FRDC FINAL REPORT SPATIAL MANAGEMENT OF REEF FISHERIES AND ECOSYSTEMS: UNDERSTANDING THE IMPORTANCE OF MOVEMENT Colin D. Buxton, Jayson M. Semmens, Edward Forbes, Jeremy M. Lyle, Neville S. Barrett and Michael J. Phelan May 2010 FRDC Project 2004/002 Buxton, C.D., Semmens, J.M., Forbes, E., Lyle, J.M., Barrett, N.S., Phelan, M.J. Spatial management of reef fisheries and ecosystems: Understanding the importance of movement. ISBN 978-1-86295-570-7 The Tasmanian Aquaculture and Fisheries Institute, University of Tasmania and Fisheries Research and Development Corporation 2010. 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. 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 reader’s particular circumstance. Opinions expressed by the authors are the individual opinions expressed by those persons and are not necessarily those of the Tasmanian Aquaculture and Fisheries Institute or the University of Tasmania or the FRDC. Enquires should be directed to: Prof Colin Buxton Director Tasmanian Aquaculture and Fisheries Institute University of Tasmania Private Bag 49, Hobart, Tasmania 7001 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 Reef fish movement TABLE OF CONTENTS NON-TECHNICAL SUMMARY................................................................................. 1 ACKNOWLEDGEMENTS .......................................................................................... 4 BACKGROUND ............................................................................................................ 5 CHAPTER 1: SPATIAL AND TEMPORAL USE OF AGGREGATION SITES BY THE TROPICAL SCIAENID PROTONIBEA DIACANTHUS.......................... 7 1.1 INTRODUCTION ............................................................................................. 8 1.2 MATERIALS AND METHODS .................................................................... 10 1.2.1 Study sites and acoustic receiver deployment ................................................................10 1.2.2 Receiver range testing ......................................................................................................14 1.2.3 Acoustic tags .....................................................................................................................14 1.2.4 Tagging trial .....................................................................................................................15 1.2.5 Tagging .............................................................................................................................15 1.2.6 Analysis .............................................................................................................................16 1.3 RESULTS ......................................................................................................... 17 1.3.1 Receiver range tests .........................................................................................................17 1.3.2 Acoustic monitoring .........................................................................................................21 1.3.3 Spectral analysis ...............................................................................................................23 1.4 DISCUSSION................................................................................................... 29 CHAPTER 2: SPATIAL AND TEMPORAL MOVEMENT PATTERNS, SITE FIDELITY AND RESIDENCY OF TWO VULNERABLE TEMPERATE ROCKY-REEF FISH, CHEILODACTYLUS SPECTABILIS AND LATRIDOPSIS FORSTERI .................................................................................................................... 33 2.1 INTRODUCTION ........................................................................................... 34 2.2 MATERIALS AND METHODS .................................................................... 36 2.2.1 Study site and acoustic receiver deployment .................................................................36 2.2.2 Study site bathymetry and habitat classification ...........................................................44 2.2.3 Acoustic transmitters .......................................................................................................45 2.2.4 VRAP positional error testing .........................................................................................45 2.2.5 VR2 range testing .............................................................................................................45 2.2.6 Tagging .............................................................................................................................47 2.2.7 Analysis .............................................................................................................................48 2.3 RESULTS ......................................................................................................... 53 2.3.1 VR2 Receiver range tests .................................................................................................53 2.3.2 VR2 acoustic monitoring .................................................................................................53 2.3.3 VRAP positional error .....................................................................................................72 2.3.4 VRAP tracking .................................................................................................................72 2.4 DISCUSSION................................................................................................... 77 BENEFITS AND ADOPTION ................................................................................... 80 FURTHER DEVELOPMENT.................................................................................... 80 i FRDC Project 2004/002 Reef fish movement PLANNED OUTCOMES ............................................................................................82 CONCLUSION.............................................................................................................82 LITERATURE CITED................................................................................................84 APPENDIX 1: INTELLECTUAL PROPERTY ......................................................91 APPENDIX 2: STAFF ................................................................................................91 FRDC Project 2004/002 ii Reef fish movement 2004/002 Evaluation of spatial management of reef fisheries and ecosystems: understanding the importance of movement PRINCIPAL INVESTIGATOR Professor Colin D. Buxton ADDRESS University of Tasmania Tasmanian Aquaculture and Fisheries Institute Private Bag 49 Hobart TAS 7001 Telephone: 03 6227 7277 Fax: 03 6227 8035 OBJECTIVES 1. To study the movement patterns of key reef associated fishes in Tasmania and the Northern Territory. 2. To link movement patterns with critical life history events and habitat utilisation. 3. To evaluate these results in the context of spatial management options for specific fisheries, including performance of closed areas. NON-TECHNICAL SUMMARY OUTCOMES ACHIEVED TO DATE In the Northern Territory, the primary outcome was an improved understanding of the temporal and spatial dynamics of Protonibea diacanthus aggregations. Most importantly, the study demonstrated that the aggregations are likely to be separate adult populations. This has significant implications for stock assessment and management of the resource as such populations are likely to be highly vulnerable to localised depletion. In Tasmania, the primary outcome was an improved understanding of the temporal and spatial movement patterns of Cheilodactylus spectabilis and Latridopsis forsteri . C spectabilis only moved to depth during the spawning season, suggesting that the deep water stocks that fishers believe act as a refuge population are in fact temporary residents during the spawning season, and the fishery may in fact target a major component of the stock. The result of C. spectabilis being highly site attached and occupying very small core areas of reef suggests that fishing has the potential to cause localised and serial depletion of this species. Despite being a mobile species, some L. forsteri individuals were site attached, suggesting that closed areas may be of some benefit for the sustainable management of this species. Movement information is essential to understanding many aspects of exploited populations such as replenishment of fished reefs (from local, adjacent or deep reefs), aggregation behaviour, critical habitat requirements and cyclic variation in catch rates. 1 FRDC Project 2004/002 Reef fish movement It is particularly important to the understanding and application