Razor Clams and Domoic Acid Testing

March 22, 2018

Question: My friend and I are enthusiastic razor clam harvesters in Del Norte. For the last two years, however, we have been unable to take part in this popular fishery because of high domoic acid levels in the clams. We noticed that the last published domoic acid tests were from Nov. 13, 2016. We were wondering if testing of domoic acid levels has continued over the last year but has not been published on the California Department of Fish and Wildlife (CDFW) health advisory website. Does CDFW need volunteers to collect clams for testing? If so, how would we go about doing this? (Jolyon)

Answer: Razor clams are known for bioaccumulating domoic acid, which basically means they concentrate the toxin and are slow to excrete it. Unfortunately, concentrations of domoic acid continue to remain high in samples and it does not look likely the fishery will open soon.

The California Department of Public Health’s Marine Biotoxin Monitoring Program coordinates all bivalve shellfish and phytoplankton monitoring in the state for public health protection. For razor clam sampling, they work with individual volunteers, the Tolowa Dee-ni’ Nation and CDFW staff from the Eureka office.

If you are interested in volunteering for the program you can contact CDPH Senior Environmental Scientist Vanessa Zubkousky-White, who coordinates the bivalve shellfish and phytoplankton sampling effort. She can be reached at (510) 412-4635, or vanessa.zubkousky@cdph.ca.gov.