A life-threatening poison affecting shellfish has reached Grays Harbor.

Paralytic Shellfish Poison (PSP,) formerly known as “Red tide,” has been detected at concentrations above the closure level in shellfish samples collected from Westport, according to a news release sent from Jeff Nelson, environmental health director for Grays Harbor County. The release was sent out on Tuesday afternoon, Sept. 27.

To combat the threat of PSP, the Washington State Department of Health has closed all of Grays Harbor to the recreational harvest of shellfish.

“The closure area boundary is inside Grays Harbor only and does not affect ocean beaches,” the release states. “Commercial beaches are sampled separately, and commercial products should be safe to eat.”

Crab are not part of the Paralytic Shellfish Poison exposure, but a variety of mollusks are. Those species include clams, oysters, mussels, scallops and other species of mollusks.

“Continued sampling will determine when closures will be lifted or expanded,” the release states.

PSP, formerly known as “red tide,” can be life-threatening and is caused by eating shellfish that contain a potent toxin. The toxin is produced by a naturally occurring organism.

The toxin cannot be destroyed by cooking or freezing, the release states.

The early symptoms from PSP can set in within 30 minutes of shellfish consumption and they have serious symptoms.

Those symptoms may include numbness and tingling around the lips and-or tongue, vomiting, diarrhea and abdominal pain, numbness in arms and-or legs, muscular paralysis or coordination loss, dizziness and incoherence, headache, rapid pulse and-or respiratory distress.

PSP poisoning can only be detected by laboratory testing, the release states. A person cannot determine if the toxin is present by visual inspection.

“If you experience any of these symptoms after eating shellfish, have someone take you to the emergency room immediately, or call 911 for assistance,” the release states.