Bear necessities: the climate science of Bearfest

Wrangell's annual Bearfest offers a unique opportunity each year for biologists, researchers, photographers and artists to come together for a common cause, and last week's event was no exception.

With an international climate conference set to meet in Paris this November, it seemed appropriate that this year's Bearfest lectures revolved around climate change and its anticipated effect on bears and other species.

Speakers were invited and an overall theme was arranged by Lance Craighead, a researcher and environmental advocate who heads the Craighead Institute. Speaking at the Wednesday symposium, he presented climate change from a United States policy perspective.

"A lot of the government agencies have come to understand the science of climate change and have begun to take it seriously," Craighead began. Across agencies, he explained "connectivity" has become a key focus in developing domestic policy.

While curbing greenhouse gas emissions may be one of the more widely known strategies for combatting anthropogenic climate change, Craighead said another aspect to consider is human-fragmented landscapes.

Climactic conditions are understood to have shifted substantially throughout Earth's history, but enduring species of all stripes have been able to migrate in response to these processes and adapt over time. Presently, habitats have become fractured and isolated by human development; highways, farms, mines and metropolitan areas have all contributed to this process at the same time habitats have been reduced. And this comes at a time when species have the highest need to move around in response to shifting climactic realities.

"That ability to move around is crucial to maintaining genetic variability," Craighead summarized.

Government agencies are undertaking initiatives to mitigate the problem of connectivity. These include the U.S. Forest Service's 2008 Strategic Framework for Responding to Climate Change, which among other things called for eliminating or modifying impediments to animal movement, which includes restoring habitat corridors and working with other agencies to improve migratory flow.

Similar concepts have become key components to the USFS forest plan revisions in 2012, the Interior Department's America's Great Outdoors Initiative, and the Western Governors Association's Corridor and Habitat Initiative. Even the Department of Transportation has begun taking animal connectivity into consideration as part of the 2012 Transportation Act.

Taking bears as an example, International Bear Association president Harry Reynolds explained the Gobi bear demonstrates what can befall a species' population when it becomes isolated and immobile.

A possibly distant relative to the North American brown bear, the smaller Gobi has lately been restricted to the arid southern plateaus of Mongolia by herding and mineral development. At present Reynolds said there may only be between 30 and 40 left.

The Gobi is a vegetarian species that relies on a tiny amount of rainfall each year-about four to five inches-to provide vegetation. However, precipitation amounts have dropped to scarcely an inch of rain in the past couple years. A dearth of food sources has pressed the bears to seek out carrion and other animals for sustenance.

Much further north in the Arctic, polar bears have been affected by an opposite water problem as ice coverage over the planet's northernmost ocean continues to shrink each year.

Speaking on these Arctic dwellers was Department of Wildlife Management biologist Andy Von Duyke, a polar bear specialist and the ice seal baseline study project coordinator for the department.

The polar bear is another species pegged into one place. Though its range is wide, stretching across Russia, Alaska and Canada, the loss of sea ice habitat bodes ill for the bear's future. Von Duyke explained polar bears are adapted to eat other marine creatures and cannot subsist on terrestrial diets alone.

The grizzly bear has proven more adaptable than other ursine species, and Von Duyke pointed out its range has actually widened as the polar bear's gradually recedes. But in Alaska primary food sources, such as salmon, are at risk as the habitats and water temperatures conducive to spawning are undermined.

The underlying point being made by Bearfest's speakers was that climate change will affect people, too-even in Wrangell.

"The future in Wrangell is going to be hotter," Craighead said, referring to a projection prepared by the United States Geological Survey.

While local temperatures may increase by about seven degrees over the next 50 years, he said rainfall may remain about as frequent. And while a rise in sea level may not greatly affect Wrangell the town, even a moderate rise could push the mouth of the Stikine River back toward the Canadian border.

Going forward, Craighead said the goal of addressing aggregated environmental impact id about more than protecting bears. It is about preserving quality of life and biodiversity in general.

Cooperative international initiatives are being undertaken as well, such as the Circumpolar Action Plan, which coordinates national plans for conserving polar bears between Norway, Canada, Russia, Greenland and the United States.

The 21st Session of the Conference of the Parties to the United Nations Framework Convention on Climate Change will be meeting this winter in Paris to reach consensus on how to reduce greenhouse gas emissions. The undertaking is huge: The agreement will go into effect in 2020 and will have to be sustainable to have lasting impact.

But if successful, the rewards may be great.

"Moderate improvements will have a significant effect," Von Duyke said. "There is hope. It will just take a unified effort."