SACRAMENTO - California Department of Public Health (CDPH) Director and State Public Health Officer Dr. Karen Smith announced today the statewide annual quarantine on mussels gathered by sport harvesters from California's ocean waters ends at midnight on Wednesday, October 31, 2018, for all coastal counties except for Del Norte and Humboldt counties.

Dangerous levels of domoic acid have been detected in mussels from Del Norte and Humboldt counties, making them unsafe to consume. Concentrated levels of domoic acid and paralytic shellfish poisoning (PSP) 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.

Domoic acid and 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 October 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 RedTide@cdph.ca.gov 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 (CDFW) 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.