article_snippet: The number is almost five times higher than the 250 pups which would usually be expected in the key monitoring period between January and April - and no one knows why.
article_snippet: For rescue centers like Pacific Marine Mammal, that translates into round-the-clock, back-breaking work for dozens of volunteers who've arrived from all over the U.S. to help.
article_snippet: Volunteers have been arriving from all over the U.S. the U.S. to help with the escalating crisis.
highlights_snippet: Rising sea temperatures could be one cause of the surge in numbers .