POULSBO — Liberty Bay is closed to shellfish harvesting because of a biotoxin that’s “a little different,” said Karen McKay Bevers, spokeswoman for the Kitsap Public Health District.
While the bay has been closed in the past for paralytic shellfish poisoning (PSP), the toxin that has it closed now is known as diarrhetic shellfish poisoning (DSP). This is the first time DSP has been a problem in Liberty Bay.
Jim Zimny, the health district’s Food Safety and Living Environment manager, said, “DSP is kind of the flavor of the month.”
The health district checks samples from the bay every two weeks, Zimny said. The samples from July 13 contained 59 micrograms per 100 grams of DSP. The tolerance level is only 16 micrograms.
Because of the high level of biotoxin, the bay is closed to shellfish harvesting. However, Zimny said people can still harvest shrimp and crabs for consumption, so long as they don’t consume the “crab butter.” Clams, oysters and mussels are restricted.
Zimny’s not sure how long the bay will be under harvesting restrictions. With the presence of high toxin levels, the district tests twice a week and the bay won’t be reopened until they’ve had two clean samples.
Symptoms of DSP show quickly, Zimny said. The most obvious symptom is diarrhea, which can last for one to three hours, he said.
“The effects are pretty quick; there is no lag time,” Zimny said. “It usually happens in about 20 minutes. Anybody who had eaten that shellfish would’ve already had those symptoms.”
Zimny said marine biotoxins are created by plankton. Different types of plankton produce different toxins.
“There’s probably hundreds of different toxins being produced,” Zimny said. “There’s three we look for in this region.”
Those three include PSP, DSP and amnesic shellfish poisoning.
Marine biotoxins can’t be destroyed by cooking or freezing, and can be life-threatening.
“If you harvested shellfish in that time period, you need to destroy them,” Zimny said. “Or at least not use them for human consumption.”
For more information or up-to-date closure lists, go to www.kitsappublichealth.org/shellfish.
