All of Willapa Bay is currently closed to recreational shellfish harvest due to an elevated Diarrhetic Shellfish Poison toxin result in testing by the Washington State Department of Health, the Pacific County Emergency Management Agency said on social media.

There is currently no commercial shellfish closure due to DSP toxin in Willapa Bay. The closure also does not apply to recreational crabbing or razor clamming.

A commercial oyster grower offered this explanation of the regulatory testing process: There are test sites of mussels all around Willapa Bay, which is about a 70,000-acre estuary. Samples are tested regularly for many different things. Mussels will test positive and take up many pollutants before clams or oysters do.

Action thresholds are set well below levels that are considered dangerous to human health, which means one of these test mussels might get a “hit” and they will close the growing area to recreational harvest because they can’t test each recreational harvest site individually.

Meanwhile, when this happens commercial harvesters have to start submitting meat samples of everything harvested commercially in the are of the “hit” and these samples have to be tested and deemed safe before that product can leave the processing facility and be shipped out.

Most growers harvest, then wait to start processing until the sample comes back clean before they start running the product so they don’t risk having to dump it.

In the meantime DOH will keep testing the mussel sites to see if they see levels rising or falling. If levels are rising, they usually end up closing the commercial harvest and then commercial operations go into a very long process of getting reopened based on a few clean tests in a row over a course of weeks.