Adelaide Desalination Infauna Monitoring Final Report winter sampling 2011 December 2011

Ramsdale, T.M., Keuning, J., Stewart, T. and Dittmann, S. * School of Biological Sciences, Flinders University *Author for correspondence e-mail: [email protected]

May be cited as: Ramsdale, T.M., Keuning, J., Stewart, T. and Dittmann, S. (2011) Adelaide Desalination Infauna Monitoring Final Report winter sampling December 2011, Flinders University, Adelaide.

Contents

Executive Summary ...... 1

1 Introduction ...... 2

2 Methods ...... 3 2.1 Sampling sites ...... 3 2.2 Field Methodology ...... 3 2.3 Sample Collection ...... 4 2.4 Field Sampling ...... 8 2.4.1 Suction Sampling ...... 8 2.4.2 Core Sampling ...... 8 2.5 Laboratory Analyses ...... 9 2.5.1 Macrofauna Sorting and Identification ...... 9 2.5.2 Meiofauna Sorting and Identification ...... 9 2.5.3 Sediment Grain Size Analysis ...... 9 2.6 Data Analyses ...... 9 2.6.1 Macro-infauna ...... 9 2.6.2 Meiofauna ...... 9 2.6.3 Sediments ...... 9 2.6.4 Statistical Design ...... 9 3 Results ...... 13 3.1 Summary of collections ...... 13 3.1.1 Macro-infauna ...... 13 3.1.2 Meiofauna ...... 13 3.2 Spatial differences within the Port Stanvac construciton zone and control zones ...... 14 3.2.1 Macro-infauna ...... 14 3.2.2 Meiofauna ...... 25 3.2.3 Sediments ...... 35 3.3 Comparisons between Impacted and Control zones ...... 40 3.3.1 Macro-infauna ...... 40 3.3.2 Meiofauna ...... 44 3.3.3 Sediments ...... 47 3.4 Infauna-Sediment Relationships ...... 49 4 Comparison to previous sampling occasions ...... 54

5 References ...... 59

6 Appendices ...... 61

Benthic Fauna Monitoring for the Adelaide Desalination Plant Final Report on Monitoring undertaken in Winter 2011 Executive Summary This final report of the winter sampling in 2011 presents the findings of the subtidal benthic infaunal monitoring undertaken during July and August 2011 as a requirement for the Adelaide Desalination environmental monitoring program proposed by the South Australian Water Corporation in conjunction with Adelaide Aqua. This winter monitoring is part of a long term study to monitor the benthic infauna and sediments within the construction zone at Port Stanvac and at two reference zones (North and South), to determine if any disturbance occurred due to the construction works of the desalination plant, and, if found, the spatial and temporal extent of any such disturbance. Benthic infaunal communities (macro- and meiofauna) were sampled along 20 transects (representing the sites required by the EPA licence). Ten transects were within the Port Stanvac zone and a further 10 transects in South and North control zones (5 transects at each reference site), with replicate samples collected along each transect. Both suction and coring sampling techniques were used to assess the subtidal benthic communities of all three zones. The approach was designed to quantify the natural spatial variation inherent in marine benthic communities and separate this from any effects of the plants’ construction. Macro-infaunal communities sampled during the Winter 2011 survey were dominated numerically by amphipod crustaceans (Arthropoda), with polychaetes and molluscs also frequently occurring, as well as a variety of other taxa (i.e. bryozoans, other crustaceans, echinoderms, chordates, hemichordates etc.). Species numbers and abundance of macro-infauna were greater in the north control relative to both the south control and Port Stanvac during winter 2011, which had not been observed previously. Spatial differences in macro-infaunal abundances were not well explained by sediment characteristics. Meiofaunal communities were numerically dominated by nematode worms during the Winter 2011 survey, with copepods and tardigrads also being abundant. Meiofauna community structure was not well explained by sediment characteristics in comparison to previous occasions, as the sediment at Port Stanvac became more uniform during Winter 2011. Importantly, during Winter 2011, as for previous sampling occasions, there were no patterns in macro-infaunal or meiofaunal diversity, abundance or community structure based on proximity to the discharge pipeline. The survey did not reveal any effect of construction on the subtidal benthic infaunal species communities or their habitat (i.e. sediments). As such, the results obtained can contribute towards the baseline data set for future monitoring of effects of the desalination plant at Port Stanvac when the plant becomes operational.

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 1

1 Introduction To secure a climate-independent water source to complement and stabilise current supplies, many countries around the world (Roberts et al. 2010) are building desalination plants. South Australia is constructing a desalination plant approximately 30 km south of the Adelaide central business district at Port Stanvac, to meet future expected increases in water demand due to population growth (SA Water 2008). It will have an initial capacity of 50 GL per annum (which represents approximately 25 % of metropolitan Adelaide’s annual water consumption) and will have infrastructure to expand to 100 GL per annum. The plant will be based on reverse osmosis technology using seawater sourced from Gulf St. Vincent, and will discharge saline concentrate back to the sea via an outfall tunnel. Saline concentrate will be discharged into a predominantly soft sediment near-shore marine environment.

The effects of desalination plant effluent on benthic marine infauna have been reviewed by Roberts and others (2010) and in previous monitoring reports for this project (see Ramsdale et al. 2011). Benthic fauna can show negative responses, such as decline in abundance (or in some cases, abundance increase of opportunistic taxa), deterioration of condition, reduced feeding rates, altered community structure and death or otherwise loss of organisms to increased concentrations of desalination effluent in water (Roberts et al. 2010; Ramsdale et al. 2011, and references therein). This interim report presents information on a sampling event undertaken after the completion of marine construction works, during testing and initial commissioning phases of the desalination plant, as part of an ongoing monitoring program.

An EIS prepared by SA Water identified that there was a potential for a negative effect on the marine benthic infauna and sediments by the construction and operation of a desalination plant at Port Stanvac (SA Water 2008). As a condition of the licence to construct and operate the desalination plant, the Environment Protection Authority have ordered that the company in charge of construction of the plant, Adelaide Aqua, must meet strict ecological monitoring requirements including surveying benthic infauna (comprising both macro- and meiofauna) at 20 sites, including 5 reference sites, with multiple samples at each site to characterise variability (EPA Licence; available at URL: http://www.epa.sa.gov.au/xstd_files/Water/Other/desal_licence.pdf; accessed 18/08/2011). Monitoring was designed to test for any negative effects of the marine construction works and initial operation of the desalination plant in the Port Stanvac area on the subtidal benthic infauna and sediments in relation to natural levels of background spatial and temporal variation, in order to: 1. Determine if there was any disturbance on the benthic infauna and sediments at Port Stanvac, due to construction works or initial operation of the desalination plant, that was detectable over background levels of natural variation in benthic marine habitats quantified at nearby, unimpacted control sites; and 2. Determine the spatial and temporal extent of any disturbance due to the desalination plant construction within Port Stanvac, relative to background spatial and temporal variation, measured at nearby, unimpacted control sites. To achieve these aims a complex monitoring programme was designed, including sampling of sediments, meiofauna and macrofauna living in marine sediments at Port Stanvac. Sampling on multiple spatial scales was also incorporated to quantify natural variation in the benthic marine Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 2

habitat at Port Stanvac (Morrisey et al. 1992a,b; Comín et al. 2004). Sampling at two un-impacted locations that match the environmental conditions at Port Stanvac was included to monitor changes at Port Stanvac with reference to natural changes on a regional scale (Underwood 1992). This complex design should detect disturbance of construction at Port Stanvac, over natural background levels of variation, in a beyond-BACI-type design (Underwood 1991, 1992).

Here we report on the findings of this infauna monitoring that was undertaken in Winter 2011 (July – August 2011) along 20 transects (representing the sites required by the EPA licence), 10 transects within the Port Stanvac construction zone and a further 10 transects from two reference locations (5 transects at each reference site), with replicate samples collected along each transect.

2 Methods 2.1 Sampling sites All sampling was undertaken in Gulf St. Vincent off the metropolitan coastline of Adelaide, South Australia. Three sites (hereafter referred to as Zones) were sampled in total, comprising a putative ‘impacted’ site at the location of the Port Stanvac desalination plant marine construction zone (35°06’ S, 138°28’ E), and two control, ‘un-impacted’ zones, one each to the north and south of the construction zone, at Glenelg (34°59’ S, 138°27’ E) and Port Noarlunga (35°09’ S, 138°27’ E), respectively (Figure 1). The water depth in the Port Stanvac Construction zone ranged from 12 - 18 m and the sediments were characterised by a highly variable composition of fine and coarse sand, shell grit, rock and sporadic macroalgae, which are characteristic of subtidal habitats within Gulf St. Vincent (Benkendorff et al. 2008; Bryars et al. 2008; Edyvane 2008; Loo and Drabsch 2008; Loo et al. 2008; Turner and Collings 2008; Table 1). The habitat heterogeneity created by patches of the aforementioned substrates and vegetation in what is an otherwise predominantly soft sediment, supports a diverse community of benthic organisms with representatives from almost 20 different phyla identified in the region (Loo et al. 2008; Ramsdale et al. 2011). Control sites were selected on the basis of having similar sediment structure and water depth to Port Stanvac. 2.2 Field Methodology Survey transects, 800 m in length, were established in each sampling zone. Five transects were established radiating south (A-E) and five to the north (F-J) of the proposed location of the effluent discharge pipeline at Port Stanvac, and five transects radiating from an arbitrarily selected point at each of the two control zones (i.e. 20 transects in total; Figure 2; Table 1). Two methods of faunal collection were employed in this study, each targeting a different group of the infauna, in order to capture representative information on the abundance and diversity of all subtidal benthic infauna. Both macrofauna (those invertebrate organisms greater than 500 µm [0.5 mm] in size) and meiofauna (invertebrate organisms greater than 52 µm but less than 500 µm in size) communities were sampled. Suction sampling was used to target macrofaunal invertebrates living within the sediments. Core sampling was used to target meiofaunal invertebrates living within the sediments. Four sampling stations, at least 200 m apart, were established on each transect for suction and core sampling. Sampling stations represented distances (0 m, then 200 m, 400 m and 800 m) along each transect. The 0 m station was closest to the discharge pipeline at Port

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 3

Stanvac (approx. 200 m from the pipeline) or the centre of the sampling site for control zones (Figure 2). GPS co-ordinates and the water depth were recorded for each position along each transect. Organisms were collected and processed under the collection exemption number 9902250 and 9902462 and the animal ethics permit number E322. 2.3 Sample collection Sites were sampled over 9 days of favourable weather conditions between the 18th July and 31st August 2011 (Table 2). Sampling was unexpectedly suspended in late July due to a delay in issuing a new sampling permit, and resumed as quickly as possible once the new permit was obtained.

Adelaide CBD

North Control Glenelg

Brighton

Port Stanvac South Australia

Port Stanvac

O’Sullivan Beach boat ramp

Port Noarlunga South Control

5km

Figure 1. Map of Adelaide metropolitan coastline showing the approximate locations of the Port Stanvac sampling zone (red marker) and the north (blue marker) and south (green marker) control subtidal benthic sampling zones. Inset map shows the location of the study region (red shading).

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 4

a)

b)

c)

Figure 2: Transect orientations of the a) North Control Zone; offshore from Glenelg area; b) Port Stanvac Construction Zone; and c) South Control Zone; offshore from Noarlunga.

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 5

Table 1: Location and description of transect ends ‘Near’ and ‘Far’ from either outlet pipe at Port Stanvac Construction Zone, or the centre of the Control Zones at the North and South Control Zones. Near Far Depth Substrate notes from Site Transect Latitude Longitude Latitude Longitude (m) sample processing Fine sand and shell grit, A 35°05.785’ 138°28.252’ 35°06.138’ 138°28.002’ 13 some seagrass and algae Fine/medium sand and shell B 35°05.774’ 138°28.154’ 35°06.135’ 138°27.902’ 15 grit, some algae C 35°05.779’ 138°28.030’ 35°06.111’ 138°27.770’ 18 Fine to coarse sands Medium to coarse sand, D 35°05.757’ 138°27.903’ 35°06.054’ 138°27.489’ 18 some silt, algae patches E 35°05.583’ 138°28.022’ 35°05.476’ 138°27.498’ 20 Fine - coarse sand, silt Medium to coarse sand, F 35°05.429’ 138°28.055’ 35°05.014’ 138°28.009’ 20 some silt

Port StanvacPort Sands with shell grit, rocks, G 35°05.386’ 138°28.215’ 35°04.982’ 138°28.328’ 18 seagrass/algae patches Coarse sand, gravel and silt, H 35°05.416’ 138°28.259’ 35°05.070’ 138°28.474’ 18 some algae Coarse sand and silt with I 35°05.440’ 138°28.322’ 35°05.096’ 138°28.597’ 15 gravel, some algae Coarse sand with shell grit J 35°05.485 138°28.462’ 35°05.144' 138°28.704' 13 and silt, some algae Fine to coarse sand and silts, A 34°59.952’ 138°27.163’ 34°59.603’ 138°27.411’ 16 some wrack1 material

B 35°00.317’ 138°26.920’ 35°00.703’ 138°26.663’ 18 Sand and seagrass C 35°00.052’ 138°26.832’ 34°59.866’ 138°26.384’ 16 Sand, shell grit and seagrass North D 35°00.214’ 138°27.249’ 35°00.386’ 138°27.688’ 18 Sand, shell grit and seagrass Coarse sand, shell grit, some E 35°00.302’ 138°27.132’ 35°00.657’ 138°27.342’ 18 algae Fine sand and shell grit, A 35°09.135’ 138°26.475’ 35°09.124’ 138°27.002’ 16 some seagrass B 35°09.145’ 138°26.212’ 35°09.170’ 138°25.685’ 18 Sand and silt, some gravel

Shell grit and gravel, some C 35°09.250’ 138°26.382’ 35°09.680’ 138°26.370’ 16 seagrass South Shell grit, some algae and D 35°09.040’ 138°26.364’ 35°08.623’ 138°26.359’ 18 seagrass Coarse sand, shell grit and E 35°09.197’ 138°26.307’ 35°09.513’ 138°25.956’ 18 gravel 1detached algae and seagrass

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 6

Table 2: Collection dates for both sampling methods; suction (S) and coring (C) across all transects within Port Stanvac Construction Zone and North and South Control Zones for the Winter 2011 sampling event.

