Stay Eat Events Weather Beaches

An Eyebrow-Raising Natural Litter on Oregon, Washington Coast: Crab Shells

Published 08/29/20 at 6:11 PM PDT
By Oregon Coast Beach Connection staff

An Eyebrow-Raising Natural Litter on Oregon, Washington Coast: Crab Shells

Latest Coastal Lodging News Alerts
In Seaside:
Includes exclusive listings; major specials now that winter is here
In Cannon Beach:
Includes rentals not listed anywhere else
In Manzanita, Wheeler, Rockaway Beach:
major specials for winter
In Pacific City, Oceanside:
Winter's enticing specials now
In Lincoln City:
Major winter specials now
In Depoe Bay, Gleneden Beach:
major specials this season
In Newport:
Look for many specials
In Waldport
New amenities offered; specials and tempting prices now
In Yachats, Florence
Big deals available; lodgings not listed anywhere else

(Waldport, Oregon) – During August along the Washington and Oregon coast, it’s been a common but slightly unnerving sight. Loads of crab “bodies” have been littering the beaches, as if there’s been some sort of mass die-off. (Photos courtesy Seaside Aquarium)

Nope, say experts: it’s simply a natural occurrence that happens twice a year along these beaches. Those aren’t dead crabs you’re seeing everywhere, they’re discarded crab shells. You may be seeing other body parts of crabs lying around as well, and it’s all part of a cycle crabs go through every summer.

In early summer, you’ll see lots of them from female crabs. In and around August it’s the males that molt, leaving behind their shells as they outgrow them.

Science calls it crab exuvia, and it’s startling to many, according to Oregon Department of Fish and Wildlife (ODFW).

“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.

This time around there doesn’t appear to be many reports, not as much as usual. Even CoastWatch – a volunteer group that keeps an eye on beaches – has only one recent report of the crab shells scattered around. That was near Waldport.

These are the famed and yummy Dungeness crab. But before you let your stomach start to growl over this, there’s no meat in there. The actual crab itself has left the building and skittered off to hide in the sand.

ODFW’s descriptions of this sound like a monster movie: crabs will lose large chunks of their bodies. Antennae, old gills, chunks of legs and even parts of the mouth fall off. This is what’s called a “whole exuvia.”

Ocean currents simply wash the bits ashore via an upwelling – which is where colder water from down deep rises to the top, bringing all sorts of stuff with it.

“Every detail is there except the crab,” ODFW said. “In summer months, when Dungeness crab molting activity peaks, ODFW usually receives calls reporting 'many dead crab on the beach' which are almost always these molts.”

Tiffany Boothe, with Seaside Aquarium, said some people don’t immediately take to this explanation because they think it doesn’t explain all the legs washing up – but it does. Those parts of the exoskeletons come off as well.

“If you break open the legs and it’s empty, it’s a molt,” Boothe said. “If you break it open and there’s meat in there, it’s a dead crab.”

When Dungeness crab reach a certain age, they start growing new shells underneath the old one, which soon loosens it. Water starts to build up between the two and the first shell falls off. For awhile, the newly-molted crab is a bit defenseless without its exoskeleton and it hides in the sands to keep away from predators.

By December they have started to fill out their new shells, and this is when crabs have their juiciest meat. It’s really the best time to catch crab along the Washington or Oregon coast. (More photos below, all courtesy Seaside Aquarium)

Oregon Coast Hotels in this area - Where to eat - Maps - Virtual Tours

More About Oregon Coast hotels, lodging.....

More About Oregon Coast Restaurants, Dining.....


Oregon Coast event or adventure you can't miss


Coastal Spotlight

LATEST Related Oregon Coast Articles

Fiery Scottish / Irish Christmas Show Comes to South Oregon Coast's Coos Bay
A sizzling blend of Celtic cultures in music happens Dec 16. South coast events
Central Oregon Coast's Florence Holiday Festival Expands, with Gnomes, Lighte...
December 3: new additions to the festival, one starts Black Friday. Florence events
Spectacular Geminid Meteor Showers Coming to Oregon Coast, Washington Coast
Perfect conditions may yield as many as 120 fireballs per hour
South Oregon Coast's Hughes House Christmas Returns to Port Orford
Christmas Tea on Dec 17, 18 - Tours Dec 22, 23 and 26. South coast events
Recreational Crabbing Banned on South Oregon Coast; Commercial Season Delayed
The marine toxin domoic acid is high in crab. Weather
Small Quake Rattles Off South Oregon Coast, 112 Miles from Bandon
It struck off Friday morning, clocking in at a magnitude 4.5. Geology
Get Ready for Wild(ish?) King Tides on Oregon Coast, Washington Coast
First round starts November 24 - 26, and it may or not be big. Weather
Two Little Ghost Towns on S. Oregon Coast Near Bandon: History of Prosper, Ra...
At one time, they were bustling ports, filled with workers, ships

Back to Oregon Coast

Contact Advertise on
All Content, unless otherwise attributed, copyright Unauthorized use or publication is not permitted

Oregon Coast Lodging


Events Calendar

Oregon Coast Weather

Travel News

Search for Oregon Coast Subjects, Articles

Virtual Tours, Maps
Deep Details