually, WHB bears came ashore in excellent condition last year).
Compare to previous years:
Last week biologist Andrew Derocher recently implied via twitter that less sea ice in the eastern portion of the Southern Beaufort (SB) this year at mid-May is harmful to polar bears (calling it “a hole in the ice where polar bears used to live“), but both long-term and short-term data don’t support such a glass-half-empty interpretation.
Not only does spring breakup of sea ice in the SB normally begin with such open patches of water (see the video above from last year) — driven by the powerful currents of the Beaufort Gyre, not ice melt (explained in detail here) — it may actually be necessary for the survival of local seals, polar bears and whales in spring and early summer (Citta et al. 2015; Crawford et al. 2015; Harwood et al. 2015; Stirling et al. 1981).
As I’ve pointed out before, the biggest threat to SB bears is thick sea ice in spring and its associated late breakup, a 2-3 year-long phenomenon unique to this region known to have occurred about every 10 years since the early 1960s (well documented in the scientific literature) but which has not (as far as I know) happened since 2004-2006.
In other words, a considerable patch of open water and less concentrated ice in the eastern SB around Cape Bathurst is almost certainly a good thing for this particular subpopulation (see previous post here for an in-depth discussion) because historically, when a polynya of some extent has not formed by April or May it has been devastating for local marine mammals.
The fact that an extensive patch of open water existed at mid-May in this region last year and the year before (2015 and 2016) — with no public hue-and-cry about a great dying of SB bears from Derocher or anyone else — suggests that open water in the eastern SB this year is likely to be beneficial for SB polar bears, or at least benign. Continue reading
Posted in Life History, Population, Sea ice habitat
Tagged bearded seals, Beaufort Gyre, Cape Bathurst, Derocher, hole in the ice, polar bear, polynya, ringed seals, sea ice, shore leads, Southern Beaufort, thick spring ice
Habitat for polar bears is abundant worldwide as the prime feeding season passes its peak and mating season for sexually mature bears winds down.
Battle among polar bear males for the right to mate, from this 2011 DailyMail story here.
There is much more ice than usual around Svalbard in the Barents Sea and off Newfoundland and southern Labrador, home to ‘Davis Strait’ bears. There have been no media reports of polar bears onshore anywhere (since the third week of April in Newfoundland and late January in Svalbard).
Sea ice map below for 12 May 2017:
Compare the extent and concentration of ice around Svalbard above (at 12 May 2017) to conditions that prevailed on the same date in 2015 (below), considered a “good ice” year for local polar bears (and the year of the last population size count which registered an increase over the 2004 count):
There hasn’t been this much ice in the area at this point in the season for many years, especially to the north of Svalbard, and levels since late April have been above even the long-term average (disregard the huge downward blip, which is clearly a sensor malfunction of some kind):
In fact, ice is pretty solid throughout the Barents Sea and East Greenland at this time:
Across the Atlantic, the situation is similar, with unseasonably heavy sea ice off eastern North America and the Southern Beaufort Sea.
Posted in Life History, Sea ice habitat
Tagged body condition, Churchill, fighting, Hudson Bay, mating, polar bear, problem bears, ringed seals, sea ice, snow depth, Svalbard
Polar bear populations in most of the Canadian Arctic Archipelago (CAA) must be booming, as they are elsewhere. That’s because the ‘experts’ were even more wrong in their predictions of future sea ice conditions than most people realize: they expected the CAA would remain choked with ice during a ‘nearly ice-free’ summer driven by human-caused global warming.
Map presented by Wang and Overland (2012: Fig 3) shows what these experts thought a ‘nearly ice-free’ summer would look like, which they expected to occur by 2030 or so.
Look at the map from Wang and Overland (2012) above, which is what they thought a ‘nearly ice-free’ summer would look like in the year 2030 or so.
Wang and Overland used the same models used by USGS biologists to predict the future survival of polar bears based on habitat loss (Amstrup et al. 2007; Atwood et al. 2016; Durner et al. 2007, 2009). Note the thick ice in the CAA — what USGS experts call the ‘Archipelago’ sea ice ecoregion (denoted by white in the map), indicating ice about 1 metre thick (2-3 feet) — expected to remain at the height of summer in 2030.
[Earlier renditions of sea ice projections (e.g. ACIA 2005) show something similar. The second update of the ACIA released just yesterday (AMAP 2017, described here by the CBC) has prudently included no such firm predictions in their Summary for Policy Makers, just dire warnings of future catastrophe. But see the 2012 update.]
The problem is that ice in this region has been largely absent most summers since 2006, even though overall ice extent has been much more extensive than expected for a ‘nearly ice-free’ summer, as I show below.
This is not another “worse than we thought” moment (Amstrup et al. 2007) — this is sea ice models so wrong as to be useless: failed models used to inform future polar bear survival models that got the bears declared ‘threatened’ with extinction in the US in 2008 (Crockford 2017).
