By Vernon E. Ansdell Seafood poisoning from marine toxins is an underrecognized hazard for travelers, particularly in the tropics and subtropics. Furthermore, the risk is increasing because of factors such as climate change, coral reef damage, and spread of toxic algal blooms. CIGUATERA FISH POISONING Ciguatera fish poisoning occurs after eating reef fish contaminated with toxins such as ciguatoxin or maitotoxin. These potent toxins originate from small marine organisms (dinoflagellates) that grow on and around coral reefs. Dinoflagellates are ingested by herbivorous fish. The toxins are then concentrated as they pass up the food chain to large carnivorous fish (usually >6 lb, 2.7 kg) and finally to humans. Toxins are concentrated in fish liver, intestinals, roe, and head. Gambierdiscus toxicus, which produces ciguatoxin, may proliferate on dead coral reefs more quickly than other dinoflagellates. … Read entire article »