State public health officials have issued a that consumers should avoid eating rock crabs caught in Half Moon Bay and bivalve shellfish and rock crabs caught in Monterey Bay.
The warning applies to state waters in the Central Coast, according to health officials, pointing to an area roughly between Cypress Point and Pigeon Point in Monterey County.Unsafe levels of domoic acid have been detected in some of these species and are also likely to be present in the other species mentioned above. Domoic acid is a naturally occurring potent neurotoxin produced by Harmful algae blooms (HAB). Symptoms in mild cases can include vomiting, diarrhea, abdominal cramps, headache and dizziness. The conditions that support the growth of this plant are impossible to predict.
In more severe circumstances, an infected person may experience trouble in breathing, confusion, being disoriented, seizures, excessive bronchial secretions, cardiovascular instability, permanent loss of short term-memory, coma or death.
Specifically, Half Moon Bay rock crabs and Monterey Bay rock crabs and bivalve shellfish are on the danger list for now, according to the California Department of Public Health.
No illnesses have been reported as a result of the recent event.
Tests of rock crabs recently caught in Half Moon Bay revealed domoic acid levels at more than 10 times the action level, which is 30 parts per million, according to the agency.
Bivalve shellfish have a two-part, hinged, shell. The reason behind the Friday warning is presence of domoic acid found in these rock crabs and bivalve shellfish such as oysters, clams, mussels and scallops. However, there comes much concern after reports of higher levels of domoic acid detected in the rock crabs in Half Moon Bay and the crabs and shellfish in Monterey Bay. State law permits only state-certified commercial shellfish harvesters or dealers to sell these products. 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. For additional information, visit CDPH's Natural Marine Toxins: PSP and Domoic Acid Web page and CDPH's Domoic Acid health information Web page.