Mild summer weather is nice for enjoying a day at the beach. But the sunny days also create favorable conditions for poisonous bacteria that can cause illness and closures for shellfish harvesting.
Numerous beaches in the central Puget Sound area are closed to recreational shellfish harvesting. The presence of Paralytic Shellfish Poison, known as PSP, resulted in a new closure extending from Seattle’s Alki Beach south to the Pierce County line, including Vashon Island. It spread there from Kitsap County.
In other areas, harvesting can be safe, but the state Department of Health is urging caution.
“Always check before you dig,” says Jerry Borchert, who monitors marine biotoxins for the health department's shellfish program, which maintains a safety map showing all the most up to date closures.
He says PSP, which is also sometimes called “red tide,” can actually show up in a variety of colors.
“But you can never tell if shellfish are safe to eat by the color of the water. The only way to tell is to test the shellfish tissue for the presence of these toxins, which is what we do here Washington state,” Borchert said, adding that the state opens and closes beaches based on extensive testing protocols.
The PSP toxin is not destroyed by cooking or freezing and consuming it can be life-threatening. The symptoms often come on quickly as numbness or tingling that can lead to paralysis and respiratory failure.
In such cases, death can occur in 2 to 24 hours. If symptoms are severe, it’s important to call 911 or get to an emergency room immediately.
The health department says beaches that are open could still be at risk for vibrio bacteria, which is also showing up at higher levels this year. More than ten cases of illness have already been reported from raw or undercooked oysters collected locally.
“This year we are seeing higher levels of vibrio bacteria in the environment and people should take precautions when they go to the beach,” said Shellfish Illness Prevention Coordinator Clara Hard.
The health department is urging people to follow “The Three Cs” when harvesting shellfish recreationally: “check, chill and cook.”
Hard says ‘check’ is a reminder for people to check the DOH Shellfish Safety Map for health related closures and other information on conditions before heading out, such as tide times.
“Harvest as the tide goes out, chill the shellfish as quickly as they can in ice or refrigeration and then cook it thoroughly – to 145 degrees for 15 seconds, whenever they’re harvesting between late May and September,” she says.
Vibrio bacteria is naturally occurring and thrives in warm temperatures. It causes flu-like symptoms including diarrhea, abdominal cramps, nausea and vomiting. Health officials say the illness is usually mild or moderate and runs its course in two to three days.