Two recent sightings of polar bears along the north shore of Newfoundland are a reminder that sea ice is still a prominent feature of the Davis Strait polar bear subpopulation landscape at this time of year.
A polar bear was sighted in the community of La Scie, northern Newfoundland Monday, 27 April (pictured above, swimming in the harbour), while another landed in the town of Fogo, on Fogo Island, last week (see maps below).
Continue reading
Comments Off on Polar bear season for Newfoundland residents still going strong, recent sightings confirm
Posted in Life History, Sea ice habitat
Tagged Davis Strait, Fogo, Gray, La Scie, Labrador, Newfoundland, polar bear, sea ice, sightings, spring, swimming
Polar bear habitat in the eastern Bering Sea has expanded since the official spring “maximum extent” was called for late February, and Davis Strait sea ice is tied for 2nd highest since 1971 for this week. Both regions have healthy polar bear populations and spring conditions suggest this will continue into this year.
Although the melt season is underway, as of yesterday (22 April, Julian day 112) overall Arctic sea ice extent (Fig. 1) was higher than it was on the same date in 2014, 2007, and 2004 (see also Fig. 2). Despite the record low extent in February (Fig. 3), that pessimists at Polar Bears International suggested was relevant to polar bear heath and survival, I showed that was misleading.
Figure 1. Sea ice extent at 22 April (Julian day 112) for 2015, at 13.976 mkm2, was well within 2 standard deviations and higher than 2007 (shown), as well as higher than 2004 and 2014 (not shown – see it for yourself here). Click to enlarge.
Sea ice maps and charts tell the story of current polar bear habitat throughout the Arctic.
Continue reading
Comments Off on Melt season update – Bering Sea ice abundant & Davis Strait ice 2nd highest since 1971
Posted in Sea ice habitat
Tagged arctic sea ice, Barents Sea, Bering Sea, Chukchi Sea, Davis Strait, Newfoundland, Regehr, Rode, sea ice extent, spring maximum
While the polar bear is an Ice Age species, genetic and fossil evidence suggests it barely survived the profound sea ice changes associated with the Last Glacial Maximum, one of the most severe glacial periods of the Pleistocene.
A map of sea ice extent at the climax of the Last Glacial Maximum (both perennial and seasonal ice), prepared with the help of a colleague, makes it possible to discuss what genetic and fossil evidence can tell us about the probable effects of glacial conditions on polar bears and ringed seals.
Comments Off on Polar bears barely survived the sea ice habitat changes of the last Ice Age, evidence suggests
Posted in Evolution, Sea ice habitat
Tagged Arctic basin, genetic bottleneck, ice age, last glacial maximum, LGM, perennial ice, Pleistocene, polar bear, population bottleneck, population decline, ringed seal, sea ice, sea ice habitat, sea level, seasonal ice
Men recreating the 1938 expedition of explorer David Haig-Thomas have a mid-April 2015 polar bear encounter reminiscent of two recent polar bear attacks (Labrador, 2013, Svalbard, 2011) but with a happier ending.
Comments Off on Polar bear encounter in the Canadian High Arctic reminiscent of recent attacks
Posted in Polar bear attacks
Tagged Arctic, attack, Labrador, polar bear, Svalbard, trip-wire, warning
Arctic ice extent (at 14.1mkm2) on 15 April, was virtually identical to 2014 on that date, and higher than 2006. But the record goes to Davis Strait, which recorded the highest ice extent since 1971 for the week of April 16, while the waters of Eastern Newfoundland to the south (where most harp seals have their pups) had the third highest ice extent since 1969. Lots of fat baby seals are just what polar bears need at this time of year.
Comments Off on Spring ice alarm deflated – 2015 ice now as high as 2014 & Davis Strait highest since 1971
Posted in Life History, Sea ice habitat
Tagged Barents Sea, Canadian Ice Service, Davis Strait, harp seal, Newfoundland, NSIDC, polar bear, sea ice, seals, spring sea ice
Sea ice in eastern Hudson Bay (bright white in the map below) is more concentrated than at this time last year and similar to the ice found in the Central Canadian Arctic.
There is more concentrated ice (10/10 concentration) in the east side of the Bay than there was in 1992, a heavy ice year blamed in part on the eruption of Mt. Pinatubo (Chambellant et al. 2012) that resulted in the latest breakup date for Western Hudson Bay since 1991.
Comments Off on Polar bear habitat update: highly concentrated ice in eastern Hudson Bay this spring
Posted in Sea ice habitat
Tagged average breakup date, breakup, Canadian Ice Service, concentration, eastern Hudson Bay, habitat, Hudson Bay, Mt. Pinatubo, sea ice, spring ice conditions, western hudson bay
Here are some facts to counter the misinformation and fearmongering being spread via twitter by a polar bear biologist who is getting carried away with his conservation activism.
Following up on my last post, I note that Arctic regions with sea ice but not polar bears were about 0.32 mkm2 below last year’s March average extent – which means the total ice decline from 2014 (0.4 mkm2) represents only a slight decline in polar bear habitat, most of which is in the Barents Sea (and due primarily to the state of the AMO, not global warming).
