Queensland the Smart State National strategy for the survival of released line-caught fish: tropical reef species I.W. Brown, W.D. Sumpton, M. McLennan, D.J. Welch, J. Kirkwood, A. Butcher, A. Mapleston1, D. Mayer, G. Begg1, M. Campbell, I. Halliday and W. Sawynok2. Queensland Department of Primary Industries and Fisheries 1 Fish and Fisheries Research Centre, James Cook University, Townsville 2 Australian National Sportfishing Association; Infofish Services, Rockhampton PROJECT REPORT PR07-3313 FRDC Project no. 2003/019 July 2008 National strategy for the survival of released line-caught fish: tropical reef species I.W. Brown, W.D. Sumpton, M. McLennan, D.J. Welch, J. Kirkwood, A. Butcher, A. Mapleston1, D. Mayer, G. Begg1, M. Campbell, I. Halliday and W. Sawynok2 Queensland Department of Primary Industries and Fisheries 1 Fish and Fisheries Research Centre, James Cook University, Townsville 2 Australian National Sportfishing Association; Infofish Services, Rockhampton Project No. 2003/019 National strategy for the survival of released line-caught fish: tropical reef species (FRDC 2003/019) I.W. Brown, W.D. Sumpton, M. McLennan, D.J. Welch, J. Kirkwood, A. Butcher, A. Mapleston, D. Mayer, G. Begg, M. Campbell, I. Halliday and W. Sawynok. Published by the Department of Primary Industries and Fisheries, Queensland. © Fisheries Research and Development Corporation, the Queensland Department of Primary Industries and Fisheries, and the Reef and Rainforest Research Centre Limited (2008). This work is copyright. Except as permitted by the Copyright Act 1968 (Commonwealth), reproduction by any means (photocopying, electronic, mechanical, recording or otherwise), making available on-line, electronic transmission or other publication of this material is prohibited without the specific prior written permission of the copyright owners. Neither may information be stored electronically in any form whatsoever without such permission. The Department of Primary Industries and Fisheries (DPI&F) seeks to maximise the economic potential of Queensland’s primary industries on a sustainable basis. The Fisheries Research and Development Corporation plans, invests in and manages fisheries research and development throughout Australia. It is a statutory authority within the portfolio of the federal Minister for Agriculture, Fisheries and Forestry, jointly funded by the Australian Government and the fishing industry. This publication has been compiled by Dr Ian W Brown (Southern Fisheries Centre, Department of Primary Industries and Fisheries). While every care has been taken in preparing this publication, the State of Queensland accepts no responsibility for decisions or actions taken as a result of data, information, statement or advice, expressed or implied, contained in this report. The authors do not warrant that that the information in this publiction is free from errors or omissions. Nor do the authors accept any form of liability, be it contractual, tortious or otherwise, for the contents of this publication or for any consequences arising from its use or any reliance placed upon it. The information, opinions and advice contained in this publication may not relate to, or be relevant to, a reader’s particular circumstances. Opinions expressed by the authors are the individual opinions of those persons and are not necessarily those of the publisher or research provider. PR07-3313 ISBN 978 0 7345 0393 0 Enquiries should be addressed to: Intellectual Property and Commercialisation Unit Department of Primary Industries and Fisheries GPO Box 46 Brisbane Qld 4001 or [email protected] Tel.: +61 7 3404 6999 TABLE OF CONTENTS List of Figures………………………………………………………………………………………………v List of Tables ……………………………………………………………………………………………...ix Objectives ...………………...………………………………………………………………………….... xv Non-Technical Summary…………………...…………………………………………….……………….xv Acknowledgements…………………...……………………...………………………...……………….xviii Background…………………...…………………………………………..…………………………….xviii Need…………………...……………………………………………………………………………….…xix Chapter 1. EFFECT OF BAROTRAUMA-RELIEF PROCEDURES ON THE SHORT-TERM SURVIVAL OF RELEASED LINE-CAUGHT RED EMPEROR (Lutjanus sebae). ...........................1 1.1 ABSTRACT ................................................................................................................................................ 1 1.2 INTRODUCTION....................................................................................................................................... 1 1.3 MATERIALS AND METHODS ................................................................................................................ 4 1.3.1 Experimental site selection...................................................................................................................... 4 1.3.2 Experimental design: small cage and large vertical enclosure comparison............................................. 5 1.3.3 Apparatus design..................................................................................................................................... 5 Experiment A: Comparison of cages and vertical enclosures.......................................................................... 6 Experiment B: Effect of release method on survival. ...................................................................................... 7 1.3.4 Data analysis ........................................................................................................................................... 8 1.4 RESULTS.................................................................................................................................................... 8 1.4.1 Experiment A: Comparison of cages and vertical enclosures. ................................................................ 8 Deployment of apparatus ................................................................................................................................. 8 Experimental apparatus comparison ................................................................................................................ 9 1.4.2 Experiment B: Effect of release method on survival............................................................................... 9 Comparison of barotrauma-relief release methods .......................................................................................... 9 Effect of capture depth and body size on barotrauma.................................................................................... 11 Multiple recaptures of tagged red emperor .................................................................................................... 14 1.5 DISCUSSION............................................................................................................................................ 14 1.6 ACKNOWLEDGEMENTS....................................................................................................................... 16 1.7 REFERENCES.......................................................................................................................................... 16 Chapter 2. DOES BAROTRAUMA-RELIEF REDUCE SHORT TERM POST-RELEASE MORTALITY OF LINE-CAUGHT REEF FISH?................................................................................20 2.1 ABSTRACT .............................................................................................................................................. 20 2.2 INTRODUCTION..................................................................................................................................... 21 2.3 MATERIALS AND METHODS .............................................................................................................. 22 2.3.1 Site selection ......................................................................................................................................... 22 2.3.2 Experimental design.............................................................................................................................. 22 2.3.3 Apparatus design................................................................................................................................... 22 2.3.4 Operational details ................................................................................................................................ 22 2.3.5 Data analysis ......................................................................................................................................... 24 2.3.6 Release capsule – preliminary trials...................................................................................................... 24 ____________________________________________________________________________________________________________________ Page i FRDC Project 2003/019 2.4 RESULTS ................................................................................................................................................. 25 2.4.1 General overview of sample characteristics.......................................................................................... 25 2.4.2 Sample sizes and losses ........................................................................................................................ 25 2.4.3 Size-structure of experimental samples ................................................................................................ 26 2.4.4 Capture depth of samples.....................................................................................................................