SARDI Report Series Is an Administrative Report Series Which Has Not Been Reviewed Outside the Department and Is Not Considered Peer-Reviewed Literature

Seagrass Biodiversity Surveys in Yankalilla Bay

Jason Tanner and Mandee Theil

SARDI Publication No. F2016/000099-1 SARDI Research Report Series No. 890

SARDI Aquatics Sciences PO Box 120 Henley Beach SA 5022

April 2016

Final report prepared for the Adelaide and Mount Lofty Ranges Natural Resources Management Board

Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

Seagrass Biodiversity Surveys in Yankalilla Bay

Final report prepared for the Adelaide and Mount Lofty Ranges Natural Resources Management Board

Jason Tanner and Mandee Theil

SARDI Publication No. F2016/000099-1 SARDI Research Report Series No. 890

April 2016

II Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

This publication may be cited as: Tanner, J.E., and Theil, M.J. (2016). Seagrass biodiversity surveys in Yankalilla Bay. Final report prepared for the Adelaide and Mount Lofty Ranges Natural Resources Management Board. South Australian Research and Development Institute (Aquatic Sciences), Adelaide. SARDI Publication No. F2016/000099-1. SARDI Research Report Series No. 890. 33pp.

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.

© 2016 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: April 2016

SARDI Publication No. F2016/000099-1 SARDI Research Report Series No. 890

Author(s): Jason Tanner and Mandee Theil

Reviewer(s): Kathryn Wiltshire and Ana Redondo Rodriguez

Approved by: A/Prof Qifeng Ye Science Leader – Inland Waters & Catchment Ecology

Signed:

Date: 5 April 2016

Distribution: Adelaide and Mount Lofty Ranges Natural Resources Management Board, SAASC Library, University of Adelaide Library, Parliamentary Library, State Library and National Library

Circulation: Public Domain

III Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

TABLE OF CONTENTS

LIST OF FIGURES ...... V LIST OF TABLES ...... VII ACKNOWLEDGEMENTS ...... VIII EXECUTIVE SUMMARY ...... 1 1. INTRODUCTION ...... 2 1.1. Background...... 2 1.2. Objectives ...... 3 2. METHODS ...... 4 2.1. Site selection ...... 4 2.2. Fauna and Flora Survey...... 6 2.3. Data analysis ...... 7 3. RESULTS ...... 9 3.1. Seagrass structure and habitat condition ...... 9 3.2. Infauna ...... 11 3.3. Epifauna ...... 16 3.4. Fish and Larger Invertebrates ...... 20 4. DISCUSSION ...... 23 REFERENCES ...... 27 APPENDIX 1: INFAUNAL TAXA COLLECTED AT YANKALILLA BAY. NUMBERS ARE THE SUM OVER 8 CORES ON EACH TRANSECT...... 29 APPENDIX 2: EPIFAUNAL TAXA COLLECTED AT YANKALILLA BAY. NUMBERS ARE THE SUM OVER 8 CORES ON EACH TRANSECT...... 31 APPENDIX 3: LARGE INVERTEBRATES COLLECTED AT YANKALILLA BAY. NUMBERS ARE THE TOTAL NUMBER OF INDIVIDUALS/COLONIES ON EACH 50 M TRANSECT.. 33

IV Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

LIST OF FIGURES Figure 1: Map of Yankalilla Bay showing the 2009 mega-transect lines (red) and the 2015 transects (blue) surveyed for seagrass fauna, overlaid on broader scale DEWNR habitat mapping...... 5 Figure 2: Dendrogram showing the results of an average linkage hierarchical cluster analysis on habitat cover along line intercept transects in Yankalilla Bay. Horizontal line indicates groupings at a similarity of 55% (A - Amphibolis, M - Mixed seagrass, P - Posidonia)...... 9 Figure 3: Principal coordinates analysis of seagrass structural characteristics (SGdw – Seagrass dry weight, Epidw – Epiphyte dry weight)...... 11 Figure 4. Infaunal abundance (upper panel) and taxonomic richness (lower panel) in different habitats in Yankalilla Bay. A - Amphibolis, M - Mixed Amphibolis and Posidonia, P - Posidonia, S - Sand...... 12 Figure 5: Canonical analysis of principal coordinates plot showing discrimination between infaunal assemblages in different habitats in Yankalilla Bay. A - Amphibolis, M - Mixed Amphibolis and Posidonia, P - Posidonia, S - Sand. Biplot on right shows taxa with correlations >0.5 (taxa in the lower left are Ophiuroidea, Nematoda, Syllidae, Glyceridae and Hesionidae)...... 13 Figure 6: Species accumulation curves (solid symbols) and predicted total number of taxa using the Chao 2 estimator (hollow symbols) for infauna in Yankalilla Bay...... 14 Figure 7: Typical examples of infauna found at Yankalilla Bay. From left to right and top to bottom: Amphipods – Ampithoinae, Aoridae, Lysianassidae, Phoxocephalidae; Isopod – Janiridae; Ostracod – Cylindroleberididae; Polychaetes – Clyceridae, Hesionidae, Nereididae, Opheliidae, Spionidae...... 15 Figure 8: Epifaunal abundance (upper panel) and taxonomic richness (lower panel) in different habitats in Yankalilla Bay. A - Amphibolis, M - Mixed Amphibolis and Posidonia, P - Posidonia...... 16 Figure 9: Canonical analysis of principal coordinates plot showing discrimination between epifaunal assemblages in different habitats in Yankalilla Bay. A - Amphibolis, M - Mixed Amphibolis and Posidonia, P - Posidonia. Biplot on right shows taxa with correlations >0.6 (obscured taxa on the left are Lysianassidae, Nereididae and Syllidae)...... 17 Figure 10: Species accumulation curves (solid symbols) and predicted total number of taxa using the Chao 2 estimator (hollow symbols) for epifauna in Yankalilla Bay...... 18 Figure 11: Typical examples of epifauna found at Yankalilla Bay. From left to right and top to bottom: Amphipods – Aoridae, Maeridae; Isopods – Anthuridae, Cirolanidae Janiridae; Tanaid – Leptochelidae; Pycnogonid; Polychaetes – Dorvilleidae, Nereididae, Syllidae; Mollusacs – Ischnochitonidae, Trochidae...... 19

V Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

Figure 12: Large Invertebrate abundance (upper panel) and taxonomic richness (lower panel) in different habitats in Yankalilla Bay...... 21 Figure 13: Principal coordinates analysis plot showing discrimination between large invertebrate assemblages in different habitats in Yankalilla Bay. A - Amphibolis, M - Mixed Amphibolis and Posidonia, P - Posidonia, S - Sand. Biplot on right shows taxa with correlations >0.7 (taxa in the upper right are Phasianella australis (pheasant shell) and Tosia australis (biscuit star) and lower center are unidentified holothurians, echinoids and asteroids (sea cucumbers, sea urchins and starfish))...... 22

VI Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

LIST OF TABLES Table 1: Coordinates for the start and end points of the survey transects in Yankalila Bay (GDA 94)...... 4 Table 2: Percent cover of different taxa on line-intercept transects in 3 habitat types (A - Amphibolis, M - Mixed seagrass, P - Posidonia)...... 9 Table 3: Seagrass habitat condition indices for 2015 (H'), compared to mean condition for 2009 along the same transects...... 10 Table 4: Seagrass structural characteristics in Yankalilla Bay (mean ± se, dw - dry weight). Note: belowground samples could not be obtained at A1 and A3 due to the rocky nature of the substrate...... 11 Table 5: PERMANOVA pairwise tests for differences in infaunal composition between habitats. Significant p-values are shown in bold ...... 13 Table 6: PERMANOVA pairwise tests for differences in epifaunal composition between habitats...... 17 Table 7: Fish observed on seagrass and sand transects in Yankalilla Bay...... 20 Table 8: PERMANOVA pairwise tests for differences in large invertebrate composition between habitats...... 22 Table 9: Compilation of structural characteristics for Amphibolis and Posidonia seagrasses in South Australia. Values in parentheses are standard errors...... 24 Table 10: Comparison of infaunal abundance and taxonomic richness in Amphibolis and bare sand in South Australia. Values in parentheses are standard errors...... 25 Table 11: Comparison of epifaunal abundance and taxonomic richness in Amphibolis in South Australia. Values in parentheses are standard errors...... 26

VII Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

ACKNOWLEDGEMENTS We thank Ian Moody, Leo Mantilla, Kathryn Wiltshire and Alex Dobrovolskis for their assistance with undertaking field and laboratory work. Comments on an earlier draft of this report from Kathryn Wiltshire and Dr Anna Redondo Rodriguez, and the editorial oversight of A/Prof. Qifeng Ye are greatly appreciated. The encouragement of Tony Flaherty (Adelaide & Mount Lofty Ranges Natural Resources Management Board), and the financial support of this organization, are gratefully acknowledged.

VIII Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

EXECUTIVE SUMMARY Previous studies using remote video in 2009 showed that seagrasses in Yankalilla Bay were in good condition, with high scores for the habitat condition index developed by the South Australian Research and Development Institute and now routinely used by the South Australian Environmental Protection Authority. At the same time, recruitment of Amphibolis juveniles was also high, further suggesting that these meadows were in good condition. Subsequent work showed strong geographic gradients in epiphyte cover, with offshore waters of the northern part of the study area having much higher cover than elsewhere. Levels of epiphyte cover observed (generally <20%) were similar to those documented previously in the Adelaide metropolitan area as part of the Adelaide Coastal Waters Study.

