A new paper on Baffin Bay polar bears reports data on body condition and litter sizes collected as part of a major study of the region completed in 2013 compared to sea ice declines since the 1990s; based on a computer model, the authors predict that in 37 years time (if sea ice declines continuously), the incidence of twin litters could “largely disappear.” However, no decline in population numbers was predicted and a critical caveat acknowledges that factors other than changes in sea ice could have affected the body condition and litter size data the authors analyzed, which means the conclusions are scientifically inconclusive.
The last (2013) polar bear population survey of Baffin Bay (SWG 2016) generated an estimate of almost 3,000 (2,826; range 2,059-3,593), which means that regardless of some slight changes in body condition and litter size over the last two decades (which may or may not have been caused by loss of sea ice), there are currently a lot of bears in Baffin Bay.
Posted in Conservation Status, Life History, Sea ice habitat
Tagged baffin bay, body condition, causation, correlation, extinction, fatness, Greenland, litter size, NASA, polar bear, sea ice, weight
There is no evidence that slightly less winter sea ice than the average since 1979 has had any negative impact on polar bear health or survival: the difference is simply not biologically meaningful to Arctic animals.
Polar bear on winter sea ice around the yearly maximum in the Beaufort Sea, 2010 (March 21).
NASA’s 23 March 2018 announcement regarding the Arctic sea ice maximum this year:
“Sea ice in the Arctic grew to its annual maximum extent last week, and joined 2015, 2016 and 2017 as the four lowest maximum extents on record, according to scientists at the NASA-supported National Snow and Ice Data Center (NSIDC) and NASA.”
Except, what they don’t tell you is that 2006 had almost the same extent as 2018 and 2006 wasn’t far behind according to the official, averaged data presented at NSIDC’s Arctic Sea Ice News & Analysis:
Current conditions at the winter maximum (at 17 March 2018, from NSIDC Masie, extent measured at 14.7 mkm2, using software able to discern more ice than used for the figures in Table 1), shown below: Continue reading
Posted in Sea ice habitat
Tagged Arctic, climate change, global warming, health, maximum, melting, NASA, polar bear, sea ice, survival, warm, winter
Walt Meier, sea ice scientist at NASA Goddard, made a statement yesterday about this year’s ice conditions [2016 Climate Trends Continue to Break Records: July 19, 2016]:
“It has been a record year so far for global temperatures, but the record high temperatures in the Arctic over the past six months have been even more extreme,” Meier said. “This warmth as well as unusual weather patterns have led to the record low sea ice extents so far this year.“ [my bold]
Well, except for Davis Strait/Labrador Sea this spring. And Western Hudson Bay/Foxe Basin this month – plus the fact that late July sea ice in the Laptev Sea is higher than it’s been for more than a decade (more on that below).
I guess totals matter for some things – just not for polar bears. However, it’s nice to see the issue of melt ponds get some attention, since they are such a prominent feature of polar bear habitat during the summer melt season.
Posted in Life History, Sea ice habitat
Tagged accuracy, Beaufort, Chukchi, extent, ICEBRIDGE, Laptev Sea, melt ponds, NASA, Northeast Passage, satellite radio collars, sea ice, summer
The Canadian Ice Service has a cool NASA animated video showing the Beaufort Gyre in action – you can actually see the solid mass of ice crack and swirl west and north under the pressure of the massive corkscrew current – see original here (tips on getting yourself oriented in the video below the screencap) and view below, for Apri 4- May 3, 2016:
Note that the video is oriented with Banks Island on the bottom and the shore of Alaska along the left-hand side, as if the locator map provided was rotated as below:
The big ‘bite” of ice being torn out to the south of Banks Island is the Amundsen Gulf.
The caption for the NASA video says this (my bold):
“MODIS Terra imagery taken between April 4 and May 3, 2016 of the Beaufort Sea. The animation highlights the gradual ice breakup due to the Beaufort gyre.”
So, early breakup here is due to Beaufort Gyre action – not early seasonal melt.
Posted in Life History, Sea ice habitat
Tagged Amundsen Gulf, Arctic, Banks Island, Beaufort Gyre, Beaufort Sea, Canadian Ice Service, circulation, facts, ice thickness, NASA, polynya, sea ice, spring, video