This is the most important time of year for Arctic marine mammals that spend time above the ice: birthing, breeding, and feeding. And there is plenty of the right kind of ice available for those activities this year, as there was two years ago at the same time.
Comments Off on Earth Day sea ice habitat during critical spring season for Arctic seals, polar bears, and walrus
Posted in Life History, Sea ice habitat
Tagged bearded seal, Earth Day, East Greenland, Hudson Bay, ice thickness, polar bear, ringed seal, sea ice, Svalbard, walrus
Recent reports out of southern Labrador highlight how common it is to find polar bears onshore at this time of year. The small coastal community of Black Tickle seems to take the prize for the highest number of incidents and sightings but Happy Valley-Goose Bay is the somewhat surprising contender. [see correction below] Photo below is from Black Tickle.
Since early March, polar bear sightings in Newfoundland and Labrador have been common. The bears, of course, have come south on the Labrador Sea pack ice looking for fat newborn harp seals, which are now so abundant in the region that nearly a year’s worth of food could probably be consumed in a week or so. It appears that already well-fed bears may look around for what else could be added to their menu or just need a break to digest between meals. Photos of some of the bears sighted are all in good or excellent condition, and few of the animals seem to be intent on causing real trouble for locals–a far cry from the bear that wandered off the ice into Wales, Alaska earlier this year and killed a young mother and her infant son.
Continue readingComments Off on Southern Labrador coastal landscape dominated by fat polar bears in March
Posted in Life History, Polar bear attacks, Sea ice habitat
Tagged Black Tickle, encounters, fjord, Goose Bay, Happy Valley, harp seals, Jeffrey Keefe, Labrador, pack ice, polar bear, ringed seal, sightings
As well as summarizing sea ice changes, NOAA’s 2020 Arctic Report Card features two reports that document the biggest advantage of much less summer sea ice than there was before 2003: increased primary productivity. Being at the top of the Arctic food chain, polar bears have been beneficiaries of this phenomenon because the Arctic marine mammals they depend on for food – seals, walrus and bowhead whales – have been thriving despite less ice in summer.
Comments Off on Arctic report card 2020 highlights the huge benefit of less summer sea ice: more food
Posted in Life History, Sea ice habitat, walrus
Tagged Arctic food chain, bearded seal, bowhead whale, NOAA, polar bear, primary productivity, ringed seal, sea ice, walrus
This isn’t news but it’s good to hear it again, this time from the mouth of one of the biologists who collects the data: against all odds, the primary prey species of polar bears are doing spectacularly well.
According to leading seal biologist Lori Quakenbush of Alaska Department of Fish and Game, ringed and bearded seals in the Chukchi Sea are doing great (ADN, 11 February 2019, “Seals seem to be adapting to shrinking sea ice off Alaska”):
“We’re seeing fat seals,” said Lori Quakenbush, a wildlife biologist with the Alaska Department of Fish and Game’s Arctic Marine Mammal Program. “They are reproducing earlier than they have in the past, which says they are getting enough nutrition at this point to grow quickly and become reproductive at an earlier age.”
Ringed and bearded seals across the Arctic, including the Chukchi and Bering Seas, were listed as threatened in 2012 by the US, hot on the heels of polar bears given the same status in 2008 (USFWS 2008, 2012a, 2012b). But American biologists didn’t even pretend that the seals were currently suffering, they simply assumed they would sometime in the future (Cameron et al. 2010; Kelly et al. 2010).
Now, ten years worth of low sea ice of the kind expected to drive polar bears to the brink of extinction later, and ringed and bearded seals are doing better than they did in the late 1970s and early 1980s when there was more summer ice (Adam et al. 2019; Crawford and Quakenbush 2013; Crawford et al. 2015). Quakenbush now has data that extends the period of recent research to 2016, from 2013 previously.
It’s hard to imagine stronger evidence in support of retracting the ESA ‘threatened’ species status designation for ringed and bearded seals: clearly, ringed and bearded seals did not respond as expected when summer sea ice declined dramatically in 2007.
