Fish communities of the Murrumbidgee catchment: Status and trends Dr Dean Gilligan NSW Department of Primary Industries Narrandera Fisheries Centre Buckingbong Road, Narrandera, NSW, 2700 Australia Murrumbidgee Catchment Management Authority Project No. BG4_03 March 2005 NSW Department of Primary Industries – Fisheries Final Report Series No. 75 ISSN 1449-9967 Fish communities of the Murrumbidgee catchment: Status and trends March 2005 Author: Gilligan, D. M. Published By: NSW Department of Primary Industries (now incorporating NSW Fisheries) Postal Address: Cronulla Fisheries Centre, PO Box 21, NSW, 2230 Internet: www.fisheries.nsw.gov.au NSW Department of Primary Industries 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. Cover photo credits: Gunther Schmida – freshwater catfish, carp-gudgeon, golden perch, silver perch, Macquarie perch, Murray-Darling rainbowfish and southern purple-spotted gudgeon. Ian Wooden – river scene and common carp. Kris Pitman – southern pygmy perch, Nicole McKirdy – trout cod. 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 1449-9967 (Note: Prior to July 2004, this report series was published as the ‘NSW Fisheries Final Report Series’ with ISSN number 1440-3544) Contents i TABLE OF CONTENTS TABLE OF CONTENTS.................................................................................................................................I LIST OF TABLES.........................................................................................................................................III LIST OF FIGURES ......................................................................................................................................IV ACKNOWLEDGEMENTS..........................................................................................................................VI NON-TECHNICAL SUMMARY .............................................................................................................. VII 1. INTRODUCTION ................................................................................................................................ 13 2. SITE SELECTION, SAMPLING PROTOCOL AND DATA MANAGEMENT........................... 21 2.1. SITE SELECTION ............................................................................................................................ 21 2.1.1. Randomly selected monitoring sites.................................................................................... 21 2.1.2. Targeted threatened species sites........................................................................................ 22 2.2. SAMPLING PROCEDURE ................................................................................................................. 27 2.2.1. Riverine sites ....................................................................................................................... 27 2.2.2. Wetland sites ....................................................................................................................... 28 2.2.3. Habitat assessment..............................................................................................................28 2.3. DATA ENTRY AND QUALITY ASSURANCE ...................................................................................... 28 3. STATUS OF FISH COMMUNITIES OF THE MURRUMBIDGEE CATCHMENT IN 2004 .... 29 3.1. INTRODUCTION ............................................................................................................................. 29 3.2. METHODS ..................................................................................................................................... 29 3.2.1. Site selection and sampling procedure ............................................................................... 29 3.2.2. Data analysis....................................................................................................................... 30 3.3. RESULTS ....................................................................................................................................... 33 3.3.1. Catch data........................................................................................................................... 33 3.3.2. Spatial structure of fish communities within the Murrumbidgee catchment....................... 33 3.3.3. Analysis of altitude zones.................................................................................................... 37 3.3.4. Analysis of functional eco-types.......................................................................................... 37 3.3.5. 2004 benchmark of fish communities in the Murrumbidgee catchment.............................. 42 3.3.5.1. Species richness ................................................................................................................................ 42 3.3.5.2. Total abundance................................................................................................................................ 42 3.3.5.3. Total biomass.................................................................................................................................... 42 3.3.5.4. Shannon’s Diversity H and evenness J ............................................................................................. 51 3.3.5.5. Proportion native fish........................................................................................................................ 51 3.3.5.6. Proportion recruits ............................................................................................................................ 51 3.3.5.7. Power analyses.................................................................................................................................. 60 3.4. DISCUSSION .................................................................................................................................. 61 4. STATUS OF INDIVIDUAL SPECIES IN THE MURRUMBIDGEE CATCHMENT IN 2S04... 63 4.1. INTRODUCTION ............................................................................................................................. 63 4.2. METHODS ..................................................................................................................................... 63 4.3. RESULTS AND DISCUSSION ........................................................................................................... 63 4.3.1. Proportion of catch .............................................................................................................63 4.3.2. Proportion of biomass......................................................................................................... 64 4.3.3. Proportion of sites............................................................................................................... 64 4.3.4. Proportion recruits .............................................................................................................64 5. TARGETED ASSESSMENT OF POPULATIONS OF THREATENED FISH SPECIES WITHIN THE MURRUMBIDGEE.................................................................................................... 69 5.1. INTRODUCTION ............................................................................................................................. 69 5.2. METHODS ..................................................................................................................................... 69 5.2.1. Site selection and sampling procedure ............................................................................... 69 5.2.2. Data analysis....................................................................................................................... 70 5.3. RESULTS ....................................................................................................................................... 70 5.3.1. Trout cod – Endangered (FM Act 1994)............................................................................. 70 Fish in the Murrumbidgee, Gilligan CMA Project No. BG4_03 ii Contents 5.3.2. Murray hardyhead – Endangered (FM Act 1994)...............................................................73 5.3.3. Olive perchlet – Endangered (western population) (FM Act 1994) ....................................74 5.3.4. Southern purple–spotted gudgeon – Endangered (western population) (FM Act 1994).....75 5.3.5. Silver perch – Vulnerable (FM Act 1994)............................................................................77 5.3.6. Macquarie perch – Vulnerable (FM Act 1994) ...................................................................79 5.3.7. Southern pygmy perch – Vulnerable (FM Act 1994)...........................................................81 5.4. DISCUSSION...................................................................................................................................82