Saturday, January 22, 2011

Melting Arctic ice means loss of wildlife habitat

The female polar bear swam 370 nautical miles for nine days through the open water in the Beaufort Sea. After that, she alternately swam and walked on sea ice for another 970 miles.
By the time the bear returned to the coast near Kaktovik, she had lost her cub and about 22 percent of her weight. Her travails were recorded by scientists who captured the bear after her August-October 2008 journey and published their findings in a peer-reviewed journal in December.
The journey to find food in the Arctic will only get worse for Alaska's polar bears if global temperatures continue rising - as the world's leading climate scientists predict they will. With summer sea ice-pack projected to decline more severely in coming years, polar bears will have even more trouble hunting for seals and feeding their cubs. It's unlikely that the bears will find an alternate food supply on land, scientists. This is why the bears were listed as a federal threatened species several years ago.
This year, the U.S. Fish & Wildlife Service is trying to devise a plan to "recover" Alaska's polar bears, as required by the Endangered Species Act. But given the ongoing global debate and lack of progress on controlling global warming, many people are curious exactly how the agency is going to do that. "Without addressing greenhouse gas emissions, there is very little you can do," said Steven Amstrup, a longtime Alaska polar bear biologist who has been studying the Beaufort Sea's bears for several decades.
The Fish & Wildlife Service hosted a major meeting in downtown Anchorage on Friday to brainstorm ideas that could be used in a polar bear recovery plan. The event drew a few dozen academic, federal, non-profit and oil-industry biologists from Alaska and the Lower 48.
One thing was clear on Friday: the Fish & Wildlife Service wanted ideas other than limiting greenhouse gas emissions to help polar bears.
But that didn't keep some people from stressing the need to address greenhouse gas emissions. Some jokingly called it the elephant in the room.
Two years ago, when George W. Bush administration listed polar bears as a threatened species, it stressed that the law shouldn't be "abused to make global warming policies." It's not clear yet how the Obama administration will deal with greenhouse gas emissions and polar bears.
Fish & Wildlife Service polar bear biologist Jim Wilder pointed out that his agency has no jurisdiction over greenhouse gases.
Alaska polar bears prefer to hunt for their main prey - ringed and bearded seals - in offshore waters of the continental shelf. The seals spend most of their lives on or near the sea ice. But as ice recedes, it's harder for bears to reach the seals in the summer, especially for mothers and their cubs emerging from onshore dens.
Recent studies show that reduced summer ice cover corresponds to a decreased size of cubs and growing bears, and a lower survival rate for female adult bears and cubs, according to Karyn Rode, an agency scientist.
The agency said Friday that its data show polar bear numbers have declined in the Beaufort over the past 26 years.
The agency is at least two years away from publishing a population count for the less-studied polar bears of the Chukchi Sea. However, based on limited data so far, it appears that the number of Chukchi bears is holding steady, it said.
Coming up with ideas other than controlling greenhouse gases to help polar bears may seem futile, but it isn't a waste of time, some scientists said.
More polar bears are coming on shore to look for food. More people are pushing into polar bears' sea-ice habitat to look for oil and other valuable resources. Many participants in Friday's workshop offered ideas to help stave off problems arising from those increasing interactions. Their ideas ranged from warning villagers and drilling companies not to disturb polar bear dens to figuring out a new way to handle the bone piles that accumulate after subsistence whale hunts in North Slope villages. Polar bears often gorge on the bone piles.
Amstrup, who used to work for the U.S. Geological Survey and now works for Polar Bears International, a conservation group, said hunting for polar bears may need to be curtailed in areas where the population is now declining. That may not be necessary in areas where the population is holding steady, he said.
The Fish & Wildlife Service plans to hold a Feb. 8 public meeting in Anchorage during the Alaska Forum on the Environment to gather more input on how to address polar bear losses from hunting and other human activity. Additional meetings will be held throughout the year.
The agency said it hopes to publish a draft recovery plan for public comment next January.

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