A polar bear mom and cubs rest on the sea ice off the coast from the Arctic National Wildlife Refuge in Alaska, a key denning area for Southern Beaufort Sea polar bears.

© Dr. Steven Amstrup/Polar Bears International

10/8/2018 6:11:45 PM

Arctic National Wildlife Refuge Vital to Denning Polar Bears

By Dr. Steven C. Amstrup, Chief Scientist

A prime polar bear maternal denning area in the Coastal Plain of the Arctic National Wildlife Refuge could be disrupted by seismic testing if the Trump administration proceeds with a proposed oil exploration plan. Often called America’s Serengeti, the Arctic Refuge is essentially intact wilderness in northern Alaska. It’s known for its populations of caribou, muskoxen, and migratory birds, and for the number of female polar bears that give birth to cubs there.

I’ve studied the polar bears that den in this area for most of my career and am keenly aware of how important the Arctic Refuge is to their reproduction. Yet, if the Bureau of Land Management (BLM) approves a proposal by SAExploration, this vital habitat could be green-lighted for seismic exploration as early as this winter—with potentially dire consequences for an already threatened polar bear population.

Pregnant polar bears dig dens in snow drifts that form in autumn. They give birth in mid-winter and remain in their dens until spring when their cubs are finally large enough to survive the rigors of outside Arctic conditions. While denning, polar bears are unable to simply move away from a disturbance without substantial risk to newborn cubs.

The polar bears that den on the Arctic Refuge Coastal Plain are part of the Southern Beaufort Sea population. Due to global-warming-induced sea ice loss, the estimated size of this population has already declined to about half of what it was in the 1980s. Nearly one third of pregnant polar bears in the Southern Beaufort Sea population depend on the Coastal Plain to give birth to their cubs.

Polar bears are listed as a threatened species under the Endangered Species Act. The U.S. Fish and Wildlife Service has concluded that protecting denning bears is vital to population management and recovery and has designated the Arctic Refuge Coastal Plain as critical habitat for polar bears. Allowing seismic testing to go forward in this area would be inconsistent with the polar bear’s threatened status and with recovery objectives.

To date, the BLM has provided the public only with a seven-page summary of the seismic exploration proposal and a proposed plan of operations. It is unclear what other proposal documents BLM is reviewing, or whether BLM will make that information available for public comment.

As part of a joint effort between the Sierra Club and Polar Bears International, I reviewed the SAExploration proposal and produced a 20-page report highlighting the potential impacts of seismic testing on polar bear maternal dens and the bear families within. We submitted the report to BLM officials last month.

Because polar bear maternal dens are essentially invisible under the snow, SAExploration proposes using aircraft-mounted Forward-Looking Infrared (FLIR) imagery to detect dens before seismic surveys begin. FLIR surveys however, have an unacceptably low record of success in detecting those dens.

I led the original research testing the effectiveness of FLIR. My work highlighted the numerous limitations that compromise the ability of FLIR to detect polar bear dens.

Subsequent FLIR research has emphasized these limitations, and in 12 years of application by industry, FLIR surveys have detected only about half of the polar bear dens within the searched areas. 

Based on previous observations of polar bear response thresholds, the SAExploration seismic survey could disturb over 96 percent of denning habitat on the Coastal Plain. In addition, there is a 25 percent probability that heavy vehicles could drive right over one or more dens—with fatal consequences for mother polar bears and cubs. Even if a mother bear escaped before being crushed, young cubs are unlikely to do so.   

Existing data indicate that the seismic testing proposed by SAExploration is likely to reduce polar bear cub survival rates and possibly those of mother bears as well. Any decisions affecting the Coastal Plain of the Arctic Refuge must be based on science, and the science is clear: these proposed activities would pose an unacceptable risk to an already threatened polar bear population.

Dr. Steven C. Amstrup was Polar Bear Project Leader for the U.S. Geological Survey for 30 years, where he pioneered modern research techniques on polar bears in Alaska. Much of his research focused on maternal denning and verified the special significance of the Arctic Refuge coastal plain.

This piece originally appeared in The Hill.

 

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