Warning lifted for Sport-Harvested Shellfish from San Mateo, Monterey, and

December 13, 2022



The California Department of Public Health (CDPH) has lifted the shellfish safety notifications today related to sport-harvested mussels, scallops, and clams in San Mateo, Monterey, and San Luis Obispo counties. The safety notifications were issued due to dangerous levels of naturally occurring paralytic shellfish poisoning (PSP) toxins that can cause illness or death. Recent testing shows PSP toxins have decreased to safe or undetectable levels for bivalve shellfish in these areas. The shellfish safety notification for Humboldt County remains in place due to continuing dangerous levels of PSP toxins.  

These notifications do not apply to commercially sold clams, mussels, scallops, or oysters from approved sources. State law permits only state-certified commercial shellfish harvesters or dealers to sell these products. Shellfish sold by certified harvesters and dealers are subject to frequent mandatory testing to monitor for toxins. 

PSP toxins affect the central nervous system, producing a tingling around the mouth and fingertips within a few minutes to a few hours after eating toxic shellfish. These symptoms are typically followed by loss of balance, lack of muscular coordination, slurred speech and difficulty swallowing. In severe poisonings, complete muscular paralysis and death from asphyxiation can occur. 

You can get the most current information on shellfish advisories and quarantines by calling CDPH’s toll-free Shellfish Information Line at (800) 553-4133 or viewing the recreational bivalve shellfish advisory interactive map (https://experience.arcgis.com/experience/394836318cfe4f7494e1c09097a43559/?utm_medium=email&utm_source=govdelivery). For additional information, please visit the CDPH Marine Biotoxin Monitoring web page (https://www.cdph.ca.gov/Programs/CEH/DRSEM/Pages/EMB/Shellfish/Marine-Biotoxin-Monitoring-Program.aspx?utm_medium=email&utm_source=govdelivery).