Fish Poisoning: A Problem in Food Toxication

INTEREST IN POISONOUS FISHES has intensified greatly in recent years. World Wat II brought many Americans and Europeans to tropical areas of the world where fish poisoning is common. Also, interest in the welfare of native populations of the Pacific islands has developed widely, and there is an impression that fish poisoning is increasing. In spite of an extensive literature, there is considerable confusion on the subject. Some marine organisms are dangerous because of their venomous stings or bites, while others are poisonous to eat. Among the latter are shellfish of several kinds, including mussels, clams, and oysters. Some fin fishes also are poisonous to eat. They are intrinsically poisonous and, like the toxic shellfish, do not produce their undesirable effects through bacterial spoilage. Such fishes are the subject of this paper. The fish poisoning problem is especially insidious because of its inconsistencies. For example; a species is not always poisonous and therefore summarily rejected; it may be eaten safely in some localities and not in others, or at some times of year and not at others. Large specimens, otherwise attractive as food, are believed more likely to be dangerous than smaller ones. Different from the usual fish poisoning episodes is Haffs' disease noted among fishermen along the Baltic Sea coast of East Prussia and at Lake Ysmen in Sweden (Schwimmer and Schwimmer, 1955). The more than a thousand victims had consumed eels, eel livers, and a few other kinds of fish. Animals that ate the fish also became ill and died. Selenium was once thought to be involved in the etiology (Berlin, 1948); toxic blue-green or other algae in the food chain of the fish have been suspected, also. Another atypical episode occurred recently