Vashon Island beaches closed for shellfish harvesting: Paralytic shellfish poison found at unsafe levels

Paralytic shellfish poison (PSP) has been detected at unsafe levels on Vashon-Maury Island's Quartermaster Harbor beaches. As a result, the Washington State Department of Health (DOH) has closed these shores to recreational shellfish harvest. Working with partners, Public Health – Seattle & King County is posting advisory signs at beaches warning people to not collect shellfish.

This announcement applies only to recreation shellfish. Commercial shellfish harvesting sites are monitored separately.

What's the risk?

Anyone who eats PSP-contaminated shellfish is at risk for illness and death. PSP poisoning is caused by eating shellfish containing this potent neurotoxin. A naturally occurring marine organism produces the toxin. The toxin is not destroyed by cooking or freezing.

A person cannot determine if PSP toxin is present by visual inspection of the water or shellfish. For this reason, the term "red tide" is misleading and inaccurate. PSP can only be detected by laboratory testing.

Species of shellfish affected

The closure includes all species of shellfish including clams, geoduck, scallops, mussels, oysters, snails and other invertebrates; the closure does not include crab or shrimp. Crabmeat is not known to contain the PSP toxin, but the guts can contain unsafe levels. To be safe, clean crab thoroughly and discard the guts ("butter").

Symptoms

Symptoms of PSP usually begin 30-60 minutes after eating the contaminated shellfish but may take several hours. Symptoms are generally mild, and begin with numbness or tingling of the face, arms, and legs. This is followed by headache, dizziness, nausea, and loss of muscle coordination. Sometimes a floating sensation occurs. In cases of severe poisoning, muscle paralysis and respiratory failure occur, and in these cases death may occur in 2 to 25 hours.