Tag Archives: Gulf of Boothia

Good news: Gulf of Boothia and M’Clintock Channel polar bear survey results

Final reports for two Canadian subpopulations reveal the number of polar bears in M’Clintock Channel has more than doubled since 2000 while Gulf of Boothia as remained about the same despite moderate declines in summer sea ice cover. All of the survey results were published online yesterday (16 November 2020) and I was alerted to the posting this morning via email by a Nunavut employee.

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Experts’ vision of an ice-free summer is already wrong & benefitting polar bears

Polar bear populations in most of the Canadian Arctic Archipelago (CAA) must be booming, as they are elsewhere. That’s because the ‘experts’ were even more wrong in their predictions of future sea ice conditions than most people realize: they expected the CAA would remain choked with ice during a ‘nearly ice-free’ summer driven by human-caused global warming.

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Wang and Overland 2012 fig 3b marked

Map presented by Wang and Overland (2012: Fig 3) shows what these experts thought a ‘nearly ice-free’ summer would look like, which they expected to occur by 2030 or so.

Look at the map from Wang and Overland (2012) above, which is what they thought a ‘nearly ice-free’ summer would look like in the year 2030 or so.

Wang and Overland used the same models used by USGS biologists to predict the future survival of polar bears based on habitat loss (Amstrup et al. 2007; Atwood et al. 2016; Durner et al. 2007, 2009). Note the thick ice in the CAA — what USGS experts call the ‘Archipelago’ sea ice ecoregion (denoted by white in the map), indicating ice about 1 metre thick (2-3 feet) — expected to remain at the height of summer in 2030.

[Earlier renditions of sea ice projections (e.g. ACIA 2005) show something similar. The second update of the ACIA released just yesterday (AMAP 2017, described here by the CBC) has prudently included no such firm predictions in their Summary for Policy Makers, just dire warnings of future catastrophe. But see the 2012 update.]

 

The problem is that ice in this region has been largely absent most summers since 2006, even though overall ice extent has been much more extensive than expected for a ‘nearly ice-free’ summer, as I show below.

This is not another “worse than we thought” moment (Amstrup et al. 2007) — this is sea ice models so wrong as to be useless: failed models used to inform future polar bear survival models that got the bears declared ‘threatened’ with extinction in the US in 2008 (Crockford 2017).

It also means polar bears are almost certainly doing much better than recent population counts indicate, since only one subpopulation out of the six in the CAA has recently been assessed. But since polar bear specialists have consistently underestimated the adaptability of this species and the resilience of the Arctic ecosystem to respond to changing conditions, it’s hard to take any of their hyperbole about the future of polar bears seriously. Continue reading

Inuit resist government requests to tag and collar polar bears in MClintock Channel

Inuit residents of Cambridge Bay in the Central Canadian Arctic are resisting requests by the Nunavut Government to tranquilize, collar and tag polar bears to assist in their population survey.

“A female polar bear and her two cubs dash across the ice near Gjoa Haven, where the polar bear hunt has been limited for nearly 15 years. (PHOTO BY JANE GEORGE)” Story here, also by Jane George.

“A female polar bear and her two cubs dash across the ice near Gjoa Haven, where the polar bear hunt has been limited for nearly 15 years. (PHOTO BY JANE GEORGE)” Story here, also by Jane George.

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Beluga whales frolic in the High Arctic

Belugas at arcticwatch_with addressIt’s Thanksgiving weekend here in Canada. As a special treat, I thought I’d point you in the direction of a delightful bit of video footage of beluga whales.

If you haven’t seen this Arctic Watch Beluga Foundation clip already, it’s worth a few minutes. It’s footage of belugas and their calves frolicking in the shallow water of Cunningham Inlet, on Somerset Island, Nunavut (within the Lancaster Sound polar bear subpopulation, which is north of the Gulf of Boothia subpopulation region that I discussed previously here and here).

While I previously surmised that Gulf of Boothia polar bears might hunt beluga from remnant ice during the summer in years when the ice doesn’t totally melt (like they do in Hudson Bay, see belugas as food for hungry polar bears), it appears they also successfully hunt beluga in shallow waters like those found in Cunningham Inlet. But there is no hunting footage in this post.

Link and further info below, including a map and references on beluga, and polar bear predation on beluga in this region.

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Sea ice, beluga whales, and polar bear densities in the Gulf of Boothia

As I discussed in my last post, the Gulf of Boothia subpopulation in the central Canadian Arctic has the highest density of polar bears anywhere in the world. The question is, why?

