NESP MaC Project 5.11 – Water quality trends analysis at key GBR basins (sediment and DIN) (JCU, CSIRO)

Updated: 2026-09-14

This record provides an overview of the NESP Marine and Coastal Hub Project 'Water quality trends analysis at key GBR basins (sediment and DIN)'. For specific data outputs from this project, please see child records associated with this metadata. Despite considerable government investment in Great Barrier Reef catchment area (GBRCA) water quality programs (>$2B) including on-ground works and regulation, this is the first comprehensive analysis of long-term trends in empirical water quality monitoring data to test and quantify any detectable changes. Building on the definitive compilation of four decades of historical water quality data for key river basins of the GBRCA (James at al., 2025), this project will examine long-term trends in Reef 2050 Plan priority constituents, dissolved inorganic nitrogen (DIN) and suspended sediment. To compliment this evaluation, this project will compile and evaluate changes in fertiliser application amounts across the river basins of the GBRCA over the same time period. This compilation of land use specific fertiliser application data also provides a foundational record of long-term changes in land management over annual timesteps. This project will inform current and future Reef policy and on-ground investment programs, as well as support on-going catchment modelling efforts. This record provides an overview of the NESP Marine and Coastal Hub Project 5.11 'Water quality trends analysis at key GBR basins (sediment and DIN)'. For specific data outputs from this project, please see child records associated with this metadata. Project outputs: • A time series compilation of nitrogen and phosphorus fertiliser application amounts in the river basins of the Great Barrier Reef catchment area [Journal paper] • Statistical water quality trend analysis of priority basin sites across the Great Barrier Reef catchment area, including measures of uncertainty [Journal paper].