FRESHWATER FISH EPIDEMICS IN QUEENSLAND RIVERS. 185 



"with mineral. Artesian bore water did not enter the creeks. 

 All permanent waterholes were affected irrespective of depth. 

 The colour of the water during the epidemic was milky or 

 muddy, which was the normal appearance in the district. 



He concurred in the opinion generally held in the locality 

 that the cause of the mortality was " overstocking," since 

 fish were present in enormous numbers in the rivers and creeks. 

 Birds such as ibises, spoonbills, pelicans, jabirus, herons, 

 cormorants, v.ere extremely abundant at the time. 



Owing to the amount of pollvition which had occurred, Mr. 

 Stre ton forwarded a sample of the water to the Health Depart- 

 ment, Darwin, with a view to ascertaining whether it was fit 

 for human consumption. The report of the analysis is referred 

 to later. 



WARREGO RIVER. 



Mr. Caldwell, in a letter to the Brisbane " Daily Mail " of 

 7th December 1918, stated that, though the epidemic was :n 

 evidence in the more northerly situated rivers in this State, 

 it had not appeared in the Warrego and its tributaries, e.g. 

 Langlo and Ward Rivers, during 1918, whereas it had caused 

 heavy mortality in these rivers during 1918. He mentioned 

 the current belief that it was due to overstocking in stagnant 

 pools, and stated that though fish might be dying in the main 

 streams, yet in the billabongs or lagoons only a short distance 

 away, and fed by the flood- waters of these streams, fish life 

 was healthy and plentiful. 



He informed us by letter dated November 1919 that 

 he had been told that the epidemic had made its appearance 

 in the Warrego River near Cunnamulla and that the decom- 

 posing fish were constituting a nuisance to the townspeople 

 (October). Conditions were hot and very dry, stock dying 

 from drought. At Dillalah, also on the Warrego but some 

 distance to the north, a very large waterhole was at the time 

 apparently free from the disease. 



OTHER LOCALITIES. 

 jMr. R. Varney reported (April 1920) that he had observed 

 the epidemic amongst yellow-bellies and black bream, par- 

 ticularly in the muddy water of lagoons in the Longreach and 

 Winton districts, during very dry weather in 1918 and 1919. 

 The condition was noticed in the Cork Lagoon near Winton 

 late in 1919. [Thomson and Diamantina Rivers.] 



