Sport-Harvested Bivalve Shellfish Advisory

Advisory Information

On April 9, 2026 the California Department of Public Health (CDPH) issued a health advisory alerting the public to not eat sport-harvested mussels, clams, scallops or oysters gathered from Sonoma County due to dangerous levels of paralytic shellfish poisoning toxins detected in mussels from these waters.

Additional Information

For more information and the most current information on shellfish advisories and quarantines call  CDPH’s toll-free Shellfish Information Line at (800) 553-4133 or visit CDPH Marine Biotoxin Monitoring Program webpage. 

For information about advisories in other areas, please go to the CDPH Recreational Bivalve Shellfish Advisory Interactive map.

Why are biotoxins in shellfish dangerous?

Dangerous levels of paralytic shellfish poisoning (PSP) toxins have been detected in mussels from Sonoma County. These naturally occurring toxins are not destroyed by cooking and can cause serious illness or death.

Some species of algae (phytoplankton) produce natural biotoxins that can accumulate in shellfish such as mussels, clams, oysters, crabs, and lobsters. Consuming contaminated shellfish can cause serious illnesses, including PSP and domoic acid poisoning, posing a risk to humans and wildlife.

PSP attacks the nervous system, with symptoms appearing within minutes to hours after consumption. Early signs include tingling around the mouth and fingertips, followed by loss of balance, poor coordination, slurred speech, and difficulty swallowing. Severe cases can lead to paralysis and death from asphyxiation.

Is it safe to eat commercially sold mussels, clams, scallops, and oysters?

This warning does not apply to shellfish sold commercially from approved sources. State law allows only certified harvesters and dealers to sell shellfish, and these products are regularly tested to ensure they meet safety standards.

Visit the California Department of Public Health’s Marine Biotoxin Monitoring Program website or call 1-800-553-4133 for the latest quarantine and health advisory updates.