S. Beaufort polar bear population stable since 2010 not declining new report reveals

Posted on October 4, 2020 | 

S. Beaufort polar bear population stable since 2010 not declining new report reveals

A just-released report on the latest count for the Alaska portion of the Southern Beaufort subpopulation reveals that numbers have been stable since 2010 despite claims the population has continued to decline. However, the study also has a very odd feature: 2012 had the highest population estimate over the decade of 2006-2015 yet also had the lowest survival of all age classes since 2001.

Healthy polar bear male at Kaktovik, Alaska on the Southern Beaufort Sea, September 2019, Ed Boudreau photo, with permission.

However, what is essentially good news about polar bear health and survival in the Southern Beaufort has so far been glossed over by the media because the report prominently includes estimates of polar bear dens on land in areas of potential oil exploration, a highly politicized topic. Accordingly, the Washington Post (picked up by other outlets) focused a statement in the paper that “long-term persistence of polar bears (Ursus maritimus) is threatened by sea-ice loss due to climate change” and on the denning issue rather than the new population count.  As far as I am aware, no other population estimate report has included such distracting information.

Recent claim of a polar bear expert [my bold]:

In 2015…the polar bear population in the Beaufort Sea had declined by 40% over the previous decade. “We can only anticipate that those declines have continued.” Steven Amstrup, 29 September 2019.



For the last five years, the Southern Beaufort subpopulation has been the jewel in the crown of those who promote the notion that polar bears are threatened with extinction due to man-made global warming. With an estimated decline of 25-50% between 2001 and 2010 (often ‘simplified’ as “40%”, see quote above), it has been the most dramatic example of a population decline blamed on lack of summer sea ice – even though it is known that the decline was actually the result of thick spring ice conditions in the period 2004-2006 and that Inuit in the Canadian portion of the Southern Beaufort disagree with this assessment (Crockford 2019, 2020).

The last population count of polar bears in the Southern Beaufort Sea covered the years 2001-2010 (Bromaghin et al. 2015). In that study, the 2010 estimate for the same area of Alaska as the most recent study was 562 (range, 363-873). For 2015 , the estimate was 573 (range, 232-1,140) – see their Fig. 4 below – and the average estimated abundance for the entire 2006-2015 period was 563 (range, 340-920)(Atwood et al. 2020).

In other words, no change.

However, not mentioned in the paper but obvious in the graph below is that the population count in 2012 was the highest over the 2006-2015 period – an average of about 750 bears.


Oddly, all age classes (including adults) had extremely low apparent survival rates in 2012 compared to all other years since 2001: not even the known ‘poor survival’ years of 2004-2006 shown in the graphs were as bad (see also Bromaghin et al. 2015; Stirling et al. 2008). Even more peculiar is the fact that no suggestions whatsoever are offered by the authors to explain this phenomenon: it is simply dismissed as a fluctuation. Similarly, nothing is said about the surprising fact that the population estimate for that year was the highest over the ten year period of 2006-2015 (see section above).

Was the apparent low survival in 2012 a result of the failure to account for movement of bears? This seems likely, as the authors don’t attempt to blame this on lack of summer sea ice, which would be the predictable response. If there had been a negative impact of much reduced summer sea ice or even thick spring ice on Southern Beaufort bears in 2012, it wasn’t evident by the fall of 2012, when a US Fish and Wildlife Service survey found polar bear numbers higher than they had been in a decade (USFWS 2013:17). Neither were starving bears or reduced numbers of cubs evident by 2013, when researchers were doing field research in the area (Rode et al 2013, 2014, 2018).


Perhaps critically, this study model was not able to adequately account for the fact that Alaskan polar bears move around: they are known to move to and from nearshore and offshore locations (see map of study area above), as well as to and from neighbouring subpopulations (see also next section), which may have affected the accuracy of the population and survival estimates. For example:

Analyses of relocations of polar bears carrying satellite radio collars suggested that at Utqiağvik (formerly Barrow), Alaska, in the west, 50% of polar bears were from the SB subpopulation and 50% were from the Chukchi Sea (CS) subpopulation.” PBSG.

