Associated Press
SEATTLE (AP) – U.S. scientists will investigate why an unusual number of gray whales are washing up dead on West Coast beaches.

About 70 whales have been stranded so far this year on the coasts of California, Oregon, Washington and Alaska, the most since 2000. About five more have been found on British Columbia beaches.

NOAA Fisheries on Friday declared it an “unusual mortality event,” providing additional resources to respond to the deaths and triggering the investigation into the cause.

The agency says the population of the gray whales has grown significantly in the last decade and is now estimated at 27,000. They were removed from the endangered species list in 1994.

In 2000, more than 100 washed up. A similar investigation into those deaths failed to identify a cause.