Fisheries Status of the Western Zone Greenlip Abalone (Haliotis laevigata) Fishery in 2014 B. Stobart, S. Mayfield and J. Dent SARDI Publication No. F2014/000361-2 SARDI Research Report Series No. 865 SARDI Aquatics Sciences PO Box 120 Henley Beach SA 5022 September 2015 Report to PIRSA Fisheries and Aquaculture Stobart et al. 2015 Western Zone Greenlip Harvest Strategy Report Status of the Western Zone Greenlip Abalone (Haliotis laevigata) Fishery in 2014 Report to PIRSA Fisheries and Aquaculture B. Stobart, S. Mayfield and J. Dent SARDI Publication No. F2014/000361-2 SARDI Research Report Series No. 865 September 2015 II Stobart et al. 2015 Western Zone Greenlip Harvest Strategy Report This publication may be cited as: Stobart, B., Mayfield, S. and Dent J. (2015). Status of the Western Zone Greenlip Abalone (Haliotis laevigata) Fishery in 2014. Report to PIRSA Fisheries and Aquaculture. South Australian Research and Development Institute (Aquatic Sciences), Adelaide. SARDI Publication No. F2014/000361-2. SARDI Research Report Series No. 865. 14pp. Cover photograph: Juvenile greenlip abalone (Haliotis laevigata), 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 5406 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 does not accept any liability for the contents of this report or for any consequences arising from its use or any reliance placed upon it. 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. © 2015 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: September 2015 SARDI Publication No. F2014/000361-2 SARDI Research Report Series No. 865 Author(s): B. Stobart, S. Mayfield and J. Dent Reviewer(s): L. McLeay and C Noell Approved by: Dr Q. Ye Science Leader – Inland Waters & Catchment Ecology Signed: Date: September 2015 Distribution: PIRSA Fisheries and Aquaculture, Western Zone Abalone Fishery licence holders, SAASC Library, University of Adelaide Library, Parliamentary Library, State Library and National Library Circulation: Public Domain III Stobart et al. 2015 Western Zone Greenlip Harvest Strategy Report TABLE OF CONTENTS ACKNOWLEDGEMENTS ......................................................................................................... VI EXECUTIVE SUMMARY ............................................................................................................ 1 1. INTRODUCTION ................................................................................................................. 2 2. METHODS ........................................................................................................................... 2 3. RESULTS ............................................................................................................................ 3 Temporal patterns in catch, effort and CPUE .......................................................................... 3 Spatial assessment units: ....................................................................................................... 3 Risk of overfishing in SAUs and zonal stock status ................................................................ 3 4. SUMMARY ........................................................................................................................ 13 5. REFERENCES .................................................................................................................. 13 IV Stobart et al. 2015 Western Zone Greenlip Harvest Strategy Report LIST OF FIGURES Figure 3.1. Catch, CPUE, PropG1 and TACC amendments of greenlip from the Western Zone from 1968 to 2014. ................................................................................................. 5 Figure 3.2. Anxious Bay (high importance). Performance indicators catch, CPUE, PropG1, legal density, pre-recruit density, mortality and scores from the harvest strategy. .......... 6 Figure 3.3. The Gap (high importance). Performance indicators catch, CPUE, PropG1, legal density, pre-recruit density, mortality and scores from the harvest strategy. .......... 7 Figure 3.4. Avoid Bay (high importance). Performance indicators catch, CPUE, PropG1, legal density, pre-recruit density, mortality and scores from the harvest strategy. .......... 8 Figure 3.5. Flinders Island, Ward Island, Hotspot, Taylor Island and Point Avoid (medium importance). Performance indicators catch, CPUE, PropG1 and scores from the harvest strategy. .................................................................................................... 10 Figure 3.6. South Nuyts Archipelago, Drummond, Reef Head, Baird Bay and Point Westall (medium importance). Performance indicators catch, CPUE, PropG1 and scores from the harvest strategy. ...................................................................................... 10 Figure 3.7. Catch, CPUE and PropG1 of greenlip from low importance SAUs: Cape Bauer, Cape Catastrophe, Coffin Bay, D’Entrecasteaux Reef, Elliston Cliffs, Fishery Bay, Franklin Islands, Greenly Island, NE Thistle, Neptune Islands, North Nuyts Archipelago and Pearson Island from 1979 to 2014. .............................................. 11 Figure 3.8. Catch, CPUE and PropG1 of greenlip from low importance SAUs: Searcy Bay, Sheringa, Sir Joseph Banks, SW Thistle, Unassigned Region A, Unassigned Region B, Venus Bay, Waterloo Bay and Wedge Island from 1979 to 2014. ...................... 12 LIST OF TABLES Table 3.1. Outcome from application of the harvest strategy described in the Management Plan for the SAAF against the greenlip fishery in the Western Zone for 2014. ................. 4 V Stobart et al. 2015 Western Zone Greenlip Harvest Strategy Report ACKNOWLEDGEMENTS Funds for this research were provided by PIRSA Fisheries and Aquaculture, obtained through licence fees. SARDI Aquatic Sciences provided substantial in-kind support. We thank the Western Zone licence holders, fishers and shellers for providing length measurements of abalone in the commercial catch, and for their contribution to our understanding of the information presented in this report. We are grateful to Toby Fox, Dr Rowan Chick, Brian Foureur, Damian Matthews, Andrew Hogg, and other SARDI past and present divers for assistance with diving, and the collection and management of data. We thank Drs Paul Burch and Jonathan Carroll for statistical support and programming. This report was formally reviewed by Drs Lachlan McLeay and Craig Noell (SARDI Aquatic Sciences), Prof. Gavin Begg, Research Chief (SARDI Aquatic Sciences) and Dr Annabel Jones (PIRSA Fisheries and Aquaculture). It was formally approved for release by Dr Qifeng Ye, Science Leader – Inland Waters & Catchment Ecology, SARDI Aquatic Sciences. VI Stobart et al. 2015 Western Zone Greenlip Harvest Strategy Report EXECUTIVE SUMMARY This report provides an assessment of the current stock status of Haliotis laevigata (greenlip abalone; hereafter termed greenlip) in the Western Zone (WZ) of the South Australian Abalone Fishery. The assessment is required under the Management Plan for the South Australian Abalone Fishery which specifies the need for annual application of the harvest strategy to determine stock status and review the total allowable commercial catch. The harvest strategy is relatively new and several limitations have been identified. These include stock status classifications which are considered over-optimistic (e.g. Mayfield et al. 2014; Stobart et al. 2014) and the absence of a definition of recruitment overfished, to link the assessment to the National Fishery Status Reporting Framework (NFSRF; Flood et al. 2014). Consequently, the stock status outcome from the harvest strategy was compared to the traditional, weight-of-evidence analysis using the NFSRF framework. The harvest strategy classified the zonal stock status for WZ greenlip in 2014 as ‘sustainably fished’. This was different from the classification of ‘under-fished’ in 2013. The stock status classification from the harvest strategy – ‘sustainably fished’ – was not consistent with much of the data available for the fishery, because these data suggest greenlip stocks are at their weakest position in over 25 years; therefore, highlighting the limitations of the harvest strategy approach. These data include: (1) a 14% reduction in zonal CPUE between 2012 and 2014, following a four-year period of stability, to a value among the lowest on record and lower than the mean CPUE in the 1980s; (2) declines in CPUE being spatially consistent across SAUs; (3) a reduced proportion of large greenlip in the catch from many SAUs despite market