Causitive toxin(s) in the death of two Atlantic dolphins

Following the death of two Atlantic dolphins in a lagoon in March of 1989, the Hawaiian fishes in the lagoon were examined as a potential source of toxin(s). This study reports the findings of the causitive toxin(s) involved, utilizing the stick enzyme immunoassay (S-EIA) and the mouse and guinea pig atrium assays. The S-EIA proved effective in screening the toxic fishes (mullet, wrasse, manini, and aholehole). Following extraction, the major toxin was found in the viscera of these fishes, as confirmed in the mouse assay. The most toxic level was shown in the viscera of the mullet (13.2 mouse units/mg of extract). The viscera of the wrasse, aholehole, and manini also showed high levels of the toxic substance. The guinea pig atrium assay showed the presence of a potent Na+ channel inhibitor, characteristic of tetrodotoxin and saxitoxin. The toxin was also demonstrated in low levels in the dolphin liver and gut content and in the sand and algae extracts from the lagoon. This is the first report of this type of toxin in Hawaii.