QUILCENE — A biotoxin that causes flu-like symptoms has prompted the closure of Quilcene, Dabob and Discovery bays to recreational shellfish harvesting.
The recent discovery was the first time any toxin has been found in shellfish in either Quilcene Bay or Dabob Bay.
The toxin, called diarrhetic shellfish poisoning, or DSP, closed Sequim Bay last year after three King County residents who ate mussels they harvested there fell ill in late June.
DSP can causes nausea, vomiting, diarrhea, abdominal cramps and chills. The symptoms typically pass quickly.
“It [Sequim Bay] is the first site that we had a confirmed illness for DSP in the United States,” said Greg Combs of the state Department of Health Office of Shellfish and Water Protection.
“It’s difficult to say whether or not it was toxic in other areas.”
Commercially harvested shellfish are sampled separately, and products on the market should be safe to eat, the Jefferson County Health Department said.
Frank Cox, marine biotoxin coordinator with the state Department of Health, said a mussel containing 32 micrograms of DSP toxin recently was found at a mussel-monitoring site for Quilcene and Dabob bays.
“We close it when it hits 16,” Cox said.
Other samples of shellfish taken from Quilcene and Dabob bays are being tested at a National Oceanic and Atmospheric Administration lab in Seattle and a Food and Drug Administration lab on Dauphin Island, Ala.
The state Department of Health has purchased new lab equipment for DSP testing, but the equipment has not been calibrated.
The results of the lab tests will be known later this week, perhaps Wednesday, Cox said.
The cause of the latest DSP bloom is still unknown, but monitoring will continue.
“We have not had any illnesses reported this year from anywhere,” Cox said.
Sequim Bay is also closed now because of DSP.
Food contaminated with DSP biotoxins may not look or smell spoiled. Marine biotoxins are not destroyed by cooking or freezing.
The Jefferson County Public Health Department announced the closure of Discovery, Quilcene and Dabob bays Monday.
Other beaches along the Strait of Juan de Fuca already were closed to recreational harvesting for elevated levels of potentially deadly paralytic shellfish poisoning, or PSP.
Seasonal closures for shellfish harvesting are in effect for Pacific Ocean beaches.
Kilisut Harbor, including Mystery Bay, is closed to butter clams only. Butter clams hold toxins for a longer period of time than other shellfish.
PSP, commonly known as “red tide,” is a neurotoxin that can trigger paralysis at high concentrations.
Its prevalence tends to rise in the summer, Cox said.
Closures for DSP or PSP include the recreational harvest of clams, including geoducks, oysters, mussels and other invertebrates.
The closures do not apply to shrimp or crab.
“We’ve had three PSP deaths in Washington over the years,” Cox said.
“And we’ve had a number of close calls with PSP. I think a lot of people have learned to pay attention to our website.”
DSP comes from a toxin produced by a type of plankton long known to live in high concentrations in Sequim Bay and around Puget Sound.
Mussels tend to ingest higher amounts of DSP than other invertebrates.
“Mussels are indiscriminate feeders,” Cox said.
“They will feed on this kind of plankton and pick up the toxin more quickly and at higher levels.”
Health officials do not expect the lab results to show dangerous levels of DSP in the other species being tested.
Canada has seen “a whole slug of illnesses” attributed to biotoxins this year.
“In Europe, there have been outbreaks that involved hundreds of people,” Cox added.
Health officials are still learning about DSP’s prevalence in the region.
“We’ve got a lot more work,” Cox said.
“That’s the bottom line.”
The Health Department maintains a list of beaches affected by shellfish closures at ww4.doh.wa.gov/gis/mogifs/biotoxin.htm.
More information also is available at the Marine Biotoxin Hotline at 800-562-5632.
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Reporter Rob Ollikainen can be reached at 360-452-2345, ext. 5072, or at rob.ollikainen@peninsuladailynews.com.
