Determining appropriate sizes at harvest for species shared by the commercial trap and recreational fisheries in New South Wales John Stewart and Julian M. Hughes NSW Department of Primary Industries Cronulla Fisheries Research Centre of Excellence PO Box 21 Cronulla NSW 2230 Australia FRDC Project No. 2004/035 February 2008 NSW Department of Primary Industries – Fisheries Final Report Series No. 97 ISSN 1449-9967 Determining appropriate sizes at harvest for species shared by the commercial trap and recreational fisheries in New South Wales February 2008 Authors: John Stewart & Julian M. Hughes Published By: NSW Department of Primary Industries (now incorporating NSW Fisheries) Postal Address: Cronulla Fisheries Research Centre of Excellence, PO Box 21, NSW, 2230 Internet: www.dpi.nsw.gov.au © NSW Department of Primary Industries and the Fisheries Research and Development Corporation This work is copyright. 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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 iii TABLE OF CONTENTS TABLE OF CONTENTS ..............................................................................................................................III LIST OF TABLES .......................................................................................................................................... V LIST OF FIGURES....................................................................................................................................... VI ACKNOWLEDGEMENTS ........................................................................................................................... X NON-TECHNICAL SUMMARY ................................................................................................................XI 1. INTRODUCTION...................................................................................................................................... 13 1.1. Background................................................................................................................................ 13 1.2. Need ........................................................................................................................................... 13 1.3. Objectives .................................................................................................................................. 13 2. GENERAL MATERIALS AND METHODS.................................................................................................... 14 2.1. Landings in NSW ....................................................................................................................... 14 2.2. Reproduction ............................................................................................................................. 15 2.3. Age and growth.......................................................................................................................... 17 2.4. Mortality estimates .................................................................................................................... 17 2.5. Market price............................................................................................................................... 18 2.6. Per recruit analyses ................................................................................................................... 18 2.7. Spawning potential ratio............................................................................................................ 18 2.8. Information fact sheets .............................................................................................................. 19 3. BIOLOGY AND FISHERY FOR RUBBERLIP MORWONG .............................................................................. 20 3.1. Introduction ............................................................................................................................... 20 3.2. Materials and methods .............................................................................................................. 20 3.3. Results........................................................................................................................................ 20 3.4. Discussion.................................................................................................................................. 38 4. BIOLOGY AND FISHERY FOR TARWHINE................................................................................................. 40 4.1. Introduction ............................................................................................................................... 40 4.2. Materials and methods .............................................................................................................. 41 4.3. Results........................................................................................................................................ 42 4.4. Discussion.................................................................................................................................. 63 5. BIOLOGY AND FISHERY FOR BLACKSPOT PIGFISH .................................................................................. 67 5.1. Introduction ............................................................................................................................... 67 5.2. Materials and methods .............................................................................................................. 67 5.3. Results........................................................................................................................................ 68 5.4. Discussion.................................................................................................................................. 87 6. BIOLOGY AND FISHERY FOR MAORI WRASSE ......................................................................................... 89 6.1. Introduction ............................................................................................................................... 89 6.2. Materials and methods .............................................................................................................. 89 6.3. Results........................................................................................................................................ 90 6.4. Discussion................................................................................................................................ 107 7. BIOLOGY AND FISHERY FOR RED ROCKCOD ......................................................................................... 109 7.1. Introduction ............................................................................................................................. 109 7.2. Materials and methods ............................................................................................................ 109 7.3. Results...................................................................................................................................... 110 7.4. Discussion................................................................................................................................ 130 8. BIOLOGY AND FISHERY FOR PEARL PERCH........................................................................................... 132 8.1. Introduction ............................................................................................................................. 132 8.2. Materials and methods ............................................................................................................ 133 8.3. Results...................................................................................................................................... 134 Project No. 2004/035 Biology of coastal fish, Stewart & Hughes iv Contents 8.4. Discussion ................................................................................................................................ 157 9. BIOLOGY AND FISHERY FOR OCEAN LEATHERJACKET .......................................................................... 161 9.1. Introduction.............................................................................................................................. 161 9.2. Materials and methods............................................................................................................. 161 9.3. Results ...................................................................................................................................... 162 9.4. Discussion ................................................................................................................................ 171 10. BIOLOGY