Federal scientists are opening an official investigation into what’s causing the spike in gray whale deaths in the Pacific Ocean, including along Alaska’s coast.
The National Oceanic and Atmospheric Administration announced Friday that the 70 dead whales seen this year constitutes an “unusual mortality event.”
The agency also announced that a dead gray whale was discovered this week in the Alaska Peninsula town of Chignik Bay. It’s the fifth one found in state waters this migratory season.
Scientists say many of the dead whales appear to be very skinny. That’s raising questions about whether global warming and reduced sea ice are affecting their feeding grounds in the Arctic, and their primary prey, shrimp-like creatures called amphipods.
But on a call with reporters, University of Washington oceanographer Sue Moore said the explanation is elusive.
“The Arctic is changing very, very quickly. And whales are going to have to adjust to that,” she said. “But gray whales are good at eating a variety of things. So it becomes a complex question very quickly.”
NOAA officials say it could takes months to years to assign a cause to the deaths.