Tag Archives: ringed seal

‘Threatened’ Arctic species comparison shows USA most assertive about global warming

A cross-Arctic comparison shows that the US has been the most aggressive in designating polar bears and their main prey species as ‘threatened with extinction’ due to the predicted effects of human-caused (“anthropogenic”) global warming (AGW), even though the US has the least amount of sea ice habit of all circumpolar nations.

Arctic marine mammals_Dec 31 2014_Polarbearscience

I’ve made a chart listing the conservation status of these species across all Arctic nations (Canada, Russia, Norway, Denmark (for Greenland) and the USA), as well as the one international body that considers the conservation status of all species (International Union for Conservation of Nature, IUCN).

Oddly, the IUCN considers the polar bear vulnerable due to future threats from predicted sea ice losses but not ringed seals or bearded seals. This situation highlights the capricious nature of the use of “future threats” (almost exclusively based on predictions of AGW) as a valid criteria for evaluating the conservation status of Arctic marine mammals. It also suggests why the IUCN has tightened considerably its rules regarding this practice.

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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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