This shortcoming was also present in the model used to generate the last population estimate but the potential effect was dismissed as “likely to be small” (Bromaghin et al. 2015:646). However, rather than do the work necessary to resolve this potentially critical problem, USGS authors went ahead and generated another population estimate and more survival estimates using a model with a known flaw. We know this because the authors (Atwood et al. 2020:12) state: “Additional work to investigate the influence of bear movement on abundance estimates is underway.”


Ian Stirling (2002:68) had this to say about the reduced survival of polar bears due thick spring ice in the Beaufort Sea, that could also be said to apply to the similar events that took place in 2004-2006:

In the eastern Beaufort Sea, in years during and following heavy ice conditions in spring, we found a marked reduction in production of ringed seal pups and consequently in the natality of polar bears (Stirling and Lunn, 1997). The effect appeared to last for about three years, after which productivity of both seals and bears increased again. These clear and major reductions in productivity of ringed seals in relation to ice conditions occurred at decadal scale intervals in the mid-1970s and 1980s (Fig. 5) and, on the basis of less complete data, probably in the mid-1960s as well (Stirling et al., 1977b; Stirling and Lunn, 1997).” [my bold]

Below is an excerpt from a previous post on an incident of cannibalism that occurred in 1976 that’s pertinent because of the descriptions of the spring ice conditions for 1975 and 1976, and the effects these had on both ringed seals and polar bears. A report of an incident of cannibalism in 1976 was made by biologist Jack Lentfer in his summary of polar bear research in Alaska for the IUCN Polar Bear Specialist Group’s 6th meeting (1976, pg. 187 and 192, “Polar bear management and research in Alaska 1974-76”). See the map below for locations of communities mentioned:

Both 1975 and 1976 were “heavy” ice years. Bears traveled south to the southern Chukchi Sea and northern Bering Sea with a movement of heavy ice south early in the winter of these years. Unusually high kills [of polar bears] occurred on St. Lawrence Island and near the villages of Wales and Shishmaref in areas where bears are seldom encountered.

Sea ice was heavier than usual and heavy ice extended further south than usual in 1975 and 1976. This may have caused a movement of ringed seals, the principal food of bears, to the west and south (Burns et al. 1976) and a similar movement of some bears. In both years significantly fewer seals were killed by bears in the Barrow, Alaska area than in years when ice had not been so heavy. Also, perhaps related to reduced availability of seals, the first instance of predation by an adult bear, a male, on cubs was noted.

Both cubs in a litter were nearly completely consumed on 13 April 1976.” [my bold]

Seal biologists John Burns and colleagues described the unusual nature of the movements of seals and bears in their quarterly report on research they were doing on the distribution and abundance of seals in 1974 and 1975 (Burns et al. 1975). They say (in part):

“Survey results substantiated that a major, short-term shift in density had indeed occurred. Density of seals in the Beaufort Sea was down 10 fold with a corresponding increase in the Chukchi Sea of between 10 and 15 fold.

…In my opinion, the overriding factor affecting ringed seal distribution is the distribution of favorable sea ice conditions. From past experience it was obvious the prevailing sea ice conditions in the Beaufort Sea were, by and large, unfavorable for breeding ringed seals whereas they were excellent in the Chukchi Sea.

The distribution of ringed seals directly affected the distribution of their most significant predator, the polar bear. [my bold]

Chukchi Beaufort locations_PolarBearScience_sm As Burns and colleagues pointed out, the ice conditions of 1974-1976 in Alaska and western Canada were unusual. In their 2008 paper on Eastern Beaufort polar bears, Ian Stirling and colleagues said that prior to 2004-2006 (when there was heavy spring ice and some very thin bears), they had not seen similar development of shorefast pressure ridges since 1974 — even though they had worked there from 1971 to 1979 and from 1985 to 1987. This suggests that conditions in the eastern Beaufort were worse in the spring of 1974 (with almost as bad conditions the following two years, see previous post here), but that in the Chukchi Sea and western Beaufort, the worst effects were evident in 1975 and 1976.


