Tag Archives: Beaufort Sea

Ten out of ten polar bears being tracked this summer in the Beaufort Sea are on the ice

Posted on August 29, 2013 | Comments Off on Ten out of ten polar bears being tracked this summer in the Beaufort Sea are on the ice

PB_male on ice_Regehr USFWS_March 2010_labeledTracking Beaufort Sea polar bears over the summer — what can it tell us about how important the position of summer sea ice relative to the shoreline in this region is to these bears? Do Beaufort Sea bears get stranded on shore like the polar bears in Davis Strait and Hudson Bay?

Polar bear biologist Eric Regehr (with the US Fish & Wildlife Service, or FWS) has a team working with US Geological Survey researchers (USGS) in the southern Beaufort tracking where adult female polar bears go throughout the year. This is part of on-going research in the Beaufort and Chukchi Sea (see previous post here; see also Fish & Wildlife 2009; Polar Bear News 2010 and 2013; Rode and Regehr 2010, pdfs below; and just out, the “accepted” version of the Rode et al. paper discussed here, and announced in my last post here).

The researchers have been posting a summary map at the end of each month on the USGS website showing the tracks of the females they fitted with radio collars the previous spring — for 2013, and back to 2010. They can’t put collars on male bears because their necks are larger around than their heads, so a collar would just slip off.

I’ve posted the July 2013 track map below, which shows all ten bears out on the ice, and the previous month (June 2013) to compare it to (the August map should be out shortly). I’ve included a few maps from 2012 to allow you to compare this year’s results to the situation last summer.

The August tracks should be available after the Labour Day weekend – check back next week to see where the bears have been this month. I’ll post the map here or you can go to the USGS website directly. [UPDATE Sept 4, 2013: The August map is up, posted here.]

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Polar bears have not been harmed by sea ice declines in summer – the evidence

Posted on August 18, 2013 | Comments Off on Polar bears have not been harmed by sea ice declines in summer – the evidence

PB logo colouredThe polar bear biologists and professional activists of the IUCN Polar Bear Specialist Group (PBSG) continue to insist that since 1979 increasingly smaller amounts of Arctic sea ice left at the end of summer (the September ice minimum) have already caused harm to polar bears. They contend that global warming due to CO2 from fossil fuels (“climate warming” in their lexicon) is the cause of this decline in summer ice.

In a recent (2012) paper published in the journal Global Change Biology (“Effects of climate warming on polar bears: a review of the evidence”), long-time Canadian PBSG  members Ian Stirling and Andrew Derocher (both of University of Alberta) summarized their position this way:

“Climate warming is causing unidirectional changes to annual patterns of sea ice distribution, structure, and freeze-up. We summarize evidence that documents how loss of sea ice, the primary habitat of polar bears (Ursus maritimus), negatively affects their long-term survival”

I’ve spent the last year examining their evidence of on-going harm, but in addition, I’ve looked at the evidence (much of it not mentioned in the Stirling and Derocher paper1) that polar bears have either not been harmed by less sea ice in summer or have thrived in spite of it.

This is a summary of my findings. I’ve provided links to my original essays on individual topics, which are fully referenced and illustrated. You are encouraged to consult them for complete details. This synopsis (pdf with links preserved, updated; pdf with links as footnotes, updated) complements and updates a previous summary, “Ten good reasons not to worry about polar bears” (pdf with links preserved; pdf with a foreword by Dr. Matt Ridley, with links as footnotes).

Update 8 September 2013: to include links to my post on the recently published Chukchi population report; updated pdfs have been added above.

Update 22 January 2014: added figure comparing March vs. September sea ice extent using the same scale, from NOAA’s “2014 Arctic Report Card,” discussed here.
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Chukchi-Beaufort ice extent comparison – why feature only the last 7 years?

Posted on July 21, 2013 | Comments Off on Chukchi-Beaufort ice extent comparison – why feature only the last 7 years?

The most recent issue of Arctic Sea Ice News provided by the National Snow and Ice Data Center (NSIDC) – the official US keeper of sea ice data – (July 17, 2013) included an interesting graph of sea ice extent in the Chukchi and Beaufort Seas at July 12.

They present the data for 2007 to 2013, compared to the new 30 year average1, and note that the Beaufort Sea had “the most extensive ice cover seen there in the last seven summers.” It is also clear from their graph that the 2013 extent was virtually identical to the average in both regions (Fig. 1).

Figure 1. Graph of sea ice extent at July 12 each year from 2007 to 2013 from the National Snow and Ice Data Center, NSIDC. “Climatology” (last set of bars) is the 30 year average (1981-2010) extent at this date.1 In 2013, the Beaufort Sea had “the most extensive ice cover seen there in the last seven summers” (NSIDC). It is also clear from the graph that the 2013 extent was virtually identical to the 30-year average. Map from Wikipedia. Click to enlarge.

Figure 1. Graph of sea ice extent at July 12 each year from 2007 to 2013 from the National Snow and Ice Data Center, NSIDC. “Climatology” (last set of bars) is the 30 year average (1981-2010) extent at this date.1 It is clear from the graph that the 2013 extent was virtually identical to the 30-year average. Map from Wikipedia.

What puzzled me was why they featured only the last 7 years when satellite data go back to at least 1979. Is there something in that data they don’t want us to see?

There is no similar data in graph form available that I could find but there is the wonderful comparative sea ice mapping tool provided by Cryosphere Today, operated by the University of Illinois.

So, in the absence of numerical data to compare to the Fig. 1 graph, I chose visual data to ask the question: what could there be about the long-term record of Chukchi/Beaufort sea ice data that the NSIDC might not want us to know?

