The Kitsap Public Health District announced Oct. 26 that shellfish harvesting is closed in Liberty Bay near Poulsbo due to high levels of marine biotoxin diarrhetic shellfish poison.

Samples were tested Oct. 24, and results show concentrations of 29 micrograms of toxin per 100 grams of shellfish tissue. Shellfish harvesting is closed when DSP toxin levels meet or exceed 16 micrograms per 100 grams of tissue.

The closure includes all recreational shellfish harvesting for all species of clams, oysters and mussels. Shrimp and crab are not included, but crabs should be cleaned prior to cooking and the “crab butter” should be discarded.

DSP symptoms include nausea, vomiting and abdominal pain with diarrhea being the most common symptom. Warning signs have been posted at public beaches alerting people not to collect shellfish from the closure areas. KPHD will monitor the bay on a weekly basis until toxins return to safer levels.