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A12 science
Friday 17 June 2022

Shaky oasis for some polar bears

found, but not for species

polar bears can as a spe-
cies hang on, where they
might persist."
The freshwater ice will keep
coming off the ice sheet
for centuries giving limited
hope that this is "a place
that polar bears might con-
tinue to survive'' but it's sep-
arate from an overall trend
of sea ice loss in the sum-
mer because of emissions
of heat-trapping gases
from the burning of coal, oil
Three adult polar bears walk in Southeast Greenland in April and natural gas, said Na-
2015 over sea ice during the limited time when it is available. tional Snow and Ice Data
Associated Press Center deputy lead scien-
tist Twila Moon, a study co-
By SETH BORENSTEIN the shrinking Greenland ice author. These bears hunt
AP Science Writer sheet as makeshift hunting on the fresh glacial ice that
With the polar bear species grounds, according to a has more peaks and val-
in a fight for survival be- study in Thursday's journal leys than the flatter sea ice,
cause of disappearing Arc- Science. However, scien- often in house- or car-sized
tic sea ice, a new distinct tists aren't sure if they are bergs, called bergy bits,
group of Greenland bears thriving because they are Moon said.
seem to have stumbled on smaller and have fewer This population of polar
an icy oasis that might al- cubs than other polar bear bears are on the south-
low a small remote popula- populations. east tip of the giant island,
tion to "hang on." "These polar bears are where there are no towns.
But it's far from "a life raft" adapted to living in an en- For years scientists figured
for the endangered spe- vironment that looks like these bears were part of
cies that has long been a the future," said study lead the same population in
symbol of climate change, author Kristin Laidre, a po- Northeast Greenland, just
scientists said. lar bear biologist at the Uni- roaming up and down the
A team of scientists tracked versity of Washington, who massive coast. But they
a group of a few hundred over nine years tracked, don't, Laidre said. An un-
polar bears in Southeast collared and tested the usual set up of winds, cur-
Greenland that they show all-white bears usually from rents and geographical
are genetically distinct and a helicopter hovering the features around 64 degrees
geographically separate white snow and ice back- North make it next to im-
from others, something drop. "But most bears in the possible for bears to move
not considered before. But Arctic don't have glacial north of that point, the cur-
what's really distinct is that ice. They don't have ac- rent sends them south fast,
these bears manage to sur- cess to this. So it can't be she said.
vive despite only having 100 taken out of context like While most bears travel 25
days a year when there's somehow this is like a life miles (40 kilometers) over
sea ice to hunt seals from. raft for polar bears around four days, the Southeast
Elsewhere in the world, po- the Arctic. It's not. Green- Greenland bears go about
lar bears need at least 180 land is unique." 6 miles (10 kilometers) in the
days, usually more, of sea "We project large declines same time, the study said.
ice for them to use as their of polar bears across the "They just stay in the same
hunting base. When there's Arctic and this study does place for years and years,"
no sea ice bears often not change that very im- Laidre said.
don't eat for months. portant message," Laidre Genetic testing Laidre and
With limited sea ice, which said. "What this study does colleagues did showed
is frozen ocean water, is show that we find this they are more different
these Southeast Greenland isolated group living in this from the neighboring pop-
polar bears use freshwater unique place... We're look- ulations than any other pair
icebergs spawned from ing at where in the Arctic of polar bear populations
on Earth, said study co-au-
thor Beth Shapiro, a Univer-
sity of California Santa Cruz
evolutionary geneticist.
Occasionally, a bear from
elsewhere breeds with the
southeast bear, but Shap-
iro said it's infrequent and
only one-way with no bear
heading north and breed-
ing with that population.q