The ice coverage at mid-summer (July 12) provides a snapshot of what sea ice  conditions are like for polar bears before the summer melt season gets into full swing, so this historical perspective is quite revealing. [See previous posts here, here, and here for more on Chukchi/Beaufort polar bears.]
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Great polar bear red herring in the Southern Beaufort

Posted on July 4, 2013 | Comments Off on Great polar bear red herring in the Southern Beaufort

Red herring iconWe know that thick-ice springs occurred in 1974, 1975, 1986, 1992, 2004, and 2005 in the former ‘Eastern Beaufort’ – now the southern portion of the ‘Northern Beaufort’ and the eastern portion of the ‘Southern Beaufort.’ We know that these severe spring ice conditions negatively impacted both polar bears and ringed seals in this region every decade since the 1960s because the effects have been documented by numerous studies conducted in April through May for polar bears (Amstrup et al. 2006; Cherry et al. 2009; Pilfold et al. 2012; Stirling 2002; Stirling and Lunn 1997; Stirling et al. 1980; Stirling et al. 1993; Stirling et al. 2008) and in June and July for ringed seals (Harwood et al. 2012; Smith 1987), see previous posts here, here, and here.

For example, even though Ian Stirling and colleagues argued in their 2008 paper that the thick spring ice conditions in 2004, 2005 and 2006 (but not those in previous decades) were caused by storms initiated or intensified by greater amounts of open water in previous summers, they did not deny that the thick-ice springs occurred. They stated quite clearly that:

“The 1960s, 1970s, and 1980s each experienced a two- to three-year decline in seal productivity in the eastern Beaufort Sea and Amundsen Gulf, associated with heavy ice conditions, around mid-decade. Each was followed by a decline in polar bear reproduction and condition, after which both seal and bear populations recovered (Smith, 1987; Harwood et al., 2000; Stirling, 2002). The beginning of each of those three periods was associated with heavy ice conditions through the winter before the reproductive decline of the seals, followed by a late spring breakup.” [my bold]

So, I have to say, I was shocked but not surprised to find that in the more recent scientific literature, the phenomenon of thick-ice springs every decade in Southern and Northern Beaufort has been deliberately ‘disappeared.’ 

Not surprised because I suspected it had happened — this issue was a feature of the Stirling and Derocher (2012) paper from late last year which was the topic of my very first blog post, “Cooling the polar bear spin.”

However, I think it is important to document how the transmogrification of sea ice effects on polar bears was managed in the scientific literature so that everyone can see exactly what has been done. In a truly astonishing move for what is supposed to be a field of science, thick-ice springs have been effectively replaced by an open-water red herring as the scourge of Southern Beaufort polar bears.

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Guest post: How ‘science’ counts bears

Posted on July 3, 2013 | Comments Off on Guest post: How ‘science’ counts bears

This essay by Dr. Jim Steele, professor emeritus, San Francisco State University, is reblogged from a July 3 2013 post at WUWT post, with Dr. Steele’s permission. I am not a field biologist and have never done a mark-recapture study but Dr. Steele has. His perspective on the way polar bear biologists count bears and estimate survival in the Southern Beaufort is a perfect companion to yesterday’s post, a related post that I’ll put up later this week, and this one from December, among others. I’ve added links to the references cited in this essay where they are available, as is my custom. See the original post for Jim’s responses to comments and questions.

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Guest post by Jim Steele   “How ‘science’ counts bears”

The Inuit claim “it is the time of the most polar bears.” By synthesizing their community’s observations they have demonstrated a greater accuracy counting Bowhead whales and polar bears than the models of credentialed scientists. To estimate correctly, it takes a village. In contrast the “mark and recapture” study, which claimed the polar bears along South Beaufort Sea were victims of catastrophic global warming and threatened with extinction, relied on the subjective decisions of a handful of modelers.

In mark and recapture studies, the estimate of population abundance is skewed by the estimate of survival. For example, acknowledging the great uncertainty in his calculations of survival, in his earlier studies polar beat expert Steven Amstrup reported three different population estimates for bears along the South Beaufort Sea. If he assumed the adult bears had an 82% chance of surviving into the next year, the models calculated there were 1301 bears. If survivorship was 88%, the abundance climbed to 1776 bears. If he estimated survivorship at a more robust 94%, then polar bear abundance climbed to 2490.1 Thus depending on estimated survival rates, a mark-and-recapture study may conclude that the population has doubled, or that it has suddenly crashed.

Here are the simplified basics of estimating survival.

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Where were the appeals to feed starving polar bears in 1974?

Posted on February 21, 2013 | Comments Off on Where were the appeals to feed starving polar bears in 1974?

The so-called “policy paper” that polar bear biologist Andrew Derocher has been promoting over the last few weeks, which I commented on briefly when the press release came out, is still grabbing headlines. Online news outlets continue to run stories on this bizarre discussion of what officials might decide to do 40 years from now if global warming causes Western Hudson Bay polar bears to spend 6 months on land (Molnar et al. 2010), causing some of those polar bears to starve (see here, here, and here) – as if this is something likely to happen within the next couple of years.

But forget imagined future starvation: where was the media attention on the plight of starving polar bears back in 1974  and 1975 when polar bears were actually starving in large numbers in the eastern Beaufort Sea?

At least two of the co-authors of the paper getting all the attention – Drs. Ian Stirling and Nick Lunn – witnessed polar bears starving in the Beaufort in 1974 because of an especially cold winter and said nothing – even though polar bear populations worldwide at the time were already low due to the wanton slaughter of previous decades. Did Stirling and Lunn humanely euthanize the bears they saw starving? Contact the media? [If they did, I’d like to know.] Appeal to governments to make a plan in case it happened again? Apparently not, because it did happen again, at least twice in the following two decades – with no attendant hue and cry then either. No, those Beaufort Sea bears starved to death, time and time again, without a word to the media from Ian Stirling and Nick Lunn.
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