Atwood, T.C., Bromaghin, J.F., Patil, V.P., Durner, G.M., Douglas, D.C., and Simac, K.S., 2020. Analyses on subpopulation abundance and annual number of maternal dens for the U.S. Fish and Wildlife Service on polar bears (Ursus maritimus) in the southern Beaufort Sea, Alaska: U.S. Geological Survey Open-File Report 2020-1087. https://doi.org/10.3133/ofr20201087. pdf here.

Abstract The long-term persistence of polar bears (Ursus maritimus) is threatened by sea-ice loss due to climate change, which is concurrently providing an opportunity in the Arctic for increased anthropogenic activities including natural resource extraction. Mitigating the risk of those activities, which can adversely affect the population dynamics of the southern Beaufort Sea (SBS) subpopulation, is an emerging challenge as polar bears become more reliant on land and come into more frequent contact with humans. The Marine Mammal Protection Act and Endangered Species Act require the U.S. Fish and Wildlife Service to determine whether industrial activities will have a negligible impact on the SBS subpopulation. Information important to making that determination includes estimates of subpopulation abundance and the number of maternal dens likely to be present in areas where industrial activities occur. We analyzed mark-recapture data collected from SBS polar bears sampled in Alaska during 2001–16 using multistate Cormack-Jolly-Seber models. Estimated survival rates were relatively high during 2001–03, lower during 2004–08, then higher during 2009–15 except for 2012. Estimated abundance in the Alaska part of the SBS was consistent with the estimated survival rates, declining from about 1,300 bears in 2003 to 525 bears in 2006 and then remaining generally stable during 2006–15. The point estimate for the Alaska part of the SBS in 2015, the last year in which abundance could be estimated, was 573 bears (95-percent credible interval = 232, 1,140 bears). To estimate the expected number of terrestrial dens likely to be present in a given region in a given year, we used a Bayesian modeling approach based on calculations derived from SBS demographic and denning data. We estimated that the entire SBS subpopulation produced 123 dens per year (median; 95-percent credible interval = 69, 198 dens), 66 (median; 95-percent credible interval = 35, 110 dens) of which were land-based. Most land-based dens were located between the Colville and Canning Rivers (which includes the Prudhoe Bay-Kuparuk industrial footprint), followed by the 1002 Area of the Arctic National Wildlife Refuge and the National Petroleum Reserve-Alaska.

Bromaghin, J.F., McDonald, T.L., Stirling, I., Derocher, A.E., Richardson, E.S., Rehehr, E.V., Douglas, D.C., Durner, G.M., Atwood, T. and Amstrup, S.C. 2015. Polar bear population dynamics in the southern Beaufort Sea during a period of sea ice decline. Ecological Applications 25(3):634-651. http://www.esajournals.org/doi/abs/10.1890/14-1129.1

Burns, J. J., Fay, F. H., and Shapiro, L.H. 1975. The relationships of marine mammal distributions, densities, and activities to sea ice conditions (Quarterly report for quarter ending September 30, 1975, projects #248 and 249), pp. 77-78 in Environmental Assessment of the Alaskan Continental Shelf, Principal Investiagors’ Reports. July-September 1975, Volume 1. NOAA, Environmental Research Laboratories, Boulder Colorado. pdf here.

Crockford, S.J. 2019The Polar Bear Catastrophe That Never Happened. Global Warming Policy Foundation, London. Available in paperback and ebook formats. Crockford, S.J. 2020. State of the Polar Bear Report 2019. Global Warming Policy Foundation Report 39, London. pdf here.

Lentfer 1976. Polar bear management and research in Alaska 1974-76. Pg. 187-197 in [Anonymous]. Polar Bears: Proceedings of the 6th meeting of the Polar Bear Specialists Group IUCN/SSC, 7 December, 1976, Morges, Switzerland. Gland, Switzerland and Cambridge UK, IUCN. http://pbsg.npolar.no/en/meetings/

Regehr, E.V., Amstrup, S.C., and Stirling, I. 2006. Polar bear population status in the Southern Beaufort Sea. US Geological Survey Open-File Report 2006-1337. pdf here.

