The California Department of Public Health (CDPH) is reminding consumers to avoid eating the viscera of rock crabs caught in state waters north of Latitude 37° 11′ N. (near Pigeon Point in San Mateo County). This warning is due to high levels of domoic acid, a naturally occurring marine toxin that can lead to illness or death.
CDPH believes that rock crab meat is safe to consume, however, as a precaution, consumers are advised not to eat the viscera (internal organs, also known as “butter” or “guts”) of crabs.
The Department also issued a November 2 warning urging recreational anglers to avoid eating the viscera of Dungeness crab caught north of Point Reyes. That warning is still in place.
While domoic acid levels may vary, consumers should always follow these best preparation practices to avoid any inadvertent exposure to domoic acid that might be sporadically found in some crab’s viscera. When whole crabs are cooked in liquid, domoic acid can leach from the viscera into the cooking liquid. Water or broth used to cook whole crabs should be discarded and not used to prepare dishes such as sauces, broths, soups or stews (for example, cioppino or gumbo), stocks, roux, dressings or dips.
The best ways to reduce risk are:
- Remove the crab viscera and rinse out the body cavity prior to cooking, or
- Boil or steam whole crabs, instead of frying or broiling, and discard cooking liquids.
Symptoms of domoic acid poisoning can occur within 30 minutes to 24 hours after eating toxic seafood. In mild cases, symptoms may include vomiting, diarrhea, abdominal cramps, headache and dizziness. These symptoms disappear within several days. In severe cases, the victim may experience trouble breathing, confusion, disorientation, cardiovascular instability, seizures, excessive bronchial secretions, permanent loss of short-term memory (a condition known as Amnesic Shellfish Poisoning), coma or death. There have been no reported illnesses associated with this year’s domoic acid event.
Domoic acid accumulation in seafood is a natural occurrence that is related to a “bloom” of a particular single-celled plant. The conditions that support the growth of this plant are impossible to predict. CDPH routinely monitors phytoplankton levels in coastal waters and bi-valve shellfish, and will increase sampling of other species when monitoring indicates that an event may be occurring.
CDPH will continue to coordinate its efforts with the California Department of Fish and Wildlife (CDFW) and the fishing community to collect and test rock crab samples from the northern California coast until the domoic acid levels have dissipated.
CDFW is in the process of closing the commercial rock crab fishery in state waters north of Pigeon Point in San Mateo County and the commercial Dungeness crab season between Point Reyes and the Sonoma/Mendocino county line. More information is available on the CDFW website.
To receive updated information about shellfish poisoning and quarantines, call CDPH’s toll-free Shellfish Information Line at (800) 553-4133. For additional information, visit CDPH’s Natural Marine Toxins: PSP and Domoic Acid Web page and CDPH’s Domoic Acid health information Web page.