SAN FRANCISCO (CBS SF) – State health officials are warning consumers not to eat certain shellfish sport-harvested from the coast stretching from San Francisco to Monterey County, after a toxin was found.

According to the California Department of Public Health, mussels, clams and whole scallops harvested from San Francisco, San Mateo, Santa Cruz and Monterey counties should be avoided.

CDPH issued the warning Wednesday after paralytic shellfish poisoning (PSP) toxins were found in mussels from the four counties. PSP toxins, which are naturally occurring and can’t be destroyed by cooking, affect the central nervous system.

Symptoms from eating the toxic shellfish include a tingling sensation in the mouth and fingertips, typically followed by loss of balance, slurred speech and difficulty swallowing. In severe cases, complete muscular paralysis and death from asphyxiation can occur, health officials warned.

Commercially sold clams, mussels, scallops or oysters are not impacted by the warning.