Polar bear walking on pack ice with water pond

Polar bears survived in Greenland despite no sea ice – EcoWatch

Few animals represent the face of the Arctic As Polar bears. The largest bears in the world, polar bears are excellent swimmers who spend more time at sea than on land. The sea ice is the platform from which they hunt the seals needed to obtain the calories necessary for their survival.

Now, scientists have found a subpopulation of polar bears in southeast Greenland that were able to survive by hunting using mostly freshwater ice that flows into the ocean from glaciers on the mainland. The isolated and genetically unique population could provide insight into the future of polar bears in a changing Arctic landscape.

The study of this rare subpopulation of polar bears, “Glacial ice supports a distinct and undocumented subpopulation of polar bears persisting in late 21st century sea ice conditions,” was published in the journal Science.

“We wanted to study this area because we didn’t know much about polar bears in southeast Greenland, but we didn’t expect to find a new subpopulation living there,” said a polar scientist. from the University of Washington Applied Physics Laboratory. Kristin Laidre, who was the lead author of the study, as reported by the University of Washington (UW). “We knew there were bears in the area based on historical records and Indigenous knowledge. We just didn’t know how special they were.

For the study, the researchers collected data from the southeast coast of Greenland and combined it with three decades of data from across the continent’s east coast. The area hadn’t received much attention from researchers due to its rugged terrain and extreme conditions, but the new data demonstrates the bears’ ability to survive using mostly glacier ice.

“Polar bears are threatened by the loss of sea ice due to climate change. This new population gives us insight into how the species might persist into the future,” Laidre said, as reported by UW. “But we have to be careful about extrapolating our findings, because the glacier ice that allows bears in southeast Greenland to survive is not available in most of the Arctic.”

Professor and geneticist at the University of California, Santa Cruz, Beth Shapiro, who was co-author of the study, said the population in southeast Greenland is the most genetically isolated in the world. The subpopulation lived apart from other polar bear populations for at least several hundred years, according to Shapiro. The subpopulation differs genetically from its closest genetic neighbor more than any of the other 19 documented populations of polar bears.

The bears have remained isolated as they are surrounded by mountains, water and the massive Greenland Ice Cap. According to satellite data, they also tend to be “homebodies”, spending most of their time in sheltered local fjords or neighboring fjords instead of traveling long distances through sea ice like most polar bears.

“I think they can teach us something about where rare and small numbers of polar bears might hang in a without ice Arctic,” Laidre said, as reported by The Guardian.

The researchers benefited from the knowledge of East Greenland subsistence hunters before and during the study, who provided them with samples to analyze.

Laidre said habitat conditions for the southeastern Greenland polar bear subpopulation are similar to what future terrain could be further north.

“In a sense, these bears provide insight into how Greenland bears might behave under future climate scenarios,” Laidre said, as reported by UW. “Sea ice conditions in southeast Greenland today resemble what is predicted for northeast Greenland by the end of this century.”

From February to the end of May, polar bears in southeast Greenland can access the sea ice, but for the rest of the year the bears hunt in portions of freshwater ice that have broken free from the Greenland ice cap.

This means glaciers that regularly calve into the ocean could become a lifeline for polar bears as sea ice shrinks due to climate change.

“Even with rapid changes to the ice sheet, this area of ​​Greenland has the potential to continue producing glacial ice, with a coast that could [look] like today, for a long time,” National Snow and Ice Data Center deputy chief scientist and study co-author Twila Moon said, as reported by UW.

However, Laidre added that the unique glacial habitat was not large enough for a large population of polar bears.

“If you are concerned about the preservation of the species, then yes, our findings are hopeful – I think they show us how some polar bears might persist under climate change,” Laidre commented, according to UW. “But I don’t think glacier habitat will support large numbers of polar bears. There just aren’t enough of them. We still expect to see a significant decline in polar bears in the Arctic due of climate change.

The southeastern Greenland polar bear subpopulation has been estimated by researchers at a few hundred bears, with smaller than average adult females with fewer cubs, which could suggest difficulties in finding bears. partners because of the difficult landscape.

“The low body condition and low birth rate reported in southeast Greenland suggest that this group of bears may already be living on the edge of persistence,” said Andrew Derocher, polar bear expert at the University of Alberta, which did not participate in the study. , as reported by The Guardian.

Recognizing polar bears in southeast Greenland as the world’s 20th unique population would help protect them, a move that would be made by the International Union for Conservation of Nature. Decisions regarding the management and protection of the species would be made by the government of Greenland.

“Preserving the genetic diversity of Polar bears is crucial to moving forward on climate change,” Laidre said, as reported by UW. “Official recognition of these bears as a distinct population will be important for conservation and management.”

#Polar #bears #survived #Greenland #sea #ice #EcoWatch

Leave a Comment

Your email address will not be published. Required fields are marked *