Environment Protection Authority The South Australian monitoring, evaluation and reporting program for aquatic ecosystems Rationale and methods for the assessment of nearshore marine waters The South Australian monitoring, evaluation and reporting program for aquatic ecosystems: Rationale and methods for the assessment of nearshore marine waters Authors: Sam Gaylard, Matt Nelson and Warwick Noble For further information please contact: Information Officer Environment Protection Authority GPO Box 2607 Adelaide SA 5001 Telephone: (08) 8204 2004 Facsimile: (08) 8124 4670 Free call (country): 1800 623 445 Website: <www.epa.sa.gov.au> Email: <[email protected]> ISBN 978-1-921495-39-7 July 2013 © Environment Protection Authority This document may be reproduced in whole or part for the purpose of study or training, subject to the inclusion of an acknowledgment of the source and to it not being used for commercial purposes or sale. Reproduction for purposes other than those given above requires the prior written permission of the Environment Protection Authority. Contents Summary ..............................................................................................................................................................................1 Acknowledgments...............................................................................................................................................................3 1 Introduction...................................................................................................................................................................5 2 South Australian nearshore marine ecosystems, threats and responses..............................................................7 3 The nearshore MER Framework................................................................................................................................11 4 Conceptual models and ecological condition..........................................................................................................17 5 Tier 1 desktop assessment and expected condition...............................................................................................30 6 Tier 2 monitoring and evaluation methods ..............................................................................................................31 7 Panel assessment of nearshore marine condition..................................................................................................41 8 Reporting.....................................................................................................................................................................42 9 References...................................................................................................................................................................43 10 Glossary.......................................................................................................................................................................52 Appendix 1 Assessment of reference condition .....................................................................................................53 Appendix 2 Historical EPA monitoring – impacted sites........................................................................................61 Appendix 3 Power analysis for seagrass condition................................................................................................63 Appendix 4 Towed video standard operating procedure .......................................................................................65 Appendix 5 Compositing water samples standard operating procedure .............................................................66 Appendix 6 Visual estimates of cover on belt transects ........................................................................................67 Appendix 7 Example of the online Aquatic Ecosystem Condition Report ...........................................................70 List of figures Figure 1 Circular scours in seagrass meadows in the South East and Kangaroo Island of South Australia .................8 Figure 2 Nested design of nearshore marine monitoring and evaluation program ......................................................12 Figure 3 IMCRA Bioregions..........................................................................................................................................13 Figure 4 Example biounits within the Gulf St Vincent bioregion...................................................................................14 Figure 5 Example of 10 random sampling locations within a site.................................................................................16 Figure 6 Ecological condition gradient for nearshore marine environments ................................................................19 Figure 7 Conceptual diagram for increasing nutrients and/or decreased light penetration and its effects on seagrass meadows in South Australia within this MER program...................................................................21 Figure 8 Conceptual diagram for increasing nutrients and/or decreased light penetration and its effects on shallow rocky reefs in South Australia within this MER program ...................................................................22 Figure 9 Conceptual diagram for increasing organic loading and/or nutrient enrichment of unvegetated sediments in shallow nearshore waters in South Australia within this MER program....................................23 Figure 10 Schematic representation of a 50-m transect of mixed seagrass and reef habitat and the assessment methods .........................................................................................................................................................35 Figure 11 Position of 49 sampling locations at Flinders Island in June 2009.................................................................55 Figure 12 Position of 21 sampling locations at Pearson Island during June 2009.........................................................56 Figure 13 Location of 14 sampling sites in Sir Joseph Banks Group of Islands during May 2010 57 Figure 14 Screen capture of epiphytes on Posidonia seagrass.....................................................................................59 Figure 15 Epochs of seagrass loss along the Adelaide metropolitan coast showing the location of the EPA ambient water quality monitoring sites used in the assessment of impacted water chemistry ..............62 Figure 16 Visual cue board used in EPA underwater video collection...........................................................................65 Figure 17 Schematic of composite sampling process at each AECR site......................................................................66 List of tables Table 1 Generic conceptual model of disturbance gradient – seagrass habitats........................................................20 Table 2 Generic conceptual model of disturbance gradient – rocky reef habitats ......................................................20 Table 3 Generic conceptual model of disturbance gradient – unvegetated sediment habitats...................................24 Table 4 Conclusions based on the conceptual model of disturbance gradient...........................................................24 Table 5 Conceptual model – biological modifiers along a nutrient enrichment gradient.............................................25 Table 6 Conceptual model – water chemistry modifiers along a nutrient enrichment gradient...................................26 Table 7 Conceptual model water chemistry modifiers along a water clarity gradient .................................................27 Table 8 Reef condition index.......................................................................................................................................34 Table 9 Scaling system for water chemistry, chlorophyll a & turbidity variables .........................................................37 Table 10 Total nitrogen scale........................................................................................................................................38 Table 11 Turbidity index................................................................................................................................................39 Table 12 Chlorophyll a index.........................................................................................................................................39 Table 13 Summary statistics for water chemistry parameters at Flinders and Pearson Islands...................................56 Table 14 Summary statistics for water chemistry parameters at Sir Joseph Banks group of islands...........................58 Table 15 Descriptive statistics for reference sites.........................................................................................................60 Table 16 Descriptive statistics for ‘Impacted’ sites from 1998–2008 ............................................................................61 Table 17 Power analysis of habitat structure index throughout Gulf St Vincent 2009 ..................................................63 Table 18 Retrospective power analysis using 10 replicates within a site......................................................................64 Summary The Environment Protection Authority (EPA) has managed a monitoring, evaluation and reporting