“Pihoqahiak” means “ever-wandering one,” and is an Inuit title for the polar bear, a creature identified to roam huge expanses of sea ice, generally plodding 1000’s of kilometers a 12 months in the hunt for seals.
But alongside the fjord-cut shoreline of southeast Greenland, the place the ocean freezes over for just some months of the 12 months, some remoted polar bears are surviving as homebodies.
Unlike most polar bears, these bears don’t comply with the ocean ice throughout its annual recession or transfer onto land to hunt. Instead, the artful ursids stalk seals on close by glacial mélange — a floating mishmash of icebergs, sea ice fragments and snow that persists year-round close to the entrance of glaciers within the fjords, researchers report within the June 17 Science.
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“They’re residents in fjords that are sea ice–free for more than eight months of the year,” says Kristin Laidre, a biologist on the University of Washington in Seattle. “Normally, a polar bear wouldn’t be able to survive without sea ice for that long.”
For polar bears (Ursus maritimus), sea ice isn’t simply frozen seawater; it’s the platform they often use to hunt their most well-liked prey — seals. But as human-caused local weather change raises Earth’s world temperature, that ice is disappearing. The variety of polar bears that dwell on sea ice within the Beaufort Sea within the Arctic Ocean and Canada’s Hudson Bay is already declining. Researchers estimate that the majority different subpopulations of the bears will collapse by 2100 except greenhouse gasoline emissions are curbed. The International Union for Conservation of Nature classifies the species as “vulnerable.”
The fjords of southeast Greenland and related, restricted areas might change into a final, momentary refuge for a small variety of bears, although solely curbing local weather change can save the ice-dependent species, Laidre and her colleagues say. Glacial mélange isn’t widespread within the Arctic, and what exists might disappear if temperatures rise an excessive amount of.
Laidre and her colleagues estimate that a number of hundred bears could dwell within the fjords of southeast Greenland, although additional work is required to acquire a extra exact rely.
The southeast Greenland group got here to the researchers’ consideration whereas they had been learning polar bears alongside east Greenland’s coast to supply recommendation to the Indigenous peoples who hunt the bears for subsistence. An evaluation of 83 receiver-tagged polar bears from 1993 to 2021 revealed that, for essentially the most half, bears dwelling south of about 64° N latitude don’t work together with bears to the north, and vice versa.
Southeast Greenland bears could also be largely remoted by Greenland’s ice sheet to the west and a speedy present to the east, which might sweep seafaring bears south and stifle northward motion, the researchers say.
In northeast Greenland, the median distance traveled by tagged bears was 40 kilometers each 4 days. But within the southeast area, the median distance traveled was simply 10 kilometers each 4 days, with bears generally touring between neighboring fjords and generally remaining in the identical fjord all 12 months.
“For a polar bear, that’s nothing,” says Steven Amstrup, a zoologist and chief scientist of the conservation group Polar Bears International, primarily based in Bozeman, Mont., who was not concerned within the examine. “Apparently they’re finding enough resources there that they don’t have to make these huge, big movements.”
Southeast Greenland bears hunted on sea ice when it was current throughout a couple of months in winter and spring, the researchers discovered. For the remainder of the 12 months, the ursids used the glacial mélange that packed the fjords as searching grounds.
“They use it just like sea ice,” Laidre says. “They’re able to walk [and hunt] on the mélange … and they can swim around between the pieces of ice and ambush seals.”
It’s not totally stunning that polar bears have settled on the fronts — or toes — of glaciers within the fjords, Amstrup says. “Oftentimes, the toes of these glaciers are very productive areas,” he says, as a result of glacial meltwater can flush vitamins from deeper within the ocean up towards the water’s floor. “You might expect that they would have seal populations [that] could support bears.”
The researchers additionally analyzed uncommon genetic variations within the southeast Greenland bears. That work revealed that the sampled animals shared a standard ancestor about 200 years in the past and have basically stored to themselves since. “They’re the most genetically isolated polar bears in the world,” Laidre says. Conserving the distinctive bears might be essential for shielding the species’ genetic variety, which is already low, she says.
But for all their peculiarity, even southeast Greenland polar bears will perish with out human local weather motion, Laidre and Amstrup agree (SN: 12/15/10). “Loss of Arctic sea ice is still the primary threat to all polar bears,” Laidre says. “This study does not change that.”