It also means polar bears are almost certainly doing much better than recent population counts indicate, since only one subpopulation out of the six in the CAA has recently been assessed. But since polar bear specialists have consistently underestimated the adaptability of this species and the resilience of the Arctic ecosystem to respond to changing conditions, it’s hard to take any of their hyperbole about the future of polar bears seriously. Continue reading
Posted in Conservation Status, Population, Sea ice habitat
Tagged Canadian Arctic Archipelago, Crockford, first year ice, Gulf of Boothia, ice-free, IUCN Polar Bear Specialist Group, IUCN Red List, Kane Basin, Lancaster Sound, multiyear ice, Northwest Passage, PBSG, predictions, sea ice, wrong
Amid reports that ice conditions between Newfoundland and southern Labrador are the worst in living memory, another polar bear was reported ashore in the area — just after biologist Andrew Derocher explained to the CBC that bears only come on land when sea ice conditions “fail.”
“Ice too thick for coast guard’s heavy icebreaker” said a 20 April 2017 CBC report on the state of ice in the Strait of Belle Isle. The pack is thick first year ice (four feet thick or more in places) and embedded with icebergs of much older, thicker ice. The ice packed along the northern shore of Newfoundland is hampering fishermen from getting out to sea and is not expected to clear until mid-May.
NASA Worldview shows the extent of the pack ice over northwest Newfoundland and southern Labrador on 19 April 2017 (the Strait of Belle Isle is the bit between the two):
The same day that the above satellite image was taken (19 April), at the north end of the Strait on the Newfoundland side, a polar bear was spotted in a small community northwest of St. Anthony (marked below, “Wildberry Country Lodge” at Parker’s Brook). It’s on the shore of north-facing Pistolet Bay on the Great Northern Peninsula, near the 1000 year old Viking occupation site of L’Anse aux Meadows.
There were no photos of the Parker’s Brook bear but lots of others have been taken this year of almost a dozen seen along Newfoundland shorelines since early March: see my recently updated post, with an updated map of reported sightings. Harp seals are now abundant in the pack ice of southern Davis Strait, providing polar bears with an ample source of food when they need it most and therefore, a strong attractant to the area.
Yet, as I reported yesterday, polar bear specialist Andrew Derocher told the CBC this week that polar bears are almost always “forced” ashore by poor ice conditions. The CBC report included his tweet from 10 April, where he suggested “failed” Newfoundland ice conditions were the cause of multiple bears onshore in Newfoundland this year.
Similar thick ice conditions off northern Newfoundland (perhaps even worse) occurred in 2007, see Twillingate in the spring of 2007 below:
Yet, in 2007 there was not a single polar bear reported onshore in Newfoundland (as far as I am aware) but this year there were almost a dozen. And the photos taken this year show fat, healthy bears – not animals struggling to survive.
Posted in Polar bear attacks, Sea ice habitat
Tagged Davis Strait, expert, harp seals, Labrador, Newfoundland, onshore, polar bears, population increase, sea ice, sightings
Davis Strait polar bears around Newfoundland and Labrador are currently experiencing what one polar bear specialist refers to as “failed” sea ice conditions, causing bears to come ashore in droves. I’m not making this up.
The ice was so thick in the Strait of Belle Isle between Newfoundland and southern Labrador last week that a ferry was stuck for 24 hours and had to be rescued by an icebreaker.
The boats of fisherman on the north shore of Newfoundland are stuck in thick ice that’s not expected to clear until mid-May at the earliest and they can’t get out to fish.
See this video posted on Twitter two days ago.
The same thing (perhaps even worse) happened in 2007, see Twillingate in the spring of 2007 below:
Yet, in 2007 there was not a single polar bear reported onshore in Newfoundland (as far as I am aware) but this year there were almost a dozen. And the photos show fat, healthy bears – not animals struggling to survive.
According to Andrew Derocher, that’s proof “failed” sea ice is the reason that polar bears came ashore this year but not last year (when there was also lots of ice in late March/early April, see additional maps and graphs below). Last year there were sightings in the middle of winter (January/February) in Labrador and Newfoundland (which I reported here) and one bear was shot in Newfoundland in early May when he advanced on local RCMP officers.
I think Derocher believes he’s set the record straight by offering an interview of his own to refute the things I said to the CBC last week (I talked on two Newfoundland radio stations, which generated a print CBC article). But Newfoundlanders have to deal with used car salesmen just like the everyone else, so I expect they are having a good laugh right now at the expert who’s blaming their polar bear troubles on a lack of sea ice.
Without a shred of evidence, Canada’s Maclean’s magazine claims recent polar bear sightings in Newfoundland and Labrador are due to global warming — and concludes that such incidents are bound to get worse.
But since it’s likely that polar bear populations in Davis Strait are still increasing (as they were in 2007), Maclean’s might be correct in their prophesy that bear visitations are bound to get worse — just not for the reason they think.
Without any justification or even a quote from an expert, the author of this piece (Meagan Campbell) blames man-made global warming for recent polar bear visits to Labrador and Newfoundland:
“Since bear sightings in the early winter have been linked to climate change, some parents are more concerned for their future grandchildren.”
That’s just bad logic. Actually, the fact that global warming has not killed off polar bears as predicted means there are lots of bears to come ashore causing problems in late winter (while they wait for Arctic seal pups to be born, so they can eat them).