SAN FRANCISCO—On Wednesday, July 1, officials from the California Department of Public Health (CDPH) cautioned the public to avoid consuming shellfish that has been sport-harvested from the coast of San Francisco to Monterey County following the discovery of a toxin in the shellfish.

In a news release from the CDPH, it is stated that “Dangerous levels of paralytic shellfish poisoning (PSP) toxins have been detected in mussels from those four counties. The naturally occurring PSP toxins can cause illness or death in humans. Cooking does not destroy the toxin.”

“PSP toxins affect the central 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,” states the release.

According to the CDPH, shellfish including mussels, clams and scallops that have been sport-harvested from San Francisco, San Mateo, Santa Cruz, and Monterey counties should be avoided by the public. The warning does not apply to mussels, clams, scallops, and oysters that are commercially sold from approved sources.