The Washington state Department of Health and the Public Health division of Seattle and King County posted signs at the beaches in the area warning of the fatal Paralytic Shellfish Poison (PSP) discovered in the seafood.
PSP can be fatal if eaten and symptoms can begin immediately or within a few hours. Typically, they include tongue, lip, finger and toe tingling before potentially advancing to loss of limb control, difficulty breathing and nausea. In some instances, muscles paralysis and death can occur within 30 minutes, the Department of Health reports.
Washington authorities said the PSP has been discovered in clams, geoducks, scallops, mussels and oysters at the beaches.
State officials posted an interactive map of places where shellfish harvesting is prohibited.