Fish kill reports confirm value of science

Reports commissioned by the Federal Government and Opposition into the Menindee Lakes fish kills have a very high level of agreement, demonstrating the quality of the science underpinning both.

That is the finding of a review of the two documents by the Australian Academy of Technology and Engineering, which shows they share fundamental agreement on a range of issues.

Both reports agree on:

• The negative weather, water quality, water flow and volume, and fish mobility conditions at the times of the fish deaths. The reports agree exactly how these conditions killed the fish.
• Short-term measures to mitigate further fish deaths such as mechanical aeration measures to improve fish mobility and adding water when available to the system.
• The strong need for much more measurement, monitoring, research and forecasting on several aspects of how the Darling system functions. The underlying purpose of those recommendations is that such a complex system can’t be managed without knowledge and measurement.

Academy President, Professor Hugh Bradlow FTSE, congratulated those involved in producing the reports, including Academy Fellows Professor Rob Vertessy and Professor John Williams.

“Both reports demonstrate a very high level of understanding of the challenges involved in managing the Murray-Darling Basin’s water resources and underline the importance of bringing cool, scientific objectivity to bear,” he said.

The Academy’s experts are planning a roundtable on the management challenges in the Murray-Darling Basin with the aim of developing a plan for how the complex issues can be addressed for the short, medium and long term.

“The reports do a good job of identifying why the mass fish kills happened,” Professor Bradlow said. “Now the challenge is to come up with practical measures that will help governments balance the needs of all stakeholders within the Basin.”

Other areas of substantial agreement between the reports include:

• The core problem of low flows
• Several recommendations for improved management of the Menindee Lakes
• Identifying a lack of information about flood plain harvesting of water in the upper Darling system
• Agreement that the amount of diversions for human use in the upper Darling system could be a significant concern
• The need for an active event-based system flow management
• The need for improved predictions and models of Basin water balance in the light of climate change

The Academy looks forward to the release of the Vertessy panel’s final report at the end of March.