However, all that seems to have happened is that Quakenbush is willing to admit to a journalist that biologists can’t tell the future:
“…two predictions that we made about what could be bad for walruses, just within a couple of years turned around and were sort of the opposite.”
Quakenbush has been watching marine mammals throughout her long career, and she has given up predicting their future. She says that biologists know what the animals do with ice because they have studied that, but we don’t know what they do without it.
Read the whole thing here.
Unfortunately, predicting the future was precisely what US biologists insisted they could do accurately in 2012, even though no other conservation organization in the world concurred with their assessemnt, including the IUCN. The IUCN Red List classified both ringed and bearded seals as species of ‘Least Concern’ in 2008 and in 2016 (Kovacs 2016; Lowry 2016; Kovaks and Lowry 2008; Kovacs et al. 2008).1
Footnote 1. The suggestion made in this article that Sea of Okhotsk ringed seals have only recently begun to give birth on the sea ice without making snow caves or ‘lairs’ is not true. Sea of Okhotsk ringed seals have been known to give birth in the pack ice (not on fast ice) without snow dens since at least the 1960s (Fedoseev 1975:158; Kelly et al. 2010a:10) and also in the ice of western Svalbard (Smith et al. 1991:129).
Adam, R., Bryan, A., Quakenbush, L., Crawford, J., and Biderman, L.2019. Bearded seal productivity in Alaska using harvest-based monitoring, 1975-2016. Poster presentation, Alaska Marine Science Symposium, 28 January-1 February.
Abstract: Declines in arctic sea ice extent, thickness, and duration are projected to negatively impact bearded seals (Erignathus barbatus) by reducing their time to rest, pup, nurse, and molt on sea ice. Existing population estimates for bearded seals in Alaska cannot be used to detect trends; however, the Alaska Department of Fish and Game works with Alaska Native hunters to collect data from the subsistence harvest that are used to determine several population health indices, such as: pregnancy rate, age of maturity, and the proportion of pups in the sampled harvest. These indices were previously used to determine if declines in sea ice have affected bearded seals between 1975–1984 and 2003–2014.
During these time periods pregnancy rates varied minimally (92–99%); however, the average age of maturity decreased from 4.2 years in 1975–1984 to 2.9 years in 2003–2014. Additionally, pups were harvested in lower proportions during 1975–1984 than during 2003–2014 (26% and 48%, respectively), indicating that pups are still being produced, weaned, and are surviving to be harvested. Through 2014, we have not detected the decreases in population indices that have been predicted to occur with climate change. However, due to continued declines in sea ice, further monitoring is important; therefore, here we update our 1975–2014 results to include samples from 2015 and 2016.
Cameron, M. F., Bengtson, J. L., Boveng, J. K., Jansen, J. K., Kelly, B. P., Dahle, S. P., Logerwell, E. A., Overland, J. E., Sabine, C. L., Waring, G. T. and Wilder, J. M. 2010. Status review of the bearded (Erignatha barbatus). NOAA Technical Memorandum NMFS-AFSC-211.
www.afsc.noaa.gov/Publications/AFSC-TM/NOAA-TM-AFSC-211.pdf
Crawford, J. and Quakenbush, L. 2013. Ringed seals and climate change: early predictions versus recent observations in Alaska. Oral presentation by Justin Crawfort, 28th Lowell Wakefield Fisheries Symposium, March 26-29. Anchorage, AK. Abstract below, find pdf here:http://seagrant.uaf.edu/conferences/2013/wakefield-arctic-ecosystems/program.php
Crawford, J.A., Quakenbush, L.T. and Citta, J.J. 2015. A comparison of ringed and bearded seal diet, condition and productivity between historical (1975–1984) and recent (2003–2012) periods in the Alaskan Bering and Chukchi seas. Progress in Oceanography 136:133-150.
Fedoseev, G. A. 1975. Ecotypes of the ringed seal (Pusa hispida Schreber, 1777) and their reproductive capabilities. In Biology of the Seal, K. Ronald and A.W. Mansfield (eds.), pp. 156-160. Rapports et Proces-verbaux des Reunions, Conseil International Pour L’Exploration de la Mer 169.
