Due to the growing presence of a marine biotoxin, shellfish harvesting is closed throughout Skagit County.

Skagit County Public Health announced Thursday a closure to recreational shellfish harvesting due to potentially dangerous levels of the biotoxin found in shellfish samples taken from area beaches.

On Wednesday, the state Department of Health closed all commercial shellfish harvesting in Samish Bay. The commercial harvesting of geoduck clams has been closed since the last week of July.

The biotoxin is produced by a type of algae found in marine water and that tends to bloom in the region during the summer.

When consumed the biotoxin can cause paralytic shellfish poisoning that affects the central nervous system.

The closure applies to all clams, oysters, mussels and scallops, according to a Skagit County news release.


While the closure does not apply to crab because the biotoxin does not affect the meat, it can accumulate in what’s called crab butter, which should be discarded while the biotoxin is known to be present.

How long the recreational and commercial closures last will depend on the presence of the biotoxin in ongoing shellfish sampling.

“Harvest will remain closed until testing shows that (the) marine biotoxin is no longer at a level of public health concern,” the release states.