Research affirms sorry state of the Richmond River Catchment

Almost two years after the catastrophic floods of early 2022, the catchment has received an Ecological Health Grade of just C minus (C-), reflecting the ongoing impact of the floods on top of damaging historical land use.

The Richmond River Ecological Health Program was made possible by a Southern Cross University Vice Chancellor’s Flood Recovery Grant. Seven grants each worth $25,000 were funded in October 2022 to support ongoing flood recovery in the Northern Rivers.

Lead researcher and PhD candidate, Mr Brendan Cox, said the project to assess the catchment’s freshwater rivers, streams and riparian zones had  aligned University expertise with the citizen science of the Richmond Riverkeeper Association, local indigenous knowledge and the environmental advocacy of River Ecology Australia.

 “A major component of the program is to examine the type and number of macroinvertebrates, or water bugs, collected at various sites throughout the catchment,” said Mr Cox.

“Water bugs tell us a lot about river health because they have varying sensitivity to pollution. Some will survive pretty much anywhere while others require the most pristine waters.

“Integrating data on these macroinvertebrates, water quality and the condition of riparian zones – those areas of land along the banks of rivers and streams – provides a holistic picture of river health.”

For the moment that picture is anything but healthy, with issues such as bank slumping, exposed tree roots, reduced riparian vegetation, land clearing, erosion and sedimentation all affecting river recovery and overall health.

“The lower catchment sites tend to have poorer water quality and low macroinvertebrate diversity,” said Mr Cox. “Yet even in the upper catchment sites, where the water quality is better, macroinvertebrate diversity is still quite low.

“This indicates that aquatic habitat is compromised and that is a concern. Water bugs are also an important food source for fish, birds, platypus and turtles, so the low abundance of macroinvertebrates may have impacts across the food web.”

Mr Cox said these first findings can help guide future restoration actions and adaptive management strategies. Sampling is ongoing and updated data will be released every six months.

“The community commitment is there. For this program, we had almost 30 community and indigenous groups doing the sampling, and the message from all that work is clear,” he said.

“If the waters of the Richmond River Catchment are to be drinkable, swimmable and fishable again, we need committed partnerships that focus on habitat restoration, enhancing riverbank stability, reducing the loss of our precious soils and reducing pollutant loads.”

Committed partnerships are at the core of the University's diverse flood recovery projects currently underway; from the VC Flood Recovery grants through to the Living Lab Northern Rivers and the wide-ranging research of the Catchments, Coasts and Communities research cluster.