Most of the southwest side of Whidbey Island has been closed to recreational shellfish harvesting following the discovery of high concentrations of marine biotoxins that cause paralytic shellfish poisoning.

The closure extends from Admiralty Head south to Possession Point. Signs warning people of the danger of harvesting shellfish have been posted at popular beaches.

Clams, oysters, mussels, scallops and other species of molluscan shellfish are off limits. Although crab is not included in the closure, Island County Public Health advises people to clean crab thoroughly and eat only the meat. The biotoxin can accumulate in the crab’s internal organs, also known as crab butter.

The biotoxins cannot be destroyed by cooking, rinsing or freezing and can be life threatening to people who ingest it. Symptoms typically begin with tingling lips and tongue, moving to the hands and feet, followed by difficulty breathing. The symptoms can appear within minutes or hours.

Anyone experiencing these symptoms should contact a health care provider or if having an extreme reaction, call 911.

Commercially harvested shellfish undergoes a separate sampling process, so products on the market should be safe to eat.

Recreational shellfish harvesters are advised to check the Washington Department of Health website at doh.wa.gov/ehp/sf/biotoxin.htm or to call the hotline at 1-800-562-5632 before harvesting in Washington.