In this report, we document in more detail the structural characteristics of seagrass meadows in Yankalilla Bay in 2015, and compare habitat condition to that recorded in 2009. We also examine faunal assemblages in seagrasses and adjacent bare sand, including infauna, small motile epifauna, larger invertebrates, and fish. We used line-intercept transects to document meadow composition, habitat condition and the abundance of larger invertebrates and fish along nine seagrass and three sand transects in shallow (2-4 m water depth) areas of the bay. We also collected eight infaunal cores and eight epifaunal samples along each transect.

As in 2009, the habitat condition index scores were high in 2015, with no differences between years or seagrass habitat types (Amphibolis, Posidonia and Mixed). Seagrasses at Yankalilla had greater biomass and stem density than those found off the Adelaide coast, but shorter stem/leaf lengths. Epiphyte biomass was also high. Infaunal assemblages differed between sand and Posidonia, with Amphibolis and mixed habitats being intermediate. Epifaunal assembalges differed between Posidonia and Amphibolis/Mixed habitats. Both infauna and epifauna were more abundant and diverse at Yankalilla than off Grange (Adelaide) in Amphibolis seagrass, whereas infauna in sand showed typical values in what is an extremely large range for both variables. Larger invertebrates did not clearly separate out according to habitat type, and very few fish were documented.

1 Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

1. INTRODUCTION

1.1. Background

In 2009, the Department for Environment and Heritage (DEH, now Department for Environment Water and Natural Resources - DEWNR) and the South Australian Research and Development Institute (SARDI) undertook a joint program to assess the condition of seagrasses in Yankalilla Bay (Murray-Jones et al. 2009). In that project, a standardised methodology was developed to assess seagrass condition from data that can be collected using a remote video camera. The technique was then applied to a series of video transects running offshore in the vicinity of the Bungala River and Carrickalinga Creek in Yankalilla Bay. Seagrasses were found to be in good condition in these areas. Additionally, recruitment of Amphibolis juveniles to recruitment units was high, providing further evidence that the seagrasses were in generally good condition.

Following on from this work, Tanner et al. (2012) examined epiphyte cover in the video footage recorded in 2009. Epiphyte cover did not vary in response to proximity to Bungala River or Carrickalinga Creek. There were, however, strong geographic gradients, with epiphyte cover in offshore waters of the northern part of the study area much higher than elsewhere. Offshore transects around Carrickalinga Creek had 154% greater epiphyte cover than inshore transects, and 296% more than those around Bungala River. Inshore transects at Carrickalinga also had slightly higher (63%) cover than inshore transects at Bungala. Levels of epiphyte cover observed (generally <20%) were similar to those documented previously in the Adelaide metropolitan area as part of the Adelaide Coastal Waters Study (Bryars et al. 2006).

In 2013/14, Bryars (2014) surveyed the health of seagrasses (and reefs) in the nearshore area of Yankalilla Bay (< 500 m from shore). He observed unhealthy Amphibolis at a number of locations, particularly focused around the mouth of the Yankalilla River, which is further south than the studies mentioned above extended. He also documented an extensive erosion scarp along the inshore edge of the seagrass meadow, further inshore than the previous sampling occurred. This erosion scarp extended down to the underlying hard substrate, with subsequent colonisation of macroalgae.

The previous studies showed that the seagrass habitat in Yankalilla Bay was generally in good condition in offshore areas, but with some areas of poor health in shallower water, and suggestions of seagrass loss in very shallow waters (1-2 m). However, none of these studies examined seagrass ecosystem function. A key function performed by seagrasses is to act as a habitat for a wide variety of fauna (e.g. Tanner and McDonald 2014). These fauna range

2 Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity from polychaetes living in the sediments, to small crustaceans living in amongst the seagrass blades, to larger invertebrates (both sessile, such as ascidians and sponges, and mobile, such as gastropods and squid), and fish. Bryars (2013) reported on nearshore marine habitats in the Adelaide and Mount Lofty Ranges Natural Resources Management region, and one of his recommendations was to undertake surveys of biodiversity in understudied habitats. The two key habitats identified were seagrasses and sand.

1.2. Objectives

The primary objective of this report is to document faunal use of seagrass and sand habitats in Yankalilla Bay. We also examine the relationship between faunal assemblage structure and seagrass habitat characteristics such as biomass, stem density etc. The specific aims are:

1. Assess infaunal assemblages present in Amphibolis, Posidonia, Mixed seagrass and sand habitats, and if they are influenced by seagrass belowground biomass. 2. Assess motile epifaunal assemblages in the above seagrass habitats, and how they are influenced by seagrass structural characteristics. 3. Assess the fish and larger invertebrate assemblages in the above habitats. 4. Assess seagrass condition in the above habitats, and where possible, compare it to the condition documented in 2009.

While it is acknowledged that these assemblages may change over time and with depth, this study provides a single snapshot for October 2015 (mid-spring) in shallower water (2-4 m depth).

3 Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

2. METHODS

2.1. Site selection

Faunal sampling locations were chosen based on results from the previous survey that assessed the condition of seagrass in Yankalilla Bay (Murray-Jones et al. 2009, Tanner et al. 2012). A series of video ‘mega-transects’ running offshore in 2009 identified three main seagrass habitats: Amphibolis, mixed Amphibolis/Posidonia, and some Posidonia. Fifty metre sub-transects were then analysed to determine seagrass condition. In October 2015, three 50 m transects in a similar depth range (2-4 m) were established using GPS start and end points (Table 1) for each of these habitat types along the mega-transect lines previously used for seagrass condition monitoring (Figure 1). Where possible, these transects were intended to coincide with sub-transects that were scored for seagrass condition in 2009. In addition, three transects were established in sand, with their location decided in the field due to the lack of sand within a similar depth range identified in the previous video surveys. These transects were only 20-30 m, as there were no sand patches sufficiently large to establish a 50 m transect.

Table 1: Coordinates for the start and end points of the survey transects in Yankalila Bay (GDA 94).

Transect Start End Latitude Longitude Latitude Longitude Sand 1 -35.4387 138.3077 -35.4386 138.3075 Sand 2 -35.4436 138.3051 -35.4435 138.3049 Sand 3 -35.4474 138.3039 -35.4473 138.3036 Mixed 1 -35.4457 138.3032 -35.4456 138.3027 Mixed 2 -35.4439 138.3032 -35.4437 138.3027 Mixed 3 -35.4485 138.3013 -35.4483 138.3008 Amphibolis 1 -35.439 138.3064 -35.4388 138.3059 Amphibolis 2 -35.4427 138.3045 -35.4426 138.304 Amphibolis 3 -35.4302 138.3163 -35.43 138.3158 Posidonia 1 -35.4522 138.2997 -35.4521 138.2992 Posidonia 2 -35.4463 138.3049 -35.446 138.3043 Posidonia 3 -35.4493 138.3025 -35.4492 138.3019

4 Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

Figure 1: Map of Yankalilla Bay showing the 2009 mega-transect lines (red) and the 2015 transects (blue) surveyed for seagrass fauna, overlaid on broader scale DEWNR habitat mapping.

5 Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

2.2. Fauna and Flora Survey

Using the established GPS start and end points for each 50 m transect, a rope with a measuring tape attached and weighted at each end was deployed from the boat. Divers inspected the position of the rope along the entire transect and ensured it ran along the substrate (not over the canopy). On return, divers conducted a fish survey in a 5 m wide belt (2.5 m either side of tape). The line-intercept transect method (LIT), a survey protocol developed for the “Reef Health” program (Turner et al. 2007), was used to survey sessile fauna and flora. Due to the soft sediment habitat in Yankalilla Bay, a modification of this protocol, which has previously been used as part of the baseline surveys for the Adelaide desalination plant (Theil and Tanner 2009), was used. Starting at the inshore end of the transect line, a diver used the measuring tape to score habitat transitions along the entire length of the transect based on where seagrass emerged from the substrate. Gaps in seagrass cover were only scored if no canopy was present. The second diver conducted an invertebrate and cryptic fish survey in a 1 m wide belt for the entire length of the transect.

In addition, at predetermined random points along the first 20 m of each transect a set of eight infaunal samples and eight epifaunal samples were collected in the target habitat. For the Mixed seagrass habitat, Amphibolis and Posidonia were collected in each core. Infaunal samples were collected using 90 mm diameter corers made from PVC piping (with rubber bungs) and inserted 10 cm deep into the substrate. Adjacent to the infauna cores, 90 x 200 mm epifauna ‘corers’ made from PVC piping were used to collect seagrass aboveground material and associated fauna by carefully placing the core and a fine mesh bag over the seagrass. The seagrass was then cut at substrate level using a knife and the bag tied shut, enclosing the ‘core’ inside the bag. All samples were placed in 2L plastic jars and fixed in 10% Formalin immediately on return to the surface for processing in the laboratory. All fieldwork was undertaken in October 2015.

