CDPH Lifts Warnings about Sport-Harvested Bivalve Shellfish from San Mateo County
May 26, 2026
SN26-011
What You Need to Know: CDPH has removed the warning that advised against eating recreationally harvested bivalve shellfish from the waters of San Mateo County. The
annual mussel quarantine for recreationally harvested mussels along the entire California coast remains in effect.
SACRAMENTO – The California Department of Public Health (CDPH) has lifted the shellfish safety notification today related to sport-harvested bivalve shellfish from San Mateo County.
The safety notification for San Mateo County was issued on
March 30, 2026, due to dangerous levels of paralytic shellfish poisoning toxins in mussels. These naturally occurring toxins can cause illness or death in humans. Recent testing shows paralytic shellfish poisoning toxins have decreased to safe levels in bivalve shellfish in this area.
While this warning for scallops, clams and oysters in San Mateo County waters has been lifted, the
annual mussel quarantine remains in effect. The annual mussel quarantine prohibits the sport-harvest of mussels for human consumption and applies to all species of mussels harvested along the California coast, as well as all bays and estuaries through at least October 31. The purpose of the annual mussel quarantine is to prevent paralytic shellfish poisoning (PSP) and domoic acid poisoning. Cooking does not destroy the toxins.
There are also shellfish safety notifications in effect warning against eating sport-harvested bivalve shellfish in
Del Norte and
Sonoma counties due to marine biotoxins. Additionally, there is a
razor clam advisory for Humboldt County due to domoic acid.
For the most current information on shellfish advisories and quarantines, call 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.