Fisheries Research Report No. 271, 2017 Status of southern garfish (Hyporhamphus melanochir) in Cockburn Sound, Western Australia K. Smith, C. Dowling, S. Mountford, A. Hesp, A. Howard & J. Brown Fisheries Research Division Western Australian Fisheries and Marine Research Laboratories PO Box 20 NORTH BEACH, Western Australia 6920 9060Fisheries/15 Research Report [Western Australia] No. 271, 2015 i Correct citation: K. Smith, C. Dowling, S. Mountford, A. Hesp, A. Howard & J. Brown. 2017. Status of southern garfish (Hyporhamphus melanochir) in Cockburn Sound, Western Australia. Fisheries Research Report No. 271, Department of Fisheries, Western Australia. 140pp. Enquiries: WA Fisheries and Marine Research Laboratories, PO Box 20, North Beach, WA 6920 Tel: +61 8 9203 0111 Email: [email protected] Website: www.fish.wa.gov.au ABN: 55 689 794 771 A complete list of Fisheries Research Reports is available online at www.fish.wa.gov.au Department of Fisheries 3rd floor, The Atrium 168 – 170 St Georges Terrace PERTH WA 6000 Telephone: (08) 9482 7333 Facsimile: (08) 9482 7389 Website: www.fish.wa.gov.au ABN: 55 689 794 771 © Department of Fisheries, Western Australia. January 2017. ISSN: 1035-4549 (Print) ISBN: 978-1-877098-14-7 (Print) ISSN: 2202-5758 (Online) ISBN: 978-1-877098-15-4 (Online) ii Fisheries Research Report [Western Australia] No. 271, 2017 Table of Contents Executive Summary ............................................................................................ 1 1 Introduction .................................................................................................. 3 1.1 Background ................................................................................................................ 3 1.2 Resource assessment framework – finfish suites and indicator species ............... 4 1.3 Weight of evidence assessment ................................................................................. 4 1.4 Objectives ................................................................................................................... 5 2 Biological synopsis ...................................................................................................... 7 2.1 Taxonomy ................................................................................................................... 7 2.2 Garfish species in Western Australia ...................................................................... 7 2.3 Distribution, habitat and diet ................................................................................... 7 2.4 Stock structure........................................................................................................... 8 2.5 Morphometrics .......................................................................................................... 9 2.6 Eggs and larvae.......................................................................................................... 9 2.7 Fecundity .................................................................................................................. 10 2.8 Spawning period ...................................................................................................... 11 2.9 Sex ratio .................................................................................................................... 11 2.10 Length at maturity .................................................................................................. 12 2.11 Age at maturity ........................................................................................................ 12 2.12 Maximum age and length ....................................................................................... 13 2.13 Growth characteristics ............................................................................................ 13 2.14 Mortality .................................................................................................................. 14 3 Biology of Hyporhamphus melanochir in WA ................................................. 20 3.1 Introduction ............................................................................................................. 20 3.2 Methods .................................................................................................................... 21 3.2.1 Fishery-independent sampling ........................................................................... 21 3.2.2 Sampling of fishery landings ............................................................................. 22 3.2.3 Laboratory .......................................................................................................... 23 3.2.4 Otoliths and age estimation ................................................................................ 24 3.2.5 Analysis of length and weight data .................................................................... 25 3.2.6 Growth ............................................................................................................... 25 3.2.7 Timing of reproduction ...................................................................................... 25 3.3 Results ...................................................................................................................... 26 3.3.1 Spawning period ................................................................................................ 26 3.3.2 Length-at-maturity ............................................................................................. 27 3.3.3 Age-at maturity .................................................................................................. 28 3.3.4 Growth ............................................................................................................... 28 3.4 Discussion ................................................................................................................. 28 3.4.1 Spawning period ................................................................................................ 28 3.4.2 Length at maturity .............................................................................................. 29 3.4.3 Age at maturity .................................................................................................. 29 3.4.4 Growth and longevity ........................................................................................ 29 3.4.5 Conclusion ......................................................................................................... 30 4 Fishery catch and effort .......................................................................................... 41 4.1 Introduction ............................................................................................................. 42 Fisheries Research Report [Western Australia] No. 271, 2017 iii 4.2 Methods .................................................................................................................... 42 4.2.1 Fisheries management ........................................................................................ 42 4.2.2 Sources of commercial catch data ...................................................................... 43 4.2.3 Calculation of commercial catch-per-unit-effort (CPUE) ................................. 44 4.2.4 Recreational fishery catch and effort ................................................................. 46 4.3 Results ...................................................................................................................... 48 4.3.1 Total commercial catch by Bioregion ................................................................ 48 4.3.2 Wilson Inlet commercial fishery ........................................................................ 49 4.3.3 South Coast Bioregion ocean beach commercial fishery .................................. 50 4.3.4 Cockburn Sound commercial fishery ................................................................. 50 4.3.5 West Coast Bioregion recreational fishery ........................................................ 51 4.4 Discussion ................................................................................................................. 53 5 Composition of fishery catches ................................................................. 77 5.1 Introduction ............................................................................................................. 78 5.2 Methods .................................................................................................................... 78 5.2.1 Composition of fishery landings - current ......................................................... 78 5.2.2 Composition of fishery landings – historical ..................................................... 79 5.2.3 Analysis.............................................................................................................. 79 5.2.4 Recreational fishing surveys and logbooks ........................................................ 80 5.3 Results ...................................................................................................................... 81 5.3.1 Cockburn Sound (WCB) commercial catch composition .................................. 81 5.3.2 WCB recreational catch composition ................................................................ 82 5.3.3 SCB commercial catch composition .................................................................. 83 5.3.4 SCB recreational catch composition .................................................................