Marine biotoxins that cause paralytic shellfish poisoning (PSP) — also known as “red tide” — have been detected in high levels in shellfish samples collected from Dyes Inlet in Silverdale. As a result, the Washington State Department of Health and the Kitsap County Health District have closed recreational shellfish harvesting in all of Dyes Inlet and the Port Washington Narrows, including all bays and inlets within the area. The closure is for all species of clams, oysters and mussels.

Samples of mussels collected on Monday contained toxin concentrations of 108 micrograms per 100 grams of shellfish tissue. Beaches are closed when the toxin level exceeds 80 micrograms per 100 grams of tissue. Toxin levels this high may cause illness and could be potentially life threatening.

Shrimp and crab are not included in this closure, but crabs should be cleaned prior to cooking, and the “crab butter” should be discarded. Shellfish harvested commercially that are available in stores and restaurants are tested for toxins prior to distribution and are safe to eat.

Marine biotoxins are not destroyed by cooking or freezing and can be life-threatening. People can become ill from eating shellfish contaminated with the naturally occurring marine algae which contains toxins that are harmful to humans. Symptoms of PSP can appear within minutes or hours and usually begin with tingling lips and tongue, moving to the hands and feet, followed by difficulty breathing and potentially death. For extreme reactions, call 911.

In most cases, the algae containing the toxins cannot be seen and must be detected using laboratory testing. The health district will continue to monitor shellfish at Kitsap County beaches, and notify the public if the levels of PSP toxins become unsafe in other areas.

For current shellfish closures in Kitsap County, call the hotline at (800) 2BE-WELL or visit www.kitsapcountyhealth.com.