Movement, residency and habitat use of pelagic sharks in Spencer Gulf: resolving overlaps with marine industries and community activities Final Report to the Fisheries Research and Development Corporation Editors: Paul Rogers and Michael Drew September 2018 FRDC Project No. 2014/020 © 2018 Fisheries Research and Development Corporation and South Australian Research and Development Institute. All rights reserved. ISBN: 978-1-876007-09-6 Movement, residency and habitat use of pelagic sharks in Spencer Gulf: resolving overlaps with marine industries and community activities. 2014/020 Ownership of Intellectual property rights Unless otherwise noted, copyright (and any other intellectual property rights, if any) in this publication is owned by the Fisheries Research and Development Corporation and the South Australian Research and Development Institute. This work is copyright. 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Researcher Contact Details FRDC Contact Details Name: SARDI Aquatic Sciences Address: 25 Geils Court Address: 2 Hamra Avenue Deakin ACT 2600 West Beach Phone: 02 6285 0400 Fax: 08 8207 5415 Fax: 02 6285 0499 Phone: 08 8429 0503 Email: [email protected] Email: [email protected] Web: www.frdc.com.au In submitting this report, the researcher has agreed to FRDC publishing this material in its edited form. 2 Table of Contents Figures ................................................................................................................................... 5 Tables .................................................................................................................................... 6 Acknowledgements .............................................................................................................. 7 Executive Summary ............................................................................................................. 9 1. Background ................................................................................................................ 13 Need ................................................................................................................................. 15 2. Movement, Fidelity and Habitat Use of White Sharks and Bronze Whalers: Overlap with Ecologically Important Areas, Marine Industries and the Community ................. 16 Introduction ....................................................................................................................... 16 Objectives ......................................................................................................................... 18 Methods ............................................................................................................................ 19 Study area .................................................................................................................... 19 Acoustic telemetry: site selection and experimental design ........................................ 19 Acoustic telemetry: tagging .......................................................................................... 23 Satellite telemetry: tagging........................................................................................... 27 Data analyses .............................................................................................................. 30 Acoustic telemetry ................................................................................................... 30 Satellite telemetry .................................................................................................... 30 Results ............................................................................................................................. 33 Monitoring periods ....................................................................................................... 33 Acoustic telemetry ........................................................................................................ 33 White Sharks ................................................................................................................ 34 Acoustic detections .................................................................................................. 34 Spatial and seasonal patterns by region ................................................................. 34 Seasonal patterns by site type ................................................................................ 34 Site affinity and fidelity ............................................................................................. 38 Relationships with environmental, spatio-temporal, and activity variables ............. 42 Bronze Whalers ........................................................................................................... 44 Acoustic detections .................................................................................................. 44 Spatial and seasonal patterns by region ................................................................. 44 Seasonal patterns by site type ................................................................................ 44 Site affinity and fidelity ............................................................................................. 45 Relationships with environmental, spatio-temporal, and activity variables ............. 46 Satellite telemetry: Broad scale habitat use ................................................................. 50 Correlations between satellite tracks, remote-sensed environmental and physical variables ....................................................................................................................... 55 Sea-surface temperature ......................................................................................... 55 Chlorophyll-a............................................................................................................ 55 Bottom depth ........................................................................................................... 55 Spatial patterns of area use ......................................................................................... 57 Discussion ........................................................................................................................ 65 3. Industry guidelines for managing White Sharks during static tuna aquaculture operations in State managed aquaculture zones ............................................................ 70 Introduction ....................................................................................................................... 70 Guidelines ........................................................................................................................ 72 Discussion ........................................................................................................................ 73 4. Perception surveys .......................................................................................................