MURRAY–DARLING BASIN AUTHORITY Environmental Watering for Food Webs in The Living Murray Icon Sites A literature review and identification of research priorities relevant to the environmental watering actions of flow enhancement and retaining floodwater on floodplains Report to the Murray–Darling Basin Authority Project number MD1253 September 2009 Environmental Watering for Food Webs in The Living Murray Icon Sites A literature review and identification of research priorities relevant to the environmental watering actions of flow enhancement and retaining floodwater on floodplains Report to the Murray–Darling Basin Authority Project number MD1253 Justin Brookes, Kane Aldridge, George Ganf, David Paton, Russell Shiel, Scotte Wedderburn University of Adelaide September 2009 Murray–Darling Basin Authority MDBA Publication No. 11/12 Authors: Justin Brookes, Kane Aldridge, George Ganf, ISBN (on‑line) 978‑1‑922068‑12‑5 David Paton, Russell Shiel, Scotte Wedderburn The MDBA provides this information in good faith © Copyright Murray‑Darling Basin Authority (MDBA), but to the extent permitted by law, the MDBA and on behalf of the Commonwealth of Australia 2012. the Commonwealth exclude all liability for adverse consequences arising directly or indirectly from using With the exception of the Commonwealth Coat of any information or material contained within this Arms, the MDBA logo, all photographs, graphics publication. and trademarks, this publication is provided under a Creative Commons Attribution 3.0 Australia Licence. cover images: Sedge (Eleocharis spatheolata) in Barmah–Millewa Forest icon site (photo by Keith Ward, Goulburn Broken CMA) Small mouthed hardyhead (photo by Gunther Schmida ©MDBA) Royal spoonbill adult and chick (photo by Keith Ward, http://creativecommons.org/licenses/by/3.0/au Goulburn Broken CMA) The MDBA’s preference is that you attribute this River red gum in Gunbower–Koondrook–Perricoota Forest publication (and any material sourced from it) using icon site (photo by David Kleinert ©MDBA) the following wording: Title: Environmental Watering for Food Webs in The Living Murray Icon Sites — A literature review Murray–Darling Basin Authority and identification of research priorities relevant Postal Address: GPO Box 1801, Canberra ACT 2601 to the environmental watering actions of flow enhancement and retaining floodwater on Office location: Level 4, 51 Allara Street, floodplains Canberra City, Australian Capital Territory Source: Licensed from the Murray–Darling Basin Tel: (02) 6279 0100, international + 61 2 6279 0100 Authority, under a Creative Commons Fax: (02) 6248 8053, international + 61 2 6248 8053 Attribution 3.0 Australia Licence. E‑mail: [email protected] Website: www.mdba.gov.au For further information contact the Murray–Darling Basin Authority office on (02) 6279 0100. ii EnvIRonMEntal WaterinG FoR FooD WEBS In ThE LIvInG MURRAy Icon SITES Contents Background ..................................................................................................................................................................................................................................................................................................... 1 1. Literature review .................................................................................................................................................................................................................................................................. 2 Food web studies in the Murray–Darling Basin ......................................................................................................................................................................... 2 Zooplankton ecology—linking productivity to higher organisms ...................................................................................................................... 5 Fish, diets and habitat ................................................................................................................................................................................................................................................13 Larval fish diets ...................................................................................................................................................................................................................................................................13 Adult fish diets ......................................................................................................................................................................................................................................................................14 Effects of flooding on fish food items, spawning and recruitment ...............................................................................................................14 Fish movement through connectivity between floodplain habitats and the river channel or Lower Lakes ....................................................................................................................................................................................................................................................................15 Dietary response of native fish species to flooding ...........................................................................................................................................................15 Fish water quality tolerances (e.g. salinity, pH, dissolved oxygen) .............................................................................................................15 Diets and food resources of waterbirds .............................................................................................................................................................................................16 Aquatic and riparian vegetation; growth and distribution in relation to key environmental factors in the River Murray ..................................................................................................................................................................................................................................17 Carbon sources, leaf litter inputs and phytoplankton primary productivity ...................................................................................22 Nutrient flux on inundated floodplains .............................................................................................................................................................................................26 Future flow, flooding and wetland response ..............................................................................................................................................................................28 Techniques for assessing food webs ......................................................................................................................................................................................................29 Conclusions ...............................................................................................................................................................................................................................................................................30 2. Conceptual models: linking flow enhancement and water retention on floodplains with aquatic food sources response ........................................................................................................................................................................................................31 3. Knowledge gaps and key hypotheses ...................................................................................................................................................................................................40 4. Options to assess knowledge gaps during dry periods ................................................................................................................................................42 5. Data sources to inform future projects ...............................................................................................................................................................................................43 6. References..................................................................................................................................................................................................................................................................................44 Appendix 1 ....................................................................................................................................................................................................................................................................................................53 Appendix 2 ....................................................................................................................................................................................................................................................................................................55 Appendix 3 ....................................................................................................................................................................................................................................................................................................58 EnvIRonMEntal WaterinG