FRESHWATER FISH EPIDEMICS IN QUEENSLAND RIVERS. 1(5 



Territory. We are also indebted to the Comniom^ealth Bureau 

 of Meteorology for furnishing full particulars regarding tempera- 

 tures and rainfall recorded at various Queensland stations. 



A preliminary report was published in 1917 by the senior 

 author, but the information and material then available were 

 very scant}'. In that report it was regarded as likely that, 

 prolonged dry weather having converted the rivers into a 

 chain of stagnant waterholes, an unhealthy environment 

 for fish had been created, such leading to wealaiess which 

 gave the fungus Saprolegnia an opportunity to exchange its 

 saprophytic life for a parasitic mode of existence, the invasion 

 of the gills leading to death. Decomposing fish Avould cause 

 a still further reduction of the oxj^gen supply and thus aggravate 

 the condition. It was believed that the arrival of good rains 

 would remove the stagnation, improve the aeration of the 

 water, and establish a suitable environment for healthy fish 

 life (Johnston, 1917, p. 131). 



OCCURRENCE OF EPIDEMICS ALREADY RECORDED. 



1892. — An officer of the Fisheries Department, N.S.W., 

 mentioned the occurrence in 1892 of an epidemic causing 

 mortality among fish in a tributar}" of the Barcoo near Lammer- 

 moor Station, in the vicinity of Winton, Queensland (Johnston, 

 1917, p. 126). A Longreach resident (Mr. Coleman) informed 

 us that a similar outbreak happened in the Thomson River in 

 that year. 



No other record of such an occurrence was made until 

 1917, when widespread mortality appeared among the fishes 

 of the western rivers of Queensland, A\hile milder outbreaks 

 occurred in certain rivers in the south-eastern portion of this 

 State. 



1917. — In July, Mr. F. Mills, Clerk of Longreach Shire, 

 reported that fish were dying in the Thomson River and that 

 similar conditions prevailed right out to the MacKanley River, 

 nearly all species being affected. 



In August of the same year Mr. A. Sugden sent down a 

 catfish {Neosiluriis hyrtlii Steind.), taken from the Bulloo 

 River near Quilpie, and reported that fish \A'ere dying in large 

 numbers in that river, and that similar conditions had occurred 

 in Cooper's Creek. 



In August and September 1917^ Dr J. S. Elkington saw 