In the laboratory, both infauna and epifauna samples were rinsed in fresh water over a 0.5 mm mesh sieve and placed in a glass petri dish. Sediment level in each infauna jar was recorded prior to rinsing. Samples were sorted under a magnifying lamp and identified to the lowest taxonomic level feasible, generally family.

To characterise the seagrass present, stem (Amphibolis) or leaf (Posidonia) counts and lengths (mm) were measured for each epifauna core. To measure epiphyte biomass, epiphytes were scraped from all stems or leaves with a razor blade and placed in foil containers in an oven for 70 hours at 65°C. Dry weight was then recorded (gDW). Aboveground biomass (gDW) was also measured for each epifauna core by drying the seagrass in the oven (as above). In the case of Mixed habitat, stem/leaf counts and lengths,

6 Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity and seagrass and epiphyte biomass were measured for each of Amphibolis and Posidonia. In addition, belowground biomass (root material) from each infauna core was removed from each sample and measured to obtain dry weight (gDW) as above. Unless noted otherwise, all results for seagrass structure, infauna and epifauna are on a per core basis (i.e. per 63.6 cm2).

Seagrass condition index (H’) was calculated for each seagrass transect following the methods previously used (Murray-Jones et al. 2009, Irving et al. 2013), with the exception that data were taken directly from the line-intercept transects, rather than from video. This modification involved calculating the percent cover of each seagrass species in each 1 m segment of the transect, rather than in a video frame each 1 m.

Although not analysed here, the following samples were also collected and are available for analysis if needed to further elucidate the relationships between fauna and the habitats:

 Sediment samples preserved for analysis of physical and chemical characteristics (grain size and/or organic matter content).  20 x 20 cm quadrats of seagrass aboveground biomass for more detailed characterization of structural characteristics.  Video footage along each 50 m transect line in the seagrass habitats.

2.3. Data analysis

To assess whether the nine seagrass transects grouped into their a priori habitat designations, hierarchical cluster analysis was undertaken with group average linkage. Data on cover of each habitat type along the line-intercept transects were square root transformed, and the Bray-Curtis similarity measure was used. To determine if the habitat condition index varied between transects, and between 2015 and 2009, PERMANOVA (Anderson 2001) was used, with 9999 permutations of residuals under a reduced model. No transformation was applied, and Euclidean distances were used. The 2009 data used for this comparison comprised the three H’ values calculated for the inshore section of each mega-transect on which a 2015 transect occurred.

Seagrass structural characteristics (seagrass and epiphyte biomass, stem/leaf count and canopy height) were also compared between habitat types using PERMANOVA. Principal coordinates analysis (PCO) was used to visualise patterns. Data were normalised for each variable prior to analysis to eliminate the effects of different measurement scales, and Euclidean distances were used. Belowground biomass was not included in this analysis, as rocky substrate on some Amphibolis transects prevented these data from being obtained.

7 Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

Infauna and epifauna were compared between habitats using PERMANOVA followed by canonical analysis of principal coordinates (CAP). CAP is used in preference to PCO when the PERMANOVA shows significant differences, as it specifically shows the axes of greatest difference between groups (whereas PCO shows the axes of greatest variability). For both data sets, data were fourth root transformed to reduce the influence of abundant taxa, and the Bray-Curtis similarity measure was used. Both taxonomic richness and total abundance of each group were also analysed with PERMANOVA (untransformed and using Euclidean distances). Where PERMANOVA showed significant differences between habitats, permutational analysis of dispersions (PERMDISP) was used with 9999 permutations to determine if these differences might be due to differences in variability rather than differences in location. The relationship between each of assemblage structure, taxonomic richness, and total abundance, and seagrass structural variables, was examined using the BEST procedure with 999 permutations. For infauna, the belowground biomass and amount of sediment obtained in the core were used as environmental variables, while for epifauna, aboveground biomass, epiphyte biomass, stem/leaf count and canopy height were used. Finally, species accumulation curves were constructed using 999 random permutations of the data, and the Chao-2 estimator (Colwell and Coddington 1994) was used to predict the likely total number of taxa present in each habitat.

Larger invertebrates were analysed in a similar fashion to infauna and epifauna, except at the transect level. In this case, CAP was unable to resolve differences between transects within a habitat type, so PCO was used to visualise patterns. The percent cover of each habitat type was used as the environmental data set for the BEST procedure.

All statistical analyses were performed using Primer version 7.0.10 with the PERMANOVA+ add-on (Clarke and Gorley 2015). Significance levels were set at =0.05.

8 Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

3. RESULTS

3.1. Seagrass structure and habitat condition

The a priori classification of transects into habitats based on the 2009 video data was not always borne out in the line-intercept transects conducted six years later, with two Amphibolis transects having substantial sections of mixed seagrass, one Mixed having substantial monospecific Amphibolis and two Posidonia having substantial areas of mixed (Table 2). Large brown algae, particularly Cystophora and Scaberia agardhii, were recorded on several transects. Cluster analysis showed three groupings at the 55% similarity level, with a single transect with 100% cover of Posidonia being an outlier (Figure 2).

Table 2: Percent cover of different taxa on line-intercept transects in 3 habitat types (A - Amphibolis, M - Mixed seagrass, P - Posidonia).

A1 A2 A3 M1 M2 M3 P1 P2 P3 Amphibolis 6.6 44.8 59.5 0 1 39.8 12.4 1.6 0 Posidonia 9.4 0 0 0 4.2 0 23.6 54.6 100 Mixed Seagrass 45.6 46 2.8 100 87.6 53.6 45.6 36.7 0 Cystophora 0 0 25.5 0 0 3.6 2 0 0 Cystophora & Scaberia 0 8 9.6 0 0 0 0 7.1 0 Scaberia 0 0.2 1.8 0 0 1.2 4.2 0 0 Brown foliaceous algae 0 0 0 0 0 0 1 0 0 Rock 0 1 0 0 7.2 0.6 6.6 0 0 Sand 38.4 0 0.8 0 0 1.2 4.6 0 0

S 60

100

3 3 2 3 1 2 2 1 1

P A A P A P

M M M Samples

Figure 2: Dendrogram showing the results of an average linkage hierarchical cluster analysis on habitat cover along line intercept transects in Yankalilla Bay. Horizontal line indicates groupings at a similarity of 55% (A - Amphibolis, M - Mixed seagrass, P - Posidonia).

9 Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

Habitat condition (Table 3) on the transects was generally high (91.6 ± 2.9 se), and did not vary between 2015 and 2009 (PERMANOVA: F1,6=0.000002, P=1). Nor were there any differences between transects (F6,6=2.25, P=0.11), or an interaction between transect and year (F6,16=0.71, P=0.59).

Table 3: Seagrass habitat condition indices for 2015 (H'), compared to mean condition for 2009 along the same transects.

Transect H’ 2009 H’ (se) A1 97.7 84.3 (10.2) A2 88.2 90.2 (6.7) A3 72.6 80.2 (0.3) M1 99.6 96.7 (3.0) M2 94.0 87.8 (4.2) M3 94.4 96.2 (0.6) P1 84.6 95.4 (2.3) P2 93.6 96.7 (3.0) P3 99.6 96.2 (0.6)

Seagrass structural characteristics (Table 4) did not vary between habitat types

(PERMANOVA: F2,6=2.24, P=0.092), although there was substantial variability between transects (F6,63=9.98, P<0.001). While Posidonia samples could have greater canopy height, biomass and stem/leaf counts than the other two habitats, there was still significant overlap with these habitats (Figure 3). Note that as all seagrass (and infaunal and epifaunal) samples were taken in the habitat that each individual transect was selected to represent, habitat designations are as per these initial targets, and are not based on the overall habitat present on the transect.

10 Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

6 Habitat

Epidw A M P

) 4

v SGdw

o 2

% Count

5 . Height

(

P 0

-2 -6 -4 -2 0 2 4 PCO1 (56.6% of total variation)

Figure 3: Principal coordinates analysis of seagrass structural characteristics (SGdw – Seagrass dry weight, Epidw – Epiphyte dry weight).

Table 4: Seagrass structural characteristics in Yankalilla Bay (mean ± se, dw - dry weight). Note: belowground samples could not be obtained at A1 and A3 due to the rocky nature of the substrate.

