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(CNN) --
Scientists have documented the existence of an isolated, genetically distinctive population of polar bears living in southeastern Greenland.
Scientists determined that they survive despite having limited access to sea ice, something that is critical for polar bears, instead using freshwater ice supplied by the Greenland ice sheet.
The study describing the findings was published Thursday in the journal
Science
.
"We knew there were some bears in the area from historical records and indigenous knowledge. We just didn't know how special they were," said lead study author Kristin Laidre, of the University of Washington Applied Physics Laboratory. .
Fur Seals' Need for Ice
Away from this area, the 19 polar bear populations known so far rely on sea ice to hunt their prey, such as ringed seals, sitting near breathing holes to capture it.
The calories provided by the seals can help them store energy for the months when food and sea ice are scarcer.
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Global warming is causing sea ice to melt and disappear rapidly, while the Arctic is warming more than twice as much as the rest of the planet.
When the sea ice disappears, polar bears must move overland, giving them fewer opportunities to feed.
Three adult polar bears photographed in 2015
Meanwhile, the polar bears of southeastern Greenland tend to stay close to home, so they have adapted to their environment in a unique way.
Although isolated due to the Greenland Ice Sheet, mountains, open water, and fast-moving coastal currents, polar bears have access to freshwater ice and some limited access to sea ice, which helps them catch seals.
The bears can use the sea ice between February and the end of May.
The rest of the year, they hunt seals using freshwater ice as it breaks off the ice sheet.
"Polar bears are threatened by loss of sea ice due to climate change. This new population gives us insight into how the species might persist in the future," said Laidre, also an associate professor of aquatic and fisheries sciences at the University of Washington.
"But we need to be careful about extrapolating our findings, because the glacial ice that makes bear survival possible in southeastern Greenland is not available in most of the Arctic."
The environment of southeastern Greenland is a unique, small-scale climatic refuge 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 exist elsewhere in the Arctic, but the combination of fjord shapes, high glacial ice production and the large ice reservoir that is available from the Greenland Ice Sheet is what currently provides a steady supply of glacial ice," said study co-author Twila Moon, deputy senior scientist at the US National Snow and Ice Data Center in Boulder, Colorado.
aerial investigation
The researchers, working with the Greenland Institute of Natural Resources in Nuuk, were able to study and track the bears by flying over the sea ice in helicopters.
They estimate there are a few hundred bears living in the remote area, similar to other small populations in different areas.
Female polar bears in southeastern Greenland are smaller and also have fewer cubs, which could be related to an attempt to find a mate while roaming the surrounding fjords and mountains.
Bears travel across the ice of fjords or climb mountains to reach neighboring fjords.
Of the 27 bears tracked during the study, half of them accidentally floated an average of 120 miles south, stuck on small ice floes trapped within Greenland's strong East Coastal Current.
Once the bears had a chance, they jumped off the ice and headed back to the fjord they call home.
Fjords are long, narrow, deep sea inlets that lie between high cliffs.
The researchers warn, however, that this habitat may not be enough for other polar bears suffering from the consequences of the climate crisis.
"If you're worried about preserving the species, then yes, our findings are hopeful: I think they show us how some polar bears might persist under climate change," Laidre said.
"But I don't think glacial habitat is going to support large numbers of polar bears. There just aren't enough. We continue to expect to see large declines in polar bears across the Arctic from climate change."
An adult female polar bear and two one-year-old cubs walk on the ice of a snow-covered freshwater glacier in March 2015.
Uncertain future
Researchers believe that the polar bears of southeastern Greenland have evolved in isolation for several hundred years.
The earliest known reference to bears at this location dates back to the 1300s.
The status of polar bears remains unknown.
The researchers don't know if the population is stable, increasing or decreasing.
Due to their isolation, these polar bears are so genetically distinct that researchers propose they be considered the 20th subpopulation of the species.
Ultimately, that determination rests with the International Union for Conservation of Nature, which helps oversee protected species.
And the Greenland government will make any decisions regarding bear protection.