Zone North Port Stanvac South A B C D E A B C D E F G H I J A B C D E Date S C S C S C S C S C S C S C S C S C S C S C S C S C S C S C S C S C S C S C S C 18/07/2011 ü ü ü ü 19/07/2011 ü ü ü ü 20/07/2011 ü ü ü ü 21/07/2011 ü ü ü ü 22/07/2011 ü ü ü ü 25/07/2011 ü ü ü ü ü ü 26/07/2011 ü ü ü ü ü ü 30/08/2011 ü ü ü ü ü ü 31/08/2011 ü ü ü ü ü ü

2.4 Field Sampling 2.4.1 Suction Sampling Suction sampling was used to target macrofauna living within the top 5-10 cm of subtidal sediments. A suction sampler was constructed at the Flinders University, Adelaide, Australia (Barrett 2009), based on a model described by Brown et al. (1987). The suction sampler operates through the addition of compressed air into the base of a submerged vertical tube (10 cm diameter, approx. 1 m long) which is weighted to remain on the bottom (see Ramsdale et al. 2011 for diagram). The addition of compressed air creates a vacuum and draws a sediment sample upwards to be deposited in the catchment bag. Samples were taken using controlled air pressure (200 psi) for the duration of 1 minute, which equated to an average sample size of approximately 0.25 L of sediment. Three replicate samples were collected from each distance station along each transect, giving 12 samples per transect per sampling occasion. 2.4.2 Core Sampling Sediment core samples were obtained to assess both meiofaunal communities and sediment size structure. A box corer (Wildco®, model: 191-A12, internal dimensions: 0.15 x 0.15 x 0.23 m, total weight: 30 kg) was deployed and retrieved using an electric drum winch, which maintained a constant speed of descent and ascent to optimise operation of the corer’s release mechanism. The methodology used enabled a successful closure rate of between 55 and 92 %; with the variation in success highly dependent on weather conditions and sediment type. Three replicate core samples were taken at each of the five transect distances (Figure 3) and two subsamples were taken from each core (max. 71 mL each), one each for meiofauna and sediment grain size analysis. In some cases, for example, where substrate consisted of rocky reef, no sediment was collected in the box corer for analysis, and these sites are therefore missing from the analysis.

Suction samples Box core samples

100 m

800 m Transect Near Far

0 m 200 m 400 m 800 m

Figure 3: Schematic diagram displaying organisation of the two sampling methods along an 800 m long transect. ‘Near’ and ‘Far’ indicate the outer ends of the transect closest or furthest (respectively) to/from either the proposed outlet pipe (Port Stanvac Construction Zone) or the centre of the Control Zone (North and South Control Zones). Diagram not to scale.

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 8

2.5 Laboratory Analyses 2.5.1 Macrofauna Sorting and Identification Macrofauna from suction samples were immediately sieved in the field using a 500 µm mesh to remove as much sediment and detritus as possible, then preserved in 70 % ethanol solution for transport to the laboratory. On return to the laboratory, samples were rinsed to remove ethanol, and all macrofauna were extracted from the remaining sediment. Macrofauna were identified using Shepherd and Thomas (1982; 1989), Shepherd and Davies (1997), Edgar (2008), Gowlett-Holmes (2008) and taxon-specific references, and a stereomicroscope to the lowest possible taxonomic level, often species. Individuals were then enumerated and then transferred into 70 % ethanol for storage and later lodgement at the South Australian Museum. 2.5.2 Meiofauna Sorting and Identification Meiofauna samples were initially frozen (at -20 °C) prior to processing. Meiofauna were extracted from sediments using the LudoxTM flotation method (Somerfield and Warwick, 1996). This process removes meiofauna from sediments by repeated decantations in fresh water through a pair of sieves, the first to remove the macrofauna (500 µm mesh), and a second, finer sieve (53 µm mesh) to separate the meiofauna and smaller, unicellular organisms. The material retained on the finer sieve contains both meiofauna and fine sediments and detritus. Flotation in LudoxTM (Somerfield & Warwick, 1996) was used to separate the meiofauna from this other detritus. The extracted meiofauna were then evaporated to pure glycerol and mounted onto slides for identification, counting and storage. Meiofauna were identified to family level where possible using Higgins and Thiel (1988). 2.5.3 Sediment Grain Size Analysis Sediment samples were initially frozen (at -20 °C) prior to processing. Grain-size distribution was obtained using laser diffraction granulometry (Malvern Instruments Mastersizer with Hydro 2000 attachment). Prior to processing, samples were dried (at 80 °C for 24 hours) to constant weight and total dry weight obtained in grams. Samples were then pre-screened to remove particles greater than 1 mm, an operational requirement because larger particles can damage pipes in the machine. The fraction retained on the 1 mm sieve was weighed and recombined into the grain-size distribution data after the remaining sample was processed by the Mastersizer. A standard operating procedure was used across all samples (pump speed 3500 rpm; target obscuration 7-10 %; data obtained were the average of 5 replicate measurements of grain-size distribution for each subsample). Data were then extracted from the Malvern software in quarter phi intervals, allowing the fraction greater than 1 mm to be reincorporated into the total distribution and the resulting data analysed for grain-size distribution statistics using GRADISTAT (Blott & Pye 2001). 2.6 Data Analyses 2.6.1 Macro-infauna Species numbers, species diversity and relative abundances were determined for each site. Data shown in this report are total numbers per sample and displayed as catch per unit effort (CPUE). Three different indices (Shannon-Wiener index, Pielou’s evenness and Simpson’s index) were used to determine the diversity and evenness of macrofaunal species composition at all sites. These indices Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 9

were calculated based on the total number of individuals (N) from the number of each taxa (ni). The Shannon-Wiener index (H’) identifies greater species diversity as index values increase, with values of 1 or more indicating highly diverse communities. Pielou’s index is a measure of how evenly the individuals are distributed among the different taxonomic groups, where values equal to one indicate even species distribution among samples. The Simpson’s index is a measure of ecological diversity with diversity increasing as the value approaches one, and values below 0.5 indicate dominance of a single species (Clarke & Warwick 2001). 2.6.2 Meiofauna For analyses, abundance of meiofauna in each sample were standardised to abundance per mL of sediment collected, which varied for each sample. The volume of sediment was measured for each sample and the number of organisms per mL calculated by dividing the abundances by the volume of sediment. Because the ecological knowledge of individual meiofaunal species is limited, species identifications are of limited use in ecological monitoring, and use of higher taxonomic categories is recommended (Bouwman 1987). The total abundance of meiofauna, the abundance of major groups (Nematoda and Copepoda), the ratio of nematode to copepod abundance (N:C; Warwick 1981) and the number of taxa collected were calculated for each sample. 2.6.3 Sediments Because the majority of samples were multimodal, median grain-size and dispersion spread

(D90 – D10) were selected for PERMANOVA analysis, as these are more reliable for multimodal sediments (Blott & Pye 2001). Sediment percent grade scale fractions were also calculated based on the Udden/Wentworth grade scale for sediments (Wentworth 1922). 2.6.4 Statistical Design There was a great degree of highly significant small-scale (i.e. among transects within zones) and very small-scale (i.e. among distances within transects) spatial variation inherent in the data when analysed for each individual sampling occasion which has been analysed and presented in previous interim reports (Glavinic et al. 2009, 2010, 2011; Beattie et al. 2010; Ramsdale et al. 2011). This small- scale spatial variation is inherent in subtidal marine benthic ecosystems, and, having been reported and acknowledged in the systems sampled for this monitoring programme at Port Stanvac, these small-scale factors will be pooled into the analyses of higher-level factors of key interest, namely temporal differences and differences between the Port Stanvac impact zone and the control zones to the north (‘north control zone’) and south (‘south control zone’). Spatial analyses within the Port Stanvac Construction Zone Analyses of spatial differences in faunal abundance was undertaken to determine if there were any effects of proximity to construction works and discharge pipeline on the abundance, diversity and community structure of macro-infauna and meiofauna, and on the composition of sediments within the Port Stanvac Zone. These tests were made under the null hypothesis that there should be no differences in these variables based on spatial factors (i.e. among transects or distances from the pipeline). A series of one-way PERMANOVAs (Anderson 2001; McArdle & Anderson 2001; Anderson et al. 2008) using 9999 permutations were used to test for differences in abundance and diversity variables

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 10

described above, and in community structure for infaunal macrofauna and meiofauna. Euclidian distance similarity matrices were used for univariate data (e.g. total abundance, sediment variables, etc.) while Bray-Curtis similarity matrices were used for multivariate data (e.g. community structure based on species composition and abundances). Macrofauna data were fourth-root transformed prior to analysis to decrease the influence of dominant species on the analysis, and a dummy variable of one added with Bray-Curtis similarities to eliminate the effects of joint absence of taxa where the data set contained many zeros. Meiofauna data were fourth-root transformed to reduce the influence of dominant taxa. One sample (Port Stanvac transect B distance 400 replicate 3) which contained no meiofauna was removed from the analysis as an outlier. The spatial factors of transect (a fixed-factor with 10 levels, Transects A – J) and distance (a fixed-factor with 4 levels, 0 m, 200 m, 400 m and 800 m from the end of the transect closest to the saline concentrate discharge pipeline) were tested separately to allow detection of any spatial differences based on proximity to the pipeline. Differences in infauna variables were investigated using bar-graphs of mean values with standard deviation (where appropriate) for univariate measures and PCO plots (Torgerson 1958; Gower 1966; Anderson et al. 2008) for community structure for both macro-infauna and meiofauna. SIMPER (Clarke 1993) was used to identify species with high contributions to similarities among samples from each Zone (i.e. species that characterised communities from each Zone). PERMDISP (which tests for differences between factors in dispersion of points within groups of a factor; Anderson 2006; Anderson et al. 2008) and post hoc pair-wise tests were used where appropriate to further investigate differences among levels of factors found to be significantly different by PERMANOVA. Comparative analyses between Impact and Control Zones

Comparisons among zones were made for the purpose of determining if there were any difference in the diversity, abundance and/or community structure of infaunal groups and sediments between the Port Stanvac impact zone and control zones to the north and south. These tests were made under the null hypothesis that there should be no differences in these variables between impact and control (i.e. reference) sites. Comparisons amongst lower level spatial factors, such as transects or distances were omitted for analysis of differences amongst zones to allow focus on the higher level factors of interest, Types and Zones (nested in Types). A series to two-factor PERMANOVAs (with 9999 permutations) were used as described above for both macrofaunal and meiofaunal groups. Comparisons were made among Types (a fixed-factor with two levels, impact and control) and Zones (a fixed-factor with 4 levels, Port Stanvac North, Port Stanvac South, South Control and North Control, nested in Types). Port Stanvac was split into two zones (Figure 1), North (transects F – J) and South (transects A – E), based on sediment grain size (determined visually). The southern transects contained visually finer sediments than those in the north. Bar-graphs, PCO plots, SIMPER, PERMDISP and pair-wise tests were again used where appropriate to investigate any apparent spatial differences.

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 11

Sediment-Infauna Relationships analyses

Relationships between sediment structure (using grade scale fractions in a multivariate analysis) and infaunal abundance and community structure were investigated using forward selection distance- based linear models (DistLM; Legendre & Anderson 1999; McArdle & Anderson 2001; Anderson et al. 2008) with 999 permutations. Meiofauna samples were compared directly with paired sediment samples. Macrofauna data were averaged across replicate samples and compared to similarly averaged sediment data, because these samples were not implicitly paired. Distance-based redundancy analysis plots (dbRDA; Legendre & Anderson 1999; McArdle & Anderson 2001; Anderson et al. 2008) were used to interpret trends.

