It’s encouraging to see signs of improvement. But our findings should not be interpreted as meaning all rivers in these catchments are now healthy.

Although the trends are improving, nitrogen and sediment levels in many rivers are still higher than the thresholds considered suitable for supporting healthy coastal and marine ecosystems, such as wetlands, seagrass and near-shore coral reefs.

This isn’t surprising. Environmental recovery rarely happens quickly or evenly. River catchments often take several years to respond to improvement efforts, such as riverbank revegetation for sediment erosion control.

That’s why long-term river monitoring data is so important. Without this, it’s difficult to distinguish short-term fluctuations from genuine change.

The reef still faces enormous challenges from climate change, extreme weather and ongoing land-use pressures, including tree clearing.

What our findings suggest is that water quality trends in many of the river catchments discharging to the Great Barrier Reef are moving in the right direction.

It has not been easy to get here. It has taken long-term effort from farmers, graziers, catchment managers and researchers. Our scientific evidence demonstrates previous management efforts have made an impact, at scale – and that current and future efforts are worthwhile.

In a world increasingly dominated by stories of environmental decline, these slow signs of improvement are worth celebrating.