Diagnosis of a fish kill in Georgetown Billabong near Ranger Uranium Mine on 11 October 2001

2002

Internal Report 390
Pidgeon R, Bouckaert F & Boyden J
Supervising Scientist Division
Department of the Environment, Water, Heritage and the Arts

About the report

Georgetown Billabong is a shallow back-flow lagoon adjacent to Magela Creek and close to Ranger Uranium Mine. In the wet season it receives water from two sources: water from Magela Creek during backflow and overbank flows that is unaffected by the mine, and water from Georgetown Creek that can potentially be influenced by mining activity. There have been a number of small-scale accidental contamination events on the headwaters of Georgetown Creek during the operation of the mine. The fish community of Georgetown Billabong is monitored annually by eriss as part of the biological monitoring program for Ranger mine.

On 11 October 2001 eriss was informed by ERA Ranger Mine Environmental section that a small fish kill had been observed at Georgetown Billabong. Fish kills caused by natural environmental processes are very common in wetlands of the Alligator Rivers Region (Pidgeon 2001). However, since sudden fish kills can also result from some kinds of mine effluent, such as acid mine drainage, eriss acted quickly to determine whether the fish kill observed in Georgetown Billabong was a natural phenomenon or a result of mining activities.