After being pulled off menus since November, California crabs are no longer banned in certain areas, more specifically the Santa Barbara coast and the counties of San Luis Obispo. The reason why the Dungeness crabs were banned in the first place was due to their toxicity level, given by an intake of toxic algae called Pseudo-nitzchia.
If one would eat infected crab meat in low levels, symptoms similar to food poisoning would arise, like nausea, vomiting episodes, stomach pains, and severe diarrhea. If large doses of domoic acid would be ingested by the patient, a byproduct of pseudo-nitzchia, extensive short-term memory loss and seizures will start occurring, in some cases leading to the person’s death.
Although the ban was lifted, doctors and state officials still advise the general public to refrain from eating the crab’s viscera. This part would normally contain the highest amount of domoic acid, thus leading to a higher chance of infection.
After several tests were conducted on the crabs, their toxicity level has been reported to have gone back to original levels or even disappear completely, but only in the areas where the ban was lifted. Crabs from other areas will still be banned until their domoic acid levels reach undetectable levels.
This crab toxicity stemmed from the overgrown population of algae, suffering from a massive bloom due to the warm water temperatures brought forth by El Nino and helped by the current warm Winter. Climate change also has a rather important part in the occurrence of this phenomenon and algae blooms have affected other species as well, not only crabs.
Several oyster farms have also been closed to due the extended red algae tide that poisons said creatures and it can also lead to an increase in sea lion strandings and other similar events. This change in temperatures has also affected inland lakes, suffocating several species of fish due to extensive algae blooms. Besides the environmental impact, various industries ranging from fishing farms to hydro-electrical plants are also feeling the negative impact of algae infestation.
In regards to crabs, it is advised to steam or boil them instead of using broiling or frying techniques. The cooking water should also be discarded immediately. Symptoms related to domoic acid infection appear after an average of 24 hours. If one would suffer from the aforementioned symptoms, immediate medical attention is strongly advised.
Although California crabs are no longer banned in certain areas, this does not mean that the general public should stop exercising caution towards Dungeness or rock crab consumption. Keep in mind that the viscera should still be removed, as well as using the aforementioned methods of cooking in order to remove the dangers of domoic acid ingestion. With the onset of the cold season, algae blooms will start to diminish accordingly, leading to a probable ban removal for the crabs coming from the north of the Ventura county as well in the following weeks of January.