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Nepean River Ecology of the Australian bass in tributaries of the Hawkesbury- Nepean River Alan Midgley Western Sydney University i Statement of Authentication I (Alan Midgley) declare that this thesis contains no material that has been accepted for the award of any other degree or diploma and that, to the best of the candidate's knowledge and belief, this thesis contains no material previously published or written by another person, except when due reference has been made in the text of this thesis. Signature: Date: 8 December 2015 ii Acknowledgements Professor Shelley Burgin – provision of ongoing support throughout my candidature and supervisory changes during her at time at Western Sydney University and beyond seeking solutions to help in the completion of my PhD thesis that we have both worked hard on over the years. She was diligent and adaptable throughout the good and bad times with the mutual goal of academic excellence. She has always been an excellent mentor allowing me to evolve my skills throughout my research career. Shelley has remained dedicated above and beyond her supervisory role and with that I want to acknowledge my gratitude for her hard work. Doctor Adrian Renshaw – ongoing assistance and supervision with progression of aspects of final thesis throughout my PhD. PhD Student Ms Loren Hull – for assistance in collaborative fieldwork at study sites and technical support for data analysis. Always supportive throughout my candidature, without which I would not have reached this milestone. Doctor Nathan Miles - tireless dedication in the field to assist in collection of samples for the project. Extremely helpful guidance in determining otolith microchemistry and statistical analysis of that data. Western Sydney University – provision of Commonwealth scholarship and ‘top-up’ for assistance in ongoing research throughout my PhD. The New South Wales Recreational Fishing Freshwater Trust and the NSW Department of Primary Industries for funding of the data collection program “NSW DPI Bass Catch Program” used for comparative purposes in this study. Additional thanks to Danielle Ghosn for personally supplying this information with a helpful attitude. Field and laboratory assistants Mr Jabin Round, Mr Ashley Thamm, Mr Michael Aldrich and Mr Michael Franklin – tireless dedication to assist in the collection and analysis of samples for the project. iii Mr Paul Smith – for assisting with sampling gear and taking a relaxed approach to laboratory work. This thesis is written as a series of papers to be published in the near future. For this reason there may some repetition between chapters. iv Table of Contents Table of Figures .................................................... ix Table of Tables .................................................... xix Table of Plates .................................................... xxv List of Abbreviations ......................................... xxvi Abstract .......................................................... xxviii 1. Ecological attributes and recreational fishing for Macquaria novemaculeata on Australia’s East Coast ....................................................................... 1 1.1 Introduction ..................................................................................................... 1 1.1.1 The importance of fish and human impacts ............................................. 1 1.1.2 Management requires knowledge of the fishery ...................................... 2 1.1.3 Percichthyidae and Macquaria novemaculeata ........................................ 5 1.1.4 Lifecycle and lifecycle interruption ......................................................... 8 1.1.5 Habitat selection..................................................................................... 14 1.1.6 Size and sexual differentiation ............................................................... 17 1.1.7 Diet ......................................................................................................... 20 1.1.8 Recreational fishing ............................................................................... 23 1.1.9 The current project ................................................................................. 28 1.2 References ..................................................................................................... 30 2. Site Description and Sampling Method ......... 52 2.1 Study Sites ..................................................................................................... 53 2.1.1 Obstacle-Strewn Tributaries ....................................................................... 57 2.1.2 Open Tributaries ......................................................................................... 64 2.2 Sampling Method .......................................................................................... 69 2.3 References ..................................................................................................... 70 3. Attitudes and behaviour of recreational fishers of Australian bass Macquaria novemaculeata with a focus on the Hawkesbury-Nepean River .............. 73 3.1 Introduction ................................................................................................... 73 3.1.1 Recreational fishing and Macquaria novemaculeata ............................. 75 3.2 Methods ......................................................................................................... 82 3.2.1 Data Analysis ......................................................................................... 83 3.3 Results ........................................................................................................... 83 3.3.1 Gender and age of anglers...................................................................... 85 3.3.2 Fishing group size, frequency of fishing, number of years fished ......... 85 3.3.3 Fishing sites, use, and the method of selection ...................................... 87 3.3.4 Percentage of effort focused on Macquaria novemaculeata, catch data (size, release rates), changes in attitude over time ............................................... 89 v 3.4 Discussion ..................................................................................................... 93 3.4.1 Gender and age of anglers...................................................................... 94 3.4.2 Fishing group size, frequency of fishing, number of years fished ......... 98 3.4.3 Fishing sites, use, and the method of selection .................................... 103 3.4.4 Percentage of effort focused on Macquaria novemaculeata, catch data (size, release rates), changes in attitude over time ............................................. 109 3.5 Conclusions ................................................................................................. 112 3.6 References ................................................................................................... 113 4. Demography of Australian bass Macquaria novemaculeata in tributaries of the Hawkesbury- Nepean River ...................................................... 152 4.1 Introduction ................................................................................................. 152 4.1.1 Size, age and sexual differentiation in fish .......................................... 152 4.1.2 Habitat selection and density ............................................................... 158 4.2 Methods ....................................................................................................... 161 4.2.1 Length and Weight ............................................................................... 161 4.2.2 Sex........................................................................................................ 161 4.2.3 Habitat Selection and Density .............................................................. 161 4.2.4 Otolith Removal and Age .................................................................... 162 4.2.5 Data Analysis ....................................................................................... 163 4.3 Results ......................................................................................................... 166 4.3.1 Sex Ratio .............................................................................................. 166 4.3.2 Length and Sex .................................................................................... 166 4.3.3 Fish Length .......................................................................................... 168 4.3.4 Weight .................................................................................................. 169 4.3.5 Condition.............................................................................................. 171 4.3.6 Age ....................................................................................................... 174 4.3.7 Growth ................................................................................................. 175 4.3.8 Sex and Growth.................................................................................... 178 4.3.9 Density ................................................................................................. 180 4.3.10 Habitat Selection .................................................................................. 181 4.3.11 Length and Habitat Selection ............................................................... 182 4.3.12 Comparison of fish length between tributaries and riverine channel .. 184
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