More Than Water Quality: Environmental Limitations to a Fishery in Acid Pit Lakes of Collie, South-West Australia
International Mine Water Association
Computing, Health and Science
Natural Sciences, Centre for Ecosystem Management
Marron (Cherax cainii Austin) are a freshwater crayfish native to permanent waterbodies in the south-west of Western Australia. A popular aquaculture and sports species, marron are considered a potential end-use fishery species for and have been deliberately released into several historic pit lakes of the Collie coal mining region. This study investigated what environmental factors in these acid mine drainage (AMD) contaminated pit lakes might be affecting the health and success of existing marron fisheries. Although pit lake water quality was often low (pH <4 with elevated metal concentrations) this did not appear to lead to lower marron health indices. Rather, lack of burrow habitat, low biomass and quality of food with further competition for these resources from related non-fishery crayfish species may be the most important factors limiting marron health. Decreased marron health is likely to result in decreased individual growth rate and final fishery biomass. Such ecological considerations are not common to the mine water literature but offer a more holistic perspective to much mine water research and may provide more tangible environmental goals for achieving environmental and social sustainability of mine waters.