Aboveground Epiphyte Belowground Stem/leaf Canopy height biomass biomass biomass count (mm) (g dw) (g dw) (g dw) A1 8.7 (0.9) 6.4 (2.9) 15.3 (1.1) 152 (14) A2 10.6 (1.3) 5.8 (2.1) 3.4 (0.7) 14.8 (2.2) 294 (12) A3 7.8 (1.2) 5.1 (1.6) 10.9 (1.1) 231 (20) M1 3.4 (0.7) 4.5 (0.9) 0.1 (0.1) 32.0 (8.1) 248 (14) M2 13.3 (1.7) 1.9 (0.4) 3.5 (1.4) 53.4 (8.1) 283 (11) M3 11.4 (0.8) 11.5 (0.8) 2.2 (0.8) 32.8 (3.5) 257 (8) P1 6.8 (0.5) 0.8 (0.2) 1.1 (1.1) 67.5 (7.0) 268 (8) P2 8.0 (1.3) 3.0 (0.6) 5.4 (1.8) 59.5 (6.1) 352 (32) P3 22.0 (4.0) 6.4 (1.1) 0.0 (0.0) 129.4 (10.9) 443 (12)

3.2. Infauna

A total of 1305 infauna from 68 taxa (mostly families) were recorded in 79 core samples (summarised in Appendix 1). As Amphibolis was often found growing on a rocky substrate, it was only possible to obtain cores from a single transect in this habitat. There was an average of 16.5 (± 1.6 se) individuals per core, which did not vary with habitat type (PERMANOVA:

F3,6=2.02, P=0.19), although there was a great deal of variability between transects within

11 Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

habitat types (F6,69=7.04, P<0.001) (Figure 4). There were an average of 6.6 ± 0.4 taxa per core, and again, this did not vary with habitat type (PERMANOVA: F3,6=0.61, P=0.61), but did vary between transects within habitat types (F6,69=8.51, P<0.001) (Figure 4). The relationship between both abundance and richness, and sample characteristics, was significant (BEST: p=0.006 and p<0.001, respectively) but weak (=0.24 and 0.22). Individual correlations were =-0.1 and 0.15 for belowground biomass and 0.24 and 0.13 for sediment level. This indicates that there was a very small decline in abundance as belowground biomass increased, but a slight increase in taxonomic richness. Both variables increased as the amount of sediment retrieved in the core increased.

Infaunal Abundance 60

se) 50 - 40 30 20

10 Abundance(+/ 0 A1 M1 M2 M3 P1 P2 P3 S1 S2 S3 Habitat/Transect

Infaunal Taxonomic Richness 14 12

se) 10 - 8 6 4 # Taxa # (+/ 2 0 A1 M1 M2 M3 P1 P2 P3 S1 S2 S3 Habitat/Transect

Figure 4. Infaunal abundance (upper panel) and taxonomic richness (lower panel) in different habitats in Yankalilla Bay. A - Amphibolis, M - Mixed Amphibolis and Posidonia, P - Posidonia, S - Sand.

Infaunal assemblage composition, on the other hand, varied with habitat type (PERMANOVA:

F3,6=1.77, P=0.027), as well as between transects within habitat types (F6,69=2.77, P<0.001) (Figure 5). These differences were not due to differences in variability between habitats

(PERMDISP: F3,75=2.42, p=0.14). Pairwise tests indicated that the main difference was

12 Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity between Sand and both Mixed and Posidonia habitats (Table 5). This difference is clear in the CAP plot, which shows Posidonia cores primarily in the lower right, and sand in the lower left, with Mixed and Amphibolis in the middle (Figure 3). The biplot shows that Posidonia habitat is characterised by the polychaete families Cirratulidae and Spionidae, while sand is characterised by the polychates Syllidae, Glyceridae and Hesionidae, Ophiuroids (brittlestars) and nematodes. The relationship between assemblage structure and sample characteristics was significant (BEST: p<0.001), but weak (=0.22). Individual correlations were =0.15 for belowground biomass and 0.13 for sediment level.

Table 5: PERMANOVA pairwise tests for differences in infaunal composition between habitats. Significant p- values are shown in bold

Habitat Pair t P Mixed, Amphibolis 0.88 0.62 Mixed, Posidonia 1.30 0.12 Mixed, Sand 1.57 0.023 Amphibolis, Posidonia 1.02 0.46 Amphibolis, Sand 0.81 0.72 Posidonia, Sand 1.69 0.014

0.2

0.2 Habitat M A 0.1 P S 0.1

P 0

P 0 C

Ophiuroidea HesionidaeSyllidae GlyceridaeNematoda Cirratulidae

-0.1 -0.1 Spionidae

-0.2 -0.2 -0.3 -0.2 -0.1 0 0.1 0.2 CAP1 -0.3 -0.2 -0.1 0 0.1 0.2 CAP1

Figure 5: Canonical analysis of principal coordinates plot showing discrimination between infaunal assemblages in different habitats in Yankalilla Bay. A - Amphibolis, M - Mixed Amphibolis and Posidonia, P - Posidonia, S - Sand. Biplot on right shows taxa with correlations >0.5 (taxa in the lower left are Ophiuroidea, Nematoda, Syllidae, Glyceridae and Hesionidae).

13 Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

A total of 38, 19, 43 and 40 infaunal taxa were detected in Mixed, Amphibolis, Posidonia and Sand habitats, respectively. Species accumulation curves (Figure 6) indicate broadly similar accumulation rates as new samples were added in each habitat, with the exception that the Amphibolis curve was somewhat lower than the other taxa. Predictions of total taxonomic richness in each habitat in the area sampled using the Chao 2 estimator were 44, 27, 64 and 49, respectively. Examples of some typical infauna are presented in Figure 7.

Taxon Count Taxon

20 Mixed Amphibolis Posidonia Sand

0 0 5 10 15 20 25

# Samples

Figure 6: Species accumulation curves (solid symbols) and predicted total number of taxa using the Chao 2 estimator (hollow symbols) for infauna in Yankalilla Bay.

14 Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

Figure 7: Typical examples of infauna found at Yankalilla Bay. From left to right and top to bottom: Amphipods – Ampithoinae, Aoridae, Lysianassidae, Phoxocephalidae; Isopod – Janiridae; Ostracod – Cylindroleberididae; Polychaetes – Clyceridae, Hesionidae, Nereididae, Opheliidae, Spionidae.

15 Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

3.3. Epifauna

A total of 4678 epifauna from 60 taxa (mostly families) were recorded in 72 samples (summarised in Appendix 2). There was an average of 65 (± 8.2 se) individuals per sample, which did not vary with habitat type (PERMANOVA: F2,6=0.33, P=0.88), although there was a great deal of variability between transects within habitat types (F6,63=13.96, P<0.001) (Figure 8). There were an average of 10.9 ± 0.5 taxa per sample, which varied with habitat type

(PERMANOVA: F2,6=11.16, P=0.013), as well as between transects within habitat types

(F6,63=3.67, P=0.003) (Figure 8). Pairwise tests indicated that Posidonia habitat differed from both Amphibolis and Mixed, having 6.4 ± 0.6 taxa per sample compared to 13.8 ± 0.8 and 12.4 ± 0.6 respectively. The relationship between abundance and sample characteristics was significant (BEST: p<0.001) but weak (=0.39), with a combination of epiphyte biomass, canopy height and stem/leaf count providing the strongest relationship. Individual correlations were =0.30, 0.24, 0.21 and 0.17 for stem/leaf count, canopy height, epiphyte biomass and seagrass biomass, respectively. There was no significant relationship for taxonomic richness (BEST: p=0.15).

Epifaunal Abundance 300

se) 250 - 200 150 100

50 Abundance(+/ 0 A1 A2 A3 M1 M2 M3 P1 P2 P3 Habitat/Transect

Epifaunal Taxonomic Richness 20

se) - 10

5 # Taxa # (+/

0 A1 A2 A3 M1 M2 M3 P1 P2 P3 Habitat/Transect

Figure 8: Epifaunal abundance (upper panel) and taxonomic richness (lower panel) in different habitats in Yankalilla Bay. A - Amphibolis, M - Mixed Amphibolis and Posidonia, P - Posidonia.

16 Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

Epifaunal assemblage composition also varied with habitat type (PERMANOVA: F2,6=2.45,

P=0.037), as well as between transects within habitat types (F6,63=5.49, P<0.001) (Figure 9). Pairwise tests indicated that the main difference was between Posidonia and both Mixed and Amphibolis habitats (Table 6). Unlike for infauna, there were differences in variability between habitats for epifauna (PERMDISP: F3,69=5.71, p=0.01). The CAP plot shows Posidonia is clearly different in both composition and variability to the other two habitats (Figure 9). The biplot shows that a wide range of taxa are more abundant in Amphibolis and Mixed habitats than in Posidonia, including the polychaetes Chrysopetalidae, Nereididae and Syllidae, as well as the families Lysianassidae (amphipod crustacean), Leptocheliidae (tanaid crustacean), Cylindroleberidae (ostracod crustacean) and Ischnochitonidae (chiton mollusc). Gammaridea sp.1 is the major taxon separating Amphibolis and Mixed habitats. The relationship between assemblage structure and sample characteristics was not significant (BEST: =0.15, p=0.06).

Table 6: PERMANOVA pairwise tests for differences in epifaunal composition between habitats.

Habitat Pair t P Mixed, Amphibolis 1.00 0.46 Mixed, Posidonia 1.55 0.071 Amphibolis, Posidonia 1.90 0.013

0.2 0.2 Habitat A M P

0.1 0.1

Ischnochitonidae Chrysopetalidae Cylindroleberidae

P 0

P 0 C Syllidae A LysianassidaeNereididae

C Leptocheliidae

-0.1 -0.1 Gammaridea sp.1

-0.2 -0.2 -0.2 -0.1 0 0.1 0.2 0.3 -0.2 -0.1 0 0.1 0.2 0.3 CAP1 CAP1

Figure 9: Canonical analysis of principal coordinates plot showing discrimination between epifaunal assemblages in different habitats in Yankalilla Bay. A - Amphibolis, M - Mixed Amphibolis and Posidonia, P - Posidonia. Biplot on right shows taxa with correlations >0.6 (obscured taxa on the left are Lysianassidae, Nereididae and Syllidae).

