Government of Western Australia Department of Water Ecological study of the lower Canning River environmental water releases A(below technical Canning report Dam for theto Kent project Street Weir) Tackling acid sulfate soils on the WA coast Looking after all our water needs Water technical series Report no. WST 35 November 2010Science Ecological study of the lower Canning River environmental water releases (below Canning Dam to Kent Street Weir) A technical report by the Water Science Branch Looking after all our water needs Department of Water Water Science Technical Series Report no. 35 November 2010 Department of Water Perth Western Australia 6000 Telephone +61 8 6364 7600 Facsimile +61 8 6364 7601 <www.water.wa.gov.au> © Government of Western Australia 2010 November 2010 This work is copyright. You may download, display, print and reproduce this material in unaltered form only (retaining this notice) for your personal, non-commercial use or use within your organisation. Apart from any use as permitted under the Copyright Act 1968, all other rights are reserved. Requests and inquiries concerning reproduction and rights should be addressed to the Department of Water. ISSN 1836-2869 (print) ISSN 1836-2877 (online) ISBN 978-1-921789-40-3 (print) ISBN 978-1-921789-41-0 (online) Acknowledgements This study is funded by the Water Allocation Planning Branch of the Department of Water and supports the Lower Canning River surface water allocation plan and Ecological water requirements for the lower Canning River documents. The authors would like to thank Steve Fisher, Kieryn Kilminster, Fiona Lynn and Renée Rowling for their review of this document, and the following for their assistance in carrying out the field work: Bronwyn Rennie, Georgina Evans, Luke Riley, Helen Nice, Damien Buller, Artemis Kitsios, Frances Millar, Kristy Ferguson, Ben Marillier, Gillian White, Naomi Hellriegel, Michael Hammond, Kelli O’Neil, Peter Kretschmer, Steve Fisher, Kieryn Kilminster and Sarah Evans. For more information about this report, contact: Sam Norton, Water Science Branch Citation details The recommended citation for this publication is: Norton S, Storer T & Galvin L 2010, Ecological study of the Lower Canning River environmental water releases, Water Science Technical Series, Report no. 35, Department of Water, Government of Western Australia, Perth. Cover photograph: To be supplied Disclaimer This document has been published by the Department of Water. Any representation, statement, opinion or advice expressed or implied in this publication is made in good faith and on the basis that the Department of Water and its employees are not liable for any damage or loss whatsoever which may occur as a result of action taken or not taken, as the case may be in respect of any representation, statement, opinion or advice referred to herein. Professional advice should be obtained before applying the information contained in this document to particular circumstances. This publication is available on our website <www.water.wa.gov.au> or for those with special needs it can be made available in alternative formats such as audio, large print, or Braille. Water Science Technical Series, report no. 35 Contents Summary ..................................................................................................................... v 1 Introduction.............................................................................................................. 1 1.1 Environmental water releases and release points ............................................................. 1 2 Methods .................................................................................................................. 3 2.1 Site selection ......................................................................................................................3 2.2 Sampling regime .................................................................................................................4 2.3 Fish sampling ......................................................................................................................4 Data analysis ........................................................................................................................................... 5 2.4 Water quality monitoring .....................................................................................................6 2.5 Macroinvertebrate sampling ...............................................................................................7 2.6 General site and habitat assessment ................................................................................. 8 3 Results .................................................................................................................... 9 3.1 Hydrological conditions .......................................................................................................9 3.2 River connectivity................................................................................................................9 3.3 General system health ......................................................................................................12 Fish and crayfish species richness ........................................................................................................ 12 Abundance of fish and crayfish .............................................................................................................. 13 Water quality data .................................................................................................................................. 15 Macroinvertebrate data .......................................................................................................................... 15 General site and habitat assessment..................................................................................................... 17 4 Discussion ............................................................................................................. 19 4.1 Stream connectivity ..........................................................................................................19 4.2 Environmental health ........................................................................................................20 Fish and crayfish ................................................................................................................................... 21 Macroinvertebrates ................................................................................................................................ 21 Water quality .......................................................................................................................................... 22 5 Conclusions ........................................................................................................... 23 6 Recommendations ................................................................................................ 24 Appendices ................................................................................................................ 25 Glossary .................................................................................................................... 37 References ................................................................................................................ 42 Appendices Appendix A — Temporal fish catch data ................................................................... 25 Appendix B — Fish and crayfish photographs ........................................................... 28 Appendix C — Macroinvertebrate abundance ........................................................... 31 Appendix D — Habitat data ....................................................................................... 33 Appendix E — Environmental water release management ....................................... 35 Department of Water iii Ecological study of the lower Canning River environmental water releases Figures Figure 1 Location of environmental release points and study sites on the lower Canning River ............................................................................................. 3 Figure 2 Rainfall (Bickley Brook and Gosnells), streamflow (Cannington Seaforth station), ERP total daily flow, ERP trigger and sampling periods ................ 9 Figure 3 Freshwater cobbler in downstream-facing fyke nets in the lower Canning River ......................................................................................................... 10 Figure 4 Length frequency distribution of freshwater cobbler caught in the lower Canning River. Fish caught in the downstream (DS) nets were considered to be migrating upstream while those in the upstream (US) nets were migrating downstream .............................................................................. 11 Figure 5 Proportional abundance of functional feeding groups of macroinvertebrates collected at the four sites in the lower Canning River in November 2009 ........................................................................................ 16 Tables Table 1 Sampling sites, locations and coordinates .................................................. 4 Table 2 Fauna size class ......................................................................................... 5 Table 3 Components of the Fish and crayfish sub-index (Storer et al. 2010). Adapted from the sustainable river fsh index of the sustainable river audit (Davies et al. 2008) ....................................................................................