First recorded incident of animal poisoning caused by a freshwater blue-green algal bloom

This occurred in Lake Alexandrina, Australia, during the late 19th century. Following the development of a scum of Nodularia spumigene covering the lake surface, dogs, sheep, pigs, horses, and cattle all died after drinking water from this lake. This blue-green algal species produces nodularin, a hepatotoxin, which causes blood to collect in the liver, in turn inducing circulatory shock and sometimes bringing about death by internal haemorrhaging.