The poison is found in many reef fish. Poisoning is caused by a toxin produced by the marine micro-organism, Gambierdiscus toxicus , which attaches to seaweed that is eaten by reef fish. The poison accumulates when reef fish are eaten by larger fish and then by humans. All humans are believed to be susceptible to ciguatera toxins. It is also common in certain Caribbean and South Pacific countries.
Ciguatoxic fish look and taste normal.
Neither cooking, freezing nor drying deactivates this toxin. This is caused by the ingestion of certain species of tropical fish. State of Hawaii Department of Health, Epidemiology Branch, Communicable Diseases. It is caused by consumption of reef fish that feed on certain dinoflagellates associated with coral reef systems. Both had eaten barracuda at a local restaurant on October 19.