ESD REPORT SERIES No. 1 Exmouth Gulf Prawn Fishery Ecologically Sustainable Development FRDC – Subprogram Authors: Kangas, M., McCrea, J., Fletcher, W., Sporer, E. and Weir, V. Department of Fisheries Western Australian Fisheries and Marine Research Laboratories PO Box 20 North Beach WA 6920 Telephone (08) 9203 0111 Facsimile (08) 9203 0199 Website: http://www.fish.wa.gov.au Published by the Department of Fisheries, Western Australia ESD Report Series No. 1, January 2006 ISSN: 1448 - 3599 ISBN: 1 877098 21 3 ESD Report Series No. 1 – Exmouth Gulf Prawn Fishery Table of contents 1.0 Introduction .......................................................................................... 7 2.0 Overview .............................................................................................. 9 3.0 Background on the Exmouth Gulf Prawn Fishery .................................. 12 3.1 DESCRIPTION OF THE FISHERY .......................................................................... 12 3.2 BIOLOGY OF WESTERN KING PRAWNS ................................................................ 21 3.3 BIOLOGY OF BROWN TIGER PRAWNS .................................................................. 22 3.4 BIOLOGY OF ENDEAVOUR PRAWNS ..................................................................... 24 3.5 BIOLOGY OF BANANA PRAWNS ........................................................................... 25 3.6 MAJOR ENVIRONMENTS ..................................................................................... 25 3.6.1 Physical environment ............................................................................. 25 3.6.2 Economic environment ........................................................................... 26 3.6.3 Social environment ............................................................................... 26 4.0 Outline of reporting process ................................................................ 27 4.1 SCOPE .............................................................................................................. 27 4.2 OVERVIEW......................................................................................................... 27 4.3 ISSUE IDENTIFICATION (component trees) .................................................................. 28 4.4 RISK ASSESSMENT/PRIORITISATION PROCESS ................................................... 29 4.5 COMPONENT REPORTS ...................................................................................... 30 4.6 Application to meet EPBCA reQUIREMENT ..................................................... 31 4.7 OVERVIEW TABLE............................................................................................... 32 5.0 Performance reports ........................................................................... 36 5.1 RETAINED SPECIES ........................................................................................... 36 5.1.1 Primary species ..................................................................................... 36 5.1.1.1 Tiger prawns .......................................................................................... 36 5.1.1.2 King prawns ......................................................................................... 41 5.1.1.3 Endeavour prawns .................................................................................. 45 5.1.1.4 Banana prawns ..................................................................................... 47 5.1.2 By-product species ................................................................................. 50 5.1.2.1 Coral prawns ........................................................................................ 50 5.1.2.2 Blue Swimmer crabs ............................................................................. 52 5.1.2.3 Squid and cuttlefish .............................................................................. 53 5.1.2.4 Sharks .................................................................................................. 54 5.1.2.5 Bugs .................................................................................................... 54 5.1.2.6 Cobia ................................................................................................... 54 5.1.2.7 Cods ..................................................................................................... 55 5.1.2.8 Mackerel ............................................................................................... 55 5.1.2.9 Nor-west snapper ................................................................................... 55 5.1.2.10 Other species ....................................................................................... 55 ESD Report Series No. 1 – Exmouth Gulf Prawn Fishery 5.2 NON-RETAINED SPECIES .................................................................................... 56 5.2.1 Captured in nets .................................................................................... 56 5.2.1.1 Protected species – seasnakes .............................................................. 56 5.2.1.2 Protected species – Syngnathids ........................................................... 57 5.2.1.3 Protected species – Leatherback turtles .................................................. 57 5.2.1.4 Threatened/listed species – Green turtles .............................................. 58 5.2.1.5 Threatened/listed species – Loggerhead turtles....................................... 58 5.2.1.6 Threatened/listed species – Flatback turtles .......................................... 59 5.2.1.7 Threatened/listed species – Hawksbill turtles .......................................... 59 5.2.1.8 Discarded fish ....................................................................................... 60 5.2.1.9 Invertebrate species .............................................................................. 62 5.2.2 Interaction but no capture ...................................................................... 63 5.2.2.1 Protected species – Dugongs and cetaceans ........................................... 63 5.2.2.2 Protected species – Leatherback turtles .................................................. 64 5.2.2.3 Threatened/listed species – Loggerhead turtles....................................... 64 5.2.2.4 Threatened/listed species – Green turtles ............................................... 65 5.2.2.5 Threatened/listed species – Flatback turtles ........................................... 65 5.2.2.6 Threatened/listed species – Hawksbill turtles .......................................... 65 5.3.1 Impacts from removal or damage to the environment .............................. 66 5.3.1.1 Prawns ................................................................................................. 66 5.3.1.2 By-product species ................................................................................. 67 5.3.1.3 All retained and non-retained species ...................................................... 67 5.3.1.4 Impact to the mud/sand habitat ............................................................. 68 5.3.1.5 Impact to the coral/sponge habitat ......................................................... 71 5.3.1.6 Impact to the macro-algal habitats .......................................................... 71 5.3.2 Addition of materials to habitat ............................................................... 72 5.3.2.1 Discarding fish ....................................................................................... 72 5.3.3 General impacts on the environment ....................................................... 76 5.3.3.1 Creation of turbidity from trawling ........................................................... 76 5.3.3.2 Translocation ........................................................................................ 76 5.4 GOVERNANCE ................................................................................................... 77 5.4.1 Department of Fisheries – Management ................................................. 77 5.4.1.1 Management effectiveness (outcomes) ................................................... 77 5.4.1.2 Management arrangements .................................................................... 80 5.4.1.3 Compliance ........................................................................................... 83 5.4.1.4 Allocation among users .......................................................................... 84 5.4.2 Department of Fisheries – Legal arrangements ........................................ 84 5.4.2.1 OCS arrangements ................................................................................. 84 5.4.3 Department of Fisheries – Consultation ................................................... 85 5.4.3.1 Consultation ......................................................................................... 85 5.4.4 Department of Fisheries – Reporting ....................................................... 87 5.4.4.1 Assessments and reviews ...................................................................... 87 ESD Report Series No. 1 – Exmouth Gulf Prawn Fishery 6.0 Bibliography ........................................................................................ 89 7.0 Appendices ......................................................................................... 93 APPENDIX 1. Terminology ..........................................................................................