The scientists who studied and tracked the bears determined that they survive despite having limited access to sea ice, which is critical for polar bears, and that they use freshwater ice supplied by bears. Greenland ice sheet.
“We wanted to study this region because we didn’t know much about polar bears in southeastern Greenland, but we never expected to find a new subpopulation there,” said study lead author Kristin Laidre, a polar research scientist at the University of Greenland. University of Applied Physics Laboratory of Washington, in a statement.
“We knew there were some bears in the area based on historical records and indigenous knowledge. We didn’t know how special they were.”
An icy need
Traveling far away, the 19 known polar bear populations depend on sea ice to hunt their prey, such as ringed seals, and sit near breathing holes to catch their prey. The calories provided by seals can help them store energy for months when food and sea ice are scarce.
Global warming is causing sea ice to melt and disappear rapidly as the Arctic warms more than twice as much as the rest of the planet. When sea ice disappears, polar bears have to move ashore, giving them fewer opportunities to eat.
Meanwhile, polar bears in southeast Greenland tend to stay close to home, so they have adapted to their environment in a unique way. Although isolated due to Greenland’s ice sheet, mountains, open water, and fast coastal currents, polar bears have access to freshwater ice and limited access to sea ice, which helps them. to catch seals.
Bears can use sea ice between February and late May. The rest of the year, they hunt seals using freshwater ice that moves away from the ice sheet.
“Polar bears are threatened by sea ice loss due to climate change. This new population gives us a glimpse of how the species could persist in the future,” said Laidre, also an associate professor of aquatic and fisheries sciences. the University of Washington.
“But we have to be careful when extrapolating our findings, because glacier ice that makes bear survival possible in south-eastern Greenland is not available in most of the Arctic.” .
The south-eastern environment of Greenland is a unique, small-scale climate refuge where bears can survive, and similar habitats can be found along the coast of Greenland and the Norwegian island of Svalbard.
“Such glaciers exist elsewhere in the Arctic, but the combination of the shapes of the fjords, the high ice production of the glacier and the large ice deposit available in the Greenland ice sheet is what provides a steady supply of glacier ice, “said study co-author Twila Moon, chief assistant scientist at the US National Snow and Ice Data Center in Boulder, Colorado, in a statement.
“In a way, these bears provide an insight into how Greenland bears may emerge in future climate scenarios,” Laidre said. “Sea ice conditions in south-east Greenland today are similar to those forecast for north-east Greenland by the end of this century.”
Aerial research
The new study consists of 30 years of historical data from the east coast of Greenland and seven years of new data from the southeast coast. The latter is a remote region with steep mountains, heavy snowfall and unpredictable weather, which makes it difficult to study.
The research team spent two years consulting with polar bear subsistence hunters, who hunt for survival, rather than doing sport, in eastern Greenland. Hunters were able to share their experience and provide samples for genetic analysis.
Researchers working with the Greenland Institute of Natural Resources in Nuuk, Greenland, were able to study and track bears by helicopter as researchers flew over sea ice, estimating that there are several hundred living bears. in the remote area. This is similar to other small polar bear populations elsewhere.
Polar bear females in south-eastern Greenland are smaller than polar bear females in other regions. Smaller bears also have fewer cubs, which could be related to trying to find a mate while roaming the surrounding fjords and mountains. But researchers won’t know for sure until they have more data on long-term bear tracking.
Bears travel on ice inside fjords or climb mountains to reach neighboring fjords. Of the 27 bears tracked during the study, half of them accidentally floated about 120 miles (190 kilometers) south on average, clinging to small ice banks trapped within the strong coastal current of East Greenland.
When the bears had a chance, they jumped off the ice and returned to the fjord they call home. Created by glaciers, fjords are long, narrow, deep sea entrances that lie between high cliffs.
“Even with the rapid changes in the ice sheet, this area of Greenland has the potential to continue to produce glacial ice, with a coastline that may seem similar to the present for a long time,” Moon said. .
Researchers warn, however, that this habitat may not be enough for other polar bears to suffer as a result of the climate crisis.
“If you’re concerned about preserving the species, then yes, our findings are encouraging: I think they show us how some polar bears could persist under climate change,” Laidre said.
“But I don’t think glacier habitat supports a large number of polar bears. That’s not enough. We still expect to see large declines in polar bears in the Arctic under climate change.”
Uncertain future
Researchers believe that polar bears in southeastern Greenland have evolved in isolation for several hundred years. According to the study’s authors, the first known reference to bears at this location dates back to the 1300s, and the first written record of animals in the region’s fjords dates back to the 1830s.
The state of the polar bears remains unknown. Researchers do not know if the population is stable, rising or falling, but further monitoring could reveal what the future holds for this unique population, Laidre said.
Due to their isolation, polar bears are so genetically different that researchers propose that polar bears in southeastern Greenland be considered the 20th subpopulation of the species.
Ultimately, this determination depends on the International Union for Conservation of Nature, which helps monitor protected species. And the government of Greenland will make any decision regarding the protection of bears.
“Preserving the genetic diversity of polar bears is crucial to climate change,” Laidre said. “Officially recognizing these bears as a separate population will be important for conservation and management.”
Meanwhile, sea ice continues to decline in the Arctic, greatly reducing the survival rates of most polar bear populations in the future.
“Climate action is the most important thing for the future of polar bears,” Laidre said.