All statistical analyses were conducted using PRIMER version 6 +PERMANOVA add-on (Clarke & Warwick 2001; Clarke & Gorley 2006; Anderson et al. 2008).

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 12

3 Results 3.1 Summary of Collections 3.1.1 Macro-Infauna In total, 4,619 infaunal macroinvertebrate organisms, representing 234 species were identified and counted from 240 samples (Table 3a). Of these, the vast majority were arthropods (58.6%), including numerous species of amphipods, isopods, crabs and shrimp (see Appendix A; Table 3a). Annelids (comprising 26 polychaete families and one oligochaete taxa; 10.9 % of total abundance) and molluscs (including both bivalves and gastropods; 12.0 % of total abundance) were also abundant (Table 3a). 3.1.2 Meiofauna In total, 30,457 individual meiofaunal organisms were collected, representing 17 different taxa (Table 3b). The vast majority were nematode worms (19,448 individuals), followed by copepods (6,306 individuals) and tardigrads (1,412 individuals) (Table 3b). Abundances were relatively low in the northern control zone relative to Port Stanvac and the southern control zone, although fewer samples were collected in this zone due to dense seagrass beds and rocky reefs (Table 3b).

Table 3. Total abundance (N), abundance of key taxa and total number of species (S: for macrofauna) or taxa (for meiofauna) represented in sediment infauna samples for a) macrofauna; and b) meiofauna for the Winter 2011 sampling occasion. Data presented here are total counts. The number of samples analysed (n) is given, with a targeted sample size of 240 samples for each infaunal group. Some samples for the meiofauna were missing due to rocky substrate (i.e. no sediment for analysis). Note that due to the sampling design there are twice as many samples collected within the Port Stanvac zone than the northern or southern control zones.

a) Macrofauna

Abundance Zone n Total (N) Arthropoda Mollusca Annelida Other Species (S) North Control 60 1,720 1,064 204 59 393 170 Port Stanvac 120 1,798 974 265 342 217 146 South Control 60 1,101 669 87 102 243 121 Grand Total 240 4,619 2,707 556 503 853 234

b) Meiofauna

Abundance Zone n Total (N) Nematoda Copepoda Tardigrada Other Taxa North Control 46 2,816 1,186 603 130 897 16 Port Stanvac 93 18,254 13,874 2,456 546 1,378 15 South Control 54 9,387 4,388 3,247 736 1,016 17 Grand Total 193 30,457 19,448 6,306 1,412 3,219 17

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 13

3.2 Spatial differences within the Port Stanvac construction zone and control zones 3.2.1 Macro-Infauna Species numbers Numbers of infaunal species in the Port Stanvac zone were variable among transects and across distances at Port Stanvac (Figure 4a). Species richness was highest at transects on transects situated in deeper water in the Port Stanvac zone (i.e. transects E and F; Table 1; Figure 4) with lower diversity at transects closer to the shore (i.e. transects A and J; Figure 4). Species numbers were highest along transects E, F and H, with arthropods being the most diverse group (Figure 4a). The number of species differed significantly among transects but not distances at Port Stanvac (Table 4; Figure 4). Post-hoc pair-wise tests for significant differences among transects at Port Stanvac indicated that transects with lower species richness, such as A and G, were significantly different (P(perm) < 0.05) to transects with higher species richness, such as E and F (Figure 4). There were no statistically significant differences in species numbers among transects at the southern control zone (PERMANOVA; Pseudo-F = 0.083; P(perm) = 0.08; Figure Ha). Transects did, however, differ significantly in species numbers at the northern control zone (Pseudo-F = 3.591; P(perm) = 0.013; Figure 5a). Post-hoc pair-wise tests showed there were significantly more species at transect A at the northern control compared to transects D and E, and significantly fewer species on transect E relative to transect C (Figure 5a). Species numbers did not differ among distances at either control zone (P(perm) > 0.05).

Table 4. PERMANOVA main test results of comparisons of species numbers for infauna (suction sampler) among (a) transects; and (b) distances from the pipeline at Port Stanvac. Significant P values (<0.05) highlighted in bold. a) Source df MS Pseudo F P (perm) Transect 9 4.163 2.933 0.0032 Residual 110 1.479 b)

Source df MS Pseudo F P (perm) Distance 3 1.490 0.914 0.4344 Residual 116 1.631

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 14

80 a) 70 60 50 40 30

Number of of Number species 20 10 0 A B C D E F G H I J Transect Annelida Mollusca Arthropoda Other

100 b) 90 80 70 60 50 40 30 Number of of Number species 20 10 0 0 200 400 800 Distance (m) Annelida Mollusca Arthropoda Other

Figure 4. Total number of infaunal species (Annelida, Mollusca, Arthropoda and Other taxa combined: see Appendix A) collected across (a) transects A-J; and (b) near and far distances at Port Stanvac.

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 15

100 a) 90 80 70 60 50 40 30

Number of of Number species 20 10 0 A B C D E A B C D E South Control North Control Transect Annelida Mollusca Arthropoda Other

120 b) 100 80 60 40

Number of of Number species 20 0 0 200 400 800 0 200 400 800 South Control North Control Distance (m) Annelida Mollusca Arthropoda Other

Figure 5. Total number of infaunal species (Annelida, Mollusca, Arthropoda and Other taxa combined: see Appendix A) collected across (a) transects A-E; and (b) near and far distances at each of the two control sites.

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 16

Species Diversity

Values of diversity (H’), Simpson’s Index and Evenness (J’) within Port Stanvac were similar across transects and distances (Figure 6a). Values for diversity (H’) were all greater than one at all three zones, indicating highly diverse communities regardless of zone, transect or distance (Figure 6). Pielou’s index was greater than 0.8 for all transects and distances across the three zones (Figure 6), indicating fairly even species distribution among samples. Diversity (H’) differed significantly among transects at Port Stanvac (Table 5), with slightly higher diversity values at transects D, E and H and lower diversity at transects A and G (Figure 6a). These results reflected the differences seen in species numbers (Figure 4). Diversity measures at control zones indicated there were highly diverse communities at these locations, with even distribution of species. There were no statistically significant differences in species diversity indices among transects at the southern control zone (PERMANOVA; P(perm) > 0.05; Figure 6b). Diversity (H’) differed significantly among transects at the northern control zone (Pseudo- F = 3.772; P(perm) = 0.007; Figure 6b), and post-hoc pair-wise tests showed there were significantly higher diversity (H’) at transect A at the northern control compared to transects D and E, and significantly lower diversity (H’) on transect E relative to transect C (Figure 6b). There were no significant differences among transects in the other diversity indices tested (i.e. Simpson’s Index and evenness (J’); PERMANOVA; P(perm) > 0.05), and no significant differences in any diversity index based on distance at either control zone (P(perm) > 0.05).

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 17

a) 4 4 3.5 3.5 3 3 2.5 2.5 H' 2 H' 2 1.5 1.5 1 1 0.5 0.5 0 0 A B C D E F G H I J 0 200 400 800 Transect Distance (m)

1 1 0.8 0.8 0.6 0.6 J' J' 0.4 0.4

0.2 0.2

0 0 A B C D E F G H I J 0 200 400 800 Transect Distance (m) b) 4 4 3.5 3.5 3 3 2.5 2.5 H' 2 H' 2 1.5 1.5 1 1 0.5 0.5 0 0 A B C D E A B C D E 0 200 400 800 0 200 400 800 South Control North Control South Control North Control Transect Distance (m)

1 1

0.8 0.8

0.6 0.6 J' J' 0.4 0.4

0.2 0.2

0 0 A B C D E A B C D E 0 200 400 800 0 200 400 800 South Control North Control South Control North Control Transect Distance (m)

Figure 6. Diversity measures for macro-infaunal communities measured across transects and distances at a) Port Stanvac; and b) northern and southern control zones. Shannon-Wiener’s index (H’) and Pielou’s Evenness index (J’) are presented here. Please note that patterns for Simpson’s index across transects and distances for Port Stanvac and control zones were similar to H’ and J’ indices and as such, are not presented here.

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 18

Table 5. PERMANOVA main test results of comparisons of Shannon-Wiener (H’), Simpson’s index (1-Lambda) and Pielou’s Evenness (J’) for macro-infauna communities at Port Stanvac among (a) transects; and (b) distances from the pipeline. Significant P values (<0.05) highlighted in bold. a) H’ 1-Lambda J’ Source df P (perm) P (perm) P (perm) Transect 9 0.019 0.1022 0.1242 Residual 110 b) H’ 1-Lambda J’ Source df P (perm) P (perm) P (perm) Distance 3 0.4926 0.6964 0.6654 Residual 116

Abundances

Abundance of macro-infauna was highly variable across transects and distances at Port Stanvac and control zones (Figure 7). Abundance for most sampling locations at Port Stanvac was less than 20 organisms per sample, with higher values on transects E and F (Figure 7a). Average abundance values for each sampling location were similar between the southern control and Port Stanvac zones (Figure 7a,b), but higher for the northern control (Figure 7c). Values for total abundance and the abundance of annelids and ‘other’ taxa at Port Stanvac differed significantly among transects, but not among distances (Table 6). Post-hoc pair-wise tests showed that the abundances of these taxa were higher at transect E relative to other transects (P(perm) < 0.05; Figure 7). The abundance of annelids and ‘other’ taxa were also significantly more variable at transect E relative to other transects at Port Stanvac (PERMDISP; P(perm) < 0.05). These results indicate that differences in macro-infaunal abundances among transects at Port Stanvac were due to higher abundance of annelid worms and differences in the variation in abundance of other taxonomic groups at transect E (Figure 7). Total abundances and the abundance of individual taxa groups (i.e. annelids, molluscs, etc.) were more consistent across transects and distances at the northern or southern control zones compared to Port Stanvac (Figure 7). Abundances were significantly lower at the southern control transect A relative to transects B, D and E (PERMANOVA; Pseudo-F = 2.91; P(perm) = 0.02; Figure 7b). There were no other significant differences based on transects or distances at either control (PERMANOVA; P(perm) > 0.02; Figure 7b,c).

Table 6. Summary PERMANOVA main test results (P (permutations-based) values) for comparisons of total infaunal abundances among (a) transects; and (b) distances for data collected in the Port Stanvac Construction Zone. Significant P values (<0.05) highlighted in bold. a) TOTAL Annelida Mollusca Arthropoda Other Source df P (perm) P (perm) P (perm) P (perm) P (perm) Transect 9 0.0114 0.0021 0.0645 0.0802 0.0067 Residual 110 b) TOTAL Annelida Mollusca Arthropoda Other Source df P (perm) P (perm) P (perm) P (perm) P (perm) Distance 3 0.3301 0.1452 0.2532 0.2855 0.3723 Residual 116 Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 19

a)

180 Annelida 160 Mollusca 140 Arthropoda 120 100 Other 80 60 40 20 Number of organisms of (CPUE) Number organisms 0 0 0 0 0 0 0 0 0 0 0 200 400 800 200 400 800 200 400 800 200 400 800 200 400 800 200 400 800 200 400 800 200 400 800 200 400 800 200 400 800 A B C D E F G H I J b)

100 Annelida 90 Mollusca 80 70 Arthropoda 60 Other 50 40 30 20 10 Number of organisms of (CPUE) Number organisms 0 0 0 0 0 0 200 400 800 200 400 800 200 400 800 200 400 800 200 400 800 A B C D E

c)

80 Annelida 70 Mollusca 60 Arthropoda 50 Other 40 30 20 10 Number of organisms of (CPUE) Number organisms 0 0 0 0 0 0 200 400 800 200 400 800 200 400 800 200 400 800 200 400 800 A B C D E

Figure 7. Average abundance of infauna (Annelida, Mollusca, Arthropoda and Other taxa combined: see Appendix A) at (a) Port Stanvac; and (b) the southern and; (c) the northern control zones showing values for each distance (0, 200, 400 and 800 m) and transect individually. Error bars indicate +SD. Note the different scales of the y-axis for each plot. Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 20

Community Structure Community structure was highly variable among transects (Table 7) and distances (Table 8) at Port Stanvac. Average similarity was low, and average dissimilarity was high among transects and distances (Table 7, 8), indicating a great variety in community structure (in terms of both abundance and species composition) across the Port Stanvac Zone, which was reflected in the lists of characterising taxa for each transect and distance (Table 7, 8). Communities at Port Stanvac were characterised by various species of gammarid amphipods, the presence of the bryozoan, Hornera ramosa and some polychaete families (Sigalionidae, Flabelligardiae and Opheliidae).

Table 7. Summary SIMPER results for tests of macro-infaunal community average percent similarity within samples from each transect (light gray shading) and average percent dissimilarity between samples from different transects (no shading) at Port Stanvac, and a list of the characterising taxa for each transect.

