The Washington State Department of Health has closed Quilcene Bay and Dabob Bay for the recreational harvest of all species of shellfish due to marine biotoxins that cause paralytic shellfish poisoning (PSP).

The ban was announced Friday afternoon by Jefferson County health officials. Danger signs have been posted at public access points by Jefferson County Public Health.

In Jefferson County, most of the recreational shellfish harvesting beaches have been closed due the rapid spread of PSP, officials said.

In addition, levels of PSP in Discovery Bay have increased to as high as 977 micrograms of biotoxin per 100 grams of shellfish. (The closure level is 80 micrograms.)

The closure includes clams, oysters, mussels, scallops and other species of molluscan shellfish. Crabmeat is not known to contain the biotoxin, but the guts can contain unsafe levels. To be safe, people should clean crab thoroughly and discard the guts (sometimes called the “crab butter”).

Officials are also reminding residents that marine biotoxins are not destroyed by cooking or freezing.

People can become ill from eating shellfish contaminated with the naturally occurring marine algae containing toxins harmful to humans. Symptoms of PSP can appear within minutes or hours and usually begins with tingling lips and tongue, moving to the hands and feet, followed by difficulty breathing, and potentially death.

Anyone experiencing these symptoms should contact a health care provider immediately. For extreme reactions, call 911.

In most cases, the algae that contain the toxins cannot be seen and must be detected using laboratory testing.

Recreational shellfish harvesters should check the map at www.doh.wa.gov/ShellfishSafety.htm or call the Biotoxin Hotline at 1-800-562-5632 before harvesting shellfish anywhere in Washington state.