Regehr, E.V., Lunn, N.J., Amstrup, S.C., and Stirling, I. 2007. Effects of earlier sea ice breakup on survival and population size of polar bears in western Hudson Bay. Journal of Wildlife Management 71:2673-2683.

Rode, K.D., Douglas, D., Durner, G., Derocher, A.E., Thiemann, G.W., and Budge, S. 2013. Variation in the response of an Arctic top predator experiencing habitat loss: feeding and reproductive ecology of two polar bear populations. Oral presentation by Karyn Rode, 28th Lowell Wakefield Fisheries Symposium, March 26-29. Anchorage, AK.

Rode, K.D., Regehr, E.V., Douglas, D., Durner, G., Derocher, A.E., Thiemann, G.W., and Budge, S. 2014. Variation in the response of an Arctic top predator experiencing habitat loss: feeding and reproductive ecology of two polar bear populations. Global Change Biology 20(1):76-88. http://onlinelibrary.wiley.com/doi/10.1111/gcb.12339/abstract

Rode, K. D., R. R. Wilson, D. C. Douglas, V. Muhlenbruch, T.C. Atwood, E. V. Regehr, E.S. Richardson, N.W. Pilfold, A.E. Derocher, G.M Durner, I. Stirling, S.C. Amstrup, M. S. Martin, A.M. Pagano, and K. Simac. 2018. Spring fasting behavior in a marine apex predator provides an index of ecosystem productivity. Global Change Biology http://onlinelibrary.wiley.com/doi/10.1111/gcb.13933/full 

Stirling, I. 2002. Polar bears and seals in the eastern Beaufort Sea and Amundsen Gulf: a synthesis of population trends and ecological relationships over three decades. Arctic 55 (Suppl. 1):59-76. http://arctic.synergiesprairies.ca/arctic/index.php/arctic/issue/view/42

Stirling, I. and Lunn, N.J. 1997. Environmental fluctuations in arctic marine ecosystems as reflected by variability in reproduction of polar bears and ringed seals. In Ecology of Arctic Environments, Woodin, S.J. and Marquiss, M. (eds), pg. 167-181. Blackwell Science, UK.

Stirling, I., McDonald, T.L., Richardson, E.S., Regehr, E.V., and Amstrup, S.C. 2011. Polar bear population status in the northern Beaufort Sea, Canada, 1971-2006. Ecological Applications 21:859-876. http://www.esajournals.org/doi/abs/10.1890/10-0849.1

Stirling, I., Richardson, E., Thiemann, G.W. and Derocher, A.E. 2008. Unusual predation attempts of polar bears on ringed seals in the southern Beaufort Sea: possible significance of changing spring ice conditions. Arctic 61:14-22. http://arctic.synergiesprairies.ca/arctic/index.php/arctic/article/view/3/3

Stirling, I., Schweinsburg, R.E., Kolenasky, G.B., Juniper, I., Robertson, R.J., and Luttich, S. 1980. Proceedings of the 7th meeting of the Polar Bear Specialists Group IUCN/SSC, 30 January-1 February, 1979, Copenhagen, Denmark. Gland, Switzerland and Cambridge UK, IUCN., pg. 45-53.http://pbsg.npolar.no/en/meetings/ pdf of except here.

US Fish and Wildlife Service (USFWS) 2013. Polar Bear News 2013-14. Newsletter of the US Fish & Wildlife Service, Anchorage, Alaska. Pdf here.

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Joel O’Bryan
October 7, 2020 10:32 pm

Production of ringed seal pups depends on the mother seal’s nutrition. Her nutrition is dependent on the fish she can eat under the ice in the winter. The amount of fish under the ice in the winter is dependent on the previous summer fall krill. The krill populations explode when there are low summer-fall ice conditions which drive phytoplankton blooms.

Go google 2012 Arctic Sea ice extent.

