Washington’s Department of Health closed some shellfish beds in South Puget Sound Wednesday for the first time because of elevated levels of diarrhetic shellfish toxin.
The biotoxin, which can cause diarrhea and vomiting, appears to be spreading in Puget Sound.
It made three people sick after eating mussels harvested in Sequim Bay in 2011.
That was the first time anyone had been officially diagnosed with diarrhetic shellfish poisoning in the United States.
The Washington Department of Health’s Jerry Borchert oversees the monitoring and shellfish bed closures. He works at the department’s lab in Shoreline, where testing Wednesday of mussels from Budd Inlet near Olympia determined they had elevated levels of the toxins that cause diarrhetic shellfish poisoning.
“It’ll be the first area in the south part of Puget Sound where we’ve had a DSP closure,” Borchert said. “And what worries me is, is this the only one or might there be more?”
The southern part of Puget Sound is a big shellfish farming area.
DSP and other forms of shellfish poisoning is caused when certain types of algal blooms release a toxin that then gets sucked up by filter feeders like mussels and clams.
The blooms occur naturally and are strongest in the summer and early fall, though scientists don’t fully understand what makes the algae release the toxin.
This week the Department of Health has closed shellfish beds in San Juan, Thurston, King and Jefferson counties because of elevated levels of paralytic and diarrhetic shellfish toxins.
And just a reminder, cooking or freezing shellfish won’t get rid of the toxins.
For more information go to the Department of Health’s website.