17 Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

A total of 41, 49 and 23 epifaunal taxa were detected in Mixed, Amphibolis and Posidonia habitats, respectively. Species accumulation curves (Figure 10) indicate much slower accumulation rates as new samples were added in Posidonia than in the other two habitats. Predictions of total taxonomic richness in each habitat in the area sampled using the Chao 2 estimator were 47, 63 and 28, respectively. Examples of some typical epifauna are presented in Figure 11.

Taxon Count Taxon

20 Mixed Amphibolis Posidonia 0 0 5 10 15 20 25

# Samples

Figure 10: Species accumulation curves (solid symbols) and predicted total number of taxa using the Chao 2 estimator (hollow symbols) for epifauna in Yankalilla Bay.

18 Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

Figure 11: Typical examples of epifauna found at Yankalilla Bay. From left to right and top to bottom: Amphipods – Aoridae, Maeridae; Isopods – Anthuridae, Cirolanidae Janiridae; Tanaid – Leptochelidae; Pycnogonid; Polychaetes – Dorvilleidae, Nereididae, Syllidae; Mollusacs – Ischnochitonidae, Trochidae.

19 Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

3.4. Fish and Larger Invertebrates

Only six individual fish were observed on the 15 transects, 3 on one of the sand transects, and 3 across two of the Mixed transects (Table 7). Due to the low numbers, these data were not analysed statistically.

Table 7: Fish observed on seagrass and sand transects in Yankalilla Bay.

Transect Taxon Common name Count Sand 1 Pictilabrus laticlavius Senator wrasse 1 Sand 1 Fam. Odacidae Weed whiting 1 Sand 1 Fam. Gobiidae Goby 1 Mixed 2 Fam. Monacanthidae Leatherjacket 1 Mixed 3 Pictilabrus laticlavius Senator wrasse 1 Mixed 3 Fam. Odacidae Weed whiting 1

A total of 370 larger invertebrates from 25 taxa were recorded in the 12 belt transects (summarised in Appendix 3). While Sand clearly had the lowest abundance and diversity (Figure 12), with only a single hermit crab observed across the 3 transects, the differences between habitats in abundance were not significant due to high variability and low sample sizes (PERMANOVA: F3,8=1.90, P=0.17). Taxonomic richness varied with habitat type

(PERMANOVA: F3,8=8.66, P=0.012), with pairwise tests showing Sand (0.33 ± 0.33) to be different from Amphibolis (6.67 ± 0.67) and Mixed (7.33 ± 1.33), but not Posidonia (4 ± 1.5).

20 Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

Large Invertebrate Abundance

80 se)

- 60

20 Abundance(+/ 0 Amphibolis Mixed Posidonia Sand Habitat

Large Invertebrate Taxonomic Richness 10

8 se) - 6

# Taxa # (+/ 2

0 Amphibolis Mixed Posidonia Sand Habitat

Figure 12: Large Invertebrate abundance (upper panel) and taxonomic richness (lower panel) in different habitats in Yankalilla Bay.

Large invertebrate assemblage composition also varied with habitat type (PERMANOVA:

F3,6=1.77, P=0.027), as well as between transects within habitat types (F3,8=5.11, P<0.001) (Figure 13). These differences are not due to differences in variability between habitats

(PERMDISP: F3,8=6.47, p=0.088). Pairwise tests indicated that the main difference was between Sand and the three seagrass habitats (Table 8). Mixed and Amphibolis habitats form a tight intermingled group on the PCO plot (Figure 13), with Posidonia in between that group and Sand. The BEST procedure showed no significant relationship between invertebrate assemblages and habitat structure (=0.5, p=0.15).

21 Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

Table 8: PERMANOVA pairwise tests for differences in large invertebrate composition between habitats.

Habitat Pair t P Mixed, Amphibolis 1.20 0.27 Mixed, Posidonia 1.62 0.087 Mixed, Sand 3.54 0.003 Amphibolis, Posidonia 1.40 0.16 Amphibolis, Sand 3.29 0.006 Posidonia, Sand 2.60 0.015

50 50 Habitat A M P

) S

M3 n

)

i Phasianella australis

r Tosia australis

a r A3

a S1 Colonial Ascidian

v A1

M2 a

S2S3 t

t A2

o 0

o 0 M1

% P2 .

4 . P1 Sponge

(

SeaUnidentified cucumberurchin starfish

P3 -50 -50 -60 -40 -20 0 20 40 -60 -40 -20 0 20 40 PCO1 (51.4% of total variation) PCO1 (51.4% of total variation)

Figure 13: Principal coordinates analysis plot showing discrimination between large invertebrate assemblages in different habitats in Yankalilla Bay. A - Amphibolis, M - Mixed Amphibolis and Posidonia, P - Posidonia, S - Sand. Biplot on right shows taxa with correlations >0.7 (taxa in the upper right are Phasianella australis (pheasant shell) and Tosia australis (biscuit star) and lower center are unidentified holothurians, echinoids and asteroids (sea cucumbers, sea urchins and starfish)).

22 Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

4. DISCUSSION Overall, the seagrass ecosystem in shallow waters in Yankalilla Bay appears to be in good condition, with a high cover of seagrass, and a diverse array of fauna present. Although the between-year comparison should be viewed with caution due to the use of different survey techniques, the habitat condition indices calculated for 2015 did not differ from those calculated along the same mega-transect lines in 2009 (Murray-Jones et al. 2009). There was no clear pattern in habitat condition, although the single seagrass transect in the northern part of the study region (A3) had the lowest condition index, and the mixed habitats had uniformly high condition. The original intention of the survey design was to do repeat surveys of transects scored for habitat condition in 2009 that fit neatly into one of the three pre-defined habitat categories (Amphibolis, Posidonia, Mixed), and few of the northern transects met this criterion, hence the lack of 2015 transects in this area. As it eventuated, however, few of the transects surveyed in 2015 matched the habitat type recorded in 2009. This discrepancy could be due to changes in seagrass composition in the intervening 6 years, but is likely to be at least partly due to small differences in the location of the transects. As a hand-held GPS was used in 2015, rather than a precision surveying GPS as used in 2009, the differences in location could have been 5-10 m.

Amphibolis at Yankalilla has a high stem density and biomass compared to that documented in the northern Adelaide metropolitan area, but comparable to that documented by Bryars (2009) in the southern metropolitan area (Table 9). Canopy height, however, is relatively low, although again comparable to that found by Bryars (2009). There is also substantially greater epiphyte biomass at Yankalilla than in other areas of Gulf St Vincent. The 2015 values for stem density are somewhat higher than those documented in 2009, while seagrass biomass, epiphyte biomass and canopy height are similar. A major difference between Yankalilla and the sites in the northern metropolitan area is that it is much shallower (2-4 m compared to 6- 15 m), whereas Bryars (2009) also sampled from 2-4 m depth. Light availability would be higher in the shallow sites, which could explain the differences. A similar pattern is found for Posidonia, with stem densities and biomass an order of magnitude higher than elsewhere in Gulf St Vincent and Spencer Gulf, although comparable values for epiphyte biomass were not located, and there are no data from Yankalilla in 2009 (Table 9). This study did not extend into the southern region of Yankalilla Bay near the mouth of the Yankalilla River, or to the inshore edge of the seagrass bed, and so does not include the main areas where unhealthy Amphibolis and likely seagrass loss were documented by Bryars (2014).

23 Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

Table 9: Compilation of structural characteristics for Amphibolis and Posidonia seagrasses in South Australia. Values in parentheses are standard errors.

Stem/leaf Aboveground Epiphyte Canopy density biomass biomass height Site Reference (m-2) (g DW m-2) (g DW m-2) (mm) Amphibolis A1 This study 2,405 (173) 1,367 (141) 1,006 (456) 152 (14) A2 This study 2,326 (346) 1,666 (204) 912 (330) 294 (12) A3 This study 1,713 (173) 1,226 (189) 802 (251) 231 (20) Yankalilla Irving (2009) 1,472 (55) 1,214 (63) 817 (100) 228 (6) Grange 1 year McSkimming et al. (2016) 875 (127) 372 (57) 69 (8) 180 (10) Grange 3 years McSkimming et al. (2016) 1,031 (240) 863 (196) 300 (61) 330 (20) Grange 5 years McSkimming et al. (2016) 1,563 (513) 959 (240) 384 (110) 340 (10) Grange Edge McSkimming et al. (2016) 1,031 (106) 1,113 (75) 284 (47) 540 (40) Grange Interior McSkimming et al. (2016) 1,313 (145) 928 (29) 253 (49) 410 (10) West Torrens Theil and Tanner (2009) 1,091 (184) 433 (45) 312 (7) Grange (min) Tanner unpub 181 (28) 256 (40) 46 (12) Grange (max) Tanner unpub 570 (59) 1,057 (119) 358 (65) Henley (min) Tanner unpub 246 (23) 269 (40) 37 (5) Henley (max) Tanner unpub 834 (85) 863 (115) 227 (33) Largs (min) Tanner unpub 283 (38) 246 (53) 37 (12) Largs (max) Tanner unpub 763 (84) 787 (56) 338 (40) Semaphore (min) Tanner unpub 208 (21) 275 (31) 33 (7) Semaphore (max) Tanner unpub 722 (61) 1,011 (205) 289 (73) Marino (summer) Bryars (2009) 2,846 (186) 1,440 (136) 19 (8) 291 (14) Seacliff (summer) Bryars (2009) 2,437 (259) 960 (133) 28 (4) 160 (7) Hallett Cove (summer) Bryars (2009) 2,201 (197) 1,138 (197) 20 (4) 171 (10) Wool Bay (summer) Bryars (2009) 1,220 (158) 591 (66) 185 (53) 259 (17) Edithburgh (summer) Bryars (2009) 820 (97) 392 (46) 462 (144) 157 (6) Port Giles (summer) Bryars (2009) 1,006 (92) 344 (47) 373 (59) 152 (7)

