The ice breaking polar bear study

10.26.2009

Courtesy Story

U.S. Coast Guard Atlantic Area

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By Petty Officer 3rd Class Pamela Manns
U.S. Coast Guard District 11 Public Affairs

A man holding a rifle leans out of the flying helicopter and takes aim at a running polar bear. His tranquillizer dart hits the bear in the muscle between her shoulder blades. The bear slows her run, staggers, and collapses on the ground. Two more well placed shots sedate her cubs.

The helicopter lands and Eric Regehr, a biologist from U.S. Fish and Wildlife, accompanied by scientists from the U.S Geological Survey and University of Wyoming rush onto the slushy pack ice to begin research on the sleeping bear. They take vitals on the sleeping bear and her cubs and position them to begin their research.

"Scientists are going to use the data collected from the recaptured bears to analyze how ice loss is affecting these arctic creatures," said Dr. Merav Ben David, professor of Zoology at the University of Wyoming and lead scientist in charge of the mission.

The scientists needed a vessel capable of operating in the harsh and unforgiving Arctic and one that could break through the heavy ice to reach the bears. The National Science Foundation, which funded the trip, commissioned the Seattle-based U.S. Coast Guard Cutter Polar Sea, the most powerful non-nuclear icebreaker in the world, to conduct the first ever at sea polar bear study.

"Icebreaking is one of our core missions, and we perform the icebreaking to allow the researchers to perform the science," said Cmdr. Jason Hamilton, executive officer in charge of the Polar Sea.

"Scientists are going to use the data collected from the recaptured bears to analyze how ice loss is affecting these arctic creatures," said Ben David.

While the earth as a whole is getting warmer, this trend is more pronounced in Arctic regions, causing polar bears to lose their icy hunting grounds over the continental shelf. When spring temperatures melt the ice, the polar bears must choose to stay near shore, and search for food on land or follow the receding pack ice north to hunt for seals. "The bears we are trying to recapture were originally captured in the Southern Beaufort Sea in April and May of this year. This is the second year of a two-part study," said Regehr.

The cutter's crew picked up the scientists in Barrow, Alaska, Sept. 26, and polar bear mission sparked much excitement among the crew. "I am ecstatic to be apart of the science mission, it's the reason I joined the Coast Guard," said Seaman Berthena Meno, a Barrigada, Guam, native. Meno enlisted in the Coast Guard less than six months ago. This is her first mission aboard the ship, as well as, her first experience with harsh winter weather.

"I feel good knowing that I play a role in the conservation effort," said Meno.

The scientists and crew spent more than a week transiting through the Arctic Ocean seeking a bear on thick enough ice to land a helicopter and work on them.

"You need a pan of ice about the size of a football field to safely sedate a bear, and safely work on it," said Regehr. On Oct. 3 scientists found the first target bear of the trip. They sedated and processed the bear, yielding the first measurements of core-body temperatures of a free-ranging polar bear.

They collected weight information, took a sample of bear breath, extracted a tooth, and tattooed a number on its lip. They also conducted two field surgeries on the bear. The first was collecting a sample of muscle tissue and the second removed a temperature logger placed in the abdomen when the bear was previously captured in the spring.

"This is so exciting! For the first time we were be able to see if polar bears conserve energy by lowering body temperature during the ice free period," said John Whiteman who is working on his PhD at the University of Wyoming.

"In 2008, we captured and recaptured bears at the beginning and end of summer, but those bears stayed on land. This year we are doing the same thing but for bears that spent the summer on the multi-year pack ice as they retreated northwards toward the pole basin, and that is why we are on the Polar Sea," said Dr. Hank Harlow from the University of Wyoming and the second lead investigator on the project.

"A second team of U.S.G.S. and University of Wyoming biologists is again capturing those bears that remained on shore this summer," said George Durner, lead polar bear biologist from the U.S.G.S.

Because several bears have swum from shore to ice or from ice to shore, the two teams coordinate their efforts via satellite communications.

Nineteen bears were collared in the spring. Of those bears, four shook off their collars and two remained on shore, leaving13 bears for scientists to track, tranquilize, study, and release. The scientists prefer tagging female bears because they retain their collars better than males, who can easily shake them off because they have necks bigger than their heads.

In addition to those bears, the scientists will also collect samples from non-collared bears they come upon. Those bears also receive collars for later retrieval as well.

The scientists are working against time and must recapture the collard polar bears before Nov. 1, when a self-release mechanism will disconnect the transmitters.

When the scientists finish their field research on the bear, they collect their equipment and board the helicopter. The chopper flies back to the Polar Sea, where the scientists will conduct some tests on the samples they have collected. With the bears help, the scientists will gain a better understanding on how polar bears are adapting to the changing Arctic, and potentially understand how to protect future polar bears. This bear and her cubs will provide important data that will help the conservation effort to protect the polar bear. But right now the bear's main concern is the quest for food.