Western Zone Blacklip (Haliotis Rubra) and Greenlip (H
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Western Zone Blacklip (Haliotis rubra) and Greenlip (H. laevigata) Abalone Fisheries in 2016 B. Stobart, S. Mayfield and K. Heldt SARDI Publication No. F2017/000331-1 SARDI Research Report Series No. 964 SARDI Aquatics Sciences PO Box 120 Henley Beach SA 5022 October 2017 Report to PIRSA Fisheries and Aquaculture Stobart, B. et al. (2017) Western Zone Abalone Fishery Western Zone Blacklip (Haliotis rubra) and Greenlip (H. laevigata) Abalone Fisheries in 2016 Report to PIRSA Fisheries and Aquaculture B. Stobart, S. Mayfield and K. Heldt SARDI Publication No. F2017/000331-1 SARDI Research Report Series No. 964 October 2017 II Stobart, B. et al. (2017) Western Zone Abalone Fishery This publication may be cited as: Stobart, B., Mayfield, S. and Heldt, K. (2017). Western Zone Blacklip (Haliotis rubra) and Greenlip (H. laevigata) Abalone Fisheries in 2016. Report to PIRSA Fisheries and Aquaculture. South Australian Research and Development Institute (Aquatic Sciences), Adelaide. SARDI Publication No. F2017/000331-1. SARDI Research Report Series No. 964. 91pp. Cover photograph: Wanna Bay, Port Lincoln National Park, B. Stobart South Australian Research and Development Institute SARDI Aquatic Sciences 2 Hamra Avenue West Beach SA 5024 Telephone: (08) 8207 5400 Facsimile: (08) 8207 5415 http://www.pir.sa.gov.au/research DISCLAIMER The authors warrant that they have taken all reasonable care in producing this report. The report has been through the SARDI internal review process, and has been formally approved for release by the Research Chief, Aquatic Sciences. Although all reasonable efforts have been made to ensure quality, SARDI does not warrant that the information in this report is free from errors or omissions. SARDI and its employees do not warrant or make any representation regarding the use, or results of the use, of the information contained herein as regards to its correctness, accuracy, reliability and currency or otherwise. SARDI and its employees expressly disclaim all liability or responsibility to any person using the information or advice. Use of the information and data contained in this report is at the user’s sole risk. If users rely on the information they are responsible for ensuring by independent verification its accuracy, currency or completeness. The SARDI Report Series is an Administrative Report Series which has not been reviewed outside the department and is not considered peer-reviewed literature. Material presented in these Administrative Reports may later be published in formal peer-reviewed scientific literature. © 2017 SARDI This work is copyright. Apart from any use as permitted under the Copyright Act 1968 (Cth), no part may be reproduced by any process, electronic or otherwise, without the specific written permission of the copyright owner. Neither may information be stored electronically in any form whatsoever without such permission. Printed in Adelaide: October 2017 SARDI Publication No. F2017/000331-1 SARDI Research Report Series No. 964 Author(s): B. Stobart, S. Mayfield and K. Heldt Reviewer(s): M. Steer, L. McLeay (SARDI) and B. McGrath-Steer (PIRSA) Approved by: T. Ward Science leader – Marine Ecosystems Signed: Date: 13 October 2017 Distribution: PIRSA Fisheries and Aquaculture, SAASC Library, Parliamentary Library, State Library and National Library Circulation: Public Domain III Stobart, B. et al. (2017) Western Zone Abalone Fishery TABLE OF CONTENTS ACKNOWLEDGEMENTS .......................................................................................................... X EXECUTIVE SUMMARY ........................................................................................................... 1 1 GENERAL INTRODUCTION ............................................................................................... 4 1.1 Background.................................................................................................................. 4 1.2 History and description of the fishery ........................................................................... 6 1.2.1 Commercial fishery ............................................................................................... 6 1.2.2 Economic importance of the commercial fishery ................................................... 7 1.2.3 Recreational fishery .............................................................................................. 8 1.2.4 Illegal, unregulated and unreported catch ............................................................. 8 1.3 Management Plan ........................................................................................................ 8 1.4 Abalone biology ..........................................................................................................12 2 METHODS .........................................................................................................................13 2.1 Information sources for the assessment ......................................................................13 2.2 Blacklip .......................................................................................................................13 2.2.1 Catch and effort ...................................................................................................13 2.2.2 Commercial catch sampling .................................................................................14 2.2.3 Fishery-independent surveys ...............................................................................15 2.3 Greenlip ......................................................................................................................16 2.4 Harvest strategy ..........................................................................................................16 2.5 Quality Assurance .......................................................................................................16 3 RESULTS ..........................................................................................................................17 3.1 Blacklip .......................................................................................................................17 3.1.1 Western Zone ......................................................................................................17 Regions of the Western Zone .......................................................................19 Distribution of catch among spatial assessment units ...................................21 Distribution of CPUE values among spatial assessment units .......................24 Temporal patterns in HIGH importance spatial assessment units .................25 Drummond ..................................................................................................................25 Sheringa .....................................................................................................................27 Point Westall ...............................................................................................................29 Reef Head ..................................................................................................................31 Avoid Bay ...................................................................................................................32 Searcy Bay .................................................................................................................34 Anxious Bay ................................................................................................................35 Ward Island.................................................................................................................36 Temporal patterns in MEDIUM importance spatial assessment units ............38 Point Avoid .................................................................................................................38 Venus Bay ..................................................................................................................38 Hotspot .......................................................................................................................38 Temporal patterns in LOW importance spatial assessment units ..................38 3.1.2 Risk of overfishing in SAUs and zonal stock status ..............................................42 IV Stobart, B. et al. (2017) Western Zone Abalone Fishery 3.2 Greenlip ......................................................................................................................45 3.2.1 Western Zone ......................................................................................................45 3.2.1.1 Spatial assessment units ..............................................................................45 3.2.2 Risk of overfishing in SAUs and zonal stock status ..............................................45 4 DISCUSSION ....................................................................................................................58 4.1 Current status of blacklip and greenlip in the WZ ........................................................58 4.1.1 Status of blacklip in the WZ ..................................................................................58 4.1.2 Status of greenlip in the WZ .................................................................................62 4.1.3 Information, data gaps and uncertainty in the assessment ...................................63 4.2 Harvest strategy for the WZ abalone fishery ...............................................................65 4.3 Future