Scientists who have studied and tracked the bears decided that they survive despite limited access to sea ice – crucial to polar bears – and instead use the freshwater ice provided by the Greenland ice cap.
Study lead author Christine Ledri, a polar research scientist at the University of Washington Applied Physics Laboratory, said in a statement.
“We knew there were some bears in the area from historical records and Aboriginal knowledge. We didn’t know how special they were.”
icy necessity
Traveling far away, the 19 known populations of polar bears rely on sea ice to hunt their prey, such as ringed seals, and perch near their breathing holes to capture their prey. The calories that seals provide can help them store energy for months when food and sea ice are scarcer.
Global warming is causing sea ice to melt and disappear rapidly as the Arctic warms more than twice as fast as the rest of the planet. When the sea ice disappears, polar bears must move on land, providing them with fewer opportunities for food.
Meanwhile, East Greenland Antarctic polar bears tend to stay close to home, so they have adapted to their environment in a unique way. Although isolated by the Greenland ice sheet, mountains, open waters, and fast-flowing coastal currents, polar bears have access to freshwater ice and some limited access to sea ice, which helps them hunt seals.
Bears can use sea ice between February and late May. For the rest of the year, they hunt seals using freshwater ice as it separates from the ice sheet.
“Polar bears are threatened by the loss of sea ice due to climate change,” said Leader, who is also an associate professor of marine biology and fisheries at the University of Washington. “This new collection gives us insight into how this species will persist in the future.”
“But we need to be careful about extrapolating our findings, because the glacial ice that makes it possible for southeast Greenland bears to survive is not available in most of the Arctic.”
The environment of Southeast Greenland is a unique small-scale, micro-climate haven where bears can survive, and similar habitats can be found along the coast of Greenland and the Norwegian island of Svalbard.
“These types of glaciers are found elsewhere in the Arctic, but the combination of fjord forms, high ice production and the very large reservoir of ice available from the Greenland ice sheet is what currently provides a steady supply of glacier ice,” said co-author In the study Twyla Moon, deputy principal scientist at the US National Snow and Ice Data Center in Boulder, Colorado, said in a statement.
“In a sense, these bears provide a glimpse into how Greenland bears might behave under future climate scenarios,” Ledri said. “Sea ice conditions in southeast Greenland today are similar to what was expected in northeast Greenland by the end of this century.”
air search
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 snow, and unpredictable weather, which makes studying difficult.
The research team spent two years consulting with subsistence hunters of polar bears, who are looking for survival, rather than sport, in eastern Greenland. Hunters were able to share their experiences and contribute samples for genetic analysis.
The researchers, working with the Greenland Institute of Natural Resources in Nuuk, Greenland, were able to study and track bears using helicopters as the researchers flew over sea ice, estimating that there were a few hundred bears living in the remote area. This is similar to other small groups of polar bears elsewhere.
Female polar bears in southeastern Greenland are much smaller than female polar bears in other regions. Smaller bears have fewer cubs too, which can be linked to trying to find mates as they travel in the surrounding fjords and mountains. But the researchers won’t know for sure unless they get more data from long-term monitoring of the bears.
Bears either travel over the ice within the fjords or climb mountains to reach the neighboring fjords. Of the 27 bears tracked during the study, half roamed 120 miles (190 kilometers) south on average, getting stuck on small ice rafts caught within a powerful East Greenland coastal current.
As soon as the bears had a chance, they just jumped out of the ice and returned to the fjord they call home. Created by glaciers, fjords are long, narrow, and deep sea inlets found between high cliffs.
“Even with rapid changes to the ice sheet, this area of Greenland has the potential to continue to produce glacial ice, with a coastline that may look similar today, for a long time,” Moon said.
However, the researchers cautioned that this habitat may not be sufficient for other polar bears suffering in the wake of the climate crisis.
“If you’re concerned about species conservation, then yes, our results are optimistic — I think they show us how some polar bears might survive under climate change,” Lieder said.
“But I don’t think the glacier habitat will support huge numbers of polar bears. There aren’t enough of them. We still expect to see significant declines in polar bears across the Arctic under climate change.”
uncertain future
Researchers believe that polar bears in southeastern Greenland evolved in isolation for several hundred years. The oldest known reference to bears at this site dates back to the 1300s, and the first written record of animals among the region’s fjords dates back to the 1830s, according to the study’s authors.
The status of polar bears is still unknown. Researchers don’t know if the population is stable, increasing, or declining, but further observation could reveal what the future holds for this unique group, Ledri said.
Because of their isolation, polar bears are so genetically distinct that researchers suggest that East Antarctic Greenland bears should be considered the 20th subpopulation of this species.
Ultimately, that decision is up to the International Union for Conservation of Nature, which helps with stewardship of the protected species. The Greenland government will make any decisions regarding bear protection.
“Conserving the genetic diversity of polar bears is critical to moving forward under climate change,” Lieder said. “Formal recognition of these bears as a separate group will be important for conservation and management.”
Meanwhile, sea ice continues to decline in the Arctic, drastically reducing future survival rates for most polar bear populations.
“Climate action is absolutely the most important thing for the future of polar bears,” Lieder said.