How Climate Change Might Affect Polar Bears’ Bodies

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You unequivocally are what we eat. That’s a taking-off indicate for a new frigid bear study, conducted by U.S. Geological Survey researchers with an support from a Oregon Zoo — and published this week in a biography Physiological and Biochemical Zoology.

As sea ice shifts in a Arctic, scientists have remarkable a analogous change in frigid bears’ diets. In Western Hudson Bay, for example, sea-ice detriment has been compared with declines in a expenditure of benthic-feeding prey, such as bearded seals. In East Greenland, frigid bears have increasing expenditure of hooded seals and decreased expenditure of their some-more standard prey, ringed seals.

The grade to that these forms of changes are common via frigid bear populations, and their implications on bear health, are not good understood. To establish either bears are changing their diet in these remote Arctic regions, scientists are entertainment baseline information from a integrate of animals closer to home — Tasul and Conrad, dual proprietor frigid bears during a Oregon Zoo.

“Science can infrequently be a delayed process,” pronounced Amy Cutting, who oversees a zoo’s North America and sea life areas. “And meridian change is function rapidly. Anything we can do to fast benefit information about how frigid bears respond will assistance managers make vicious decisions for safeguarding them in a wild.”

Using a accessible chemical apparatus called “stable isotopes” — that embody a CO and nitrogen atoms that exist in each vital thing — researchers from a U.S. Geological Survey are divulgence how frigid bears, that now exaggerate a highest-fat diets of all a animal kingdom, routine opposite forms of meals.

“This new apparatus is permitting us to use hair and blood samples to learn either frigid bear diets have altered given a ’80s, when we began gripping records,” pronounced Dr. Karyn Rode, a USGS wildlife biologist who led a study.

This is possible, Rode says, since when a frigid bear cooking a dish of seal, whale or walrus, it takes on that organism’s isotope bucket as well.

These chemical markers can afterwards be rescued in a bears’ possess hankie samples, such as their blood or hair, that grows during a predicted rate and reveals a bear’s past “dietary signature” — or what and where their dishes were eaten, she says.

But it’s not utterly that simple.

“It’s not only that a 50 percent salmon diet shows adult as 50 percent salmon in a body,” Rode said. “Some gets routed toward physique fat, some gets stored and some is remade directly to energy. we need to know how a bear physique processes food before we can know how opposite diets might impact them.” 

During information collection, a zoo bears participated in what zoo staff dubbed a “surf and turf” examination — switching between sea and human foods. By comparing this new information to USGS repository samples from a Chukchi and Southern Beaufort Sea bear populations over a past 25 years, Rode and her group might exhibit a effects of this new dish farrago on frigid bears.

“We’re anticipating to investigate their diets over time to explain intensity changes in apparatus use as a outcome of climate-related changes in this supportive Arctic ecosystem,” pronounced USGS investigate biologist Craig Stricker.

This project, conducted by a USGS Polar Bear Team, is partial of a USGS’s Changing Arctic Ecosystems investigate on a effects of meridian change on frigid bears.

Source: USGS