Posidonia P1 This study 10,609 (1,100) 1,069 (79) 126 (31) 268 (8) P2 This study 9,352 (959) 1,257 (204) 472 (94) 252 (32) P3 This study 20,338 (1,713) 3,458 (629) 1,006 (173) 443 (12) Port Augusta C1 Wiltshire and Tanner (2010) 1,053 (116) 438 (58) 370 (28) Port Augusta C2 Wiltshire and Tanner (2010) 517 (89) 306 (76) 310 (44) Port Augusta C3 Wiltshire and Tanner (2010) 1,035 (252) 488 (151) 381 (42) Port Augusta HC Wiltshire and Tanner (2010) 1,107 (185) 365 (79) 266 (27) Pelican Point (min) Theil and Tanner (2009) 699 (68) 101 (8) 203 (5) Pelican Point (max) Theil and Tanner (2009) 1,976 (287) 323 (113) 266 (5) West Torrens (min) Theil and Tanner (2009) 852 (495) 138 (15) West Torrens (max) Theil and Tanner (2009) 1,591 (631) 337 (34)

As would be expected, infaunal assemblages differed between sand and seagrass, although interestingly with the exception of Amphibolis, which did not differ from any other habitat type. Compared to Posidonia, Amphibolis tends to have very little belowground biomass, with the

24 Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity roots primarily acting as an anchoring mechanism. As such, it is perhaps not surprising to find its infaunal assemblage composition to be intermediate between sand and Posidonia, which is where it lies in the ordination plot. As would be expected from this, infaunal assemblage structure was related to belowground biomass, although only weakly, so this was not the main driver behind structure. There was also a weak negative correlation between belowground biomass and infaunal abundance, indicating higher abundances with less seagrass. This is in accordance with recent work at the Grange rehabilitation site, where it was found that infauna are most abundant in bare sand, and decline in abundance with the age of rehabilitation plots (McSkimming and Tanner unpublished data).

Infaunal abundance and taxonomic richness in Amphibolis at Yankalilla were both substantially higher than in the same habitat at Grange (Table 10) by factors of at least 3 and 2, respectively. This was the only directly comparable study found for infauna in Amphibolis, and used the same sampling techniques. No comparable studies were located for Posidonia. For sand, only a few examples are presented in Table 10, but they indicate that both abundance and richness are highly variable, and that values for Yankalilla fall within the typical range. Note that some of the previous studies use a smaller core size, and so taxonomic richness cannot be directly compared.

Table 10: Comparison of infaunal abundance and taxonomic richness in Amphibolis and bare sand in South Australia. Values in parentheses are standard errors.

Infaunal Core Infaunal taxonomic size Site Reference abundance (m-2) richness (cm2) Amphibolis A2 This study 1,415 (314) 5.3 (0.8) 63.6 Grange 2 years McSkimming & Tanner (unpub) 570 (176) 2.5 (0.8) 63.6 Grange 4 years McSkimming & Tanner (unpub) 511 (88) 2.5 (0.4) 63.6 Grange 6 years McSkimming & Tanner (unpub) 255 (59) 1.6 (0.4) 63.6 Grange Edge McSkimming & Tanner (unpub) 314 (94) 1.3 (0.3) 63.6 Grange Interior McSkimming & Tanner (unpub) 452 (124) 1.8 (0.4) 63.6

Sand S1 This study 3,458 (599) 6.9 (0.7) 63.6 S2 This study 6,562 (1,254) 11.6 (0.9) 63.6 S3 This study 2,790 (394) 5.3 (0.6) 63.6 Port Giles Fairhead et al 2002 1,269 (177) 3.7 38.6 Port Stanvac Loo et al 2014 31,763 (4,538) 3.9 35.3 Port Stanvac Loo et al 2014 112,021 (17,300) 7.6 35.3 Grange McSkimming & Tanner (unpub) 1,414 (530) 3.0 (0.4) 63.6

Only a single comparable study on epifaunal assemblages in seagrasses in South Australia was located (Table 11). McSkimming et al. (2016) used identical techniques to those used here (including core size and taxonomy) to examine epifaunal assemblages in restored Amphibolis plots and an adjacent natural meadow at Grange. All three Amphibolis transects

25 Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity at Yankalilla had higher epifaunal abundance than was found at Grange in either natural or restored seagrass, while taxonomic richness was similar.

Table 11: Comparison of epifaunal abundance and taxonomic richness in Amphibolis in South Australia. Values in parentheses are standard errors.

Epifaunal Epifaunal taxonomic Site Reference abundance richness A1 This study 6,562 (1,538) 13 (2) A2 This study 8,055 (1,238) 14 (1) A3 This study 11,041 (1,202) 14 (1) Grange 1 year McSkimming et al. (2016) 3,125 (1,185) 12 (4) Grange 3 years McSkimming et al. (2016) 4,250 (1,934) 14 (4) Grange 5 years McSkimming et al. (2016) 6,500 (2,361) 18 (4) Grange Edge McSkimming et al. (2016) 4,125 (1,057) 14 (2) Grange Interior McSkimming et al. (2016) 3,563 (1,386) 12 (2)

In this study, we found a clear difference between epifaunal assemblages present in Posidonia samples and those present in Amphibolis or Mixed samples. Posidonia has a much simpler architecture than Amphibolis, and therefore presents a less complex habitat. It has been well established that more complex habitats provide a greater diversity of niches for fauna, and thus tend to have more abundant and diverse faunal assemblages, including in seagrass (e.g. Bell and Westoby 1986, Jenkins et al. 2002, Hovel et al. 2016). There were apparently no specialist Posidonia epifaunal taxa present at the family level, as none correlated strongly with the Posidonia samples in the CAP plot. Despite differences between habitats, there did not appear to be any relationship between the epifaunal assemblage (or taxonomic richness) and the seagrass structural characteristics measured, although total epifaunal abundance increased with increases in epiphytes, canopy height and stem/leaf density. Again, the latter is likely to be related to habitat complexity, as well as a species-area effect, that is, as the amount of seagrass increases, there is more habitable space, and thus more animals (e.g. Webster et al. 1998, Attrill et al. 2000).

Few fish were observed on the surveyed transects. This may be due at least in part to avoidance of divers by those fish present, but also that most fish in seagrass are cryptic and often live below the canopy. The survey methods used did not target these taxa, as moving the canopy out of the way would cause considerable disturbance. A more appropriate technique for targeting fish assemblages in this type of habitat may be baited underwater remote video.

26 Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

REFERENCES Anderson, M. J. 2001. A new method for non-parametric multivariate analysis of variance. Austral Ecology 26:32-46. Attrill, M. J., J. A. Strong, and A. A. Rowden. 2000. Are macroinvertebrate communities influenced by seagrass structural complexity? Ecography 23:114-121. Bell, J. D., and M. Westoby. 1986. Importance of local changes in leaf height and density to fish and decapods associated with seagrasses. Journal of Experimental Marine Biology and Ecology 104:249-274. Bryars, S. 2013. Nearshore marine habitats of the Adelaide and Mount Lofty Ranges NRM region: values, threats and actions. Report to the Adelaide and Mount Lofty Ranges Natural Resources Management Board., Adelaide. Bryars, S. 2014. Nearshore seagrass and reef condition in Yankalilla Bay. Report to the Adelaide and Mount Lofty Ranges Natural Resources Management Board., Adelaide. Bryars, S., D. Miller, G. Collings, M. Fernandes, G. Mount, and R. Wear. 2006. Field surveys 2003-2005: Assessment of the quality of Adelaide’s coastal waters, sediments and seagrasses. ACWS Technical Report No. 14 prepared for the Adelaide Coastal Waters Study Steering Committee. South Australian Research and Development Institute (Aquatic Sciences) Publication No. RD01/0208-15, Adelaide. Bryars, S. R. 2009. Can regional nutrient status be used to predict plant biomass, canopy structure and epiphyte biomass in the temperate seagrass Amphibolis antarctica? Marine and Freshwater Research 60:1054-1067. Clarke, K. R., and R. N. Gorley. 2015. PRIMER v7: User manual/tutorial. PRIMER-E, Plymouth. Colwell, R. K., and J. A. Coddington. 1994. Estimating terrestrial biodiversity through extrapolation. Philosophical Transactions of the Royal Society of London Series B- Biological Sciences 345:101-118. Hovel, K. A., A. M. Warneke, S. P. Virtue-Hilborn, and A. E. Sanchez. 2016. Mesopredator foraging success in eelgrass (Zostera marina L.): Relative effects of epiphytes, shoot density, and prey abundance. Journal of Experimental Marine Biology and Ecology 474:142-147. Irving, A. 2009. Reproduction, recruitment, and growth of the seagrass Amphibolis antarctica near the Bungala and Yankalilla rivers, South Australia. Final report prepared for the Coastal Management Branch of the Department for Environment & Heritage SA and the Adelaide & Mount Lofty Ranges Natural Resources Management Board. SARDI Publication Number F2009/000468-1., South Australian Research and Development Institute (Aquatic Sciences), Adelaide. Irving, A. D., J. E. Tanner, and S. G. Gaylard. 2013. An integrative method for the evaluation, monitoring, and comparison of seagrass habitat structure. Marine Pollution Bulletin 66:176-184. Jenkins, G. P., G. K. Walker-Smith, and P. A. Hamer. 2002. Elements of habitat complexity that influence harpacticoid copepods associated with seagrass beds in a temperate bay. Oecologia 131:598-605. McSkimming, C., S. D. Connell, B. D. Russell, and J. E. Tanner. 2016. Habitat restoration: Early signs and extent of faunal recovery relative to seagrass recovery. Estuarine Coastal & Shelf Science 171:51-57. Murray-Jones, S., A. Irving, and J. Dupavillon. 2009. Seagrass Condition Monitoring: A report to the Adelaide and Mount Lofty Ranges Natural Resources Management Board. Department for Environment and Heritage, Coastal Management Branch. . Tanner, J. E., and B. McDonald. 2014. Faunal and floral associations with seagrasses in Spencer Gulf. Pages 208-216 in S. A. Shepherd, S. M. Madigan, B. M. Gillanders, S. Murray-Jones, and D. J. Wiltshire, editors. Natural history of Spencer Gulf. Royal Society of South Australia Inc., Adelaide. Tanner, J. E., M. Theil, and D. Fotheringham. 2012. Seagrass Condition Monitoring: Yankalilla Bay, Light River and Encounter Bay. Final report prepared for the Adelaide and Mount

