How well is the Basin Plan meeting its objectives? From the perspective of the Coorong, a sentinel of change in the Murray-Darling Basin

ABSTRACT

Freshwater aquatic ecosystems can be considered sentinels of change as they integrate signals from catchment, hydrology and biogeochemistry to provide an indication of how the system fluctuates. The Coorong estuary acts as a sentinel for the Murray-Darling Basin (MDB), Australia. Its location at the terminus of the Murray-Darling River systems, which drains more than 1 million square kilometres across 22 major catchments, means that any change to climate, water extraction or land use in the upstream catchments will have repercussions for the Coorong. It therefore acts as an indicator of the health of the MDB and the effectiveness of the Murray-Darling Basin Plan at protecting this ecosystem. Environmental water secured through the Murray-Darling Basin Plan and establishment of the Commonwealth Environmental Water Holder has been critical to preventing significant ecosystem decline in the Coorong. For most water years in the last decade environmental water has contributed to the majority of flow through the barrages. This has exported salt from the basin, reduced influx of salt from the ocean, and expanded available habitat for fish in the Coorong. However, the environmental flows have not been sufficient to arrest sand build up, and dredges still operate at the Murray Mouth during all but the highest flow events. There is a clear case for continued water management and reform, extending beyond the boundaries of the MDB, to further increase security of water flowing along the river system through the barrages and supporting the ecological health of the Coorong, and by association the full MDB.

KEYWORDS:

• Murray-Darling Basin Plan
• estuary
• hypersaline
• water reform
• environmental flows

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/13241583.2023.2241161

Additional information

Notes on contributors

Justin D. Brookes

Justin D. Brookes is a Professor in the School of Biological Sciences at the University of Adelaide.

Brendan Busch

Brendan Busch is a research officer in the School of Agriculture and Environment at The University of Western Australia.

Phill Cassey

Phill Cassey is a Professor in the School of Biological Sciences at the University of Adelaide.

Daniel Chilton

Daniel Chilton is a PhD candidate in the School of Biological Sciences at the University of Adelaide.

Sabine Dittmann

Sabine Dittmann is Professor of Biological Sciences at Flinders University.

Tyler Dornan

Tyler Dornan is a PhD candidate in the School of Biological Sciences at the University of Adelaide.

George Giatas

George Giatas is a research officer at SARDI Aquatic Sciences.

Bronwyn M. Gillanders

Bronwyn M. Gillanders is a Professor in the School of Biological Sciences at the University of Adelaide.

Matt Hipsey

Matt Hipsey is an Associate Professor in the School of Agriculture and Environment at The University of Western Australia.

Peisheng Huang

Peisheng Huang a post-doctoral researcher in the School of Agriculture and Environment at The University of Western Australia.

Christopher Keneally

Christopher Keneally is a PhD candidate in the School of Biological Sciences at the University of Adelaide.

Micha V. Jackson

Micha V. Jackson completed post-doctoral research in the School of Biological Sciences at the University of Adelaide and is currently working for CSIRO.

Luke Mosley

Luke Mosley is an Associate Professor in the School of Biological Sciences at the University of Adelaide.

Rowan Mott

Rowan Mott is a post-doctoral researcher in the School of Biological Sciences at the University of Adelaide.

David Paton

David Paton is a retired Professor in the School of Biological Sciences at the University of Adelaide.

Thomas Prowse

Thomas Prowse is a post-doctoral researcher in the School of Biological Sciences at the University of Adelaide.

Michelle Waycott

Michelle Waycott is a Professor in the School of Biological Sciences at the University of Adelaide.

Qifeng Ye

Qifeng Ye is Program Leader Inland waters and catchment ecology, SARDI Ecosystems and resources.

Sherry Zhai

Sherry Zhai is a research officer in the School of Agriculture and Environment at The University of Western Australia.

Matthew Gibbs

Matthew Gibbs is a senior research scientist at CSIRO, Adelaide