Sea ice extent for the Sea of Okhotsk and Baltic Sea combined (both areas without polar bears)1 were about 0.6 mkm2 below average this year for March. Average extent for March (according to NSIDC) is 15.5 mkm2, which means this year’s extent (14.4 mkm2) was 1.1 mkm2 below average, of which less than half (0.5 mkm2) was “lost” polar bear habitat.
IUCN Polar Bear Specialist Group biologist Andrew Derocher has been saying this is a “huge loss for polar bears” (see below): rational analysis of the facts show it is not. Continue reading
Comments Off on Challenging polar bear fearmongering about Arctic sea ice extent for March 2015
Posted in Advocacy, Sea ice habitat
Tagged activism, Baltic Sea, Barents Sea, Derocher, fearmongering, loss, maximum extent, misinformation, NSIDC, polar bear, record low, sea ice, Sea of Okhotsk, spring, spring ice
Only half or less of the estimated 2.6% loss per decade of March sea ice extent since 1979 (Fig. 1, below) represents a decline in polar habitat. That’s because several regions with sea ice that are not home to polar bears, like the Sea of Okhotsk, are included in Arctic sea ice totals.
Figure 1. Average monthly Arctic sea ice extent for March 1979-2015 (which includes ice in the Sea of Okhotsk, the Sea of Japan, and the Baltic, where polar bears do not live), shows a decline of 2.6% per decade. NSIDC, March summary 2015.
Both the Sea of Okhotsk and northern Sea of Japan (Fig. 2) have sea ice in winter (which is included in total Arctic sea ice records) but they are not truly “Arctic” – neither is connected to the Arctic by continuous ice, even when the ice is at its maximum extent (nor is the Baltic Sea — in contrast to Hudson Bay and the east coast of North America, which are connected to the Arctic by continuous ice).
Figure 2. Location of the Sea of Okhotsk and Sea of Japan. Insert ice map for March 1979 from NSIDC shows it’s position relative to the Arctic proper.
That lack of connection to Arctic pack ice is probably the main reason that polar bears never colonized the Sea of Okhotsk, even though western Arctic seal species (ringed, bearded, spotted, and ribbon) and Arctic whales (bowhead and beluga) live there. Polar bears don’t currently live in the Sea of Okhotsk and all evidence suggests they never have.
Sea ice maps show that about half of the total ice extent difference between March 1979 and March 2015 was due to a relatively large decline in sea ice cover for Sea of Okhotsk and northern Sea of Japan — regions without polar bears. Surely no reputable scientist or journalist would suggest that the “record low” maximum ice extent for 2015 has any relevance for polar bear health and survival? [or for Northwest Passage travel, for that matter] Sadly, they would.
Comments Off on Arctic sea ice extent total for March does not equal global polar bear habitat
Posted in Conservation Status, Sea ice habitat
Tagged Arctic, declining sea ice, Derocher, habitat, lost ice, lowest maximum extent, March, misinformation, NSIDC, polar bear, record low, sea ice, sea ice extent, sea ice maximum, Sea of Okhotsk, spring, variation
Here is the March 2015 follow-up to my post on the July 2013 track map for female polar bears being followed by satellite in the Beaufort Sea by the US Geological Survey (USGS) – “Ten out of ten polar bears being tracked this summer in the Beaufort Sea are on the ice.”
See that post for methods and other background on this topic, and some track maps from 2012 (also available at the USGS website here). The USGS track map for March 2015 is copied below.
Three out of eight female bears tagged in the Southern Beaufort Sea were in the Chukchi Sea subpopulation region during March – not surprising, many bears cross this “boundary.”
Continue reading
Comments Off on Tracking polar bears in the Beaufort Sea – March 2015 map
Posted in Life History, Sea ice habitat
Tagged Beaufort Sea, Chukchi Sea, polar bear habitat, polar bear movements, polar bears, satellite collars, sea ice, Southern Beaufort, spring, subpopulation boundaries, tracking polar bears, USGS
Prognosis, excellent. The sea ice hunting platform that polar bears require is everywhere and Davis Strait ice extent is the fourth-highest it’s ever been at this time of year.
The spring feeding period is a messy, brutal business – many cute baby seals will die as polar bears consume 2/3rds of their yearly food supply over the next few months (April – June/early July), while sea ice is abundant.
That leaves the remaining 1/3 of their energetic needs to be met over the following 9 months (most of it in late fall (late November/December) and hardly any during the summer months, regardless of whether the bears are on land or out on the sea ice) or over the winter. Continue reading
Comments Off on Superb sea ice conditions for polar bears worldwide during their critical feeding period
Posted in Life History, Sea ice habitat
Tagged breakup, Davis Strait, habitat, harp seals, Hudson Bay, hunting platform, polar bears, ringed seals, sea ice, sea ice extent, seals, spring ice maximum
You must be logged in to post a comment.