27 Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

Lofty Ranges Natural Resources Management Board., South Australian Research and Development Institute (Aquatic Sciences), Adelaide. Theil, M., and J. E. Tanner. 2009. Marine characterisation study for a possible seawater desalination plant to supply Adelaide, final report prepared for South Australian Water Corporation. . South Australian Research and Development Institute (Aquatic Sciences), Adelaide. Turner, D., T. Kildea, and G. Westphalen. 2007. Examining the health of subtidal reef environments in South Australia. Part 2: Status of selected South Australian reefs based on the results of the 2005 surveys. South Australian Research and Development Institute (Aquatic Sciences), Adelaide. Webster, P. J., A. A. Rowden, and M. J. Attrill. 1998. Effect of shoot density on the infaunal macro-invertebrate community within a Zostera marina seagrass bed. Estuarine Coastal & Shelf Science 47:351-357. Wiltshire, K. H., and J. Tanner. 2010. Assessment of potential impacts of Alinta Energy discharges into Hospital Creek, upper Spencer Gulf, South Australia. Publication No. F2010/000810-1. Research Report Series No. 506, South Australian Research and Development Institute (Aquatic Sciences), Adelaide.

28 Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

APPENDIX 1: Infaunal taxa collected at Yankalilla Bay. Numbers are the sum over 8 cores on each transect.

Phylum Group Taxon M1 M2 M3 A1 P1 P2 P3 S1 S2 S3 Annelida Polychaeta Acoetidae 0 0 0 0 0 1 0 0 0 0 Annelida Polychaeta Capitellidae 0 1 1 2 4 0 5 5 6 0 Annelida Polychaeta Chrysopetalidae 0 4 2 2 0 2 0 1 25 0 Annelida Polychaeta Cirratulidae 0 0 0 0 4 3 3 0 0 0 Annelida Polychaeta Dorvilleidae 0 1 0 1 0 0 0 1 4 1 Annelida Polychaeta Eunicidae 0 1 0 0 0 0 0 0 0 0 Annelida Polychaeta Flabelligeridae 0 0 0 0 0 1 1 0 5 1 Annelida Polychaeta Glyceridae 0 0 0 0 0 0 0 9 8 0 Annelida Polychaeta Hesionidae 0 1 0 1 0 0 0 36 52 0 Annelida Polychaeta Lumbrineridae 0 0 0 0 0 2 0 0 1 0 Annelida Polychaeta Maldanidae 0 0 0 0 0 0 1 0 0 0 Annelida Polychaeta Nephtydae 0 1 0 0 0 0 0 1 0 0 Annelida Polychaeta Nereididae 1 1 2 4 0 0 0 3 1 0 Annelida Polychaeta Opheliidae 1 0 1 0 0 1 0 0 1 2 Annelida Polychaeta Orbiniidae 0 0 0 0 1 2 0 0 0 8 Annelida Polychaeta Paraonidae 0 0 0 0 0 0 0 5 1 1 Annelida Polychaeta Phyllodacidae 0 0 0 0 0 0 2 0 1 0 Annelida Polychaeta Poecilochaetidae 0 1 1 0 2 0 1 0 0 2 Annelida Polychaeta Polynoidae 0 0 0 0 0 0 0 0 21 0 Annelida Polychaeta Sabellidae 0 0 2 1 1 1 0 0 0 0 Annelida Polychaeta Sagittoidea 0 0 0 0 0 0 0 3 4 0 Annelida Polychaeta Sigalionidae 0 0 0 0 0 0 0 0 35 0 Annelida Polychaeta Spionidae 0 0 0 0 3 11 7 1 0 2 Annelida Polychaeta Syllidae 10 11 11 18 4 10 20 58 41 69 Annelida Polychaeta Terebellidae 0 0 0 0 0 2 0 0 0 0 Annelida Echiura 0 0 2 0 0 0 0 0 0 0 Arthropoda Amphipoda Ampithoidae 1 0 0 5 0 0 47 3 0 1 Arthropoda Amphipoda Aoridae 4 4 2 0 0 1 0 0 0 0 Arthropoda Amphipoda Caprellidae 0 0 0 0 1 0 0 1 0 0 Arthropoda Amphipoda Corophiidae 0 3 0 0 0 0 3 0 0 0 Arthropoda Amphipoda Dexaminidae 0 5 1 1 0 2 6 0 0 1 Arthropoda Amphipoda Gammaridea sp.1 11 20 5 9 13 10 48 20 55 3 Gammaridea Arthropoda Amphipoda sp.11 0 0 0 0 0 0 0 2 0 0 Gammaridea Arthropoda Amphipoda sp.12 0 0 0 0 0 0 0 0 1 0 Arthropoda Amphipoda Gammaridea sp.2 0 0 0 0 0 0 6 0 0 0 Arthropoda Amphipoda Gammaridea sp.3 0 0 0 0 0 0 1 0 0 0 Arthropoda Amphipoda Gammaridea sp.8 8 0 0 0 0 1 0 0 0 0 Arthropoda Amphipoda Ischyroceridae 0 1 1 0 0 1 0 0 0 0 Arthropoda Amphipoda Leucothoidae 0 0 0 0 0 0 1 0 0 0 Arthropoda Amphipoda Lysianassidae 1 0 2 4 0 0 1 0 0 19 Arthropoda Amphipoda Maeridae 0 0 2 3 0 1 7 6 1 0 Arthropoda Amphipoda Melitidae 0 6 0 0 1 0 2 0 0 0 Arthropoda Amphipoda Phoxocephalidae 1 10 8 4 3 5 7 4 19 6

29 Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

Arthropoda Amphipoda Platyischnopidae 0 0 0 0 0 0 0 0 4 1 Arthropoda Amphipoda Podoceridae 0 1 0 1 0 0 8 0 0 0 Arthropoda Amphipoda Pontogammaridae 0 1 0 3 0 1 12 0 0 0 Arthropoda Amphipoda Stenothoidae 0 1 1 1 0 0 2 0 0 15 Arthropoda Amphipoda Urohaustoriidae 5 4 0 0 0 0 0 0 0 0 Arthropoda Caridea Alpheidae 0 1 0 0 0 0 0 0 0 0 Arthropoda Copepoda Calanoida 0 0 0 0 0 0 0 1 0 2 Arthropoda Copepoda Cyclopoida 0 0 0 0 0 0 1 0 0 0 Arthropoda Copepoda Harpacticoida 0 0 1 0 0 0 0 0 0 0 Arthropoda Cumacea Diastylidae 5 2 1 0 3 3 3 0 0 1 Arthropoda Isopoda Anthuridae 0 0 3 1 0 3 3 3 1 2 Arthropoda Isopoda Cirolanidae 0 0 0 0 0 0 0 0 0 4 Arthropoda Isopoda Cymothoidea 0 1 1 0 0 2 1 0 0 0 Arthropoda Isopoda Janiridae 0 0 1 0 0 0 0 0 0 0 Arthropoda Ostracoda Cylindroleberidae 0 6 4 0 0 6 2 0 0 0 Arthropoda Ostracoda Philomedidae 0 1 0 0 0 0 0 0 0 0 Arthropoda Tanaidacea Apseudidae 0 0 0 0 2 1 4 0 1 0 Arthropoda Tanaidacea Leptocheliidae 4 7 11 6 4 32 3 0 2 0 Arthropoda Tanaidacea Tanaidae 0 0 0 0 4 0 0 0 0 0 Echinodermata Holothuroidea 0 0 1 0 0 0 0 0 0 0 Echinodermata Ophiuroidea 0 0 0 0 0 0 0 2 19 0 Nematoda 0 0 2 5 0 0 1 7 22 1 Nemertea 0 0 0 0 0 0 0 0 3 0 Sipuncula Golfingiidae 0 0 0 0 0 1 0 0 0 0 unknown sp1 0 0 0 0 0 0 0 4 0 0

30 Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

APPENDIX 2: Epifaunal taxa collected at Yankalilla Bay. Numbers are the sum over 8 cores on each transect.

