CDPH Warns Public Not to Consume Sport-Harvested Bivalve Shellfish from Del Norte County

July 3, 2025  

SN25-015 

What You Need to Know: CDPH warns consumers not to eat recreationally harvested mussels, clams, scallops or oysters from Del Norte County due to dangerous levels of paralytic shellfish poisoning (PSP) toxins detected in mussels from Del Norte County ​

SACRAMENTO – The California Department of Public Health (CDPH) is advising consumers not to eat sport-harvested mussels, clams, scallops, or oysters from Del Norte County.   ​

Dangerous levels of paralytic shellfish poisoning (PSP) toxins have been detected in mussels from Del Norte County. The naturally occurring PSP toxins can cause illness or death in humans. Cooking does not destroy the toxin. 

This shellfish safety notification is in addition to the warnings against eating sport-harvested bivalve shellfish in Marin, Santa Cruz, Santa Barbara, Ventura, Los Angeles, and Orange counties due to marine biotoxins, and to the ​annual mussel quarantine. The annual quarantine prohibits the sport-harvest of mussels for human consumption and applies to all species of mussels harvested for human consumption along the California coast, as well as all bays and estuaries, and will continue through at least October 31. Additionally, there is a razor clam advisory for Del Norte and Humboldt counties due to domoic acid. 

Paralytic shellfish poisoning 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. 

This warning does not apply to commercially sold mussels, clams, scallops, and 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 man​datory​ testing to monitor for toxins. ​

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.  ​​​​​