Examining the health of subtidal reef environments in South Australia Part 4: Assessment of community reef monitoring and status of selected South Australian reefs based on the results of the 2007 surveys Greg Collings, Simon Bryars, David Turner, James Brook and Mandee Theil Published August 2008 SARDI Publication number F2008/000511-1 Examining the health of subtidal reef environments in South Australia Part 4: Assessment of community reef monitoring and status of selected South Australian reefs based on the results of the 2007 surveys Greg Collings, Simon Bryars, David Turner, James Brook and Mandee Theil August 2008 SARDI Publication Number F2008/000511-1 This report contains information generated by the Reef Health program and is supported by the following agencies: This publication may be cited as: Collings, G., Bryars, S., Turner, D., Brook, J. and Theil, M. (2008) ‘Examining the health of subtidal reef environments in South Australia, Part 4: Assessment of community reef monitoring and status of selected South Australian reefs based on the results of the 2007 surveys.’ SARDI Publication Number F2008/000511-1 South Australian Research and Development Institute (Aquatic Sciences), Adelaide. More information: Further information about the Reef Health Program along with copies of reports and technical documents may be obtained from the Reef Watch website at http://www.reefwatch.asn.au, or by contacting SARDI Aquatic Sciences. 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.sardi.sa.gov.au Disclaimer. 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 Chief Scientist. Although all reasonable efforts have been made to ensure quality, SARDI Aquatic Sciences does not warrant that the information in this report is free from errors or omissions. SARDI Aquatic Sciences 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. © 2008 SARDI Aquatic Sciences This work is copyright. Apart from any use as permitted under the Copyright Act 1968, no part may be reproduced by any process without prior written permission from the authors. Printed in Adelaide August 2008 Cover photo: Alison Eaton SARDI Aquatic Sciences Publication Number F2008/000511-1 SARDI Research Report Series Number 295 ISBN Number 978-0-7308-5392-3 Author(s): Greg Collings, Simon Bryars, David Turner, James Brook, Mandee Theil Reviewers: Jason Tanner, Scoresby Shepherd (SARDI), Timothy Kildea (SA Water), Approved by: Jason Tanner Signed: Date: 5 August 2008 Circulation: Public domain Collings et al. Health of subtidal reefs in South Australia Part 4. Page 1 Table of Contents ACKNOWLEDGEMENTS ...............................................................................................................................2 EXECUTIVE SUMMARY .................................................................................................................................3 1 INTRODUCTION ...................................................................................................................................5 2 METHODS..............................................................................................................................................8 2.1 Survey sites...................................................................................................................................8 2.2 Scientific Reef Health Survey..................................................................................................10 2.3 Community Reef Watch Survey..............................................................................................10 2.4 Data manipulation - index calculation ...................................................................................11 2.4.1 Indices of areal cover ......................................................................................................................11 2.4.2 Indices of abundance ......................................................................................................................12 2.4.3 Binary indicators ...........................................................................................................................13 2.4.4 Indices of species richness................................................................................................................13 2.4.5 Scaling of indices............................................................................................................................13 2.4.6 Overall index of reef health............................................................................................................15 2.5 Data analyses..............................................................................................................................15 2.5.1 Biotic patterns of reef assemblages and reef health in 2007 .............................................................15 2.5.2 Changes in reef health 2005 - 2007..............................................................................................16 2.5.3 Comparison of community-based and professional reef monitoring data............................................17 3 RESULTS...............................................................................................................................................19 3.1 Patterns of reef assemblages and reef health in 2007..........................................................19 3.2 Changes in reef health 2005 – 2007 .......................................................................................25 3.3 Comparison of scientific and community survey data........................................................34 4 DISCUSSION ........................................................................................................................................40 4.1 Current status of Adelaide’s reefs...........................................................................................40 4.2 Temporal change in reefal communities ...............................................................................43 4.3 Efficacy of community-based monitoring ............................................................................52 4.4 Comparison of LIT ordination and index calculation methods........................................58 5 CONCLUSIONS AND RECOMMENDATIONS ...................................................................................63 REFERENCES................................................................................................................................................66 APPENDIX A: SAMPLING METHODOLOGY (ADAPTED FROM TURNER ET AL. 2007).....................72 APPENDIX B: SITE DESCRIPTIONS FOR REEFS INCLUDED IN THE 2007 SURVEYS..........................79 APPENDIX C: REPORTING CODES USED DURING DATA ANALYSIS...................................................81 Collings et al. Health of subtidal reefs in South Australia Part 4. Page 2 Acknowledgements The authors would like to thank the following people and agencies: Financial and in-kind contributions Data collection, synthesis and the production of this report were made possible through the generous financial and in-kind support of the following agencies: Fisheries Research and Development Corporation (FRDC Project Number 2004/078), South Australian Water Corporation, South Australian Department for Environment and Heritage (DEH), Environment Protection Authority (EPA), Adelaide and Mount Lofty Natural Resources Management Board, Flinders University of South Australia, Conservation Council of South Australia (CCSA), South Australian Fishing Industry Council, South Australian Recreational Fishing Advisory Council, and Seanet. Field and laboratory staff Staff from a number of agencies actively participated in the field program as divers and support staff: Bruce Miller-Smith, Sharon Drabsch, (SARDI Aquatic Sciences); Alison Eaton, Yvette Eglinton, Sue Murray-Jones, (DEH); and Tim Kildea (SA Water). Thanks to Steve Leske and the volunteers from the Reef Watch community monitoring program for conducting surveys and supplying data for comparison. Much of this study involved comparison with data from surveys conducted by Reef Watch. The quantity and quality of this dataset and the work that went into producing it cannot be overestimated. Thanks and congratulations are due to all those involved with this organization. Reviewers We thank Jason Tanner and Scoresby Shepherd (SARDI), and Tim Kildea (SA Water) for useful comments on early drafts of the report. Others Thanks to the northern fishers for supplying the coordinates for the Northern Reef. Collings et al. Health of subtidal reefs in South Australia Part 4. Page 3 Executive summary Concern over the degradation of Adelaide’s metropolitan reefs has led to several Reef Health scientific surveys since 1996 and the ongoing community Reef Watch monitoring program. The last survey was conducted in 2005, and the subsequent report provided a health ranking for a number of reefs adjacent to Adelaide. The present report extends the 2005 survey report by: 1. Providing an up-to-date assessment of the condition of Adelaide’ s reefs; 2. Comparing the condition of Adelaide’s reefs in 2007 with the 2005