Transect A B C D E F G H I J Characterising taxa Cumacean sp. 1, Sigalionidae, A 3.49 Leucothoe sp. 1 Terebellidae, Halicarcinus ovatus, B 95.00 7.26 Hornera ramosa Dorvilleidae, Tanaid sp. 1, C 95.62 94.21 10.02 Ophionereis schayeri Hornera ramosa, Flabelligardiae, D 94.56 92.38 92.82 11.16 Gammarid sp. 29 Hornera ramosa, Gammarid sp. E 91.68 89.52 88.09 85.56 21.75 29, Tanaid sp. 3 Hornera ramosa, Gammarid sp. 6, F 94.24 91.83 91.62 88.12 83.82 15.07 Modiolus areolatus Gammarid sp. 29, Gammarid sp. G 93.56 91.39 92.32 87.71 83.60 86.38 16.32 5, Halicarcinus ovatus Opheliidae, Gammarid sp. 29, H 95.21 92.64 91.92 88.59 85.65 87.50 84.77 13.21 Gammarid sp. 6 Tanaid sp. 3, Modiolus areolatus, I 95.66 95.66 93.68 92.38 89.15 92.22 91.85 91.08 7.48 Leucothoidae sp. 2 Opheliidae, Tanaid sp. 3, Limaria J 94.54 94.93 91.85 90.89 86.37 90.61 89.19 87.96 90.93 13.41 orientalis

Table 8. Summary SIMPER results for tests of macro-infaunal community average percent similarity within samples from each distance (light gray shading) and average percent dissimilarity between samples from different distances (no shading) at Port Stanvac, and a list of the characterising taxa for each distance.

Distance 0 200 400 800 Characterising taxa 0 m 9.82 Tanaid sp. 3, Halicarcinus ovatus, Gammarid sp. 6 200 m 89.68 10.64 Gammarid sp. 6, Opheliidae, Gammarid sp. 29 400 m 91.55 90.83 8.30 Gammarid sp. 29, Hornera ramosa, Tanaid sp. 1 800 m 91.17 90.40 90.45 9.82 Hornera ramosa, Mysid sp. 1, Gammarid sp. 29

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 21

Community structure differed significantly among transects but not distances at Port Stanvac (Table 9; Figure 8); however, there was no separation of samples based on transects evident from the PCO plot (Figure 8a). Post-hoc pair-wise tests showed that transect E differed significantly in community structure to all other transects at Port Stanvac (P(perm) < 0.05), and transects G and F differed significantly to most other transects except B, D and H (P(perm) < 0.05). Transects E and F had higher abundance, number of species and average similarity among samples relative to other transects, while abundance and number of species were lower on transect G (Table 7; Figure 4, 7). There were no significant differences in variation in macro-infaunal community structure based on transects (PERMDISP; P(perm) > 0.05; Figure 8a).

Table 9. Summary PERMANOVA main test results (P (permutations-based) values) for comparisons of infaunal community structure among (a) transects; and (b) distances for data collected at Port Stanvac in Winter ’11. Significant P values (<0.05) highlighted in bold. a)

Source df MS Pseudo F P (perm) Transect 9 5715 1.935 0.0001 Residual 110 2953.5 b) Source df MS Pseudo F P (perm) Distance 3 3912.1 1.2447 0.1209 Residual 116 3142.9

Community structure was significantly different among transects at both the southern (Pseudo-F4,55 =

1.879; P(perm) = 0.0001) and northern (Pseudo-F4,55 = 1.807; P(perm) = 0.0001) control zones, indicating some significant spatial variation on the scale of hundreds of metres. Post-hoc pair-wise tests revealed that there were significant differences in community structure among most combinations of transects at both the southern and northern control zones (P(perm) < 0.05). Transects that were not significantly different were D and A and D and C at the southern control zone (Figure 9a) and transects A and D and B and C at the northern control zone (Figure 9c).

There were also significant differences among distances at the southern (Pseudo-F3,56 = 2.009;

P(perm) = 0.0002) and northern (Pseudo-F3,56 = 1.458; P(perm) = 0.0095) control zones, with only the 0 m and 200 m distances being similar at the southern control zone (P(perm) > 0.05) and only the 200 m and 400 m distances being different at the northern control zone (P(perm) < 0.05; Figure 9c,d).

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 22

40 a) ) n o i t a

i 20 r a v

l

a Transect t

o A t

f 0 B o

C

% D 2 . E 9 (

F

2 -20 G O H C P

I J

-40 -40 -20 0 20 40 60

PCO1 (17.5% of total variation) 40 b)

) n o

i t a i 20 r a

v

l a t o t

f 0 o

% 2 . 9 (

2 -20 Distance

O 0 m

C 200 m P 400 m 800 m -40 -40 -20 0 20 40 60

PCO1 (17.5% of total variation)

Figure 8. PCO plots of square-root transformed averaged abundances of infaunal communities for samples at Port Stanvac. Each panel shows the same plot comparing different groupings: (a) transects (A-J) and (b)

distances from the pipeline. Each point on this plot represents the average of three replicate samples. Points plotting closely on these plots indicate similar infaunal communities. Each axis denotes the degree of variation explained by the left-right and the up-down distribution of points for the x- and y-axes, respectively.

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 23

60 60 a) b) A 0 B 200 C 400 40 40 800

D ) )

n n o o i i E t t

a a i

i r r

a a

v v

l l 20 20 a a t t o o t t

f f o o

% % 8 8 . . 3 3 0 0 1 1 ( (

2 2 O O C C P P -20 -20

-40 -40 -40 -20 0 20 40 -40 -20 0 20 40

PCO1 (14.2% of total variation) PCO1 (14.2% of total variation)

40 40 c) d)

) A 0 n ) o n

i B 200 t

20 o i a t 20 i C 400 a r i a r

v 800 D a

v l

l a

t E a

t o

t o

t

f

f

o 0

o 0

% % 6 . 6 . 3

3

1 1 (

(

2 2 O -20 O -20 C C P P

-40 -40 -20 0 20 40 60 -20 0 20 40 60 PCO1 (16.6% of total variation) PCO1 (16.6% of total variation)

Figure 9. PCO plots of fourth-root transformed averaged abundance of macro-infauna communities for samples collected during the Winter 2011 sampling occasion in the north and south control zones. Each set of panels shows the same plot comparing different groupings, firstly at the southern control by a) transects; and b) distance; and then at the northern control by c) transect; and d) distance. Each point on this plot represents the average of three replicate samples. Points plotting closely on these plots indicate similar infaunal communities. Each axis denotes the degree of variation explained by the left-right and the up-down distribution of points for the x- and y-axes, respectively.

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 24

3.2.2 Meiofauna Taxa Richness

Taxa richness was slightly lower on transect B at Port Stanvac relative to other transects at Port Stanvac as well as transects within control zones (Figure 10). Otherwise there were no noticeable differences in meiofaunal taxa richness across transects in any zone (Figure 10). There were no differences based on distance from the centre of the construction zone at Port Stanvac or sampling locations at control zones (Figure 11). Due to the low level of taxonomic differentiation applied to these data (i.e. organisms were identified to high-level taxonomic groups only, for instance Phyla [Nematoda]), these results are not expected to reflect the true level of taxonomic richness at the zones sampled, and are not tested further here. Species diversity indices, calculated for the macrofauna, are not applied to the meiofauna collection for this same reason.

a)

b)

Figure 10. Average taxa richness of meiofaunal organisms across transects at a) Port Stanvac; and b) Control zones to the north and south. Error bars indicate ±SD.

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 25

a)

b)

Figure 11. Average taxa richness of meiofaunal organisms across distances from the centre of the construction zone at a) Port Stanvac; and from the centre of sampling locations for b) Control zones to the north and south. Error bars indicate ±SD.

Abundance Average total abundance of all meiofaunal organisms declined from transect A through to transect J at Port Stanvac (Figure 12a). The decline in total abundance of meiofauna across transects at Port Stanvac reflected a decline in the most numerically dominant taxa, the nematodes (Figure 13a). Copepods showed a slight increase in abundance around transects D – G (Figure 13b); however, there was a great deal of variability across these samples, as indicated by the large error bars. There were no obvious difference among transects at either control location (Figure 12b).

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 26

There was a significant difference in total abundance among transects at Port Stanvac (PERMANOVA;

Pseudo-F9,82 = 3.151; P(perm) = 0.003; Figure 12a). Post-hoc pair-wise tests showed that average abundance was significantly lower on transect J compared to all other transects except transect I (P(perm) < 0.01). Likewise, abundance on transect I was significantly lower than on transects A, D and G (P(perm) < 0.01) and abundance on transect E was significantly lower than transect A (P(perm) < 0.01).

a)

b)

Figure 12. Average total abundance of meiofaunal organisms across transects at a) Port Stanvac; and b) Control zones to the north and south. Error bars indicate ±SD.

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 27

a)

b)

Figure 13. Average total abundance of a) nematodes; and b) copepods across transects at Port Stanvac. Error bars indicate ±SD. Note the different scale of the y-axis in each plot.

There were no noticeable differences in the total abundance of meiofauna across distances from the centre of the construction zone at Port Stanvac (Figure 14a) or from the centre of sampling locations at either control zone (Figure 14b). PERMANOVA results supported these observations, with no significant differences in abundance based on distance from the construction works at Port Stanvac

(Pseudo-F3,88 = 0.907; P(perm) = 0.437).

Total abundance at the southern control zone was significantly lower on transect C compared to transects A, B and D (PERMANOVA; Pseudo-F9,82 = 3.151; P(perm) = 0.003; Figure 12b). Otherwise, there were no significant differences in total abundance of meiofauna among transects or distances at either control zone (PERMANOVA; P(perm) > 0.05; Figure 12b, 14b).

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 28

a)

b)

Figure 14. Average abundance of meiofaunal organisms across distances from the centre of the construction zone at a) Port Stanvac; and from the centre of sampling locations for b) Control zones to the north and south. Error bars indicate ±SD. Note the different scale of the y-axis in each plot.

N:C ratio

On average, N:C values were greater than one for all distances and all transects except transect D at the southern control, where N:C was slightly less than one (N:C = 0.987). This indicates a general dominance of nematodes in samples from all sampling locations.

There was a decline in the value for N:C from transect A through to transect J at Port Stanvac (Figure 15a), indicating decreasing dominance of nematodes in samples towards the northern side of the Port Stanvac site. There were significantly lower N:C values at transect C relative to transects A and D in the south control (PERMANOVA; Pseudo-F = 2.532; P(perm) = 0.03), but no significant differences among transects at the northern control zone (Pseudo-P > 0.05; Figure 15b).

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 29

PERMANOVA results indicated that there was a significant difference in N:C values among transects at Port Stanvac (Pseudo-F9,82 = 5.980; P(perm) < 0.001). Post-hoc pair-wise tests showed that N:C values were significantly higher on transect B at Port Stanvac relative to all other transects except transect A (P(perm) < 0.05). N:C values at transect A were also significantly higher than those on transects E – H and transect J (P(perm) < 0.05).

a)

b)

Figure 15. Average ratio of nematode to copepod abundance (N:C) across transects at a) Port Stanvac; and b) Control zones to the north and south. Error bars indicate ±SD. Note the different scales of the y-axis in each plot.

There were increased values for N:C at the sampling location furthest from the centre of construction activities at Port Stanvac (800 m; Figure 16a); however, there was also a high degree of variation associated with this increase, as indicated by the large error bar. There were no significant differences in N:C values across distances at either control zone (PERMANOVA; P(perm) > 0.05; Figure 16b).

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 30

a)

b)

Figure 16. Average ratio of nematode to copepod abundance (N:C) across distances from the centre of the construction zone at a) Port Stanvac; and from the centre of sampling locations for b) Control zones to the north and south. Error bars indicate ±SD. Note the different scales of the y-axis in each plot.

PERMANOVA results indicated that there was a significant difference in N:C values among transects at Port Stanvac (Pseudo-F3,88 = 2.897; P(perm) = 0.040). Post-hoc pair-wise tests showed that N:C values were significantly higher at the 800 m end of transects compared to the 0 m and 200 m distances at Port Stanvac (P(perm) < 0.05). PERMDISP analysis revealed that this difference was due to significantly greater sample dispersion (and hence greater variability in N:C values; F3,88 = 9.110; P(perm) = 0.002) at the 800 m distance, relative to the 0 m (P(perm) = 0.002) and 200 m (P(perm) = 0.003) distances.

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 31

Community Structure Nematodes were the main characterising taxa for all transects and distances at Port Stanvac (Table 10), with SIMPER analyses showing that nematodes contributed between 26 and 80 % of the total average similarity between samples. Average similarity among samples was high for most transects except transect B, which was the only transect to lack copepods as a characterising taxa (Table 10). Likewise, average dissimilarity among samples from different transects was generally low, again with the exception of transect B (Table 10). These results are in line with the differences in taxa richness among transects with transect B having much lower richness than all other transects (Figure 10a), and the numerical dominance of nematodes at transect B (Figure 13a and 15a). Average similarity was high and average dissimilarity low between samples collected from the four distances at Port Stanvac (Table 10b).

