Polar Bear Extinction Is Imminent in Hudson Bay

The hyper-carnivorous polar bear (Ursus maritimus) evolved as a distinct species approximately 150,000 years ago, with specialized characteristics optimized for the extreme conditions of the Arctic, including fat stores to keep them warm in temperatures below -50°F, and large furry feet with short tough claws to give them traction while hunting on ice. There is unfortunately not enough time for those left to evolve further to withstand how global heating has changed their homelands. Photo: U.S. Geological Survey/Public Domain

In late summer 2021, between August and September, a Canadian government survey conducted aerial surveys of the number of polar bears in the western Hudson Bay. What they found should be a warning shot for all those tracking the decline of many species across the world because of the climate crisis.

The search was conducted using helicopters and other low-flying aircraft. The total number of bears found during the survey was just 194, which the researchers involved know from experience is only a rough fraction of the total animal population present but still hidden in the forests and occasional snow pack shielding the others from view. It was on that basis that the real population of polar bears in the region was likely approximately 618.

That new total, just released, represents a 27% drop from a previous count of 842 made during a 2016 assessment of the same region.

The principal cause for the drop is all about global heating and its effect on Arctic sea ice.

As global temperatures have increased over the past 100 years, ocean and atmospheric warming everywhere has contributed to rapid melting of glaciers and ice at the poles, in Greenland, Arctic Siberia, and Himalayan Mountain range. Of these areas, studies published in late 2021 showed the Arctic has suffered perhaps the worst of all of these regions, with its warming trends thanks to the climate crisis having begun easily over a century ago.

It was also revealed in studies published this past summer that the rate of warming there was four times faster than the rest of the planet. That discovery was linked early on first to a higher-than-previously-understood jump in greenhouse gas releases in the 1980s. Later on scientists realized there were warming feedback loops unique to the Arctic at the sea-ice and water-vapor interfaces which compounded the warming effects.

The increased rate of warming has also contributed to earlier spring melts in the Arctic ice, and extended periods into September and beyond with very little ice in what used to be a more perennially-frozen north. In October 2020, for example, it was reported that the total extent of Arctic sea ice had then shrunk to its second lowest level in history for this late in the season.

With polar bears being the largest carnivorous mammal on the planet and depending so heavily on the presence of sea ice for their hunting, the overall shrinking of the amount of Arctic sea ice,  and the shortened calendar year period where it is present in the largest quantities have had increasingly serious impacts on the ecosystems which the polar bear depends on to eat. The shrinking thickness of the sea ice also creates additional limitations as to how far into the ocean regions polar bears can forage for food.

A polar bear walking in a storm along the Beaufort Sea coast with storm waves breaking behind it, filmed during fieldwork at Barter Island, Alaska. Image source: U.S. Geological Survey

Another factor directly affecting the polar bear populations is the rapid acidification of the oceans in recent years, as more carbon dioxide is absorbed at their surfaces. This, like the heating process in the same region, is happening in the Arctic at a rate 4X that of the rate of acidification change in oceans in the rest of the world.

The acidification affects the entire marine food chain, which cuts back on what the polar bears can eat. This is understood to be behind the decline in seal populations which the bears feed on as an important staple.

The new Canadian government study also disclosed an additional serious discovery beyond just the overall decline in absolute numbers. After analysis comparing what they counted this time to what a previous 2011 population count had disclosed, the researchers found there had been “significant declines in the abundance of adult female and subadult bears between 2011 and 2021”. That suggests that, beyond the lack of food itself, something is killing off the young and adult females to breed successfully.

As to what that something might be, one on-the-ground investigation researchers reported on this fall shows that the females of 13 of the 19 global subpopulations of polar bears have been burning fat so fast – due to lack of sufficient food – that even when impregnated lack sufficient stores of fat to complete the pregnancies successfully. That comes from a parallel study of polar bears which was released just before this year’s UN COP27 Climate Change Conference.

It is also a possibility that as male hunter populations are forced to forage further away from the rest of the pack to find food is contributing to the need to burn existing fats in larger amounts than the species can tolerate.

The discovery of the 27% decline in population of the polar bears since 2016 to just 618 presents a terrifying comparison to information showing that there were around 1,200 of this species on the same western shores of Hudson Bay in the 1980s. That calculation came from a student published two years ago in the journal Nature Climate Change.

Map of the global extent of where polar bears are known to live in 2022. Photo: Public Domain

According to the most recent projections published by the conservation organization Polar Bears International, projections based on current rates of global heating show that extinction of polar bear populations in the Barents Sea and Southern Hudson Bay is “inevitable” by 2080 at the latest. In 7 populations — including the Western Hudson Bay where the latest Canadian count was conducted, East Greenland, Davis Strait, Southern Beaufort Sea, Foxe Basin, Chukchi Sea, and Kara Sea — extinction is “very likely” in the same time period. Extinction of other subpopulations is considered “likely” in Baffin Bay along the coast of Greenland, in the Northern Beaufort Sea above the Northwest Territories and the Yukon, and in the Laptev Sea just north of Siberia.

A parallel study by the International Union for the Conservation of Nature (IUCN), showed that polar bears, who evolved as a species to withstand temperatures as low as -45° C (-49° F), have already dropped in numbers to just 26,000. The IUCN, which has put the polar bear on its “Red List” of endangered species, also projects that the combination of global heating, lack of access to its conventional food sources, and scarce sea ice to live on and hunt from could cause overall populations to fall by 30% more by less than 30 years from now, just about everywhere.

Right-wing dismedia (disinformation media) continues to claim that polar bear populations are actually increasing and so the climate is not really changing and even it were, it is a good thing. The reality is that some local polar bear populations may seem to be increasing as bears congregate near humans in search of new food supplies, but overall polar populations are declining, just like almost every other mammal on Earth, except humans. 

At this point, no matter what humanity may choose to do regarding global heating and the reduction of carbon emissions, based on the current counts in Canada and other studies, by the end of the century the last polar bears will almost certainly be gone forever from the planet. The bigger question remaining is whether we can save ourselves from extinction as well.