The California Department of Public Health gave consumers a partial green light on Thursday to eat Dungeness and rock crabs, which were the focus of a health advisory in early November.
The health advisory warned that these species of crustacean, found in waters from the Oregon border to the southern Santa Barbara County line, contained dangerous levels of domoic acid — a natural toxin.
Now the CDPH says Dungeness and rock crabs are safe to eat — if they are found in waters from the Santa Barbara/Ventura County line and San Luis Obispo County near Piedras Blancas Light Station. The lift on the advisory does not include areas around the Channel Islands.
“We believe that the crab in these areas are completely safe to consume," Patrick Kennelly, chief of the CDPH's food safety section, said.
Kennelly cautioned that, while crabs from this area are safe to eat, the crab's internal organs (commonly called the "butter") should still not be consumed.
Domoic acid poisoning causes typical stomach virus symptoms like vomiting, diarrhea and headaches, but severe cases can lead to things like permanent loss of short-term memory, seizures and even death.
According to the CDPH, the toxin spawns from the "bloom" of plankton, which is then consumed by fish and shellfish.
“We have seen the levels of domoic acid rise in crabs over the years — we don’t typically see them last for this long,” Kennelly said.
One theory, Kennelly said, is that perhaps the warmer waters resulting from El Niño caused the plankton's bloom to last longer than previous years. He said that the crabs are monitored year-round, and the rise in domoic acid happens every summer, but the crustaceans are normally safe to eat by winter when they are in season.
There is no timeline for when the rest of the ban will be lifted, though Kennelly is optimistic that the toxin levels are declining.
“We are seeing steady improvement across the state with the levels of domoic acid declining with each subsequent set of samples, for the most part," Kennelly said.