Table 10. Summary SIMPER results for tests of the meiofaunal community average similarity a) among transects; and b) among distances within groups (light grey shading) and average dissimilarity between groups (no shading) at Port Stanvac, and a list of characterising taxa for each transect (N: Nematoda; C: Copepoda; T: Tardigrada; O: Ostracoda; F: Foraminifera; P: Polychaeta). a)

Transect A B C D E F G H I J Characterising taxa1 A 71.49 N,C,T,O B 48.72 50.84 N,F,T C 33.51 52.80 66.02 N,C,O,F D 27.87 49.24 32.76 73.57 N,C,T,P E 31.07 51.79 30.36 27.49 75.50 N,T,C,F F 34.80 52.16 35.11 33.52 30.70 66.75 N,C,F,O G 28.13 49.19 30.46 26.06 26.13 30.92 75.15 N,C,F,T H 32.11 52.82 31.24 30.56 28.67 31.00 27.47 70.75 N,C,F,O I 38.58 52.35 34.42 38.05 33.36 32.55 35.37 31.90 72.64 N,C,F,O J 39.16 54.64 34.26 37.05 30.40 33.05 35.33 32.78 24.49 76.64 N,C,F,O b) Distance 0 m 200 m 400 m 800 m Characterising taxa1 0 m 67.89 N,C,T,O 200 m 34.15 62.87 N,F,T 400 m 32.45 34.95 66.64 N,C,O,F 800 m 36.17 38.23 36.38 60.55 N,C,T,P

Community structure was significantly different among transects at Port Stanvac (Pseudo-F9,82 = 4.34; P(perm) = 0.0001). Post-hoc pair-wise tests indicated that community structure at transect B was significantly different to all other transects, a difference that was detected by PERMDISP to be due to a difference in dispersion (F9,82 = 5.550; P(perm) = 0.0001), with samples from transect B having a significantly greater spread (and hence being more variable in community structure) to all other transects (P(perm) < 0.05; Figure 17a). There were no significant differences in community structure based on distance from the centre of the construction site at Port Stanvac (PERMANOVA; F3,88 = 0.716; P(perm) = 0.769; Figure 17a).

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 32

20 a) A )

n B o i t C a i

r D a v

E l 0 a

t F

o t

G f

o

H

% I 6 .

J 4 -20 2 (

2 O C P -40 -20 0 20 40 60 b) PCO1 (34.1% of total variation)

20 )

n 0 o i

t 200 a i

r 400 a v

0 800 l a t

o t

f o

%

6 .

4 -20 2 (

2

O C P

-40 -20 0 20 40 60 PCO1 (34.1% of total variation)

Figure 17. PCO plots of fourth-root transformed abundance of meiofauna communities for samples collected during the Winter 2011 sampling occasion at Port Stanvac. Each panel shows the same plot comparing different groupings: a) transects; and b) distance. Each point on this plot represents the average of three replicate samples. Points plotting closely on these plots indicate similar meiofaunal communities. Each axis denotes the degree of variation explained by the left-right and the up-down distribution of points for the x- and y-axes, respectively.

Community structure was significantly different among transects at both the southern (Pseudo-F4,49 =

4.776; P(perm) = 0.0001) and northern (Pseudo-F4,41 = 1.803; P(perm) = 0.0173) control zones, indicating significant spatial variation on the scale of hundreds of metres. Post-hoc pair-wise tests revealed significant differences in community structure among all transects at the southern control Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 33

zone (P(perm) < 0.05), with differences at transect B being partially related to a relatively small dispersion spread for that transect ( PERMDISP; Figure 18a,c). Community structure among transects at the northern control site was more consistent, with post-hoc pair-wise tests revealing that there were only significant differences between transect E and transects A, B and D (P(perm) < 0.05). There were no significant differences in community structure among distances from the centre of each control site at either the nor thern (Pseudo -F3,42 = 1.188; P(perm) = 0.271) or southern (Pseudo -F3,50 = 1.029; P(perm) = 0.429) control zones (Figure 18b,d).

20 20 a) b) ) ) n

n o i

o t i t a i a i r

10 r 10 a a v v

l

l variation a a t t o o

t t

f 0 f 0 o o

% % 8 8 2 2 A ( (

B -10 2 -10 2 0 PCO2 of (28% total variation

C O O

PCO2 (28% of total PCO2 (28% 200

C

C D

P 400

P E

800

-20 -20 -30 -20 -10 0 10 20 30 -30 -20 -10 0 10 20 30

PCO1 (38% of total variation) PCO1 (38% of total variation)

) ) 20 20 n c) n d)

o o

i i

t 0 t a a

i A 200 i r B r a 400

v

C v a 800 l

l

a D t a t

o

t

E o

t

f f

o

0 o 0

% %

3 3 .

. 3 3 2 ( 2

(

2 PCO2 of (28% total variation 2 O PCO2 of(23.3% total variation O C C P -20 P -20 -40 -20 0 20 40 -40 -20 0 20 40

PCO1 (35.2% of total variation) PCO1 (35.2% of total variation)

Figure 18. PCO plots of fourth-root transformed average abundance of meiofauna communities for samples collected during the Winter 2011 sampling occasion in the north and south control zones. Each set of panels shows the same plot comparing different groupings, firstly at the southern control by a) transects; and b) distance; and then at the northern control by c) transect; and d) distance. Each point on this plot represents the average of three replicate samples. Points plotting closely on these plots indicate similar meiofaunal communities. Each axis denotes the degree of variation explained by the left-right and the up-down distribution of points for the x- and y-axes, respectively.

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 34

3.2.3 Sediments In general, sediments from all transects and distances at Port Stanvac were coarse to very coarse sands that were poorly sorted (Table 11, 12). Control sites to the north and south also had similar sediment composition across transects and distances (Table 11, 12).

Median (D50) grain sizes differed significantly among transects at Port Stanvac (Pseudo-F9,99 = 2.600; P(perm) = 0.0099), with noticeably larger median grain size values towards the northern end of the Port Stanvac zone (i.e. transects G – J; Table 11; Figure 19). There were significant differences in sample dispersion among transects at Port Stanvac (F9,99 = 14.649; P(perm) = 0.0001), with less variable median grain sizes on transect G and H compared to transects A – F (Figure 19). Median grain size was significantly greater at the 200 m distance at Port Stanvac relative to all other distances (Pseudo-F3,105 = 3.067; P(perm) = 0.030; Figure 19) but also significantly less variable according to PERMDISP (F3,105 = 18.162; P(perm) = 0.0003; Figure 19). The percentage of sediments greater than 1 mm in size differed significantly among transects at Port

Stanvac (Pseudo-F9,99 = 3.319; P(perm) = 0.0021). Transects G – I had a significantly greater percentage of sediments larger than 1 mm in size relative to transects A and C – F (P(perm) < 0.05; Figure 19). PERMDISP tests showed that the percentage of sediment greater than 1 mm was less variable on transect H than all other transects (P(perm) < 0.05) except transects G and I (Figure 19). There were no apparent differences in the percentage of sediments greater than 1 mm at either control zone (Table 11). The percentage of sediments greater than 1 mm was similar across distances from the centre of construction activities at Port Stanvac (Figure 19), and from the centre of each control site (Table 12).

Dispersion spread (D90 – D10) was very variable across transects at Port Stanvac (Table 11; Figure 19). Values for dispersion spread at control locations were similar among transects (Table 11). There were no differences in dispersion spread among distances at either Port Stanvac or either control zone (Table 12; Figure 19). Dispersion spread did not differ significantly among transects or distances at

Port Stanvac (Pseudo-F9,99 = 1.474; P(perm) = 0.1682). Differences in the percent fraction of each sediment grade scale among transects at Port Stanvac were significant for all fractions except clays (Table 13). More coarse sands and less fine sands occurred on the northern transects (i.e. transects G – J; Figure 20). Silts were also only noticeable in sediments from transects E to J (Figure 20). There was a general decline in the amount of sediment classed as medium grade scales and below from the southern to the northern section of Port Stanvac (i.e. transects A – J; Figure 20). Composition of sediments from the southern section at Port Stanvac broadly resembled those of nearby controls to the north and south, but sediments in the northern section of Port Stanvac were much coarser (Figure 20).

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 35

Table 11. Sediment grain-size distribution statistics for samples collected from transects within each zone, with overall summaries for each zone. Statistics given are the percentage of sample greater than 1mm in size (% > 1 mm), mean grain-size, median (D50) grain-size, sorting coefficient, dispersion spread (D90 – D50) and interquartile range (D75 – D25). The percentage of samples collected in each zone that were bi-modal are also given as modality.

% > 1 mm Mean Median Classification Sorting Classification Spread Range Modality

Zone Transect Min. Max. Average (μm) (μm) (μm) (μm) North A 20.6% 84.3% 53.5% 724.65 894.44 Coarse sand 1.74 Moderately sorted 765.52 483.33 control B 7.3% 93.7% 50.7% 641.00 709.41 Coarse sand 1.89 Moderately sorted 643.01 410.97 C 18.9% 93.8% 50.6% 696.91 792.51 Coarse sand 1.73 Moderately sorted 644.51 453.32 D 6.5% 88.3% 33.7% 575.51 636.74 Coarse sand 1.77 Moderately sorted 764.59 406.05 E 22.2% 99.7% 73.5% 912.14 1033.31 Coarse to very coarse sand 1.46 Moderately well sorted 524.09 157.37 Overall 6.5% 99.7% 51.0% 697.87 799.36 Coarse sand 1.73 Moderately sorted 679.64 386.38 21.3% Port A 3.3% 98.2% 43.8% 497.71 627.28 Medium to coarse sand 2.08 Poorly sorted 614.22 406.15 Stanvac B 35.0% 86.3% 61.4% 602.46 830.26 Coarse sand 2.38 Poorly sorted 902.19 609.23 C 27.0% 87.0% 58.7% 759.98 927.85 Coarse sand 1.85 Moderately sorted 696.65 359.66 D 10.2% 91.7% 42.8% 598.41 735.72 Coarse sand 1.94 Moderately sorted 826.11 486.15 E 15.5% 96.3% 49.3% 591.93 803.36 Coarse sand 3.17 Poorly sorted 807.25 573.49 F 11.4% 95.7% 45.6% 519.70 717.51 Coarse sand 3.59 Poorly sorted 834.73 520.24 G 47.0% 97.6% 75.9% 692.17 1070.26 Coarse to very coarse sand 3.52 Poorly sorted 815.59 268.73 H 67.1% 97.0% 83.0% 837.52 1080.48 Coarse to very coarse sand 2.20 Poorly sorted 652.12 132.22 I 25.6% 98.1% 81.9% 871.46 1046.98 Coarse to very coarse sand 2.26 Poorly sorted 368.74 123.14 J 9.8% 93.6% 57.8% 733.58 937.68 Coarse sand 2.26 Poorly sorted 663.37 329.85 Overall 3.3% 98.2% 58.5% 656.33 866.14 Coarse sand 2.57 Poorly sorted 736.26 393.90 64% South A 11.2% 64.0% 27.2% 443.38 512.30 Medium to coarse sand 2.04 Poorly sorted 920.68 543.98 control B 7.8% 65.3% 24.3% 442.26 465.77 Medium sand 1.94 Moderately sorted 843.65 527.76 C 8.0% 90.5% 34.0% 555.20 576.25 Coarse sand 1.76 Moderately sorted 681.68 321.52 D 4.4% 43.2% 16.7% 456.33 450.44 Medium sand 1.75 Moderately sorted 750.93 424.36 E 10.8% 95.4% 42.3% 651.07 759.99 Coarse sand 1.73 Moderately sorted 734.92 489.49 Overall 4.4% 95.4% 28.9% 510.60 555.73 Coarse sand 1.84 Moderately sorted 788.44 464.62 18.6%

Table 12. Sediment grain-size distribution statistics by distance for samples collected from transects within each zone, with overall summaries for each zone. Statistics given are the percentage of sample greater than 1mm in size (% > 1 mm), mean grain-size, median (D50) grain-size, sorting coefficient, dispersion spread (D90 – D50) and interquartile range (D75 – D25). The percentage of samples collected in each zone that were bi-modal are also given as modality.