Kelly, B. P., Bengtson, J. L., Boveng, P. L., Cameron, M. F., Dahle, S. P., Jansen, J. K., Logerwell, E. A., Overland, J. E., Sabine, C. L., Waring, G. T. and Wilder, J. M. 2010. Status review of the ringed seal (Phoca hispida). NOAA Technical Memorandum NMFS-AFSC-212.
www.afsc.noaa.gov/Publications/AFSC-TM/NOAA-TM-AFSC-212.pdf
Kovacs, K.M. 2016. Erignathus barbatus. The IUCN Red List of Threatened Species 2016: e.T8010A45225428. http://www.iucnredlist.org/details/full/8010/0
Kovacs, K. and Lowry, L. (IUCN SSC Pinniped Specialist Group) 2008. Erignathus barbatus. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. . Downloaded on 29 December 2012. http://www.iucnredlist.org/details/8010/0
Kovacs, K., Lowry, L. and Härkönen, T. (IUCN SSC Pinniped Specialist Group) 2008. Pusa hispida. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. . Downloaded on 29 December 2012. http://www.iucnredlist.org/details/41672/0
Lowry, L. 2016. Pusa hispida. The IUCN Red List of Threatened Species 2016: e.T41672A45231341. http://www.iucnredlist.org/details/41672/0
Smith, T. G., Hammill, M. O. and Taugbøl, G. 1991. A review of the development, behavioural and physiological adaptations of the ringed seal, Phoca hispida, to life in the arctic winter. Arctic 44:124-131.
US Fish & Wildlife Service (USFWS). 2008. Determination of threatened status for the polar bear (Ursus maritimus) throughout its range. Federal Register 73: 28212-28303.
US Fish & Wildlife Service (USFWS). 2012a. Threatened status for the Arctic, Okhotsk and Baltic subspecies of the ringed seal. Federal Register 77: 76706–76738.
US Fish & Wildlife Service (USFWS). 2012b. Threatened status for the Beringia and Okhotsk distinct population segments of the Erignathus barbatus nauticus subspecies of the bearded seal. Federal Register 77: 76740–76768.
Comments Off on Ringed and bearded seals, still listed as ‘threatened’, are still doing really well
Posted in Conservation Status, Life History, Sea ice habitat
Tagged Alaska, bearded seal, birth lair, Chukchi Sea, IUCN Red List, Least Concern, polar bears, prey, Quakenbush, ringed seal, sea ice, snow cave, threatened
Polar bears in virtually all regions will now have finished their intensive spring feeding, which means sea ice levels are no longer an issue. A few additional seals won’t make much difference to a bear’s condition at this point, except perhaps for young bears that haven’t had a chance to feed as heavily as necessary over the spring due to inexperience or competition.
The only seals available on the ice for polar bears to hunt in early July through October are predator-savvy adults and subadults. But since the condition of the sea ice makes escape so much easier for the seals to escape, most bears that continue to hunt are unsuccessful – and that’s been true since the 1970s. So much for the public hand-wringing over the loss of summer sea ice on behalf of polar bear survival!
Polar bears in most areas of the Arctic are at their fattest by late June. They are well prepared to go without food for a few months if necessary – a summer fast is normal for polar bears, even for those that spend their time on the sea ice.
Putting on hundreds of pounds of fat in the spring to last through periods of food scarcity later in the year (at the height of summer and over the winter) is the evolutionary adaptation that has allowed polar bears to live successfully in the Arctic.
Continue reading
Comments Off on Spring feeding for polar bears is over – sea ice levels are now largely irrelevant
Posted in Life History, Sea ice habitat
Tagged Arctic, bearded seal, ecosystem, facts, feeding, harp seal, ice loss, polar bear, research, ringed seal, save our sea ice, sea ice, sea ice day, spring, summer, video
Polar bear specialists Andrew Derocher and Steven Amstrup recently spent inordinate energy trying to refute the opinion piece I’d written for the Financial Post in celebration of International Polar Bear Day last month, ignoring my fully referenced State of the Polar Bear Report for 2017 that was released the same day (Crockford 2018) and the scientific manuscript I’d posted last year at PeerJ Preprints (Crockford 2017).
