The public is advised of a California Department of Public Health or CDPH mussel quarantine order effective May 1 through October 31, 2026. During the quarantine, all species of mussels gathered by recreational sport harvesters from California’s ocean shore should not be consumed by humans. The quarantine area extends from the Oregon border to the Mexican border, including all bays, inlets, and harbors in Los Angeles County. The Los Angeles County Department of Public Health conducts daily syndromic surveillance to identify cases of illness due to ingestion of mussels and other bivalent shellfish and works with CDPH by collecting shellfish for testing.
This quarantine is to protect and preserve public health under the California Health and Safety Code Section 131056. During the quarantine season, mussels may concentrate naturally occurring toxins that are highly poisonous to humans including paralytic shellfish poison (PSP) and domoic acid biotoxins in bivalve shellfish (mussels, clams, oysters, and scallops). Shellfish toxin levels do not have predictable cycles and can increase rapidly. Prevention of human illnesses requires the annual quarantine, combined with year-round surveillance, public education, shellfish advisories and commercial closures as needed. Cooking does not destroy the toxins.
This advisory does not apply to commercial shellfish from approved sources.
Mussels may be used or sold for use as bait when displayed and sold in containers labeled in boldfaced type letters at least one-half inch in height as follows: MUSSELS FOR BAIT ONLY, UNFIT FOR HUMAN FOOD.
Details: For additional information call the Shellfish Hotline at 1-800-553-4133 or online at the CDPH Marine Biotoxin Quarantines and Health Advisories.