Phylum Group Taxon A1 A2 A3 M1 M2 M3 P1 P2 P3 Annelida Polychaeta Capitellidae 0 0 0 0 0 0 0 0 0 Annelida Polychaeta Chrysopetalidae 17 26 11 2 11 11 0 0 0 Annelida Polychaeta Cirratulidae 0 0 0 0 0 10 0 0 0 Annelida Polychaeta Dorvilleidae 0 0 1 0 1 0 0 0 0 Annelida Polychaeta Eunicidae 0 0 4 0 2 16 0 0 0 Annelida Polychaeta Flabelligeridae 0 0 0 1 0 1 0 0 0 Annelida Polychaeta Hesionidae 0 0 2 0 2 0 0 0 1 Annelida Polychaeta Lumbrineridae 0 0 1 0 0 0 0 0 0 Annelida Polychaeta Nereididae 46 27 35 16 18 29 1 3 6 Annelida Polychaeta Oenonidae 1 1 1 0 0 0 0 0 0 Annelida Polychaeta Phyllodocidae 6 17 12 3 7 11 0 1 1 Annelida Polychaeta Polychaeta sp.13 2 0 0 0 0 0 0 0 0 Annelida Polychaeta Polynoidae 1 0 0 0 0 0 0 0 0 Annelida Polychaeta Sabellidae 10 6 5 1 4 7 1 1 1 Annelida Polychaeta Syllidae 37 28 23 51 26 11 0 11 21 Annelida Polychaeta Terebellidae 1 8 8 0 7 0 0 0 0 Arthropoda Amphipoda Ampithoidae 20 36 111 96 35 42 9 256 1217 Arthropoda Amphipoda Aoridae 14 7 2 1 1 2 0 0 0 Arthropoda Amphipoda Caprellidae 0 0 3 1 0 0 0 0 0 Arthropoda Amphipoda Corophiidae 0 0 8 0 0 0 0 0 1 Arthropoda Amphipoda Dexaminidae 24 55 94 4 12 25 0 30 33 Arthropoda Amphipoda Gammaridea sp.1 4 0 1 60 12 23 4 8 78 Arthropoda Amphipoda Gammaridea sp.12 0 0 0 0 2 0 0 0 0 Arthropoda Amphipoda Gammaridea sp.13 2 0 1 0 2 0 0 0 0 Arthropoda Amphipoda Gammaridea sp.14 0 1 0 0 0 0 0 0 0 Arthropoda Amphipoda Gammaridea sp.8 0 4 25 0 0 0 0 0 0 Arthropoda Amphipoda Ischyroceridae 0 0 38 0 0 0 0 0 2 Arthropoda Amphipoda Lysianassidae 22 36 10 7 40 24 0 1 14 Arthropoda Amphipoda Maeridae 14 25 2 38 18 1 1 17 42 Arthropoda Amphipoda Melitidae 0 0 2 6 0 0 0 0 2 Arthropoda Amphipoda Podoceridae 0 0 0 0 0 1 1 0 0 Arthropoda Amphipoda Pontogeneiidae 8 12 69 95 14 0 6 69 202 Arthropoda Amphipoda Stenothoidea 0 2 0 1 0 1 0 0 0 Arthropoda Copepoda Calanoida 0 0 0 0 1 0 0 0 0 Arthropoda Cumacea Diastylidae 0 0 0 1 1 0 0 0 0 Arthropoda Decapoda Hymenosomatidae 0 0 1 0 0 0 0 0 0 Arthropoda Isopoda Anthuridae 6 25 10 1 22 16 2 3 4 Arthropoda Isopoda Cirolanidae 1 0 0 0 0 0 0 0 0 Arthropoda Isopoda Janiridae 2 3 0 0 1 1 0 0 0 Arthropoda Isopoda Serolidae 0 0 1 3 0 0 1 0 0 Arthropoda Isopoda Sphaeromatidae 0 1 0 0 0 0 1 8 0 Arthropoda Ostracoda Cylindroleberidae 11 17 10 0 22 18 0 0 0 Arthropoda Ostracoda Philomedidae 1 7 0 2 0 0 0 0 0 Arthropoda Pycnogonida Pycnogonidae 1 0 0 0 1 0 0 0 0

31 Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

Arthropoda Tanaidacea Leptocheliidae 49 35 45 86 49 122 1 23 34 Arthropoda Eumalacostraca 0 2 0 0 0 0 0 0 0 Chaetognatha 1 0 0 0 0 0 0 0 0 Echinodermata Ophiuroidea 0 1 1 0 0 0 0 1 0 Mollusca Bivalve Mytilidae 0 0 4 0 1 0 0 0 0 Mollusca Chiton Ischnochitonidae 26 27 18 1 19 11 0 1 0 Mollusca Gastropod Littorinidae 0 0 0 0 1 0 0 0 0 Mollusca Gastropod Lottiidae 0 0 0 0 4 0 0 0 0 Mollusca Gastropod Muricidae 0 0 1 0 0 0 0 0 0 Mollusca Gastropod Phasianellidae 0 1 0 0 0 36 0 0 0 Mollusca Gastropod Rissoidae 0 0 0 0 0 0 0 0 2 Mollusca Gastropod Trochidae 3 0 1 3 1 1 4 3 4 Mollusca Gastropod Turritellidae 1 0 0 0 0 0 0 0 0 Mollusca Gastropod Volutidae 0 0 0 0 0 1 0 0 0 Nematoda 0 0 1 0 1 0 0 0 0 Nemertea 3 0 1 0 0 0 0 0 0

32 Tanner, J. & Theil, M. (2016) Yankalilla Seagrass Biodiversity

APPENDIX 3: Large invertebrates collected at Yankalilla Bay. Numbers are the total number of individuals/colonies on each 50 m transect.

Phylum Group Taxon A1 A2 A3 M1 M2 M3 P1 P2 P3 S1 S2 S3 Chordata Ascidian White ascidian 0 0 0 0 0 1 0 0 0 0 0 0 Porifera Sponge Ball sponge 0 0 0 0 0 6 0 0 0 0 0 0 Bryozoa Bryozoan Bryozoan 1 0 0 0 0 0 0 0 0 0 0 0 Mollusca Chiton Chiton 0 0 0 0 3 0 0 0 0 0 0 0 Chordata Ascidian Colonial 11 4 7 1 0 6 0 50 0 0 0 0 Ascidian Arthropoda Crustacean Crab 0 0 0 1 0 0 0 0 1 0 0 0 Arthropoda Crustacean Hermit crab 0 0 0 0 0 0 0 0 0 1 0 0 Cnidaria Hydroid Hydroid 0 1 0 0 0 0 0 0 0 0 0 0 Mollusca Gastropod Limpet 0 0 0 0 3 0 0 0 0 0 0 0 Echinodermata Starfish Meridiastra 0 0 0 0 0 0 0 1 0 0 0 0 occidens Mollusca Gastropod Nassaridae 0 0 1 0 0 0 0 0 0 0 0 0 Echinodermata Starfish Pentagonaster 0 0 1 0 0 1 0 0 0 0 0 0 dubeni Mollusca Gastropod Phasianella 0 4 2 0 3 3 0 1 0 0 0 0 australis Mollusca Gastropod Phasianotrochus 0 0 2 0 0 0 0 0 0 0 0 0 irisodontes Mollusca Gastropod Pleuroploca 2 0 0 0 0 0 0 0 0 0 0 0 australasia Chordata Ascidian Polycarpa sp. 0 0 0 0 0 38 0 0 0 0 0 0 Echinodermata Holothurian Sea cucumber 0 0 0 0 0 0 0 0 1 0 0 0 Chordata Ascidian Solitary ascidian 23 7 0 1 0 6 0 0 0 0 0 0 Porifera Sponge Sponge 48 36 4 12 7 11 8 14 13 0 0 0 Echinodermata Starfish Unidentified 0 0 0 0 0 0 0 0 1 0 0 0 starfish Mollusca Gastropod Thalotia 0 0 0 2 3 1 0 0 0 0 0 0 Echinodermata Starfish Tosia australis 1 4 0 1 1 1 0 0 0 0 0 0 Mollusca Gastropod Unidentified 0 2 0 0 0 0 0 1 1 0 0 0 gastropod Echinodermata Sea urchin Sea urchin 0 0 0 0 0 0 0 0 2 0 0 0 Cnidaria Zooanthid Zooanthid 0 2 0 0 0 0 0 0 0 0 0 0