Oregon Coast Questions Answered: Why So Many Dead Crab Shells?

Posted by The Oregon Coast / November 15, 2013

Molting CrabsFinding huge piles of crab shells on the beach? Are you wondering what’s killing off all the crabs all of a sudden?

It’s actually one of the more frequently asked questions to Oregon coast experts.

If you’re walking along the Oregon coast in the late summer or in the spring your chances of spotting this spectacle are pretty good. But they’re not a mass die-off of dead crabs at all. It’s just that crab tend to molt all at the same time.

The females molt in the spring and the males do this in late summer. This tends to happen all at once, creating masses of crab shells littered on your favorite Oregon coast beach.

Scientists call it crab exuvia.

“It can look like a major disaster occurred to the crab population, but it’s as natural as kids outgrowing their old shoes,” ODFW said.

Molting Crabs (2)

You can tell the difference between a shell from a molt and a dead crab by looking at the molt line.

 
To read the entire story on Oregon Coast Beach Connection, click here.
Story by BeachConnection.net. Photos courtesy of the Seaside Aquarium.
 
 
Leave a Comment Share This

Advertisement