The discovery of unsafe levels of Diarrhetic Shellfish Poison in samples of shellfish collected near Seattle has prompted the closing of Puget Sound beaches for recreational shellfish harvest. Washington state officials, along with Seattle and King County public health officials are warning the public to honor the harvest bans that include oysters, mussels, oysters, geoduck and scallops.

“The Washington State Department of Health (DOH) has closed beaches to recreational shellfish harvest from Three Tree Point south to the Pierce County line, including Des Moines Marina Park, Saltwater State Park and Dash Point State Park,” according to the closure notice. “Commercial beaches are sampled separately and commercial products should be safe to eat. “Although DSP (Diarrhetic Shellfish Poison) has been a problem in European countries for some time, this is an emerging health threat for Washington.” Naturally occurring algae produces the toxin, which is not destroyed by cooking or freezing. Symptoms of DSP poisoning include nausea, vomiting, abdominal pain and diarrhea with diarrhea being the most commonly reported symptom. Symptoms may appear within minutes of eating contaminated shellfish or may take several hours. “A person cannot determine if DSP toxin is present by visual inspection of the water or shellfish,” according to the state health department. “Therefore, harvesters are advised to call the DOH Biotoxin Hotline at 800-562-5632 or visit the Biotoxin website before harvesting shellfish anywhere in Puget Sound.” In addition to the new closures around Puget Sound, many other Washington beaches are closed to recreational harvesting of various species of shellfish. (To sign up for a free subscription to Food Safety News, click here.)