California quarantines recreationally harvested mussels from Oregon to Mexico due to toxin risks.

California has issued a mussel quarantine from May 1 to October 31, 2025, spanning from Oregon to the Mexican border, due to the risk of toxins like paralytic shellfish poison and domoic acid. These toxins can cause severe illness and are not destroyed by cooking. The advisory applies only to recreationally harvested mussels; commercially grown mussels are exempt as they are regularly tested. Clams and scallops are not included, but it is advised to discard the dark parts before eating.