Tag Archives: prey

Return of Svalbard sea ice in time for seal births and the polar bear feeding bonanza

It seems that every fall and winter for the last decade at least, there has been hand-wringing about the lack of Svalbard sea ice and what a tragedy this is for polar bears. And like clockwork, before the end of winter (30 March) every year, the pack ice returns in time for spring: for ringed and bearded seals to give birth–and for the polar bears to gorge themselves on the fat newborns.

This year there is even ice as far south as Bear Island (Bjørnøya) and it’s only 15 March. This has happened several times now in the last 10 year. So much for the catastrophe! And soon Norwegian biologists will be out checking on the health of these bears, which they do every year and report their results online for everyone to see.

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Birthing season for harp seals in Labrador Sea just in time to feed hungry polar bears

The main birthing period for NW Atlantic harp seals has arrived. Local populations of ringed and bearded seal pups will soon follow but in the Gulf of St. Lawrence in eastern Canada, the pupping season for harp seals that is usually in progress by this time has likely been redirected north due to lack of suitable ice conditions. Sea ice off Labrador and Newfoundland is in good condition and this is where the vast majority of the global population go to give birth (ca. 7.6 million vs. 1.5 million in the White Sea and 434,000 in east Greenland).

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Ice-entrapped dolphins in Newfoundland lucky not to have been eaten by polar bears

A small pod of white-beaked dolphins entrapped on Friday (10 March) by a sudden surge of ice along the northern Newfoundland coast were lucky to have been rescued by humans before polar bears could get to them. We know the bears are around, drawn south by the millions of harp seals giving birth to their pups in the area. In April 2014, something similar happened to white-beaked dolphins in Svalbard and they became a welcome meal for at least six polar bears (Aars et al. 2015).

UPDATE 20 March 2023: Another pod of white-beaked dolphins has perished from the ice over the weekend. More than 30 dolphins were trapped near the town of Carbonear, which is on Conception Bay (the next big bay southeast from Trinity Bay), according to CBC News. Given the ice conditions, this is almost certainly a different pod to the one reported on two weeks ago.

Dolphins getting stuck in sea ice is a fairly regular occurrence, said Ledwell. [Wayne Ledwell of Whale Release and Strandings]

“It’s been happening here forever,” he said, adding it’s not just a problem for dolphins. “It kills blue whale and humpback whales and whatever gets into it.”

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Will low sea ice threaten harp seals & polar bears on Canada’s East Coast this year?

In early February this year, sea ice was much lower than usual along the Labrador coast and virtually non-existent in the Gulf of St. Lawrence, which are two important pupping habitats for North Atlantic harp seals. The picture would have been very bleak for harp seal pups and the Davis Strait polar bears that depend on them for food if ice hadn’t expanded and thickened by early March – but it did. Past experience suggests that harp seals that usually whelp in the Gulf of St. Lawrence, where ice is still well below average this year, will move to ice off Southern Labrador (‘the Front’) to have their pups.

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New report: Harp seal population critical to Davis Strait polar bears is still increasing

The report on the latest population estimate for harp seals off the east coast of North America was released in late March without fanfare and therefore no media attention. This was one of the missing scientific reports mentioned in my State of the Polar Bear Report 2019 released in February (Crockford 2020): results of surveys promised for months or years by early 2020 but not delivered.

Harp seal on ice around PEI _DFO 2017

Not surprisingly then, we find the report has good news: the population estimate of harp seals in the NW Atlantic has risen to about 7.6 million (range 6.55-8.82) animals (DFO 2020), up from 7.4 million in 2014 (DFO 2014).

Note that the survey was done in March 2017, a low ice year for the Gulf of St. Lawrence (see discussion below) and while this may have resulted in some increased mortality for pups born there, it is also known that many ‘Gulf’ pregnant females will instead have given birth off Newfoundland and Labrador in a whelping region called ‘The Front’. Apparently, these factors were accounted for in the population model.

Harp seal pups born at the Front are an important food for Davis Strait polar bears. This increase in the prey base for Davis Strait polar bears suggests the bear population may have grown substantially since the last survey in 2007 (Peacock et al. 2013; Rode et al. 2012). Davis Strai is the only subpopulation of polar bears officially considered to have ‘likely increased’ at 2018 by Environment Canada. A new Davis Strait population size survey was apparently completed in 2018 but the results are not yet available (Crockford 2020).

