Movement patterns and stock structure of Australian sardine (Sardinops sagax) off South Australia and the East Coast: implications for future stock assessment and management 1, 2 1 2 Christopher Izzo , Bronwyn M. Gillanders and Tim M. Ward SARDI Publication No. F2011/000487-1 SARDI Research Report Series No. 611 FRDC PROJECT NO. 2009/021 SARDI Aquatic Sciences PO Box 120 Henley Beach SA 5024 March 2012 Final Report to the Fisheries Research and Development Corporation 1 Movement patterns and stock structure of Australian sardine (Sardinops sagax) off South Australia and the East Coast: implications for future stock assessment and management Final Report to the Fisheries Research and Development Corporation 1, 2 1 2 Christopher Izzo , Bronwyn M. Gillanders and Tim M. Ward SARDI Publication No. F2011/000487-1 SARDI Research Report Series No. 611 ISBN: 978-1-921563-42-3 FRDC PROJECT NO. 2009/021 March 2012 2 This publication may be cited as: Izzo, C.1, 2, Gillanders, B.M1. and Ward, T.M1 (2012). Movement patterns and stock structure of Australian sardine (Sardinops sagax) off South Australia and the East Coast: implications for future stock assessment and management. Final Report to the Fisheries Research and Development Corporation. South Australian Research and Development Institute (Aquatic Sciences), Adelaide. SARDI Publication No. F2011/000487-1. SARDI Research Report Series No. 611. 102pp. 1 School of Earth and Environmental Sciences, The University of Adelaide, South Australia 2 South Australian Research and Development Institute of Aquatic Sciences South Australian Research and Development Institute SARDI Aquatic Sciences 2 Hamra Avenue West Beach SA 5024 Telephone: +61 8 8207 5400 Facsimile: +61 8 8207 5406 www.sardi.sa.gov.au DISCLAIMER The authors do not warrant that the information in this document is free from errors or omissions. The authors do not accept any form of liability, be it contractual, tortious, or otherwise, for the contents of this document or for any consequences arising from its use or any reliance placed upon it. The information, opinions and advice contained in this document may not relate, or be relevant, to a readers particular circumstances. Opinions expressed by the authors are the individual opinions expressed by those persons and are not necessarily those of the publisher, research provider or the FRDC. 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. The authors warrant that they have taken all reasonable care in producing this report. The report has been through the SARDI Aquatic Sciences internal review process, and has been formally approved for release by the Research Chief, Aquatic Sciences. © 2012 Fisheries Research and Development Corporation and SARDI Aquatic Sciences, and the University of Adelaide This work is copyright. Except as permitted under the Copyright Act 1968 (Cth), no part of this publication may be reproduced by any process, electronic or otherwise, without the specific written permission of the copyright owners. Information may not be stored electronically in any form whatsoever without such permission. Printed in Adelaide: March 2012 SARDI Publication No. F2011/000487-1 SARDI Research Report Series No. 611 ISBN: 978-1-921563-42-3 Author(s): Christopher Izzo1, 2, Bronwyn M. Gillanders1 and Tim M. Ward2 Reviewer(s): Anthony Fowler, Gregory Ferguson and an anonymous external referee Approved by: Dr Jason Tanner Science Leader – Marine Environment & Ecology Signed: Date: 29 March 2012 Distribution: FRDC, SAASC Library, University of Adelaide Library, Parliamentary Library, State Library and National Library Circulation: Public Domain 3 TABLE OF CONTENTS TABLE OF CONTENTS .................................................................................................. 4 LIST OF FIGURES ......................................................................................................... 6 LIST OF TABLES ........................................................................................................... 8 1. NON TECHNICAL SUMMARY ................................................................................. 10 OBJECTIVES ............................................................................................................ 10 NON TECHNICAL SUMMARY .................................................................................. 10 2. ACKNOWLEDGEMENTS ......................................................................................... 12 3. BACKGROUND ........................................................................................................ 13 3.1 STOCK DELINEATION OF SMALL PELAGIC TELEOSTS ................................ 13 3.2 THE AUSTRALIAN SARDINE Sardinops sagax (Jenyns 1842) ......................... 14 4. NEED ........................................................................................................................ 19 5. OBJECTIVES ........................................................................................................... 20 6. METHODS ................................................................................................................ 21 6.1 WEIGHT OF EVIDENCE APPROACH FOR DELINEATING THE STOCK STRUCTURE OF THE AUSTRALIAN SARDINE ...................................................... 21 6.2 ARCHIVED COLLECTIONS OF SARDINE OTOLITHS ...................................... 23 6.3 OTOLITH-BASED APPROACHES TO DELINEATING FISHABLE MANAGEMENT UNITS ............................................................................................. 24 6.4 NORMALISED ELLIPTICAL FOURIER ANALYSIS OF OTOLITH SHAPE ......... 26 6.4.1 Allometric effects on otolith shapes .............................................................. 28 6.4.2 Inter-annual variability in otolith shapes ........................................................ 29 6.4.3 Stock structure of sardine throughout south-eastern Australia, inferred from otolith shape .......................................................................................................... 30 6.5 ANALYSIS OF THE ELEMENTAL COMPOSITION OF SARDINE OTOLITHS .. 31 6.5.1 Otolith preparation ........................................................................................ 31 6.5.2 Laser ablation inductively coupled plasma mass spectrometry .................... 31 6.5.3 Relating element profile to otolith region ....................................................... 32 6.5.4 Analysis of the elemental data ...................................................................... 33 6.6 STOCK STRUCTURE WITHIN REGIONS .......................................................... 33 6.6.1 New South Wales ......................................................................................... 33 6.6.2 South Australia ............................................................................................. 33 7. RESULTS ................................................................................................................. 35 7.1 WEIGHT OF EVIDENCE APPROACH FOR DELINEATING THE STOCK STRUCTURE OF THE AUSTRALIAN SARDINE ...................................................... 35 7.1.1 Integration of the available data: definition of Australian sardine management units ....................................................................................................................... 38 7.2 ANALYSIS OF OTOLITH SHAPE ....................................................................... 39 7.2.1 Allometric development of the Australian sardine otolith .............................. 39 7.2.2 Allometric effects on otolith shape ................................................................ 40 7.2.3 Comparisons of otolith shape among non-sequential sampling years .......... 43 7.2.4 Inter-annual variability in the shapes of the sardine otolith ........................... 43 7.2.5 Stock structure of sardine throughout south-eastern Australia, inferred from otolith shape .......................................................................................................... 45 7.3 ANALYSIS OF THE ELEMENTAL COMPOSITION OF SARDINE OTOLITHS .. 48 7.3.1 New South Wales ......................................................................................... 48 7.3.2 South Australia ............................................................................................. 49 8. DISCUSSION ........................................................................................................... 54 4 8.1 WEIGHT OF EVIDENCE APPROACH FOR DELINEATING THE STOCK STRUCTURE OF THE AUSTRALIAN SARDINE ...................................................... 54 8.1.1 Weight of evidence approach for delineating stock structure ........................ 54 8.2 ANALYSIS OF OTOLITH SHAPE ........................................................................ 55 8.2.1 Inter-annual variability in the shapes of the sardine otolith ............................ 55 8.2.2 Stock structure of sardine throughout south-eastern Australia, inferred from otolith shape ........................................................................................................... 56 8.3 ANALYSIS OF THE ELEMENTAL COMPOSITION OF SARDINE OTOLITHS ... 58 8.3.1 New South Wales .........................................................................................