% > 1 mm Mean Median Classification Sorting Classification Spread Range

Zone Distance Min. Max. Average (μm) (μm) (μm) (μm) North 0 m 18.9% 93.7% 53.3% 724.57 807.09 Coarse sand 1.69 Moderately sorted 662.11 351.14 control 200 m 60.4% 93.8% 81.2% 949.12 1079.43 Coarse to very coarse sand 1.48 Moderately well sorted 402.66 121.05 400 m 19.4% 99.7% 49.3% 688.57 851.37 Coarse sand 1.80 Moderately sorted 777.46 553.96 800 m 7.3% 77.2% 29.7% 525.21 536.91 Coarse sand 1.84 Moderately sorted 787.69 440.53 Port 0 m 10.2% 93.0% 55.9% 659.23 879.65 Coarse sand 2.71 Poorly sorted 728.90 354.26 Stanvac 200 m 34.1% 98.2% 73.5% 759.96 1035.69 Coarse to very coarse sand 2.80 Poorly sorted 660.05 287.02 400 m 23.5% 98.1% 65.9% 733.52 929.02 Coarse sand 2.13 Poorly sorted 741.39 348.41 800 m 7.2% 95.3% 56.4% 578.14 804.67 Coarse sand 3.14 Poorly sorted 791.28 516.44 South 0 m 13.2% 95.4% 29.7% 563.01 581.22 Coarse sand 1.80 Moderately sorted 798.06 528.31 control 200 m 7.8% 94.5% 23.6% 458.42 495.12 Medium sand 1.82 Moderately sorted 781.32 343.19 400 m 4.4% 65.3% 29.2% 485.81 587.67 Medium to coarse sand 1.90 Moderately sorted 831.98 494.37 800 m 6.0% 90.5% 44.0% 647.32 713.97 Coarse sand 1.76 Moderately sorted 695.01 449.11

a) Median grain size

c) Percent greater than 1 mm

b) Dispersion spread

Figure 19. Bar graphs for transects and distances at Port Stanvac showing averages for a) median grain size (D50 in µm); b) percentage of sediment greater than 1 mm; and c) dispersion spread (D90 – D10 in µm). Error bars indicate ±SD. Note the different scales of the y-axis in each plot.

Table 13. Summary PERMANOVA main test results (P(permutations-based) values) for comparisons of sediment percent fraction grade scales among transects and distances, separately, at Port Stanvac. Significant P values are highlighted in bold text.

Factor Coarse sand Medium sand Fine sand Very fine sand Silt Clay Transect 0.0008 0.0001 0.0003 0.0002 0.0111 0.1435 Distance 0.0213 0.4787 0.0100 0.0071 0.5069 0.3770

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 38

90% Clay 80% Silt

70% Very fine Fine 60% Medium

50%

40%

Percentage fraction Percentage

30%

20%

10%

0% * * * * 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 200 400 800 200 400 800 200 400 800 200 400 800 200 400 800 200 400 800 200 400 800 200 400 800 200 400 800 200 400 800 200 400 800 200 400 800 200 400 800 200 400 800 200 400 800 200 400 800 200 400 800 200 400 800 200 400 800 200 400 800

A B C D E A B C D E A B C D E F G H I J North control South Control Port Stanvac Zone Figure 20. Average percent fractions of sediment in each grade scale (medium sand and below on the Udden/Wentworth grade scale; Wentworth 1922) from samples collected at all zones for each transect and distance. The remaining percentage (to 100% of the sediment sample) was coarse sands (sediments greater than 500 µm). Asterix (*) indicate that there was no sediment samples collected from that sampling location (i.e. rocky reef habitat, thus no sediment for analysis).

3.3 Comparisons between Impacted and Control zones 3.3.1 Macro-Infauna Species numbers The number of species in samples differed significantly among zones (Table 14). Significantly fewer species were found in the southern control zone relative to the northern control zone (P(perm) < 0.05), but there no significant differences in species numbers at Port Stanvac (i.e. north versus south impact zones; P(perm) > 0.05; Figure 21).

Table 14. PERMANOVA main test results of comparisons of species numbers for macro-infauna among types (Ty, referring to impacted (Port Stanvac) or control (Northern and Southern)) and Zones (Zo) nested within Types. Significant P values (<0.05) highlighted in bold. Source df MS Pseudo F P (perm) Ty 1 34.031 23.421 0.0001 Zo(Ty) 2 9.046 6.226 0.0021 Residual 236 1.453

Annelida 180 Mollusca 160 Arthropoda 140 Other 120 100 80 60 Number of species 40 20 0 North Impact South Impact North Control South Control

Figure 21. Total number of infaunal species (Annelida, Mollusca, Arthropoda and Other taxa combined: see Appendix A) collected at each zone (nested in types).

Species Diversity Values for Shannon-Wiener’s diversity index (H’) differed significantly in value and variability among the four zones (nested in types; Table 15; PERMDISP P(perm) < 0.01). Post-hoc pair-wise tests revealed that variability in dispersion values was significantly greater at the southern control than the northern control zone (P(perm) < 0.05) but there were no differences in variability between the two impact zones. Although there were significant differences in evenness (J’) and diversity (1-Lambda) values between types (Table 15), there were no clear differences in average values for these measures in the bar graph (Figure 22). PERMDISP tests revealed that differences between types in these two diversity measures were due to significant differences in sample dispersion (P(perm) < 0.01). Values for evenness (J’) were significantly more variable at control zones, while those for diversity (1-Lambda) were significantly more variable at impact zones. Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 40

Table 14. PERMANOVA main test results of comparisons of species numbers for macro-infauna among types (Ty) and Zones (Zo) nested within Types. Significant P values (<0.05) highlighted in bold.

Source df H’ J’ 1-Lambda Ty 1 0.0005 0.0078 0.0089 Zo(Ty) 2 0.029 0.0832 0.081 Residual 236

a)

b)

c)

Figure 21. Average values for diversity measures: a) Shannon-Wiener index (H’); b) Pielou’s evenness (J’); and c) Simpson’s index (1-Lambda) among zones (for H’) and types (for J’ and 1-Lambda).

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 41

Abundance Total abundance of infauna was largely driven by arthropods at all zones (Figure 23a,d). Abundance differed significantly among zones for all taxa except annelids (Table 16). In all cases where there was a significant difference among zones, post-hoc pair-wise tests showed that abundance of taxa was significantly greater at the northern control zone relative to the southern control zone (P(perm) < 0.05), but that there were no differences in abundance between the two impact zones (P(perm) > 0.05). PERMDISP results indicated that abundance was significantly more variable at the impact zones compared to control zones (P(perm) < 0.05).

Table 16. PERMANOVA main test results of comparisons of total abundance and abundance of key taxa (annelids, molluscs, arthropods and other: see Appendix A) for macro-infauna among types (Ty) and Zones (Zo) nested within Types. Significant P values (<0.05) highlighted in bold. Source df Total Abundance Total Annelida Total Mollusca Total Arthropoda Total Other P (perm) P (perm) P (perm) P (perm) P (perm) Ty 1 0.0001 0.0669 0.0113 0.0001 0.0001 Zo(Ty) 2 0.0292 0.5811 0.0046 0.0047 0.0133 Residual 236

a) b)

c) d)

e)

Figure 23. Average a) total abundance; and abundance of b) annelids; c) molluscs; d) arthropods; and e) other taxa (see Appendix A), across zones (nested in types). Error bars indicate ±SD. Note the different scales of the y- axis in each plot. Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 42

Community Structure

Overall, infaunal community structure at all three zones were characterised by similar infaunal bryozoan and arthropod taxa, including Hornera ramosa and a number of amphipods (sub-order Gammaridea; Table 17). Similarity among samples for each of the zones was low and dissimilarity between zones was high (Table 17), indicating a great amount of variability in community structure over all zones.

Table 17. Summary SIMPER results for tests of infaunal community average percent similarity within samples from each zone (light gray shading) and average percent dissimilarity between samples from different zone (no shading), and a list of the characterising taxa for each zone. Zone North Port Stanvac South Characteristic taxa North 17.29 Amblypneustes ovum, Leucothoidae sp. 1., Hornera ramosa Port Stanvac 91.12 9.40 Gammarid sp. 29, Hornera ramosa, Gammarid sp. 6 South 89.34 91.82 13.82 Hornera ramosa, Ophiomyxa australis, Plagioecia sarniensis

Principle coordinate plot (PCO) of the infauna samples displayed spatial variability between the zones (nested within type) (Figure 24). The PCO plot of the three zones nested within types (north control zone, Port Stanvac north impact zone, Port Stanvac south impact zone and south control zone) showed some grouping of zone types (Figure 24), with significance detected by PERMANOVA (Table 18).

40 ) n o i t a i

r 20 a v

l a t o t

f

o 0

% 1

. 0 1

( -20 2 South control O North impact C

P South impact

-40 North control -40 -20 0 20 40 60

PCO1 (12.7% of total variation) Figure 24. PCO plots of fourth-root transformed abundances of infaunal communities for samples collected in Winter ’11 showing zones (nested in Types) (NC: north control; NI: north impact; SI: south impact; SC: south control). Each point on this plot represents a sample. Points plotting closely on this plot indicate samples with similar infaunal communities. Each axis denotes the degree of variation explained by the left-right and the up- down distribution of points for the x- and y-axes, respectively. Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 43

During the Winter 2011 sampling occasion, differences in the infaunal community assemblages were found based on Types (Factor Ty; Table 18), as well as consistent spatial differences (Factor Zo(Ty); Table 18).

Table 18. Summary PERMANOVA main test results (P (permutations-based) values) for comparisons of macro- infaunal community structure among types (Ty) and zones (Zo) nested within types for data collected in the Port Stanvac impact zone and north and south control zones in Winter ‘11. Significant P values (<0.05) highlighted in bold. Source df MS Pseudo F P (perm) Ty 1 31301 10.1 0.0001 Zo (Ty) 2 16216 5.232 0.0001 Residual 236 3099

3.3.2 Meiofauna Taxa richness was slightly higher at the southern control zone, however mean values did not differ greatly among the three zones (Figure 25a). Due to the low level of taxonomic differentiation applied to these data (i.e. organisms were identified to high-level taxonomic groups only, for instance Phyla [Nematoda]), these results are not expected to reflect the true level of taxonomic richness at the zones sampled, and are not tested further here. Species diversity indices, calculated for the macrofauna, are not applied to the meiofauna collection for this same reason. Total abundance of meiofauna was significantly different between zones (Table 19), with significantly higher abundance at the Impact (Port Stanvac) zones (Figure 25). Post-hoc pair-wise tests for differences between zones showed no differences between the two impact or two control zones (P(perm) > 0.05). A second, single-factor PERMANOVA testing zones only found a significant difference among zones (Pseudo-F3,189 = 7.096; P(perm) = 0.0002), with significantly greater abundance at the southern impact zone (southern half of Port Stanvac) compared to either the north (P(perm) = 0.0002) or south control zones (P(perm) = 0.0005). Dispersion spread was also greater for the two impacted zones within Port Stanvac (F3,189 = 12.907; P(perm) = 0.0005), indicating higher variability in total abundance within the impacted zone relative to the controls, which can be seen as the larger error value for Port Stanvac (Figure 25b). Nematode abundance differed significantly among the zones, but copepod abundance did not (Table 19; Figure 25). Nematode abundance was noticeably higher at the southern impact zone at Port Stanvac relative to both the north and south control zones (Figure 25c). Post-hoc pair-wise comparisons of differences in nematode abundance among zones revealed significant differences (P(perm) < 0.05) among pairs of control and impact zones. N:C values were significantly greater at the southern impact zone at Port Stanvac than other zones (Table 19; Figure 25e). N:C was also significantly more variable in the southern impact zone compared to all other sites (F3,189 = 17.839; P(perm) = 0.0001). These results together indicate that differences in total abundance and variation in total meiofaunal abundance among the impact and control zones tested are greatly influenced by the numerically dominant taxa, the nematodes at the southern impact zone at Port Stanvac. Meiofaunal communities at Port Stanvac and the northern control zone were characterised by nematodes, copepods and foraminiferans, with communities at the southern control zone characterised by nematodes, copepods and tardigrads (Table 20). Average similarity among samples

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 44

from each zone was high, and dissimilarity between samples from different zones was low (Table 20). Meiofaunal community structure differed significantly among zones (Table 19), with significant differences between each of the pairs of impact and control zones (P(perm) > 0.001). Dispersion

spread was also significantly different among the four zones (F3,189 = 7.420; P(perm) = 0.0005), with significantly higher dispersion spread at the southern impact zone relative to both control zones (P(perm) < 0.01), indicating greater variability in community structure at the southern half of the Port Stanvac zone. The greater variability in community structure at Port Stanvac can be seen in the PCO plot, with a greater spread of samples collected from Port Stanvac relative to the control zones (Figure 26).

Table 19. Summary of PERMANOVA results for tests between types (impact and control) and zones (nested in types) for univariate (i.e. total, nematode and copepod abundance, N:C ratio) and multivariate (i.e. community structure) analyses. Significant P(perm) values are highlighted in bold text.

