ANCHORAGE (AP) — Seabird biologist David Irons drove recently to the Prince William Sound community of Whittier to check on a friend's boat and spotted white blobs along the tide line of the rocky Alaska beach. He thought they were patches of snow.

A closer look revealed that the white patches were emaciated common murres, one of North America's most abundant seabirds, washed ashore after apparently starving to death.

“It was pretty horrifying,” Irons said. “The live ones standing along the dead ones were even worse.”

Murre die-offs have occurred in previous winters but not in the...