Jumbo flying squid are beaching themselves on a California beach and scientists do not know why.
The Humboldt squid, as it is also known, has been showing up on beaches up and down Monterey Bay for about two months. And, beginning Sunday, hundreds of the creatures began piling onto an area of coast at Rio Del Mar, near Aptos, California at the north end of the bay.
Researchers say the Humboldt hasn't been spotted in the bay since 2010 until this year. The creatures are more commonly found much further south near the Baja peninsula and not in more shallow waters, like those found in a bay.
According to Hannah Rosen, a graduate student at Stanford University who studies squid at the Hopkins Marine Station in Pacific Grove, the animals aren't normally found anywhere near the beach.
"They primarily live in the open ocean. They don't normally encounter the coast during their lifecycle," Rosen told ABCnews.com.
Also puzzling is the size of the squid. Adult Humboldt can grow to nearly six feet in length and weigh almost 100 pounds, but these squid are smaller.
"All these are juveniles," Rosen said.
And though the squid themselves are small, probably no longer than a foot and a half on average, the beaching is a big deal.
"It's pretty big compared to other beachings," Rosen said, "They usually only last a couple of weeks."
No one can say for sure what has made the squid throw themselves onto the beach in such numbers, but there are some theories. It is possible the squid ingested a type of red algae that secrets neurotoxins, causing the squid to lose control and swim where they normally would not. Rosen said the beaching could also be the result of confusion caused by the unknown surroundings of the bay.
"It's possible something drove them here, and they just didn't know when to stop," she said.
Aiding the Hopkins Marine Station in solving this mystery is the California Department of Fish and Game. They've stepped in to examine the stomach contents of the squid and test for other possible causes, like man-made pollutants.
Whatever the cause, Rosen said the squid are the only creatures being affected, at least in a negative way. It seems that much of the coastal ecosystem is benefitting from the unexpected calamari feast.
"Seagulls are really on top of it," Rosen laughed. "I've seen hermit crabs and snails eating the squid. So much of the intertidal zone is benefitting from this."