State officials have closed beaches in West Seattle and Vashon Island to recreational shellfish harvesting, after detecting unsafe levels of a potentially deadly toxin in the marine animals, Public Health — Seattle & King County announced Friday. The closure applies to shellfish, including oysters, geoduck, mussels, clams and snails, but not to crab or shrimp.
Eating shellfish contaminated with the toxin causes paralytic shellfish poisoning, an illness that can lead to hospitalization or death.
Officials detected unsafe paralytic shellfish poison levels from the north point of Alki Beach all the way south to Dash Point State Park in Federal Way, according to the county. Beaches on Vashon-Maury Island’s eastern shores, including Quartermaster Harbor, also have unsafe levels of the toxin.
Specific closure zones are on the state health department’s regularly updated shellfish safety map.
The closures do not necessarily apply to commercial shellfish harvesting, which is monitored separately, according to the county public health department.
The recent closure expands a restriction announced Wednesday, which prohibited recreational shellfish harvesting from Quartermaster Harbor.
Current toxin levels are not unprecedented, and Quartermaster Harbor is known to be a “hot spot,” said Tracie Barry, a marine biotoxin specialist for the state Department of Health. But closures reaching West Seattle are “fairly unusual,” she said.
“The last time we had a toxic hit in the shellfish sample from North King County — that kind of includes Elliott Bay — was in 2012,” she said. “So it’s been quite some time, but it’s not entirely unexpected.”
In the county overall, the last “widespread closures” were in 2018, Barry said.
Paralytic shellfish poisoning symptoms usually start 30 to 60 minutes after eating the contaminated creatures, according to the county public health department. It generally begins with numbness or tingling in the face, arms and legs and can escalate to headaches, dizziness, nausea and loss of muscle coordination. Severe cases can cause muscle paralysis, respiratory failure and death.
There have been no confirmed cases of paralytic shellfish poisoning so far this year in Washington, a state Department of Health spokesperson said. Numerous counties have seen paralytic shellfish poisoning closures in the past two weeks, but paralytic toxins and toxic algal blooms haven’t reached their peak, Barry said. That normally comes in late August to September.
Last summer, the U.S. Food and Drug Administration warned of dangerously high toxin levels in shellfish from the Oregon and Washington coasts.
Barry urged people to check the shellfish safety map and to take paralytic shellfish poisoning closures seriously.
“All it takes is one, depending on how toxic the shellfish are,” she said. “It’s very real, very serious.”
