Beaver Fever and Rotting Whale Blubber

Melting ice cellars and rotting whale meat, the arrival of beaver fever in a once-pristine land, and water supplies that might go dry are just a few of the health risks posed by climate change in the Arctic.

Now, in a newly released fifth report examining looming threats to villages, the Center for Climate and Health at the Alaska Native Tribal Health Consortium zeroes in on the Arctic Alaska village of Selawik, population 830, about 70 miles southeast of Kotzebue that's said to be sinking as permafrost thaws.

The Inupiat village has been called the "Venice of Northwest Alaska" because of the settling ground. Stairs to some houses no longer reach the ground. Shifting water pipes break more easily. And some homes tilt so much toilet bowls can't fill with water for flushing, forcing families to return to the old-fashioned honeybucket.

Sheefish threatened

The Inupiat community straddles both sides of the Selawik River, in a roadless coastal plane pitted with lakes. The village now experiences more rain and snowfall than it did five decades ago. Average monthly temperatures have risen during that period, including by 4 degrees in January, according to the report.

Threatening the village are sinkholes that have formed beside the river, sending landslides of silt, rock and gravel tumbling into spawning areas for sheefish -- an animal that plays a key role in subsistence diets in the region.

The sinkholes are thermokarsts formed when ice beneath the tundra vanishes. They produce scooped-out swaths of earth, making them a particularly visible effect of climate change. Legions of them have formed in the last decade, but the biggest one in North America emerged eight years ago about 175 miles upstream of the village.

Selawik Slump

The Selawik Slump, as it's called, is a massive pit in the ground possibly caused by the melting of "old, buried glacier ice," according to the Selawik National Wildlife Refuge. Up to 8 stories deep, its already grown to 9 square acres.

"It looks like a big asteroid hit the earth and made a crater," said James Beylund, Selawik's acting city administrator.

It's expected to keep growing, for years. The crater's steep headwall is steadily "marching" away from the river as chunks of ice and rock crash to the ground, said Lee Anne Ayres, manager of the Selawik National Wildlife Refuge.

"It's dramatic," she said. "There's constant running of water, rocks breaking off that headwall, chunks of ice falling down."

The headwall moves away from the river several feet each summer. It could expand for years: experts say it may until it reaches a ridge about a quarter-mile away.

All that sediment ends up in the river or near it, Ayres said. By mid-2011, the Slump had spilled 500,000 cubic meters of sediment and ice. That's about 50,000 dump truck loads.

Refuge scientists are working with others experts, including with the Alaska Department of Fish and Game, to learn if all that sediment has hurt sheefish reproduction. About 50,000 sheefish spawn in the river and winter in Kotzebue Sound, near the hub city. The Selawik River is one of only two spawning rivers for the region's sheefish, among the largest in the world and reaching up to 60 pounds.

"It's a pretty important fishery resource," said Ayres.

Researchers expect to see the first glimpse of the Slump's consequences this summer, when sheefish return to spawn.

"The first cohorts of fish are just starting to come back into the population, so this next year will really be revealing as to whether all the fish survive," she said.