The Feasibility of Excluding Alien Redfin Perch from Macquarie Perch Habitat in the Hawkesbury-Nepean Catchment
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The feasibility of excluding alien redfin perch from Macquarie perch habitat in the Hawkesbury-Nepean Catchment James T. Knight Industry & Investment NSW Port Stephens Fisheries Institute Locked Bag 1, Nelson Bay, NSW, 2315 Australia Threatened Macquarie perch Alien redfin perch Project No. HN 0507 B6D June 2010 Industry & Investment NSW – Fisheries Final Report Series No. 121 ISSN 1837-2112 The feasibility of excluding alien redfin perch from Macquarie perch habitat in the Hawkesbury-Nepean Catchment. June 2010 Author: James T. Knight Published By: Industry & Investment NSW (now incorporating NSW Department of Primary Industries) Postal Address: Port Stephens Fisheries Institute, Locked Bag 1, Nelson Bay, NSW, 2315 Internet: www.industry.nsw.gov.au © Department of Industry and Investment (Industry & Investment NSW) and the Hawkesbury-Nepean Catchment Management Authority This work is copyright. Except as permitted under the Copyright Act, no part of this reproduction may be reproduced by any process, electronic or otherwise, without the specific written permission of the copyright owners. Neither may information be stored electronically in any form whatsoever without such permission. DISCLAIMER The publishers do not warrant that the information in this report is free from errors or omissions. The publishers do not accept any form of liability, be it contractual, tortuous or otherwise, for the contents of this report for any consequences arising from its use or any reliance placed on it. The information, opinions and advice contained in this report may not relate to, or be relevant to, a reader’s particular circumstance. ISSN 1837-2112 Note: Prior to July 2004, this report series was published by NSW Fisheries as the ‘NSW Fisheries Final Report Series’ with ISSN number 1440-3544. Then, following the formation of the NSW Department of Primary Industries the report series was published as the ‘NSW Department of Primary Industries – Fisheries Final Report Series’ with ISSN number 1449-9967. The report series is now published by Industry & Investment NSW as the ‘Industry & Investment NSW – Fisheries Final Report Series’ with ISSN number 1837-2112 Contents i TABLE OF CONTENTS TABLE OF CONTENTS.................................................................................................................................I LIST OF TABLES.......................................................................................................................................... II LIST OF FIGURES........................................................................................................................................ II LIST OF APPENDICES................................................................................................................................ II ACKNOWLEDGEMENTS..........................................................................................................................III NON-TECHNICAL SUMMARY ................................................................................................................IV 1. BACKGROUND ..................................................................................................................................... 6 2. MACQUARIE PERCH IN THE HAWKESBURY-NEPEAN CATCHMENT ................................ 9 3. TECHNIQUES FOR EXCLUDING REDFIN PERCH FROM MACQUARIE PERCH HABITAT IN THE WARRAGAMBA DAM STUDY AREA.............................................................................. 13 3.1. Physical exclusion ....................................................................................................................... 13 3.2. Behavioural systems.................................................................................................................... 15 3.3. Comparison of exclusion devices ................................................................................................ 17 4. EFFECTS OF AN EXCLUSION DEVICE ON THE LOCAL FISH POPULATIONS................. 22 5. LOCATION OF AN EXCLUSION DEVICE WITHIN THE STUDY AREA................................ 27 5.1. Background and site assessment methodology............................................................................ 27 5.1.1. Exclusion site location.................................................................................................................. 27 5.1.2. Existing infrastructure.................................................................................................................. 27 5.1.3. River geomorphology.................................................................................................................... 30 5.1.4. Hydrology..................................................................................................................................... 30 5.2. Results and discussion................................................................................................................. 30 6. APPROVALS REQUIRED TO CONSTRUCT AN EXCLUSION DEVICE ................................. 33 7. CONCLUSIONS AND RECOMMENDATIONS .............................................................................. 35 8. REFERENCES...................................................................................................................................... 36 9. APPENDICES....................................................................................................................................... 41 Exclusion of redfin perch from Macquarie perch habitat, J.T. Knight Project No. HN 0507 B6D ii Contents LIST OF TABLES Table 1a. The suitability of available physical exclusion devices for preventing the upstream dispersal of redfin perch in the tributaries of Warragamba Dam.............................................................. 18 Table 1b. The suitability of available behavioural exclusion devices for preventing the upstream dispersal of redfin perch in the tributaries of Warragamba Dam............................................... 19 Table 2. Fish species recorded in the Warragamba Dam catchment study area by I&I NSW between 1993 and 2007 and their associated movement behaviours....................................................... 24 Table 3. Criteria used to score each survey site for its suitability for the installation of a redfin perch exclusion device. ....................................................................................................................... 29 Table 4. Assessment of each survey site for its suitability for the installation of a redfin perch exclusion device. ....................................................................................................................... 31 LIST OF FIGURES Figure 1. The Hawkesbury-Nepean catchment depicting the study area surrounding Warragamba Dam and the currently known distribution of redfin perch and Macquarie perch. ...................... 7 Figure 2. Redfin perch Perca fluviatilis Linnaeus. ..................................................................................... 8 Figure 3. The eastern and western form of Macquarie perch...................................................................... 9 Figure 4. Currently known distribution of Macquarie perch and redfin perch within the Warragamba Dam study area.......................................................................................................................... 10 Figure 5. Typical rocky habitat inhabited by Macquarie perch in Wheeny Creek.................................... 11 Figure 6. Location of I&I NSW survey sites used to assess the fish species inhabiting Warragamba Dam and its feeder tributaries that may be affected by the installation of a redfin perch exclusion device. ....................................................................................................................... 23 Figure 7. Locations of sites 1 – 7 within the Warragamba Dam catchment study area investigated for their suitability for the installation of a redfin exclusion device. The currently known distributions of Macquarie perch and redfin perch within the study area are also shown. ........ 28 Figure 8. Site 5a located at Rucksack Ridge Ford, Kedumba River. ........................................................ 32 Figure 9. Site 7 located at the Kedumba River Crossing. ......................................................................... 32 LIST OF APPENDICES Appendix 1. Fish species recorded in the Warragamba Dam study area by I&I NSW. Data sourced from the I&I NSW Freshwater Fish Research Database.................................................................... 41 Appendix 2. Details of sites assessed in the Warragamba Dam catchment area for the installation of a redfin perch exclusion device.................................................................................................... 42 Appendix 3. Summary statistics for the flow regimes of the Kedumba, Cox’s, Nattai, and Little Rivers. .... 43 Appendix 4. Photographs of sites surveyed between the 25 – 27th September 2007 that were determined to be unsuitable for the installation of a redfin perch exclusion device..................................... 46 Project No. HN 0507 B6D Exclusion of redfin perch from Macquarie perch habitat, J.T. Knight Acknowledgements iii ACKNOWLEDGEMENTS This project was funded by the Hawkesbury-Nepean Catchment Management Authority (Project: HN 0507 B6D). The author wishes to thank the Industry & Investment NSW staff who assisted with this project. Dr Bob Creese and Peter Gallagher