The Washington State Health Department has closed recreational shellfish harvesting in all of San Juan County’s waters due to high levels of a biotoxin which can cause paralytic shellfish poisoning.

The Department of Health has issued a bulletin warning, “Eating shellfish contaminated by marine biotoxin can kill you.” The poison is not destroyed by cooking or freezing.

The toxin is created by a particular type of algae bloom which County Environmental Health Manager Mark Tompkins describes as cyclical. “There have been years when we have had no closures and others where we are closed from June until January,” he said.

Currently recreational harvesting of shellfish is closed in all or parts of Clallam, Grays Harbor, Island, Jefferson, King, Kitsap, Pierce, Skagit, Snohomish and Whatcom Counties.

Tompkins emphasizes that some of San Juan County’s commercial operations, which maintain their own shellfish beds are still open and that the shellfish sold in grocery stores and by certified suppliers is tested regularly and is safe.

The County Health Department tests shellfish in test cages around the County beginning in May each year. Tompkins said that samples tested in May were free of the biotoxin, but samples taken between June 29 and July 2 were found to contain concentrations ranging from 79 to 1120 micrograms of the biotoxin per liter. The State recommends closing recreational shellfish harvesting when concentrations exceed 80 micrograms/liter.

“Concentrations generally start going down in October or November,” Tompkins said. “In the meantime we strongly advise everyone to make sure that any shellfish they eat comes from a certified source.”

Symptoms of paralytic shellfish poisoning often begins with a tingling of the tongue or lips while eating shellfish. Death can result in less than 30 minutes, so health officials say it is important to dial 911 or a health care provider as soon as poisoning is suspected. There is no known antidote to the poison so in severe cases the victim is kept on life support until the toxins pass from their system.

Recreational harvesters can get current information on closures online at www.doh.wa.gov or by phone at: 1-800-562-5632.