Their responses use misdirection and strawman arguments to make points. Such an approach would not work with the scientific community in a public review of my paper at PeerJ, but it’s perfect spin for the self-proclaimed “fact-checking” organization called Climate Feedback. The result is a wildly ineffective rebuttal of my scientific conclusion that Amstrup’s 2007 polar bear survival model has failed miserably.
This is Part 2 of my expose, see Part 1 here.
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Comments Off on Amstrup & colleages can’t refute my critique of their 2007 polar bear survival model, Part 2
Posted in Conservation Status, Population, Sea ice habitat, Summary
Tagged Amstrup, bearded seal, Beaufort, Chukchi Sea, Climate Feedback, damage control, Derocher, ESA, fact checker, failed predictions, ice-free, observations, polar bear, predictions, ringed seal, sea ice, spin, spring, Stirling, summer, survival, thick ice, threatened
Few people know that Arctic ringed seals (Phoca hispida, aka Pusa hispida) give birth and breed in the offshore pack ice in the spring, as it is seldom mentioned by either seal or polar bear specialists.
While it is true that some ringed seals give birth in stable shorefast ice close to shore, many others give birth well offshore in thick pack ice – where polar bears also live and hunt in the spring but where few Arctic scientists ever venture – and the existence of pack ice breeding ringed seals is one of the reasons that polar bears are such a resilient species.
Ringed seal pup in a snow cave, B. Kelly photo (Wikipedia).
As a consequence, despite fears expressed by Ian Stirling, low shorefast ice and associated snow around Svalbard this winter (and any time in the past) is not necessarily a hindrance to polar bear survival because there are ringed seal pups available out in the surrounding pack ice – where bearded seals also give birth.
Of course, ringed seals pups are also available to Svalbard polar bears in the shorefast ice in the Franz Josef Land archipelago to the east (see map below) but it is the pups born in the offshore pack ice that are of interest here. The existence of pack ice breeding ringed seals may be why Norwegian biologists do not currently monitor ringed seals in the Barents Sea, despite many years of poor ice conditions around Svalbard in spring – this simply is not a species of concern.
The fact that distinct ringed seal ecotypes (or habitat-specific morphotypes) exist in the Arctic – one that gives birth and breeds in shorefast ice and another that gives birth and breeds in offshore pack ice, perhaps driven by competition for limited shorefast ice habitat – is a phenomenon a colleague and I discussed in a peer-reviewed book chapter published several years ago. Have a look at the excerpt below and see what you think.
Comments Off on Svalbard polar bears thrive in part due to ringed seal pups in the spring pack ice
Posted in Life History, Sea ice habitat
Tagged birth, breeding, ecotype, fast ice, feeding, morphotype, offshore ice, pack ice, polar bear, prey, productivity, pups, ringed seal, shorefast ice
So, here we are near the end of the first month of the Arctic spring and there is still more ice than usual off Labrador and conditions in the Barents Sea are improving daily. The fear-mongers can blather all they like about the potential risks of bears swimming in summer – but spring is the critical season as far as sea ice is concerned for polar bears and all polar bear biologists know it. Polar bears consume 2/3 of all the food they need for the year during April-June and so far, ice conditions are looking just fine.
There is enough ice where there needs to be ice for polar bears to gorge themselves on new-born ringed and bearded seals – and that’s really all that matters. More ice off Labrador means more hunting ground for the Davis Strait polar bears that depend on the tens of thousands of young harp seals born this year off the Front.
Comments Off on Polar bear habitat update end of April 2016: Plenty of sea ice for feeding
Posted in Life History, Sea ice habitat
Tagged bearded seal, facts, feeding, harp seal, hunting, Labrador, polar bear, polynya, ringed seal, sea ice, Southern Beaufort, Svalbard
I have a new paper out that explains a fundamental problem with polar bear conservation.
