SACRAMENTO – The California Department of Public Health (CDPH) announced Thursday that the annual quarantine on mussels gathered by sport harvesters from California’s coastal waters ends at midnight Friday, Oct. 31, for all coastal counties except Ventura County.

Although paralytic shellfish poisoning (PSP) toxins remain at low or undetectable levels along the entire coast, another toxin, domoic acid, remains at high levels in some samples from Ventura County.

The annual quarantine, which typically runs May 1 through Oct. 31, is intended to protect the public from paralytic shellfish poisoning and amnesic shellfish poisoning (ASP).

There have been no reports of shellfish-related poisoning in California during the quarantine period.

As a result of continuing elevated levels of domoic acid, the October 10 health advisory for Ventura County remains in effect.

This advisory warns consumers not to eat certain types of seafood (recreationally harvested bivalve shellfish, such as mussels, clams or whole scallops, or the internal organs of lobster or rock crab) from the Ventura County coastline due to dangerous levels of domoic acid.

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.

ASP, also known as domoic acid poisoning (DAP), has been linked to another type of marine plankton consumed by filter-feeding animals, like bivalve shellfish.

Domoic acid has been linked to numerous poisonings of marine mammals along the Pacific Coast.

Updated information about shellfish poisoning is available by calling the Shellfish Information Line at 800-553-4133. More information can be found on the Mussel Quarantine Frequently Asked Questions (FAQ) Web page, http://www.cdph.ca.gov/Pages/MusselQuarantineFAQ.aspx .

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.