Harp seal pup_DFO Newfoundland

Highlights, quotes, and figures from the harp seal report below. Continue reading

Ringed and bearded seals, still listed as ‘threatened’, are still doing really well

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.

Ringed seal Barrow AK_Brendan Kelly

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.”

Quakenbush looking for ringed and bearded seals in Chukchi sea_11 Feb 2019 ADNRinged 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

Bearded Seal_25 Oct 2016_9th Circ. Backs Climate Predictions_The Guardian headline

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).

References

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 and Quakenbush_Wakefield Abstract_2013 Ringed Seal_predictions not met
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.

My Financial Post op-ed: Polar bears keep thriving even as global warming alarmists keep pretending they’re dying

One powerful polar bear fact is slowly rising above the message of looming catastrophe repeated endlessly by the media: More than 15,000 polar bears have not disappeared since 2005. Although the extent of the summer sea ice after 2006 dropped abruptly to levels not expected until 2050, the predicted 67-per-cent decline in polar bear numbers simply didn’t happen. Rather, global polar bear numbers have been stable or slightly improved.

lying-bear-shutterstock_244419640_cropped_web-size.jpg

The polar bear’s resilience should have meant the end of its use as a cherished icon of global warming doom, but it didn’t. The alarmism is not going away without a struggle. Continue reading

Svalbard polar bears thrive in part due to ringed seal pups in the spring pack ice

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-in-snow-cave_b-kelly-wikipedia

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.

barents-sea-ice-2017-feb-6_nis

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.

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Most polar bears easily deterred this time of year, lucky Labrador boaters discover

A polar bear female accompanied by a cub recently attempted to board a small sailboat anchored in a remote harbour off central Labrador – giving the two American boaters below deck a mighty big surprise.

Labrador polar bear encounter Torngat boat_CBC 30 Aug 2016

‘He said ‘it’s a bear, it’s right on the boat, make some noise.'” – Nancy Zydler

The encounter occurred south of the same national park where a much-publicized attack occurred in July 2013 (see previous posts here and here) but had a happier ending. See more below from a CBC report released this morning (based on a radio interview) and some ecological context for the sighting not mentioned by the reporter.
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Narwhal and beluga ice entrapment is natural – not caused by global warming

A part-time Arctic researcher eager for media attention suggested earlier today that the ice entrapment of narwhals in 2008 and again in 2015 at Pond Inlet (that made headlines around the world) was the result of “sudden changes in temperature” caused by climate change. This grossly misleading claim ignores the facts: ice entrapment of narwhals is an entirely natural feature of the Arctic that has been known about for hundreds of years.

Narwhals_at risk from climate change_CBC 13 Aug 2016 headline

Narwhals: the ‘giant unicorn of the sea’ at risk from climate change” (CBC, 13 August 2016), a print version of a CBC Radio interview with Clint Wright that aired 8 August 2016. Wright is the general manager at the Vancouver Aquarium and apparently has “joined a team of researchers to tag and study” narwhals for several years – but does not seem to know much about the history or circumstances of natural ice entrapment.

Ice entrapment of small whales is nothing new. The first formally documented incident – in English – occurred in 1915 (Porsild 1918) and the phenomenon has probably occurred as long as there has been ice in the Arctic (millions of years).

Animals routinely become trapped in a few specific areas due to local geography: when ice that forms in the north moves south quickly, it blocks the entrances to inlets or coastal bays that still have open water. The presence of the pack ice causes nearby  temperatures to drop quickly. Rapid development of ice on the bay proceeds from the mouth toward the head of the bay. Any whales present cannot escape to open water and will eventually die or be eaten.

Pond Inlet at the north end of Baffin Island is one such place but Disko Bay in western Greenland is another. In fact, Pond Inlet and Disko Bay are almost identical in geographic layout even though they lie on opposite sides of Baffin Bay, so it’s not surprising that both are locations of repeated entrapment events.

Three highly informative journal articles on the phenomenon of ice entrapment of narwhals and beluga are open access documents that reveal some fascinating details of such incidents, including polar bear predation on trapped whales. h/t T. Nelson Continue reading