The state Department of Health Services is advising sportfishermen not to eat sardines harvested from Monterey Bay.
The fish may be contaminated with a naturally occurring toxin that can cause mild to serious illnesses, or even death.
Researchers with the department have found elevated levels of domoic acid, which is produced by microscopic marine algae, in the sardines. Symptoms of domoic acid poisoning can occur within 30 minutes to 24 hours of eating the toxic fish. Symptoms include vomiting, diarrhea, abdominal cramps, headaches and dizziness in mild cases.