Really, why is this low summer ice claimed to be such a problem because when it happens, the next Spring is Arctic feeding bonanza for all the mammals?
Answer: “when a person’s paycheck depends on themnot understanding that.”

h/t: Upton Sinclair, early 20th Century human behaviorist

Reply to  Joel O’Bryan
October 8, 2020 12:13 am

Interesting comment by Joel.
There’s a lot of Krill out there
and they surely are an important foundation of the food web at both polar regions.

but don’t tell Paul Ehrlich.
He will have a fit


Tom Abbott
Reply to  chaamjamal
October 8, 2020 7:45 am

Good! 🙂

Gary Pearse
Reply to  Joel O’Bryan
October 9, 2020 10:39 am

The bear bump up year 2012 is ignored by the climate wroughters because this was also the record low ice year of the satellite period and it supports Susan’s contention that the bears do famously with less ice. 2007, the second lowest ice year, was also the second best bear year in the decade to 2015, almost as good as 2012.

October 7, 2020 11:14 pm

Not related to this particular story but is of relevance to every thing this site represents on AGW. From David Attenborough and Prince William https://www.bbc.co.uk/news/science-environment-54435638

Reply to  JohnC
October 8, 2020 1:08 am

Earthshot – name chosen to echo Moonshot – the biggest vanity project ever.

October 7, 2020 11:51 pm

This seems to cover up to 2015… but the ice has changed dramatically in the Beaufort in the last 5 years, retreating far offshore at an early date…

This year is the ‘best’ Beaufort ice in years…

I’m sorry, really this sort of propaganda just won’t do.

Reply to  griff
October 8, 2020 12:42 am

Yep , your manic dis-information propaganda should be ignored.

According to MASIE, current Beaufort Sea ice level is above the following years

2006, 2007, 2008, 2010, 2011, 2012, 2016, 2017, 2018, 2019

You are a proven LIAR, Stop it.

Reply to  griff
October 8, 2020 12:45 am

Why do you HATE Arctic wildlife SO MUCH griff[snip] ?

Not only is the land surface GREENING, but the seas are also springing BACK to life after being TOO COLD and frozen over for much of the last 500 or so years (coldest period of the Holocene)

The drop in sea ice slightly toward the pre-LIA levels has opened up the food supply for the nearly extinct Bowhead Whale, and they are returning to the waters around Svalbard.


The Blue Mussel is also making a return, having been absent for a few thousand years, apart from a brief stint during the MWP.


Many other species of whale are also returning now that the sea ice extent has dropped from the extreme highs of the LIA. Whales cannot swim on ice. !


Great thing is, that because of fossil fuels and plastics, they will no longer be hunted for whale blubber for lamps and for whale bone.

Hopefully the Arctic doesn’t re-freeze too much in the next AMO cycle, and these glorious creatures get a chance to survive and multiply.

From the second link..
“Shallow marine molluscs that are today extinct close to Svalbard, because of the cold climate, are found in deposits there dating to the early Holocene. The most warmth-demanding species found, Zirfaea crispata, currently has a northern limit 1000 km farther south, indicating that August temperatures on Svalbard were 6°C warmer at around 10.2–9.2 cal. ka BP, when this species lived there. The blue mussel, Mytilus edulis, returned to Svalbard in 2004 following recent warming, and after almost 4000 years of absence, excluding a short re-appearance during the Medieval Warm Period 900 years ago.

Arctic is so much COOLER than it was for most of the Holocene, which explains why there is still so much sea ice up there.

[We’re not doing the whole “insults through name-change” thing here. -mod]

Reply to  griff
October 8, 2020 12:53 am

And as you well know, or should by now…

the current levels of Arctic sea ice are still FAR HIGHER than for most of the last 10,000 years

And we still have polar bears. They lived through MUCH LOWER levels of sea ice.

Bill Toland
Reply to  fred250
October 8, 2020 1:56 am

Here is a link confirming that the current level of Arctic sea ice is higher than most of the last 10,000 years.

Reply to  griff
October 8, 2020 12:59 am

not much happening here , is there griff[snip]. !

comment image

Just normal variability.

