A dead gray whale sits on the beach at Limantour Beach on May 23, 2019 in Point Reyes Station, California. There have been more than 171 gray whales deaths so far this year along the Pacific Coast. Justin Sullivan/Getty Images
Seven gray whales were found dead in Alaska over the weekend in the latest development in what the National Oceanic and Atmospheric Administration declared an “unusual mortality event.”
NOAA says gray whales have been dying at an unusually high rate in an area stretching from Alaska to Mexico. The agency’s latest numbers say 171 gray whales have died this year in Canada, the U.S. and Mexico. That tally does not include the seven whales recently found in Alaska.
NOAA in May declared the deaths an unusual mortality event, defined as a “stranding event that is unexpected, involved a significant die-off of any marine mammal population, and demands an immediate response.”
The agency is investigating the deaths, and examinations conducted on some of the dead whales suggest that they died of starvation, though NOAA said the findings were not consistent across all the mammals examined.
Gray whales migrate in the summer from warm waters near Mexico to the Arctic, where they feed.
Julie Speegle, an NOAA spokeswoman, told CNN scientists think the whales’ food source may have been disrupted because of a lack of Arctic sea ice last summer.
Gray whales were on the endangered species list until 1994 but now number about 27,000 in the North Pacific. The species previously experienced an unusual mortality event in 1999 and 2000.