But now, after first declaring an "unusual mortality event" or UME back in 2019, scientists believe it's finally over.
"I wasn't surprised by the closure because we've been collecting the data and we've been involved in all the meetings discussing the decline and then the stabilization of the population," said Moe Flannery.
Some of the images in this story could be disturbing to some viewers
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Flannery works with the California Academy of Sciences and was one of the local scientists who would do necropsies on dead whales that washed ashore.
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Moe and her partners at the Marine Mammal Center say they think climate change was one of the main reasons driving the UME.
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"In the arctic where there's been all this change in the amount of ice coverage and warming there, it looks like it's affected their food supply," said The Marine Mammal Center's Bill Keener.
Researchers think with less food available for the whales in their normal feeding grounds, many didn't have the strength to make their annual migration and ultimately died.
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Recently, though, they say the whales have adapted.
"We saw for the first time, gray whales switching their prey and feeding on fish," Kenner said.
The UME may be over but local experts say there are still risks to the gray whale population. They tell us things like ship strikes remain a real and dangerous threat to the creatures.
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Beyond ship strikes, scientists say the risk of the UME reoccurring is also a possibility.
That's why they'll continue to monitor the animals and be on high alert for any changes.
"We've moved from the unusual mortality event to a post UME, or a post unusual mortality event monitoring phase. So the high numbers have decreased but we will likely still see dead animals," Flannery said.