[Seriously, this won’t be tolerated. -mod]

Reply to  fred250
October 8, 2020 1:58 pm


Patrick MJD
Reply to  griff
October 8, 2020 2:11 am

Ha ha ha ha ha…I was just about to post that “griff” would be along in a few minutes to claim that this is BS and refers to his oracle of science The Guardian, or some other proven hole of trash. But he beat me to it! Well done griff, open mouth, change foot!

Ron Long
Reply to  Patrick MJD
October 8, 2020 3:02 am

You got that right, Patrick MJD. Griff enjoys being a human piñata. Makes one wonder what else he likes.

Right-Handed Shark
Reply to  griff
October 8, 2020 5:21 am

Yes grief, your sort of propaganda really won’t do, so why keep posting it?

Reply to  griff
October 8, 2020 8:19 am

Like The Guardian, his favourite newspaper, Griff is wrong about everything, all the time.

October 8, 2020 1:02 am

“The long-term persistence of polar bears (Ursus maritimus) is threatened by sea-ice loss due to climate change,”

NO, its been threatened by there being TOO MUCH SEA ICE.

They have survived most of the last 10,000 years with MUCH LESS sea ice.

Reply to  fred250
October 8, 2020 4:30 am

TOO MUCH sea ice also threatens sea creatures.

From one of the links above…..

The ice destroyed the food source

Now, Norwegian researchers are seeking to throw new light on that explanation.

They believe there is another possible reason for the collapse of the whale population.

In the years between 1670 and 1800, the area north of Svalbard was ice-free, and thus similar to the situation researchers have observed in the past few years.

However, from 1800 and onwards, the north and west coast of Spitsbergen – the largest island in the Svalbard archipelago – gradually became covered in ice, destroying the food source which sustained the stocks of bowhead whales.

The expansion of ice led to the effective blocking of warm and nutrient-rich water welling up from the Atlantic Ocean. The ice also prevented sunlight from penetrating the water, which is necessary for phytoplankton, or plant plankton, to bloom.

Ronald Bruce
October 8, 2020 1:22 am

There never was a problem with polar bear numbers it was a series of lies by the warmists and everone of them should be held accountable.

Reply to  Ronald Bruce
October 8, 2020 1:48 am

Oh but there was a problem. It was over hunting. Once that was fixed, the polar bear population became safe.

October 8, 2020 2:05 am

Perhaps critically, this study model was not able to adequately account for the fact that Alaskan polar bears move around: …

A long time ago when I used to go to the arctic, my group had polar bear safety lessons given, as best as I can remember, by people associated with Ian Stirling. One of the salient points was to expect polar bears anywhere in the arctic, even in the middle of the mountains. The fact that they move around a lot seems to be well known.

The thing about a male polar bear eating cubs … male grizzlies eat cubs even if they’re not desperately hungry. link It shouldn’t be a surprise that genetically similar polar bears also do so.

Reply to  commieBob
October 8, 2020 8:47 am

I read somewhere that female polar bears will mate with as many males as they can. This is because male polar bears won’t kill the cubs of females that they have mated with.

Tom Abbott
October 8, 2020 7:49 am

From the article: “In 2015…the polar bear population in the Beaufort Sea had declined by 40% over the previous decade. “We can only anticipate that those declines have continued.” Steven Amstrup”

Does this guy ever get anything right?

Pat from Kerbob
Reply to  Tom Abbott
October 8, 2020 8:48 am

He posts based on what he wants to see not what does see.

mental disease

Pat from Kerbob
October 8, 2020 8:47 am

Susan, so all of the data above confirms that thick sea ice is bad for the polar bears and seals, so cold times are bad times for the bears, just like for us.

Wonder why this is still a question.

Climate believer
October 8, 2020 12:54 pm

“This seems to cover up to 2015… but the ice has changed dramatically in the Beaufort in the last 5 years, retreating far offshore at an early date…
I’m sorry, really this sort of propaganda just won’t do.”

The problem you have with untrue statements about early retreating ice is that people can actually go, in a couple of clicks, and look at a satellite image from whatever year or month they like and verify for themselves.


Ice has been present along the coast for the last 5 years at least up until the 1st week of May and often beyond.

Propaganda?……The lady doth protest too much, methinks.

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