Northern Australian sharks and rays: the sustainability of target and bycatch species, phase 2 PRINCIPAL INVESTIGATOR : John Salini Project No. 2002/064 John Salini, Rory McAuley, Steve Blaber, Rik Buckworth, Justin Chidlow, Neil Gribble, Jenny Ovenden, Stirling Peverell, Richard Pillans, John Stevens, Ilona Stobutzki, Chris Tarca, Terry Walker. January 15, 2007 FRDC Crispian Ashby, FRDC Programs Manager PO Box 222, Deakin West ACT 2600 Fisheries Research House, 25 Geils Court, Deakin Phone: 02 6285 0425; Fax: 02 6285 4421 Copyright Fisheries Research and Development Corporation and CSIRO Marine and Atmospheric Research 2006 This work is copyright. Except as permitted under the Copyright Act 1968 (Cth), no part of this publication may be reproduced by any process, electron ic or otherwise, without the specific written permission of the copyright owners. Neither may information be stored electronically in any form whatsoever without such permission. The Fisheries Research and Development Corporation plans, invests in and man ages 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. Northern Australian sharks and rays: the sustainability of target and bycatch species, phase 2 Northern Australian sharks and rays: the sustainability of target and bycatch species, phase 2. Bibliography. Includes index. ISBN 1 921061 24 3. 1. Shark fisheries - Australia, Northern. 2. Shark fisheries - Bycatches - Australia, Northern. 3. Bycatches (Fisheries) - Australia, Northern. 4. Rays (Fishes) - Australia, Northern. I. Salini, John. II. CSIRO. Marine and Atmospheric Research. 338.372730994 Northern Australian sharks and rays: the sustainability of target and bycatch species, phase 2 Enquiries should be addressed to: John Salini PO Box 120, Cleveland, Qld. 4163 Ph 07 3826 7244, Fax 07 3826 7222 Email: [email protected] Distribution list Chief of Division Operations Manager Project Manager Client Authors Other CSIRO Staff National Library CMAR Libraries Important Notice © Copyright Commonwealth Scientific and Industrial Research Organisation (‘CSIRO’) Australia 2006 All rights are reserved and no part of this publication covered by copyright may be reproduced or copied in any form or by any means except with the written permission of CSIRO. The results and analyses contained in this Report are based on a number of technical, circumstantial or otherwise specified assumptions and parameters. 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Author John Salini Richard Pillans (Chapter 4, 6), Jennifer Ovenden (Chapter 3) Contributing authors Rik Buckworth, Neil Gribble, Rory McAuley, John Stevens, Project No. 2002/064 PRINCIPAL INVESTIGATOR: John Salini ADDRESS: CSIRO Marine and Atmospheric Research Cleveland Laboratories PO Box 120 Cleveland Qld 4163 Telephone: 07 3826 7200 Fax: 07 3826 7222 Northern Australian sharks and rays: the sustainability of target and bycatch species, phase 2 CONTENTS Non-technical Summary .............................................................................................. 1 Project Objectives.............................................................................................................1 Non Technical Summary: .................................................................................................2 OUTCOMES ACHIEVED TO DATE...................................................................................2 1. Chapter 1 Introduction........................................................................................ 5 1.1 Background .............................................................................................................5 1.2 Need .........................................................................................................................9 1.3 Benefits..................................................................................................................10 1.4 Further Development............................................................................................11 1.5 Planned Outcomes ...............................................................................................13 1.6 Conclusion.............................................................................................................17 1.7 Acknowledgments ................................................................................................19 1.8 Staff ........................................................................................................................20 1.8.1 Observers:..............................................................................................20 1.8.2 Other changes during the project: ......................................................20 1.9 References.............................................................................................................21 2. CHAPTER 2 – Objective 1 Catch data from target shark fisheries............... 23 2.1 Introduction ...........................................................................................................23 2.2 Method ...................................................................................................................23 2.3 Results ...................................................................................................................23 2.4 Discussion.............................................................................................................38 2.5 References.............................................................................................................40 3. CHAPTER 3 – Objective 2 Populations structure of blacktip sharks........... 41 3.1 Introduction ...........................................................................................................41 3.2 Methods .................................................................................................................41 3.3 Results and Discussion .......................................................................................42 3.3.1 Summary ................................................................................................42 3.3.2 Introduction............................................................................................43 3.4 Methods .................................................................................................................44 3.4.1 Sampling.................................................................................................44 3.4.2 Species identification............................................................................44 3.4.3 Laboratory..............................................................................................45 Northern Australian sharks and rays: the sustainability of target and bycatch species, phase 2 3.4.4 Data analyses.........................................................................................46 3.5 Results ...................................................................................................................46 3.5.1 Species identification............................................................................46 3.5.2 Microsatellites........................................................................................47 3.5.3 Microsatellites........................................................................................48 3.5.4 Mitochondrial control region................................................................50 3.6 Discussion.............................................................................................................53 3.7 Conclusion.............................................................................................................56 3.8 References.............................................................................................................57 4. Chapter 4 – Objective 3 Shark bycatch in gillnet fisheries ........................... 59 4.1 Method ...................................................................................................................59 4.2 Results ...................................................................................................................60