what is the cause of red tide poisoning
Red tide Red tide is also potentially harmful to human health.[10] Humans can become seriously ill from eating oysters and other shellfish contaminated with red tide toxins. "In general, bivalves will contain much larger amounts of toxin compared to univalves. Symptoms are very similar to the those found in the closely related ciguatera poisoning." Shellfish consume the organisms responsible for red tide and concentrate saxitoxin (produced from these organisms) in their tissues. Saxitoxin blocks sodium channels and ingestion can cause paralysis within 30 minutes.[11] Karenia brevis blooms can potentially cause eye and respiratory irritation (coughing, sneezing, tear production, and itching) to beachgoers, boaters and coastal residents.[12] People with severe or persistent respiratory conditions (such as chronic lung disease or asthma) may experience stronger adverse reactions. The National Oceanic and Atmospheric Administration's National Ocean Service provides a public conditions report identifying possible respiratory irritation impacts in areas affected by red tides.[13]