Warning: Avoid eating Dungeness and rock crabs, California officials say

Ditch eating Dungeness and rock crabs that come from anywhere between the Oregon border and the Santa Barbara County line for now, the California Department of Public Health says. High levels of a toxin that affects the nervous system — domoic acid, which can cause seizures, coma or even death — have been found in crabs from those areas. 

"The levels that we're currently finding in crabs is still very high," Patrick Kennelly, food safety chief for the California Department of Public Health, told KPCC. Officials have been testing crabs from the area and levels are "still elevated and are indicative that, if people do consume them, they are posing a risk of injury," he said. 

Domoic acid is produced by a single-cell organism called pseudo-nitzschia, which live in the marine environment and periodically have blooms, Kennelly explained. Seafood creatures, including crabs, who live in that environment feed on the organisms — and as a result, they begin accumulating the toxins in their systems.

People who order crab at restaurants should ask about the origin of the crabs being served, Kennelly said.

"It's always good to ask the question and just make sure that the restaurant is aware of the warning and ... that they are getting crab products that are not associated with this particular warning," he said.

Officials are not certain when the levels of domoic acid will die down in the crabs. The pseudo-nitzschia blooms are difficult to predict, but Kennelly said they tend to come on more in the summer months and are associated with warmer water. He said the blooms may be affected by El Niño.

The blooms do die off and go away after some time. Marine organisms eventually clear their systems of the domoic acid, but officials are not sure when the toxins will be completely gone. Some of the areas affected are clearing, Kennelly said, but full clearing depends on the particular creatures involved.

"Some [organisms] will hold on to the domoic acid a little bit longer," Kennelly said. "We are seeing some improvement in some areas, and some of the organisms, like the mussels and the clams, they tend to clear out a little bit faster."

No information on human poisoning so far was available.