For example, is the sea ice in the Gulf of Boothia region so markedly different from its nearest subpopulation-neighbor, M’Clintock Channel (Fig. 1), that it accounts for the wide disparity in polar bear densities between the two? The differences, remember, are dramatic: Gulf of Boothia, 18.3 bears per 1000 km2 vs. M’Clintock Channel, 1.9. And while M’Clintock Channel may be low in part due to recent over-harvests (see footnote 1), even the density before over-harvests occurred in M’Clintock Channel were only 4.7, compared to 10.4 bears per 1000 km2 in Gulf of Boothia (see Table 1 in previous post).

Today, I’ll take a look at sea ice and ringed seal habitat in the Gulf of Boothia and M’Clintock Channel, as well as information from a study on polar bear diets, which together shine some light on why the Gulf of Boothia is such a great place for polar bears.

Figure 1. Map showing the side-by-side relationship of M’Clintock Channel and the Gulf of Boothia. From Barber and Iacozza (2004: Fig. 1).

Figure 1. Map showing the side-by-side relationship of M’Clintock Channel and the Gulf of Boothia. From Barber and Iacozza (2004: Fig. 1).

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Gulf of Boothia, unheralded Arctic utopia, has the highest density of polar bears worldwide

The issue of polar bear population density (# of bears per 1000 km2) came up a few posts ago, during my discussion of the new Davis Strait population study by Lily Peacock and colleagues (here). Since the various polar bear subpopulations across the Arctic are so different in size, calculating the density of bears in the various regions generates an interesting metric of how well the regional populations are doing relative to each other.

Almost 20 years ago, Taylor and Lee (1995) did just that: they determined the density of polar bears in the various Canadian subpopulations, as of the 1990s. Surprisingly, the ‘leader’ among those, by a wide margin, was one of the smallest in geographic area: the Gulf of Boothia. Located in the central Canadian Arctic (see Figs. 1 and 2 below), in the 1990s, tiny Gulf of Boothia supported a density of 10.4 polar bears per 1000 km2, the highest density of all regions examined.

 Figure 1. The Gulf of Boothia (circled) is right in the middle of the Canadian Arctic. In terms of geographic area, it is one of the smallest of all 19 subpopulations worldwide: at only 170,000 km2, only the Norwegian Bay and Kane Basin subpopulation regions, also in Canada (just to the north of Gulf of Boothia), are smaller at 150,000 and 155,000 km2 respectively (Vongraven and Peacock 2011). The Gulf of Boothia supports the highest density of polar bears known.Modified from map of polar bear protected areas provided by Environment Canada.


Figure 1. The Gulf of Boothia (circled) is right in the middle of the Canadian Arctic. In terms of geographic area, it is one of the smallest of all 19 subpopulations worldwide: at only 170,000 km2, only the Norwegian Bay and Kane Basin subpopulation regions, also in Canada (just to the north of Gulf of Boothia), are smaller at 150,000 and 155,000 km2 respectively (Vongraven and Peacock 2011). The Gulf of Boothia supports the highest density of polar bears known. Modified from the map of polar bear protected areas provided by Environment Canada.

But this density value for Gulf of Boothia was based on the 1986 population estimate of 900 bears – what is the most current figure?

For that, we need an updated population assessment. That was done in 2000 and it generated an estimate of 1,592 ± 361 bears (Taylor et al. 2009).

Taylor et al. (2009:791) said this about their assessment:

Our results suggest population size had increased steadily under a harvest regimen of approximately 40 bears/yrand added, “Barber and Iacozza (2004) found no trends in Gulf of Boothia sea ice conditions or ringed seal habitat suitability indices in the interval 1980-2000.

In other words, despite there being no trend in either sea ice conditions or habitat for seals – and a yearly harvest of 40 bears – polar bear numbers in the Gulf of Boothia increased significantly (by almost 700 bears) during the twenty years between 1980 and 2000. Even if the 1986 estimate of approximately 900 bears was somewhat less accurate than the more recent one, the fact that tiny Gulf of Boothia can support 1,592 bears is surely a remarkable feat.

Using this new population estimate and the same area of ‘available habitat’ used by Taylor and Lee in 1995, I calculated the most recent density at a spectacular 18.3 bears per 1000 km2! [note this is exactly what Peacock et al (2013) did to get their density value of 5.1 bears/1000 km2, discussed here.] But I didn’t update just Gulf of Boothia, I did them all.

The updated density values for Gulf of Boothia and several other Canadian subpopulations are listed in Table 1 below. Note that aside from Davis Strait, as far as I know these density figures have not been published elsewhere: you’re seeing them here for the first time.

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