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
Svalbard in the western Barents Sea has recently had less sea ice extent than it had in the 1980s, especially in the west and north, but this is not unprecedented.
New evidence from clams and mussels with temperature-sensitive habitat requirements confirm that warmer temperatures and less sea ice than today existed during the early Holocene period about 10.2–9.2 thousand years ago and between 8.2 and 6.0 thousand years ago (based on radio carbon dates) around Svalbard. Barents Sea polar bears almost certainly survived those previous low-ice periods, as they are doing today, by staying close to the Franz Josef Land Archipelago in the eastern half of the region where sea ice is more persistent.
As this sea ice chart for 18 April 2018 shows, ice this month has been virtually absent from the west and north coasts of the Svalbard Archipelago, while Franz Josef Land to the east is surrounded by highly concentrated pack and land-fast ice.
From a new paper by Jan Mangerud and John Svendsen (2018) [my bold]:
Svalbard, located between 74° and 81°N, is the warmest place on Earth at this latitude (Drange et al., 2013). This is because of the North Atlantic Current and large-scale atmospheric circulation which transport warm water and air masses from lower latitudes northwards across the Atlantic and along the coast of Norway to Svalbard (Figure 1). Yet, during the Holocene Thermal Maximum, the climate of Svalbard was considerably warmer than at present.
The transition from Younger Dryas cold to Holocene Thermal Maximum warm conditions took place very rapidly, according to records from nearby Greenland (Taylor et al. 1997), warming in “steps” of about five years each over a period of about 40 years. This was at least as fast, if not faster than, recent Arctic warming between the 1980s and 2015. And since polar bears of the Barents Sea and adjacent Arctic areas appear to have survived this change to Holocence Thermal Maximum conditions, it challenges the notion that recent warming has been (or will be) too fast to allow polar bears to survive without huge changes in their present distribution (Amstrup et al. 2007).
Consensus polar bear expert Andrew Derocher has been busy over the last few weeks, expounding a story of doom regarding Svalbard area polar bears (e.g. here and here), ridiculing the suggestion that Franz Josef Land is viable alternate habitat for Barents Sea bears, especially pregnant females looking for a place to den and give birth. But the facts say otherwise.
Below are the long answers, with references and ice maps, to the questions Derocher asked in his 21 December 2017 tweet (above), a refreshing change from the ‘take my word for it, I’m the official expert’ answer one gets from him, along with derogatory slurs directed at those who don’t share his pessimism.
Posted in Life History, Population, Sea ice habitat
Tagged abundance, Arctic islands, Barents Sea, den habitat, estimates, Franz Josef Land, Norway, polar bears, pregnant, Russia, sea ice, Svalbard
Sea ice development in eastern Svalbard this fall is lagging well behind the rest of the Arctic. Several polar bear researchers (e.g., Andrew Derocher here and here) have recently been raising the alarm that this might be devastating for Barents Sea females looking for suitable denning sites.
The implication is that pregnant polar bear females are inflexible – so fixated on one location to give birth that they are unable or unwilling to choose an alternative if conditions preclude using their preferred location this year. However, the available facts do not support such a pessimistic attitude.
Posted in Life History, Sea ice habitat
Tagged Aars, Barents Sea, dens, Derocher, flexibility, Franz Josef Land, Hopen Island, Kong Karls Land, nearshore, pelagic, philopatry, polar bear, polar bear facts, pregnant females, sea ice, Svalbard
Good news from Norway: polar bears around Svalbard are in excellent condition this spring and many females with new cubs have been spotted. This is a marked turn around from conditions just last year.
According to a Norwegian news outlet yesterday, Jon Aars (Fig. 1, below), from the Norwegian Polar Institute, confirms that this has been an excellent year for polar bear cubs around Svalbard because there has been abundant sea ice near denning areas on the east coast.
Figure 1. Biologist Jon Aars with a Svalbard cub.
Posted in Conservation Status, Life History, Sea ice habitat
Tagged AMO, Arctic, Atlantic Multidecadal Oscillation, Barents Sea, body condition, cubs, denning, fall, Franz Josef Land, Jon Aars, Madden-Julian Oscillation, Norwegian Polar Institute, NSIDC, polar bear, science, sea ice, spring, Svalbard, winter
With Barents Sea ice way above average this summer, Polar Bear Specialist Group biologist Ian Stirling now claims the old polar bear that he said died of climate change last year on Svalbard was “in his prime” and still blames the bear’s death on lack of sea ice — despite all evidence to the contrary.
UPDATE Sept. 19, 2014 typo fixed in Fig. 1 caption [sea ice low for 2012 was 3.41 m2km, not 4.1, see here.]
Figure 1. The National Snow and Ice Data Center (NSIDC) says the September minimum for 2014 is “imminent” and suggests the low may come in at 5.1 million square kilometers (far short of the
4.1 3.41 m2km low reached in 2012. About the much larger than average amount of ice around Svalbard and Franz Josef Land, they said only: “As was the case for the beginning of the month, extent remains below average in all sectors of the Arctic except for a region in the Barents Sea, east of Svalbard.”
Posted in Advocacy, Life History, Sea ice habitat
Tagged AMO, annual summer minimum, Atlantic Multidecadal Oscillation, Barents Sea, Franz Josef Land, Hopen Island, minimum ice extent, Mult, NSIDC, polar bear that died of climate change, Polar Bears International, sea ice extent, starving polar bear, Stirling, Svalbard
Oddly, it seems some people expect polar bears to sit around and suffer (or die) when local conditions deteriorate, rather than move elsewhere.
While there are perhaps a few places where moving is not really an option over the short term, over the long term (more than one season) polar bears are free to shift to another locale if ice conditions change (either too much ice or too little).
An announcement by the WWF last week (10 April) caught my eye, as it talked about bears moving from one area to another because of changing ice conditions — as if this was surprising, extraordinary and newsworthy. That said, at least they weren’t suggesting the bears are all going to die because of declining ice, which is a huge improvement.
See what you think of this part of the press release (below), in the context of what we know about the movement of bears between regions:
Posted in Conservation Status, Life History, Sea ice habitat
Tagged adaptation, AMO, Amstrup, Barents Sea, dens, Franz Josef Land, Kara Sea, Mauritzen, polar bear, polar bear resilience, pregnant females, satellite radio collars, spring ice conditions, Svalbard, WWF