Flowing through the Ranger uranium mine lease and into Kakadu National Park, Magela Creek is home to important populations of native fish species that need to be able to move between the river, floodplain and escarpment country at different times of the year. Fish movement around floodplains during the wet season facilitates the transport of large amounts of nutrients and energy from floodplains to creeks as flood waters recede. This process supports important food sources for Traditional Owners and protects the World Heritage values of the Park.
Weathering of waste rock from the mine releases contaminants, including magnesium sulfate. These contaminants are washed out by the rain and are predicted to move through the local groundwater towards Magela Creek. Depending on the concentration, the magnesium sulfate (a salt) has the potential to affect fish, trees and other ecosystems in and near Magela Creek downstream from the Ranger mine site.
The Ranger uranium mine is due to cease operations by 2021 and this study is leading to better knowledge about how mining waste-related salty plumes may affect ecological processes and connectivity. Researchers are studying fish migrations in the Magela Creek catchment to determine the extent to which magnesium sulfate plumes could interfere with fish movements and related ecological functions and processes. They are also recommending ongoing monitoring and evaluation activities to inform mine closure activities and trial new-generation monitoring equipment and infrastructure.
This project is:
Project update August 2019.
Fieldwork is taking place in Magela Creek, both upstream and downstream from Ranger uranium mine.
This project is being led by Associate Professor David Crook from Charles Darwin University (CDU). A/Prof Crook is being assisted by researchers from CDU and the Supervising Scientist Branch of the Department of the Environment and Energy.
David Crook, Charles Darwin University