Federal scientists in Alaska are looking for the cause of a massive die-off of one of the Arctic's most abundant seabirds, the common murre (mur).

An estimated 8,000 murres were found dead last week off Whittier, a Prince William Sound community 60 miles south of Anchorage.

U.S. Geological Survey researcher John Piatt (PEE'-aht) says winter die-offs of common murres have occurred before but the number at Whittier is unprecedented.

Researchers say they appear to have starved to death. Laboratory tests have not found parasites or diseases in carcasses.

U.S. Fish and Wildlife biologist Kathy Kuletz says warming ocean surface temperatures may be affecting the forage fish that common murres feed on.

A 2008 agency study found that previous murre die-offs occurred when surface temperatures increased by a few degrees.

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