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Spatially explicit population models for fish in the Barwon–Darling (Baaka) River

The research focused on improving understanding of low flow requirements of environmental assets and values in a climate change context and developing a conservation prioritisation method to identify priority locations for future management decisions.
MD-WERP
Science and research
Environment

 

MD-WERP theme Environmental outcomes
MD-WERP research question How can we better predict health of water dependent ecosystems? Develop tools to enable the Commonwealth to predict ecosystem responses to changes in flow?
Project title Spatially explicit population models for fish in the Barwon–Darling River system
Research lead La Trobe University
Authors L.M. McPhan, M.E. Shackleton and N.R. Bond 
Author contact details Nick Bond
Date of publication September 2024
Report full title Spatially explicit population models for fish in the Barwon–Darling (Baaka) River
Keywords Darling; Baaka; Menindee; native fish; fish kills; fish population; climate change; river management; water quality; habitat availability; freshwater fish; Murray cod; Golden perch; Bony bream; common carp; hydrology; extinction; cease to flow; waterhole; waterhole persistence; connectivity; dissolved oxygen
Summary of output
  • This project developed a spatially explicit dynamic fish population model to assess the population viability of four freshwater fish species (Murray cod, Golden perch, Bony bream and common carp) of the Darling (Baaka) River under hydrological conditions observed in the past ~40 years.
     
  • This document outlines the methods, results and discussion on population model use and performance, and management implications.  
Key findings / recommendations
  • The model results show that Golden perch and Murray cod are at risk of local extinction under multiple future scenarios.
  • These model predictions are reinforced by analyses of population age-structure, which shows that average rates of population growth within the system are well below replacement.  
  • Low abundances of the younger year classes is a notable feature of the Murray cod populations in the Darling (Baaka), particularly upstream of the Main weir at Menindee. This suggests either a decline in reproductive output or disproportionately high mortality among younger age classes.
  • The work reinforces the need to continue to seek to prevent local fish kills and shows there will be long-term population consequences unless these events can be avoided.  
Target audience Water managers, researchers, Australian Government, state governments, local governments, conservation advocacy groups, First Nations advisory groups and individual First Nations people
Report
Publication title Published File type File size
Spatially explicit population models for fish in the Barwon–Darling (Baaka) River 19 Sep 2024
PDF
6.16 MB
MD-WERP 2024 symposium poster 19 Jun 2024
PDF
1.65 MB
MD-WERP 2023 symposium poster 24 Oct 2023
PDF
4.79 MB

Published date: 19 May 2025