I’m convinced that a flawed and out-dated ecological concept — that sea ice, under natural conditions, provides a stable, predictable habitat — is what has allowed the present doom and gloom attitude of most polar bear specialists to develop.
Sea ice changes, of course, from season to season. However, the concept that sea ice is a stable habitat assumes that these seasonal changes are predictable and virtually the same from one year to the next – at least, similar enough that the differences are not responsible for causing marked declines in population size.
The assumption is that under natural, stable conditions populations of Arctic animals will either stay the same over time or increase. Biologists were taught at university that sea ice should be a stable habitat and as a result, they’ve glossed over evidence they collected to the contrary. [see recent posts here and here, for example]
Negative effects on populations of short-term natural variations in spring sea ice or spring snow cover on sea ice have been entirely ignored in modeled predictions of future conditions. The focus has been on summer ice extent.
I have summarized this evidence in a fully referenced, peer-reviewed essay that explores how the acceptance of this fallacy (“sea ice is a stable habitat”) has so skewed the conservation biology of polar bears that to outsiders it may look like a scientific integrity issue.
The summary and the essay are below (with embedded links and references). The Global Warming Policy Foundation (GWPF) has published the essay in their “Briefing Paper” series (#16, The Arctic Fallacy: Sea Ice Stability and the Polar Bear), which includes a must-read foreword by Dr. Matthew Cronin, Professor of Animal Genetics at the University of Alaska Fairbanks. Press release here, pdf here.
I think you’ll find it timely and thought-provoking.
Comments Off on My new Arctic Fallacy paper- Sea ice stability and the polar bear
Posted in Conservation Status, Sea ice habitat
Tagged Beaufort Sea, climate change, Cronin, ecology, global warming, GWPF, habitat, Hudson Bay, IUCN Polar Bear Specialist Group, K-selection, model, PBSG, polar bear, Polar Bears International, polarbearscience, population size, predictions, ringed seal, sea ice, snow depth, stable, summer, thick spring ice, variability
With masses of very thick, multiyear ice off Alaska this spring, the developing polynyas (open water) at either end of the Beaufort Sea are providing essential polar bear hunting habitat.
Patches of open water in the Beaufort Sea are naturally recurring phenomena. This year we have two excellent examples, shown by the yellow arrows in the sea ice thickness map above (from the Naval Research Laboratory).
The eastern-most polynya forms in the Canadian portion of the Beaufort most years in the spring. This open water feature is so common it has a name – the Cape Bathurst polynya. Last year, there wasn’t an obvious polynya there until sometime in June, but in 1975, a patch of open water almost as large (or larger) as this year’s had developed by the end of May (Fig. 1).
Figure 1. Cape Bathurst polynya at 28 May 1975 (Smith and Rigby 1981:Fig. 14h) and the polynya this year at 14 May (Canadian Ice Service). See discussion in the text below about the relative sizes. Click to enlarge.
According to the experts that study them, the timing and extent of the polynya formation depends on wind (Dunbar 1981:29), not temperature. This means that this spring’s polynya formation in the eastern Beaufort isn’t a symptom of global warming, it isn’t “missing polar bear habitat,” and it isn’t a sign of early sea ice breakup.
In fact, the Cape Bathurst polynya is a critical place for ringed seals and bearded seals to congregate in spring. Therefore, this is where many Southern Beaufort polar bears go to hunt. The presence of the polynya is especially crucial in years like this one, when very thick sea ice covers most of the Beaufort Sea. Continue reading
Comments Off on Beaufort Sea polynyas open two weeks before 1975 – open water is good news for polar bears
Posted in Life History, Sea ice habitat
Tagged Alaska, Arctic, bearded seal, Beaufort Sea, Cape Bathurst, Cleator, ice thickness, open water, Point Barrow, polynya, ringed seal, sea ice, spring, Stirling
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