Cyanobacterium Cylindro‐spermopsis raciborskii as a probable cause of death in cattle in northern Queensland

[Extract] Livestock deaths due to cyanobacterial (blue-green algal) poisoning have mainly been caused by toxic strains of Anabaena circinalis, A spiroides, Aphanizomenon flos-aquae, Microcystis aeruginosa and Nodularia spumigena. In Australia, cattle and sheep have since 1878 succumbed to cyanobacterial poisoning caused by A circinalis, M aeruginosa and N spumigena.\ud\udThe possibility of another cyanobacterium being a cause of poisoning in man and animals in Australia was raised by Hayman in 1992. He suggested that the signs of the illness known as Barcoo fever, which has been known in northern Australia since the 1880s, were reminiscent of those caused by the tropical cyanobacterium Cylindrospermopsis raciborskii. The severity of illness, although it only manifested in the mildest form of nausea and fever, was related to the amount of water ingested from contaminated water supplies. During the same time, there have been numerous anecdotes about losses of cattle and sheep in northern and western Queensland after drinking from dams and waterholes contaminated with scum or ‘paint slicks’ indicative of cyanobacteria. In 1992, stock poisoning due to C raciborskii was suspected in Western Australia