Total Abundance Nematode abundance Copepod abundance Community structure Factor d.f. Pseudo - F P(perm) Pseudo - F P(perm) Pseudo - F P(perm) Pseudo - F P(perm) Type 1 11.251 0.0005 19.702 0.0001 1.455 0.2459 6.345 0.0001 Zone (Type) 2 4.003 0.0155 5.110 0.0045 2.733 0.0551 9.286 0.0001 Error 189

a) b)

c) d)

e)

Figure 25. Average a) taxa richness; b) total abundance; c) nematode abundance; d) copepod abundance; and e) N:C ratio across the three zones, Port Stanvac and control zones to the north and south. Error bars indicate ±SD. Note the different scales of the y-axis in each plot. Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 45

Table 20. Summary SIMPER results for tests of the meiofaunal community average similarity a) among transects; and b) among distances within groups (light grey shading) and average dissimilarity between groups (no shading) at Port Stanvac, and a list of characterising taxa for each transect (N: Nematoda; C: Copepoda; T: Tardigrada; F: Foraminifera).

Distance North Port South Characterising Control Stanvac Control taxa1 North Control 71.20 N, C, F Port Stanvac 35.24 63.24 N, C, F South Control 32.41 33.94 72.78 N, C, T

40 ) n o i

t 20 a i r a v

l a t o t

f

o 0

% 7 . 3 2 (

2

O -20 South control C

P North impact South impact North control -40

-20 0 20 40 60 PCO1 (28.6% of total variation)

Figure 26. PCO plot of fourth-root transformed abundance of meiofauna communities for samples collected during the Winter 2011 sampling occasion from all zones. Points plotting closely on these plots indicate samples with similar meiofaunal communities. Each axis denotes the degree of variation explained by the left- right and the up-down distribution of points for the x- and y-axes, respectively.

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 46

3.3.3 Sediments On average, sediments were coarser at Port Stanvac than either control zone, while sediments in the south control were finer than other zones (Table 11). There was also a higher percentage of sediment greater than 1 mm in size at Port Stanvac, and Port Stanvac sediments were more poorly sorted than sediments at either control zone (Table 11). Port Stanvac also had a higher percentage of samples that were multimodal (Table 11). Median grain size was significantly different among zones and types (Table S). Post-hoc pair-wise tests showed that sediments were significantly finer at the south control and south impact sites (P(perm) < 0.05; Figure 27). Differences in the percentage of sediment greater than 1 mm reflected those in median grain size (Table 21; Figure 27), with significant differences in the percent of sediment greater than 1 mm in size between types and among zones, and higher percentages of sediment greater than 1 mm at the northern control and northern impact zones (P(perm) < 0.05; Figure 27). There were no significant differences in dispersion spread either between types or among zones (Table 21; Figure 27). The percentage of sediments in each grade scale differed significantly among both types and most sampling zones, with the exception of clays (Figure 28; Table 22). There were less medium sand in sediments from the impact site relative to the controls, but more silts, especially in the northern impact zone (Figure 28).

Table 21. Summary of PERMANOVA results for tests between types (impact and control) and zones (nested in types) for univariate sediment variables. Significant P(perm) values are highlighted in bold text.

Median grain size (D50) Percent > 1 mm Dispersion spread (D90 – D10) Factor d.f. Pseudo - F P(perm) Pseudo - F P(perm) Pseudo - F P(perm) Type 1 26.628 0.0001 32.948 0.0001 0.064 0.8020 Zone (Type) 2 23.182 0.0001 14.155 0.0001 2.809 0.0599 Error 199

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 47

a)

b)

c)

Figure 27. Bar graphs for transects and distances at each zone showing averages for a) median grain size (D50 in µm); b) percentage of sediment greater than 1 mm; and c) dispersion spread (D90 – D10 in µm). Error bars indicate ±SD.

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 48

100% 90% 80% 70% 60% Clay 50% Silt 40% Very fine 30%

Percentage fraction Percentage Fine 20% 10% Medium 0% Coarse North South North South Control zones Impact zones Zone

Figure 28. Average percent fractions of sediment in each grade scale of the Udden/Wentworth grade scale (Wentworth 1922) from samples collected in Winter 2011 from each sampling zone.

Table 22. Summary PERMANOVA main test results (P(permutations-based) values) for comparisons of sediment percent fraction grade scales among transects and distances, separately, at Port Stanvac. Significant P values are highlighted in bold text.

Factor Coarse sand Medium sand Fine sand Very fine sand Silt Clay Transect 0.0001 0.0001 0.0406 0.0001 0.0001 0.0009 Distance 0.0001 0.0001 0.0001 0.0001 0.0008 0.1952

3.4 Infauna-Sediment Relationships Macro-infauna Over all samples collected across the three zones, there was only a weak relationship between macro-infaunal community structure and sediment characteristics (Table 23a). Two sediment variables, the percentage of medium and very fine sands, explained only 7.2% of the variation in macro-infaunal community structure (Table 23a). Samples from the two control sites grouped towards the right hand side of the dbRDA plot (Figure 29a). Sediments in control zones had larger percentages of medium sands relative to Port Stanvac (Figure 28) and this was reflected in the dbRDA plot with control zone samples grouping along the medium sand vector (Figure 29a). Control zones showed a slightly stronger relationship with sediment characteristics on their own, with a combination of two variables, coarse sand and silt, explaining 12.9% of the total variation in the macro-infaunal community structure at those sites (Table 23b). Coarse sands and silts formed a vector following the x-axis from left to right on the dbRDA plot,

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 49

however the scatter of points did not follow this vector very tightly (Figure 29b), and these two variables together only explained a total of 12.9% of the variation in macrofaunal community structure (Table 23b). Sediment characteristics were more variable across Port Stanvac, with finer sediments in the southern section and coarser sediments in the northern section (Figure 27a). Despite this, sediment characteristics did not well explain patterns in macro-infaunal community structure, with a combination of the percentage fraction of two sediment grade scales in sediments, fine and very fine sand, only explaining 9.4% of the total variation in macro-infaunal community structure (Table 23c). These two variables formed vectors that explained left-to right variation in the data (7.2% of total variation; Figure 29c). Overall, these results indicate that there is not a very strong relationship between sediment characteristics and macro-infaunal community structure.

Table 23. Distance-based linear model (DistLM) sequential test results for relationships between sediment percent grade scale fractions and macro-infaunal community structure a) over all zones; b) at control zones only; and c) at Port Stanvac only. Variables below the line did not contribute toward the model.

a) Over all zones

Variable R2 Pseudo-F P Proportion of variance explained (%) Medium sand 0.053 4.131 0.0001 4.3 Very fine sand 0.082 2.333 0.0010 2.9 Silt 0.100 1.442 0.0547 1.8 Coarse sand 0.115 1.177 0.2270 1.5 Fine sand 0.132 1.367 0.0880 1.7 Clay 0.140 0.657 0.9286 0.8

b) Control zones only

Variable R2 Pseudo-F P Proportion of variance explained (%) Coarse sand 0.086 3.210 0.0001 8.6 Silt 0.129 1.667 0.0218 4.3 Fine sand 0.162 1.318 0.1220 3.3 Very fine sand 0.188 0.994 0.4614 2.5 Medium sand 0.204 0.656 0.9199 1.7 Clay (no clay in sediments from control sites)

c) Port Stanvac only

Variable R2 Pseudo-F P Proportion of variance explained (%) Very fine sand 0.054 1.124 0.0047 5.4 Fine sand 0.095 1.599 0.0335 4.0 Coarse sand 0.121 1.070 0.3568 2.7 Clay 0.136 0.583 0.9547 1.5 Silt 0.158 0.854 0.6721 2.2 Medium sand 0.194 1.452 0.0776 3.7

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 50

40

) n Zone o i a) t a

i Very fine sand Port Noarlunga r a v

l Glenelg

a Fine sand t o t

Port Stanvac f 20 o

% 4 .

3 Silt

, d

e t t i

f Medium sand

f Clay

o Coarse sand

% 0 1 . 4

2 (

2 A

D R b

d

-20 -40 -20 0 20 40 dbRDA1 (41.8% of fitted, 5.8% of total variation) 40 b) ) n o i

t Fine sand a i r

a Zone v

l a

t Port Noarlunga o t

f 20 Glenelg

o

% 6 . Very fine sand 3

, d

e Silt t t

i f

f Coarse sand o

% 0 6

. Medium sand 7 1 (

2

A D R b d

-20

-40 -20 0 20 40

dbRDA1 (50.7% of fitted, 10.4% of total variation) 40 )

c) n

o i t a

i r a

v

l

a 20 t o

t Fine sand Transect f o A % ClayMedium sand 5 .

4 B

,

d 0 C e t t i f

D f o E % 1

.

3 Silt Very fine sand Coarse sand F 2

( -20

2 G

A D H R

b

d I

-40 J

-60 -40 -20 0 20 40

dbRDA1 (37.2% of fitted, 7.2% of total variation) Figure 29. Distance-based redundancy analysis (dbRDA) plots of square-root transformed macro-infaunal community structure data for samples collected from a) all zones; b) control zones; and c) Port Stanvac only.

Each point on this plot represents a sample. Points plotting closely on these plots indicate samples with similar communities. Each axis denotes both the percentage of fitted and total variation explained by the left-right and the up-down distribution of points for the x- and y- axes, respectively. The vector overlays shown indicate the strength and direction of relationships between sediment variables and macro-infaunal community structure.

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 51

Meiofauna Over all the zones sampled (i.e. including both control and impact zones), variation in just two sediment grade scales, very fine and medium sand, combined to explain a total of 11.5% of the total variation in meiofaunal community structure (Table 24a). Other sediment grade scales did not contribute significantly to the model (Table 24a). When only samples from control locations were looked at, variation in the percentage of coarse and fine sands combined to explain 12.1% of the total variation in meiofaunal community structure (Table 24b; Figure 30b). Variation in the percentage of three grade scale fractions, very fine, fine and medium sands, combined to explain a total of 15.3% of the total variation in meiofaunal community structure at Port Stanvac (Table 24c). Relationships among sediment characteristic s and meiofaunal community structure were clearer at Port Stanvac, with meiofaunal communities from transects dominated by fine and very fine sands (i.e. transects A and B, respectively), grouping along these vectors on the dbRDA plot (Figure 30c). Meiofaunal communities from transects dominated by coarser sediments that were mixed with clays (i.e. transects G – J) also grouped together between these two vectors (Figure 30c). These results indicate that meiofaunal community structure is related to sediment characteristics at the zones sampled, but that other factors that have not been tested here may also be contributing to meiofaunal community structure.

Table 24. Distance-based linear model (DistLM) sequential test results for relationships between sediment percent grade scale fractions and meiofaunal community structure a) over all zones; b) at control zones only; and c) at Port Stanvac only. Variables below the line did not contribute toward the model. a) Over all zones

Variable R2 Pseudo-F P Proportion of variance explained (%) Very fine sand 0.085 16.050 0.0001 8.5 Medium sand 0.114 5.731 0.0001 3.0 Fine sand 0.125 2.020 0.0680 1.0 Clay 0.127 0.512 0.7420 0.2 Coarse sand 0.139 2.198 0.0639 1.1 Silt 0.144 1.114 0.3520 5.7 b) Control zones only R2 Pseudo-F P Proportion of variance explained (%) Variable Coarse sand 0.080 7.388 0.0001 7.9 Fine sand 0.122 3.995 0.0028 4.2 Silt 0.139 1.689 0.1412 1.8 Medium sand 0.153 1.377 0.2372 1.4 Very fine sand 0.162 0.855 0.5150 0.9 Clay (no clay in sediments from control zones) c) Port Stanvac only Variable R2 Pseudo-F P Proportion of variance explained (%) Very fine sand 0.101 9.694 0.0001 10.1 Fine sand 0.131 2.912 0.0138 2.8 Medium sand 0.155 2.377 0.0348 2.4 Clay 0.161 0.614 0.6509 0.6 Coarse sand 0.179 1.783 0.1143 1.8 Silt 0.186 0.703 0.6500 0.7

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 52

20

) n

a) o i t a i r a

v Medium sand

l

a 10 t o t

f o

% 5 . 3

,

d 0 e

t

t Fine sand i Silt f

f Very fine sand o

% 3

. Clay 4 2

( -10 Coarse sand Zone 2 A

D Port Noarlunga R b

d Glenelg -20 Port Stanvac -10 0 10 20 30 40

dbRDA1 (62.8% of fitted, 9.1% of total variation) 15

) b) n o

i t Fine sand

a i r a

v 10

l Zone a t o t

Port Noarlunga

f o

% 5 Glenelg 3 . 4

,

d Clay

e t

t Silt i f

f 0 arse sand o Very fine sand

%

4

. Medium sand 6 2

(

2 -5

A

D R b

d -10 -15 -10 -5 0 5 10 15 20 dbRDA1 (58.1% of fitted, 9.4% of total variation)

30

c) ) n

o i t a

i r

a

v 20

l a

t Fine sand o t

Transect f o A % 10 Silt

8 Medium sand .

3 B

, d

e Coarse sand C t t i f

f 0 D o

% Clay E 6 .

