SACRAMENTO – California Department of Public Health Director and State Public Health Officer Dr. Karen Smith announced the statewide annual quarantine on mussels gathered by sport harvesters will be lifted at midnight on Tuesday, Oct. 31, for all coastal counties except for Sonoma County.

Dangerous levels of paralytic shellfish poisoning, or PSP, toxins have been detected in mussels from Sonoma County, making them unsafe to consume.

PSP is a form of nervous system poisoning. Concentrated levels of the toxins can develop in mussels and other bivalve shellfish when they feed on certain naturally occurring marine plankton that can increase during favorable environmental conditions.

PSP toxins remain at low or undetectable levels along all other portions of the California coast.

The annual quarantine on sport-harvested mussels, which typically runs May 1 through Oct. 31, is intended to protect the public from shellfish poisoning caused by marine biotoxins. There have been no reports of shellfish-related poisonings in California during this quarantine period.

CDPH’s shellfish sampling and testing programs issue warnings or quarantines when needed. Local health departments, various state, federal and tribal agencies, community groups and others participate in the monitoring program.

Residents and community groups interested in volunteering to assist with the testing program should email This email address is being protected from spambots. You need JavaScript enabled to view it. or call 800-553-4133.

Updated information about current conditions is available by calling the Shellfish Information Line at 800-553-4133. More information can be found on the CDPH Marine Biotoxin Monitoring Web page or the CDPH Annual Mussel Quarantine - Frequently Asked Questions (FAQ) Web page.

Due to the persistent presence of domoic acid in razor clams from beaches in Humboldt and Del Norte counties, the California Department of Fish and Wildlife’s closure of the razor clam fishery remains in effect there. More information about the razor clam fishery closure can be found on the CDFW Ocean Health Advisories Web page.