Posted onOctober 6, 2023|Comments Off on Feeding time for Russian polar bears as shorefast ice returns to Laptev Sea, ice-generator of the Arctic
Fall is the second-most important feeding season for polar bears after spring but it comes at different times for different subpopulations. Sea ice formation along shorelines attracts fish and seals and that means polar bears which spent the summer onshore will soon eat again after their summer fast. As usual, the earliest ice formation this year is along the coast of the Laptev Sea, which is one of the primary ‘ice-generators’ of Arctic sea ice. Western and Southern Hudson Bay bears will have longer to wait but the ice will eventually come to them too.
Posted onNovember 18, 2021|Comments Off on Chukchi Sea ice that didn’t melt this summer is now 2+m thick between Wrangel Island and the shore
Thick multiyear ice between Wrangel Island and the shore is now more than 2m thick, potentially impacting fall feeding for bears that routinely summer on Wrangel or the north coast of Chukotka.
Rapidly-forming sea ice in the Laptev and East Siberian Seas this fall – generated by cold winds from Siberia in late October despite warmer than ususal temperatures earlier in the month – has trapped a number of Russian ships that are being rescued by ice-breakers (below), according to a report in the Barents Observerearlier this week.
Posted onFebruary 12, 2020|Comments Off on First-ever polar bear population survey for entire Russian coast planned for 2021-2023
Word that Russia is planning to generate a count of polar bears along its entire Arctic coast within the next few years is good news indeed, as it will resolve a long-standing gap in population estimates that have not been dealt with at all well by the polar bear community. Whether North American and European academics will accept the results of the aerial surveys is another matter entirely, especially if the numbers are higher than they like, which is what happened with the first Russian Kara Sea count in 2013.
Up first will be the Chukchi and East Siberian Seas in 2021, the Laptev and Kara Seas, in 2022, and the eastern Barents Sea around Franz Josef Land in 2023.
Posted onMay 1, 2017|Comments Off on IUCN Specialist Group now rejects polar bear numbers it used for 2015 IUCN Red List review
Is there a mutiny in the works between the IUCN Red List and the IUCN Polar Bear Specialist Group (PBSG) over polar bear population estimates or has there simply been a breach of ethics? What else explains the fact that some of the subpopulation estimates used by the PBSG to support the status of ‘vulnerable’ for the IUCN Red List in 2015 are unacceptable to them in 2017? And why are the PBSG refusing to embrace the Red List global estimate of 22,000-31,000?
The latest version of the IUCN PBSG status table was posted online 30 March 2017 without fanfare or even a note on their home page. It seems the result came from much discussion at their official meeting last summer (June 2016) that they say continued into early March 2017.
PBGS members voted to reject four subpopulation estimates used in the 2015 Red List polar bear status review — even though the inclusion of those numbers was required in order for the Red List status of ‘vulnerable’ to be upheld. The group has also chosen not to update their global population page with the Red List estimate of 22,000-31,000.
And surprise, surprise — now that only one subpopulation out of nineteen worldwide has shown a recent decline, the PBSG have removed the “trend” columns from their summary table for subpopulations.
“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 Seais 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.
However, I thought it might be interesting to graph the changes in global population estimates over time (from 1981-2013) — not just the actual estimates from PBSG status tables (with their min/max error ranges) but those totals plus the so-called “inaccurate” estimates that the PBSG have dropped from their accounts in recent (2005-2013) assessments: Chukchi Sea, East Greenland, Queen Elizabeth Islands (now known as the “Arctic Basin”), and Laptev Sea.
In 2001, those “inaccurate” estimates contributed 5,000-5,400 bears to the global total, but now they’re gone — no bears from those regions contribute to the official totals listed on recent PBSG status tables.
Adding those dropped estimates back into the global totals makes it possible to generate a graph in which the global estimates are truly comparable over time.
To see how the dropped estimates influenced the perception of population change over time, I’ve also graphed the estimates given by the PBSG in their status tables. I’ve combined the two into one image (Fig. 1, click to enlarge) to make comparison easy.
UPDATE 5 December 2014: Links to more recent posts relevant to this issue added below. The most recent numbers, added 31 May 2015, are here.
There is but one exception to this pattern: Zhokhov Island in the East Siberian Sea, Russia (see Fig. 1 below). Almost four hundred polar bear bones were recovered from two of the 13 semi-subterranian houses discovered on the island, well-preserved by permafrost for over 8,200 years. It is by far the largest – and the oldest – collection of polar bear bones left by human hunters anywhere in the world and it is described in a fascinating paper published in 1996 by Vladimir Pitul’ko and Aleksey Kasparov [contact me if you’d like to see it].
The East Siberian Islands are included in the Laptev Sea subpopulation of polar bears, the only Russian region that contributes a count (800-1,200 bears) to the global population estimate, based on an aerial survey conducted in 1993 (see previous post here).
Figure 1. Map of the New Siberian Islands off Siberia, with tiny Zhokhov Island circled. Map from Wikipedia