Fish Community and Flow Ecology in the Western Mount Lofty Ranges Environmental Water Provisions Trial Reaches Dale McNeil, David Schmarr, Phillipa Wilson and David Reid SARDI Publication No. F2011/000313-1 SARDI Research Report Series No. 581 October 2011 Fish Community and Flow Ecology in the Western Mount Lofty Ranges Environmental Water Provisions Trial Reaches Final Report to the Adelaide and Mount Lofty Ranges Natural Resources Management Board and the SA Department for Water. Dale McNeil, David Schmarr, Phillipa Wilson and David Reid SARDI Publication No. F2011/000313-1 SARDI Research Report Series No. 581 October 2011 FRONTISPIECE: Surveying Site Access above the South Para River Gorge. This Publication may be cited as: McNeil, D.G., Schmarr, D.W., Wilson, P.J. and Reid D. J (2011). Fish Community and Flow Ecology in the Western Mount Lofty Ranges Environmental Water Provisions Trial Reaches. Final Report to the Adelaide and Mount Lofty Ranges Natural Resources Management Board and the SA Department for Water. South Australian Research and Development Institute (Aquatic Sciences), Adelaide. SARDI Research Report Series No. 581. 238pp. South Australian Research and Development Institute SARDI Aquatic Sciences 2 Hamra Avenue West Beach SA 5024 Telephone: (08) 8207 5400 Facsimile: (08) 8207 5406 http://www.sardi.sa.gov.au DISCLAIMER The authors warrant that they have taken all reasonable care in producing this report. The report has been through the SARDI Aquatic Sciences internal review process, and has been formally approved for release by the Chief, Aquatic Sciences. Although all reasonable efforts have been made to ensure quality, SARDI Aquatic Sciences does not warrant that the information in this report is free from errors or omissions. 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Printed in Adelaide: October 2011 SARDI Publication No. F2011/000313-1 SARDI Research Report Series No. 581 Author(s): Dale McNeil, David Schmarr, Phillipa Wilson and David Reid Reviewer(s): Michael Hammer, Rod Ward, Kathleen Beyer, Katherine Cheshire, Rehanna Halfyard, Steve Gatti and Dean Hartwell Approved by: Dr. Jason Nicol A/Principal Scientist – Inland Waters & Catchment Ecology Signed: Date: 4 October 2011 Distribution: Adelaide and Mount Lofty Ranges NRM Board, Department for Water, SAASC Library, University of Adelaide Library, Parliamentary Library, State Library and National Library Circulation: Public Domain McNeil et al. 2011 Fish and EWPs in the WMLR TABLE OF CONTENTS TABLE OF CONTENTS .................................................................................................................................................. I ACKNOWLEDGEMENTS ........................................................................................................................................... VI EXECUTIVE SUMMARY ........................................................................................................................................... VII 1. INTRODUCTION .................................................................................................................................................... 1 1.1. CATCHMENTS OF THE MOUNT LOFTY RANGES .................................................................................................. 1 1.2. FLOW MANAGEMENT AND REGIME .................................................................................................................... 1 1.3. FLOW ECOLOGY AND FISH IN THE WMLR ......................................................................................................... 2 1.4. ENVIRONMENTAL WATER PROVISIONS IN THE WMLR ...................................................................................... 4 1.5 AIMS .......................................................................................................................................................................... 8 2. METHODS ............................................................................................................................................................... 9 2.1. SITE DESCRIPTIONS ............................................................................................................................................. 9 2.1.1. South Para River ....................................................................................................................................... 9 2.1.2. River Torrens .......................................................................................................................................... 14 2.1.3. Onkaparinga River ................................................................................................................................. 22 2.2. FIELD SAMPLING DESIGN .................................................................................................................................. 24 2.3. PHYSICAL AND CHEMICAL SITE CHARACTERISTICS ........................................................................................... 27 2.4. DATA ANALYSIS ............................................................................................................................................... 28 3. RESULTS ................................................................................................................................................................ 29 3.1. SOUTH PARA RIVER ......................................................................................................................................... 29 3.1.1. South Para Weir...................................................................................................................................... 31 3.1.1.1. Site assessment .................................................................................................................................................... 31 3.1.1.2. Water Quality ...................................................................................................................................................... 33 3.1.1.3. Hydrology............................................................................................................................................................ 33 3.1.1.4. Fish community ................................................................................................................................................... 33 3.1.2. Para Wirra .............................................................................................................................................. 34 3.1.2.1. Site assessment .................................................................................................................................................... 34 3.1.2.2. Water Quality ...................................................................................................................................................... 38 3.1.2.3. Hydrology............................................................................................................................................................ 38 3.1.2.4. Fish community ................................................................................................................................................... 38 3.1.2.5. Fish population structure ..................................................................................................................................... 40 3.1.3. Nolan’s .................................................................................................................................................... 42 3.1.3.1. Site assessment .................................................................................................................................................... 42 i McNeil et al. 2011 Fish and EWPs in the WMLR 3.1.3.2. Water Quality ...................................................................................................................................................... 44 3.1.3.3. Hydrology............................................................................................................................................................ 45 3.1.3.4. Fish community ................................................................................................................................................... 46 3.1.3.5. Fish population structure ..................................................................................................................................... 47 3.1.4. Woodlands Weir ...................................................................................................................................... 51 3.1.4.1. Site assessment .................................................................................................................................................... 51 3.1.4.2. Water Quality ...................................................................................................................................................... 53 3.1.4.3. Hydrology...........................................................................................................................................................