Seabird die-off in Alaska

More than 1,600 sea bird carcasses washed onto Unalaska, Alaska shores last week in a mysterious die-off that scientists are scrambling to understand, reports the Anchorage Daily News.

Some say they may have died of hunger. Others say they’re smashing into boats. Maybe it’s both, some scientists say.

Several hundred black, gull-like shearwaters died after flying into a crab boat in Unalaska Bay, Forrest Bowers, a fisheries biologist for the state Department of Fish and Game in Unalaska, told the ADN.

The captain of the boat walked into Bowers’ office to report that a hail of shearwaters struck his boat for up to 30 minutes. The crew threw the dead and dying birds overboard, the captain said.

The captain reported that other boats were in the area and may also have been bombarded by the sea birds.

It’s happened before in Unalaska, but usually not in such big numbers, Bowers told the newspaper. Still, he said a massive death toll due to collision is not impossible.

But seabird authority David Irons of the U.S. Fish and Wildlife Service in Anchorage said starvation would be a far more likely cause for the deaths than a collision.

“They don’t normally run into ships,” Irons said.

Shearwaters are the most abundant bird out in the Bering Sea. The population is about nine million to 20 million birds, so they could be affected by a cyclical lack of food.