The Arctic refuge is an important denning area for the Southern Beaufort Sea subpopulation of Polar Bears, one of the most threatened in the world.

Reduction in sea ice coverage, a result of rapid warming in the Arctic, has led to a sharp decline in the population, as it has become more difficult for the bears to reach seals and other food at sea.

IN the debate over the possibility of oil drilling in the Arctic National Wildlife Refuge in Alaska, polar bears play an important, if silent, role.

At issue is whether oil development. especially seismic testing to find oil reserves that would be conducted long before any drilling occurred, can be undertaken without harming the animals, which have been hard hit by climate change.

A new study casts doubt on the effectiveness of what is considered a state-of-the-art tool to help industry avoid injuring or disturbing polar bears by detecting their dens in the snow.

Over more than a decade on the North Slope of Alaska, the study found, oil companies located fewer than half the known dens of maternal bears and their infant cubs, using airborne instruments called forward-looking infrared, or FLIR, cameras.

''We wanted to make sure we throw up a cautionary flag,'' said Tom Smith, a wildlife ecologist at Brigham Young University and the lead author of the study, which was published last month in the journal PLOS ONE.

The oil industry needs to acknowledge that even with the best conditions, you're going to miss bears,'' added Dr. Smith, who is also a scientific adviser to Polar Bears International, a conservation group that provided some of the funding for the study.

Pregnant polar bears dig dens in snow late in the year and emerge with their cubs the following spring.

Undetected dens could be disturbed or even crushed during a seismic survey, in which large trucks traverse the land in a grid pattern, accompanied by movable supply depots and camps for workers.

On the North Slope of Alaska, where oil drilling has been conducted since the 1970s seismic surveys are allowed only in winter when there is enough snow to protect the delicate Arctic tundra.

FLIR cameras, which are carried by airplanes or helicopters, can detect heat under the snow. But Dr. Smith said weather conditions have to be just right - not much wind and little moisture - for the camera to get good readings.

Other factors, like too much snow cover, can also cause the cam,eras to miss dens.

''If the snow overlying the den is more than a meter thick, FLIR is not going to see it,'' Dr. Smith said. ''The heat fritters away away in the snowbank.''

Detection sis likely to become more difficult as the Arctic continues to warm under climate change , as warmer air contains more heat-scattering moisture.

Using industry reports FLIR surveys from 2004-2016 and comparing them with on-the-ground documentation of dens across North Slope, the researchers found that only 45 percent of the 33 dens were located by FLIR cameras.

The survey also produced a number of false positives, because sources like exposed soil and rocks or even discarded steel drums can radiate heat that might be interpreted as signs of a den.

The honor and serving of the latest operational research on imperiled species, continues. The World Students Society thanks author Henry Fountain.


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