1 Towards a southern connected basin flow plan: connecting rivers to recover native fish communities Ivor Stuart and Clayton Sharpe December 2017 Kingfisher Research and CPS Enviro 2 Citation: Stuart, I. and Sharpe, C. (2017). Towards a southern connected basin flow plan: connecting rivers to recover native fish communities. Kingfisher Research and CPS Enviro report to the Murray-Darling Basin Authority. Acknowledgements: This document has benefited by discussions with many riparian landholders, scientists and managers. Specifically we thank: Kat Cheshire (NSW DPI), Sam Davis (NSW DPI), Iain Ellis (NSW DPI), Tony Townsend (NSW DPI), Jarod Lyon (ARI), Martin Mallen-Cooper (Fishway Consulting Services), Wayne Smith (‘Karoola’ Station, Darling River) and Brenton Zampatti (SARDI). We appreciate help from Brayden Dykes (MDBA) who drafted many of the graphics used. Our thanks to Heleena Bamford and Stuart Little from the Murray-Darling Basin Authority for funding and supporting this work. Disclaimer: This publication may be of assistance to you but CPS Enviro Pty Ltd and Kingfisher Research Pty Ltd and its employees do not guarantee that the publication is without flaw of any kind or is wholly appropriate for your particular purposes and therefore disclaims all liability for any error, loss or other consequence which may arise from you relying on any information in this publication. This project was funded by the Murray-Darling Basin Authority. The contents of this publication do not purport to represent the position of the copyright holders or the Murray-Darling Basin Authority in any way and are presented for the purpose of informing and stimulating discussion for improved management of Basin's natural resources. The results and comments contained in this report have been provided on the basis that the recipient assumes the sole responsibility for the interpretation and application of them. Kingfisher Research and CPS Enviro and the authors give no warranty, express or implied, or assume any legal liability or responsibility for the accuracy, completeness or use of the results and comments contained in this report by the recipient or any third party. Contact Details: Name: Stuart Little Company: Murray-Darling Basin Authority Email: [email protected] Name: Dr. Ivor Stuart Company: Kingfisher Research Email: [email protected] Name: Dr. Clayton Sharpe Company: CPS Enviro Email: [email protected] Kingfisher Research and CPS Enviro 3 Contents Preamble .................................................................................................................................. 5 Executive Summary ................................................................................................................. 6 Acronyms ................................................................................................................................. 8 1. Introduction ....................................................................................................................... 9 2. Thinking big: A Southern Connected Basin Flow Plan for Native Fish ........................... 10 2.1 Vison and Objectives of a southern connected basin flow plan for native fish ............ 11 2.2 Principles of a southern connected basin flow plan for native fish .............................. 11 2.3 System scale flows: a definition ................................................................................... 12 2.4 What flows are included? ............................................................................................ 12 2.5 Rivers in the southern connected Basin flow plan for native fish................................. 13 2.6 Flows in the lower River Murray .................................................................................. 15 2.7 Approach ..................................................................................................................... 16 2.8 Fish species selection ................................................................................................. 18 2.8.1 Golden perch ........................................................................................................... 19 2.8.2 Silver perch .............................................................................................................. 21 2.8.3 Murray cod ............................................................................................................... 22 3. Case-studies for selected species .................................................................................. 25 3.1 Catchment recovery of golden perch in the southern connected rivers....................... 25 3.1.1 Golden perch population issue ................................................................................ 25 3.1.2 Hydrological issues .................................................................................................. 26 3.1.3 Recovery opportunity ............................................................................................... 26 3.1.4 Hydrograph planning ................................................................................................ 27 3.1.5 Field application and monitoring .............................................................................. 29 3.2 Local recovery of Murray cod in Gunbower Creek ...................................................... 31 3.2.1 Murray cod population issue .................................................................................... 31 3.2.2 Hydrological issues .................................................................................................. 31 3.2.3 Recovery opportunity ............................................................................................... 31 3.2.4 Hydrograph planning ................................................................................................ 31 3.2.5 Hydrograph components .......................................................................................... 32 3.2.6 Field application and monitoring .............................................................................. 33 3.2.7 Learnings ................................................................................................................. 33 3.2.8 Partnerships ............................................................................................................. 35 3.3 Reach scale recovery of silver perch in the mid-Murray .............................................. 36 3.3.1 Silver perch population issue ................................................................................... 36 3.3.2 Silver perch hydrological issue ................................................................................ 36 3.3.3 Recovery opportunity ............................................................................................... 38 Kingfisher Research and CPS Enviro 4 3.3.4 Hydrograph planning ................................................................................................ 38 3.3.5 Field application and monitoring .............................................................................. 39 4. Important considerations for long-term flow planning for native fish ............................... 40 4.1 Minimum spatial scale for fish outcomes ..................................................................... 40 4.2 River Murray system flows and fish recruitment .......................................................... 40 4.3 Hydraulics: flowing water is a pre-requisite for recovery ............................................. 41 4.4 Daily flow variability ..................................................................................................... 41 4.5 Why is a decadal flow plan needed? ........................................................................... 44 5. A long-term flow plan for native fish ................................................................................ 46 6. Implementation of the southern connected basin flow plan for native fish ...................... 57 6.1 Active testing of fish hydrographs: Darling River 2016/17 ........................................... 57 6.2 Using the Menindee Lakes and Darling River to help re-populate the southern MDB with golden perch ................................................................................................................... 58 6.3 Modified river operations that can support the fish hydrographs and outcomes ......... 59 6.4 The need for a fish management plan at Menindee Lakes ......................................... 60 6.5 Complementary actions ............................................................................................... 61 6.6 Collaboration and coordination .................................................................................... 64 6.7 Adaptive management ................................................................................................. 65 6.8 Future directions .......................................................................................................... 65 7. Summary ......................................................................................................................... 65 8. References ...................................................................................................................... 66 Appendix 1 - Who has been consulted? ................................................................................. 70 Appendix 2. Diagrammatic conceptual