County health officials in California have issued a warning against consuming sport-harvested shellfish, including mussels, clams, scallops, and oysters, due to a quarantine that is in effect until October 31. This precaution is necessary because harmful toxins, such as domoic acid and saxitoxin, can accumulate in these shellfish, especially during the summer months. Dr. Sayone Thihalolipavan, the county's public health officer, emphasized that these toxins can cause severe illness or even death, and cooking the shellfish does not eliminate the risk. Symptoms can manifest within 30 minutes to 24 hours after consumption, ranging from vomiting and diarrhea to more severe effects like seizures or coma. During this period, sport-harvested mussels can only be used as bait. In contrast, shellfish sold in stores and restaurants are considered safe, as they are subject to rigorous state testing for toxins. Residents are encouraged to contact the county's Department of Environmental Health and Quality or the California Department of Public Health's Shellfish Information Line for further information.