The NSW Office of the Chief Scientist and Engineer’s (OCSE) independent review has found failure of existing legal environmental protections in water law not being enforced as the cause of millions of fish dying in the Darling-Baaka River in March.
Handed down by the NSW Chief Scientist and Engineer, Professor Hugh Durrant-Whyte on Thursday, the Executive Summary’s findings and recommendations “reflects an understanding of the 2023 event as symptomatic of broader degradation of ecosystem health and consequential long-term pressure on the Darling-Baaka River system”.
It also addresses environmental concerns, casual factors, and the response, as well as immediate actions in recognition of short-term and long-term risks, with Prof Durrant-Whyte warning it could happen again.
“Without substantive change to our regulatory approach, paired with investment in people, data, and infrastructure, there will be further environmental degradation and recurrence of such events”, he said.
“Difficult decisions will need to be made. These are essentially social and not scientific in nature. However, it is hoped that the advice contained in our report will make a positive contribution to the discussions to follow.”
“Difficult decisions will need to be made”
Menindee resident Geoff Looney – who provided many photos during one of the OCSE’s many visits to the area over the past few months – told the Barrier Truth that “it’s not real science that the river’s got to have more water”.
“In times of flood, we’d normally have water that was a chocolate colour, but that flood went for that long that in the end, the water was nearly black,” he said.
“We didn’t know what the water was, where it was coming from, whether it was from black water or whether it was from something else. But I’ve never ever seen anything like that before. And [the OCSE] were quite astounded to see it.
“What Menindee people, in my opinion appreciate, is someone at least listening. In past times when we’ve had people come down here, they’ve told us what they want to do, and their plans weren’t working. But the people from the OCSE were quite good and if we get somebody down here doing something, which is virtually saying what we’re saying, surely people have got to listen.
“We say [there’s been] two fish kills but there’s probably been more than that. It’s definitely a case that if nothing’s done, it’ll happen again. We never thought in 2019 it would happen again in 2023. The work in progress is still in progress.”
The most likely cause of death was hypoxia, resulting in low dissolved oxygen in the water column. It was also identified that the area around the Menindee Lakes system is particularly susceptible to fish death events.
“Low dissolved oxygen in the water column was driven by many factors, including high biomass, poor water quality, reduced inflows and high temperature,” Prof Durrant-Whyte continued.
“Mass fish deaths are symptomatic of degradation of the broader river ecosystem over many years. Changes to flow regime and fish passage from water infrastructure and altered water use in the Northern Basin are likely key factors in decreasing water quality and the decline of native species.”
While the scale of any potential event was underestimated because of limited observations and monitoring data indicating compromised water quality and control, the OSCE identified that a failure in policy implementation was the root cause of the river ecosystem’s decline and subsequent fish deaths.
“Explicit environmental protections in existing water management legislation are neither enforced nor reflected in current policy and operations. Water policy and operations focus largely on water volume, not water quality,” the OCSE found.
Prof Durrant-Whyte said “there is a clear disconnect” between key stakeholders – the Department of Planning and Environment, NSW Fisheries, WaterNSW, and environmental agencies –, with the initial lack of a response hampering a swift response.
“Lack of clarity around agency responsibilities and funding streams further hindered response and recovery. Triggers for response are not clearly defined,” the OCSE said.
Inconsistent and untimely communications, a lack of consideration towards local and regional accessibility, and the use of trusted voices and group’s knowledge weren’t engaged to inform decisions. This, the OCSE says, contributed to “the local community feeling their knowledge, insights, and experience of the river, lakes, and broader environment were not given appropriate consideration”.
Suggesting a lead agency be tasked with responsibility and oversight for implementation and reporting progress and carry out the recommendations of the report, the OCSE put forward four recommendations. It included: a need for regulatory environmental protections to be enforced, a more integrated and open approach to data collection be established, and an effective emergency management framework be implemented, and strategies to mitigate against further mass fish death events.
The final report is expected to be released next week, pending availability of independent data and analysis, and final checks for accuracy.