CDPH Lifts Warnings about Sport-Harvested Shellfish from Marin and Monterey Coun

November 13, 2024

The California Department of Public Health (CDPH) lifted the shellfish safety notification on November 12, 2024 related to sport-harvested mussels, clams, and scallops from Marin and Monterey counties. 

The safety notifications for Marin County, issued July 26, 2024, and Monterey County, issued July 18, 2024, were due to dangerous levels of naturally occurring paralytic shellfish poisoning (PSP) toxins in mussels that can cause illness or death in humans. Recent testing shows PSP toxins have decreased to safe or undetectable levels for bivalve shellfish in these areas. The warning for Del Norte County remains in effect.   

This warning did not apply to commercially sold mussels, clams, 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 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. For additional information, please visit the CDPH Marine Biotoxin Monitoring web page.