Fish movement and sensitivity to contaminated mine water Go Back

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:

• investigating fish movement and abundance in Magela Creek and its floodplain at different times of year
• determining the risks to fish movement from current magnesium sulfate concentrations in Magela Creek from regulated releases of mine tailings water
• analysing the future risks to fish movement from magnesium sulfate contamination
• informing mine rehabilitation options and monitoring activities
• improving our understanding of tropical food web dynamics by using the Magela Creek findings to build on previous work.

Project activities

• Tag 100 fish with acoustic transmitters to characterise their seasonal movements between the floodplain and refugial billabongs
• Use imaging sonar to generate near-video-quality images of fish to observe their behaviour and estimate their abundance
• Deploy underwater video cameras to obtain species-level information on fish abundance and migration
• Quantify the biomass transported between floodplains and main channel habitats by fish migration
• Link fish movement data to models of surface and groundwater movement and literature review findings
• Quantify responses of migrating fish to current approved mine water releases.

Anticipated outputs

• A conceptual model of how different fish species use the creek based on quantitative information
• An assessment of the risks to Magela Creek fish species associated with mine waste water
• A report outlining future ecological risks and options associated with rehabilitation of the Ranger uranium mine site and downstream areas
• Recommendations for a monitoring program and ongoing assessment of potential impacts to fish communities from the predicted salty water
• Scientific papers and summary factsheets.

Project update August 2019.

Fieldwork is taking place in Magela Creek, both upstream and downstream from Ranger uranium mine.