State and Island County health officials closed the southwest side of Whidbey Island to shellfish harvesting Friday.

Marine biotoxins that cause paralytic shellfish poisoning (PSP) have been detected at concentrations above the closure level in shellfish samples collected from Useless Bay. High levels of PSP have also been detected in shellfish samples from the west side of Admiralty Inlet (Port Townsend, Port Ludlow, Marrowstone Island, Indian Island and Mats Bay in Jefferson County).

As a result, Roger Case, MD, health officer for Island County, and the Washington State Department of Health (DOH) have closed the southwest side of Whidbey Island to the recreational harvest of all species of shellfish.

The closure area boundaries are from Admiralty Head south to Possession Point. Warning signs have been posted at high-use beaches warning people not to collect shellfish from these areas.

The closure includes clams, oysters, mussels, scallops and other species of mollusks. Crab is not included in the closure, but crabs can concentrate the toxin in their internal organs (crab butter). You are advised to clean crabs before cooking and to eat only the meat.

Commercially harvested shellfish are sampled separately and products on the market should be safe to eat.

Marine biotoxins are not destroyed by cooking, rinsing or freezing and can be life-threatening. People can become ill from eating shellfish contaminated with the naturally occurring marine algae that contains toxins 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.

Recreational shellfish harvesters should check the DOH website at http://www.doh.wa.gov/ehp/sf/biotoxin.htm or call the DOH Biotoxin Hotline at 1-800-562-5632 before harvesting shellfish anywhere in Washington.