Fish and Flows in the Northern Basin: responses of fish to changes in flow in the Northern Murray–Darling Basin Valley Scale Report prepared for the Murray–Darling Basin Authority June 2015 © State of New South Wales through Department of Primary Industries – Fisheries NSW. With the exception of the Commonwealth Coat of Arms, the Murray–Darling Basin Authority logo, NSW Department of Primary Industries logo, and photographs, all material presented in this document is provided under a Creative Commons Attribution 3.0 Australia licence (http://creativecommons.org/licences/by/3.0/au/). For the avoidance of any doubt, this licence only applies to the material set out in this document. The details of the licence are available on the Creative Commons website (accessible using the links provided) as is the full legal code for the CC BY 3.0 AU licence (http://creativecommons.org/licences/by/3.0/legal code). MDBA’s preference is that this publication be attributed (and any material sourced from it) using: Publication title: Fish and Flows in the Northern Basin: responses of fish to changes in flow in the Northern Murray–Darling Basin – Valley Scale Report Source: Licensed from the NSW Department of Primary Industries under a Creative Commons Attribution 3.0 Australia Licence Acknowledgements: This project was funded by the Murray–Darling Basin Authority, and was undertaken by the NSW Department of Primary Industries on behalf of the Murray–Darling Basin Authority. NSW Department of Primary Industries Aquatic Habitat Rehabilitation Unit managed the project including research and report preparation. Personnel involved in completion of the project were: Anthony Townsend and Elizabeth Webb, with assistance from Karen Danaher, Craig Boys and Evan Knoll. The Aquatic Habitat Rehabilitation team would like to thank participants of the Fish and Flows in the Northern Basin workshop including Michael Hutchison, Peter Jackson, Stephen Balcombe, Jon Marshall, Sam Davis, Dean Gilligan, Craig Boys, Katherine Cheshire, Liz Webb, Neal Foster, Ivor Growns, Lee Baumgartner, Martin Mallen- Cooper, Brenton Zampatti, John Koehn, Andrew Warden, Adam Sluggett, and Heleena Bamford. The contents of this publication do not purport to represent the position of the Commonwealth of Australia or the MDBA in any way and are presented for the purpose of informing and stimulating discussion for improved management of Basin's natural resources. To the extent permitted by law, the copyright holders (including its employees and consultants) exclude all liability to any person for any consequences, including but not limited to all losses, damages, costs, expenses and any other compensation, arising directly or indirectly from using this report (in part or in whole) and any information or material contained in it. Contact us Inquiries regarding the licence and any use of the document are welcome at NSW Department of Primary Industries, 4 Marsden Park Road, CALALA 2340. This report should be cited as: NSW Department of Primary Industries (2015). Fish and Flows in the Northern Basin: responses of fish to changes in flow in the Northern Murray–Darling Basin – Valley Scale Report. Final report prepared for the Murray–Darling Basin Authority. NSW Department of Primary Industries, Tamworth. Front cover image: The threatened Murray Cod, a key native fish species of the Northern Murray–Darling Basin (photo credit – Gunther Schmida). Document accessibility: This publication is technical in nature and contains maps. If you require assistance in accessing this content in more detail than is provided, please contact the MDBA. i Executive summary Alteration of the natural flow regime across the majority of valleys in the Northern Murray–Darling Basin has had significant impacts on the hydrological, hydraulic and ecological conditions that native fish rely on for recruitment success and survival. The degradation of instream processes and habitat features across most major systems has resulted in the majority of fish communities of the Northern Basin being in poor to moderate condition. Fish and Flows in the Northern Basin will improve the understanding of environmental water requirements for fish in the Northern Murray–Darling Basin, with a focus on the Barwon–Darling, Condamine–Balonne, and regulated systems in NSW. To achieve this, existing information related to fish and flow interactions and requirements has been reviewed and compiled for specific valleys in the Northern Basin, including the Barwon–Darling, Condamine–Balonne, Border Rivers, Gwydir, Namoi and Macquarie. Initial analysis of this information has been considered in the context of water management, habitat condition and fish community status for the Northern Basin, and enhanced by the involvement of relevant expert knowledge and latest research findings to progress environmental water requirements for fish in the Northern Basin. Current activities across the Murray–Darling Basin, especially those related to water management, provide opportunities for fish communities to recover from detrimental impacts associated with river regulation. Management actions need to be developed based on best available science and knowledge in an adaptive framework. Fish and Flows in the Northern Basin has achieved this for overarching water management in the Northern Basin, with water requirements and management outcomes for fish able to be progressed through the consideration of six key outcomes: 1. Six functional groups of fish have been developed for the Northern Basin that are based on biological, hydrological and hydraulic requirements of fish for spawning, recruitment and movement. 2. Overarching conceptual flow models have been developed that identify the importance of certain flow characteristics (e.g. no-flow, baseflow, in-channel freshes and overbank) and hydrological variability for life history outcomes related to each functional group of species. 3. The overarching conceptual flow models can be used to develop specific water requirements for species where key hydrological and hydraulic information exists (including access to habitat), allowing particular flow attributes such as magnitudes, velocities, volumes and, rise and fall heights to be adapted from the conceptual models. 4. A broad range of published information, grey literature, primary data and knowledge sources relevant to fish and flows in the Northern Basin have been identified and collated. This knowledge base represents a significant step forward in building linkages between Northern and Southern fish work for a range of current and future activities. 5. Knowledge gaps still exist that limit the application of conceptual flow models to develop specific environmental water requirements, and additional activities would help gain a better understanding of habitat/flow interactions across the Northern Basin, allowing critical flow thresholds to be identified that strengthen water management actions. 6. Coordinated and targeted complementary actions also need to be considered in an adaptive management framework that incorporates rigorous scientific monitoring and evaluation, to ensure the most efficient and effective use of environmental water. ii CONTENTS 1 Introduction .............................................................................................................................. 1 1.1 Background and objectives ........................................................................................................... 1 2. Background .............................................................................................................................. 2 2.1 Northern Basin .............................................................................................................................. 2 2.2 Aquatic habitat of the Northern Basin ......................................................................................... 4 2.3 Fishes of the Northern Basin ........................................................................................................ 5 3. Fish and flows in the Northern Basin ....................................................................................... 12 3.1 Functional groups of fish in the Northern Basin ......................................................................... 14 3.2 Assemblage-based analysis of environmental flow requirements............................................. 19 3.3 Conceptual models for fish flows in the Northern Basin ............................................................ 20 4. Valleys of the Northern Basin ................................................................................................. 26 4.1 Introduction ................................................................................................................................ 26 4.2 Barwon–Darling .......................................................................................................................... 28 4.2.1 Introduction ......................................................................................................................... 28 4.2.2 Aquatic habitat of the Barwon–Darling ............................................................................... 33 4.2.3 Fishes of the Barwon–Darling .............................................................................................. 35 4.3 Condamine–Balonne .................................................................................................................. 39 4.3.1 Introduction ........................................................................................................................