California's rock and Dungeness crabs were completely banned during the holiday season in 2015. The reason was that excessive levels of toxic algae was found offshore and could have led to poisoning. However, the good news came when the state health officials partially withdrew the ban on December 31, 2015, just before the onset of New Year. The officials said that people can now consume crabs that are caught along the coasts of Santa Barbara and San Luis Obispo counties. Ban is still applicable for crabs that are found in north of those counties stretching till the Oregon border.
A ban was placed on the crabs by the California Department of Public Health in early-November 2015, after the detection of domoic acid, in levels beyond safety limits, in oceans. This indicated that crabs in north of Ventura County are not safe enough to be consumed. Domoic acid is a kind of neurotoxin and is Pseudo-nitzschia alga’s natural byproduct. Consumption of this toxin can result in nausea, diarrhea and dizziness. Worse case scenarios can be seizures and even death in rare cases.
The excessive alga bloom was likely to be an outcome of higher temperatures of water due to El Niño. However, recently the levels of domoic acids have shown decline in the state’s southern region, according to Dr. Karen Smith, the Director of California Department of Public Health. Crabs' viscera or internal organs must still be avoided.