SAN FRANCISCO, Calif. -

California public health officials are warning people to avoid eating Rock crabs caught in Half Moon Bay and shellfish caught in Monterey Bay that contain dangerous levels of a neurotoxin.
   
The Department of Public Health says high levels of domoic acid were found in Rock crabs and bivalve shellfish caught in the waters south of Pigeon Point and north of Monterey County's Cypress Point.
   
In severe poisoning cases, the toxin can cause seizures, coma or death.
   
The warning applies to mussels, clams and the internal organs of scallops caught in the area. It does not apply to commercially sold shellfish from approved sources, as certified harvesters and dealers are subject to frequent testing to monitor for toxins.