0

2 F (

2 -10 G A Very fine sand

D

R H b

d I -20 J -20 -10 0 10 20 30 40

dbRDA1 (58.8% of fitted, 10.9% of total variation)

Figure 30. Distance-based redundancy analysis (dbRDA) plots of fourth-root transformed meiofaunal community structure data for samples collected from a) all zones; b) control zones only; and c) Port Stanvac only. Each point on this plot represents a sample. Points plotting closely on these plots indicate samples with similar communities. Each axis denotes both the percentage of fitted and total variation explained by the left- right and the up-down distribution of points for the x- and y- axes, respectively. The vector overlays shown indicate the strength and direction of relationships between sediment variables and meiofaunal community structure.

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 53

4 Comparison to previous sampling occasions During the Winter 2011 sampling occasion, average abundances per sample in control zones were higher than those recorded during each of the four previous sampling occasions, apart from abundances at Port Stanvac which were higher during the Spring 2009 sampling occasion (Figure 31a; Ramsdale et al.2011). Annelid worms occurred with highest abundances in the southern control zone and at Port Stanvac and arthropod abundances were highest at the northern control during the Winter 2011 sampling occasion relative to previous occasions (Figure 31a). Abundances of ‘other’ taxa (including bryozoans, chordates, poriferans, nemerteans and hemichordates) were also increased in samples from control zones in the Winter 2011 sampling occasion relative to previous sampling occasions (Figure 31a). Compared to average values for the previous four sampling occasions, abundances appeared higher in each sampling zone, but the average abundance at Port Stanvac was within the range of variation previously observed (Figure 31b). Differences in total abundance during Winter 2011 appear to be due to an increase in abundance of macro-infaunal organisms at control zones. Species richness was above the range of variation previously observed in all three sampling zones (Figure 31c). At Port Stanvac, species numbers showed similar spatial patterns during Winter 2011 to those observed during Spring 2009, with peaks in species richness in the centre transects (E – G; Ramsdale et al.2011). Abundance was also highest on these centre transects (especially E and F) at Port Stanvac during Winter 2011, which was the same as at all previous sampling occasions (Ramsdale et al.2011). Variation in macro-infaunal community structure were not well explained by sediment characteristics during the Winter 2011 sampling occasion (Table 23, Figure 29), and are more likely related to depth, with transects E and F both lying in deeper water (approx. 20 m; Table 1), further off-shore. Gammarid amphipods were important characterising taxa during the Winter 2011 sampling occasion and during previous occasions, while Notogibbula lehmanii was not as prominent in communities as during previous occasions (Ramsdale et al.2011). There were no clear spatial differences in macrofaunal community structure at Port Stanvac during the Winter 2011 sampling occasion although differences in variability in community structure s were detected by PERMANOVA , in line with previous sampling occasions (Ramsdale et al.2011). Importantly, during Winter 2011, as for previous sampling occasions, there were no patterns in macro-infaunal diversity, abundance or community structure based on proximity to the discharge pipeline (Ramsdale et al.2011). Species numbers and abundance were greater in the north control relative to both the south control and Port Stanvac zones during winter 2011 (Figure 21), a difference that had not been observed previously, as species numbers and abundance were generally lower at the two control zones relative to Port Stanvac (Ramsdale et al.2011). Some species that had characterised communities during previous sampling occasions were not as predominant in communities during winter 2011, such as Notogibbula lehmanii at Port Stanvac (Ramsdale et al.2011). SIMPER results were similar to those observed during the Spring 2009 sampling occasion, with higher similarity among samples at Port Stanvac relative to both controls, and lowest dissimilarity between samples from the two control zones (Ramsdale et al.2011). There were no clear differences in macrofaunal community structure among zones or types during the Winter 2011 sampling occasion although PERMANOVA detected differences in variability in community structure, as during previous sampling occasions.

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 54

40 Other a) 35 Annelid 30 Molusca 25 Arthropod 20 15 10 5 0 Average abundance Average abundance (per sample) Spring 09 Spring 09 Spring 09 Spring Winter 09 Winter 10 Winter 11 Winter 09 Winter 10 Winter 11 Winter 09 Winter 10 Winter 11 Summer 11 Summer 11 Summer 11

North Control Port Stanvac South Control 35 b) Other 30 Annelid 25 Molusca

20 Arthropod

15

10

5 Average abundance Average abundance (per sample) 0 North Port South North Port South control Stanvac control control Stanvac control

Previous surveys Winter 11 c) 180 160 140 120 100 80 60 40 20 0 Average species richness sample) (per richness species Average North Port South North Port South control Stanvac control control Stanvac control

Previous surveys Winter 11

Figure 31. Bar graphs for average a) total abundance across each zone and sampling occasion (using data from Ramsdale et al.2011) divided by taxonomic group; and b) abundance (as for part a) and c) species richness averaged over the four previous sampling occasions (error bars indicate ±SD) compared to values measured during the Winter 2011 sampling occasion in each zone.

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 55

Unlike the macro-infauna, meiofaunal total abundance was lower on average during the Winter 2011 sampling occasion compared to previous sampling occasions (Figure 32). Nematode abundance was lower during Winter 2011 than previously recorded in all zones (Figure 32). Patterns for differences in total abundance for each zone did not change during the Winter 2011 sampling occasion relative to previous sampling occasions (Ramsdale et al. 2011), with meiofaunal abundance still being lowest at the northern control zone relative to Port Stanvac and the southern control zone (Figure 32b). However, although patterns for differences among zones did not change, total abundances were reduced, but within ranges previously observed at Port Stanvac and the south control zone (Figure 32b). Overall, meiofauna abundance for the northern control zone was much lower than previously observed (Figure 32b). There was no noticeable difference in meiofauna taxa richness between the Winter 2011 sampling occasion and previous sampling occasions (17 taxa found during Winter 2011 versus up to 19 taxa previously; Figure 32c). Taxa richness was notably decreased on transect B at Port Stanvac during the Winter 2011 sampling occasion relative to other transects at Port Stanvac and transects at control zones and compared to transects from previous sampling occasions (Ramsdale et al. 2011). Total meiofaunal abundance and nematode dominance (i.e. N:C ratio being greater than 1) at Port Stanvac showed a decline from the southern to the northern transects as for previous sampling occasions (Ramsdale et al. 2011), partly due to spatial variation in sediment characteristics. However, during previous sampling occasions, meiofaunal community structure was fairly well explained by sediment characteristics at Port Stanvac (37 % of total variation; Ramsdale et al. 2011), but during the Winter 2011 sampling occasion, this percentage dropped to just 15.3 %. Sediments at Port Stanvac became more uniform during Winter 2011, with large areas of the zone characterised by coarse sands and only small pockets of medium sands occurring at the 800 m ends of transect A – C, E and F, as well as the 0 m ends of transects D, F and G and the 200 m distance on transect E. Previously, sediments had ranged from fine sands at the southern end of transect A to very coarse sands along transects I and J (Ramsdale et al. 2011). It is likely that in the absence of greater diversity in sediments at the Port Stanvac zone during the Winter 2011 sampling occasion, the strength of the relationship between meiofaunal community structure and sediment patterns decreased (hence the decline in variation explained), and instead, other factors that have not been measured as part of this monitoring programme are possibly playing a more important role in determining community structure of meiofauna at Port Stanvac. Meiofaunal communities at different transects at Port Stanvac were generally dominated by nematode worms, with copepods also being prominent during the Winter 2011 sampling occasion. Copepods were absent from the list of characterising taxa at transect B and at the 200 m distance at Port Stanvac during Winter 2011, where copepods had previously been a characterising taxa for all transects and distances (Ramsdale et al. 2011). Transect B separated from other transects in terms of community structure (Figure 17), otherwise there were no clear differences in meiofaunal community structure among spatial factors, zones or types. Importantly, during Winter 2011, as for previous sampling occasions, there were no patterns in meiofaunal diversity, abundance or community structure based on proximity to the discharge pipeline.

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 56

600 Other

a) 500 Tardigrad Copepod 400 Nematode 300

200

100

0 Average abundance Average abundance (per sample) Spring 09 Spring 09 Spring 09 Spring Winter 09 Winter 10 Winter 11 Winter 09 Winter 10 Winter 11 Winter 09 Winter 10 Winter 11 Summer 11 Summer 11 Summer 11

North Control Port Stanvac South Control b) 500 450 Other 400 Tardigrad 350 Copepod 300 Nematode 250 200 150 100 50 Average abundance Average abundance (per sample) 0 North Port South North Port South control Stanvac control control Stanvac control

c) Previous surveys Winter 11 20

15

10

5 Average taxa richness

0 North Port Stanvac South North Port Stanvac South control control control control

Previous surveys Winter 11

Figure 32. Bar graphs for average a) total abundance across each zone and sampling occasion (using data from Ramsdale et al.2011) divided by taxonomic group; and b) abundance (as for part a) and c) species richness averaged over the four previous sampling occasions (error bars indicate ±SD) compared to values measured during the Winter 2011 sampling occasion in each zone.

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 57

Even though significant differences in sediment structure were detected among spatial factors (i.e. transects and distances) at Port Stanvac during the Winter sampling occasion, such differences had been identified during previous sampling occasions (Ramsdale et al. 2011). Across all three zones, sediments were characterised as coarse sands, and were similar in grain size to previous sampling occasions (Ramsdale et al. 2011). Importantly, during Winter 2011, as for previous sampling occasions, there were no patterns in macro-infaunal or meiofaunal diversity, abundance or community structure based on proximity to the discharge pipeline. The sampling occasion did not reveal any effect of construction on the subtidal benthic infauna communities or their habitat (i.e. sediments). As such, the results obtained can contribute towards the baseline data set for future monitoring of effects of the desalination plant at Port Stanvac when the plant becomes operational. Acknowledgements The Authors would like to thank S. Baggalley and L. Sylvester for assistance in the laboratory and field. Prof Peter Fairweather and Dr Kirsten Benkendorff for the loaning of equipment for meiofaunal sample processing; and Holdfast Bay Charters for assistance in the field.

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 58

5 References Anderson, M.J. (2001) A new method for non-parametric multivariate analysis of variance. Austral Ecology, 26: 32 - 46 Anderson, M.J. (2006) Distance-based tests for homogeneity of multivariate dispersions. Biometrics, 62: 245 - 253 Anderson, M.J., Gorley, R.N. & Clarke, K.R. (2008) PERMANOVA+ for PRIMER: guide to software and statistical methods. PRIMER-E, Plymouth. Barrett, M. (2009) Effects of brine discharge on infaunal survivalship. Unpublished Honours Thesis, School of Biological Sciences, Flinders University. Benkendorff, K. Fairweather, P. and Dittmann, S. (2008) Intertidal shores: life on the edge. Chapter 10 in: S.A. Shepherd, S.Bryars, I. Kirkegaard, P. Harbison, & J.T. Jennings (eds.) Natural History of Gulf St Vincent. Royal Society of South Australia Inc. Adelaide, Australia, pp. 121 – 131. Blott, S.J. & Pye, K. (2001) GRADISTAT: A grain size distribution and statistics package for the analysis of unconsolidated sediments. Earth Surface Processes and Landforms, 26: 1237 – 1248. Bouwman, L.A. (1987) Meiofauna. Chapter 7 in: Biological surveys of estuaries and coasts. J.M. Baker & W.J Wolff (eds). Cambridge University Press, Cambridge. pp. 140 – 156. Brown, A.V., Schram, M.D. & Brussock, P.P. (1987) A vacuum benthos sampler suitable for diverse habitats, Hydrobiologia, 153: 241 – 247. Bryars, S., Wear, R. & Collings, G. (2008) Seagrasses of Gulf St Vincent and Investigator Strait. Chapter 11 in: S.A. Shepherd, S.Bryars, I. Kirkegaard, P. Harbison, & J.T. Jennings (eds.) Natural History of Gulf St Vincent. Royal Society of South Australia Inc. Adelaide, Australia, pp. 132 – 147. Clarke, K.R. (1993) Non-parametric multivariate analysis of changes in community structure. Australian Journal of Ecology, 18: 117 – 143. Clarke, K.R. & Gorley, R.N. (2006) PRIMER v6: User Manual/Tutorial. PRIMER-E, Plymouth Clarke, K.R. & Warwick, R.M. (2001) Change in marine communities: an approach to statistical analysis and interpretation, 2nd edition. PRIMER-E, Plymouth Comín, F.A., Menéndez, M. & Herrera, J.A. (2004) Spatial and temporal scales for monitoring coastal aquatic systems. Aquatic Conservation Marine and Freshwater Ecosystems. 14: S5 – S17. Edgar, G.J. (2008) Australian Marine Life: the plants and animals of temperate waters. 2nd edition. Reed New Holland, Sydney. Edyvane, K.S. (2008) Macroalgal biogeography and assemblages of Gulf St Vincent. Chapter 19 in: S.A. Shepherd, S.Bryars, I. Kirkegaard, P. Harbison, & J.T. Jennings (eds.) Natural History of Gulf St Vincent. Royal Society of South Australia Inc. Adelaide, Australia, pp. 248 – 263. Gower, J.C. (1966) Some distance properties of latent rood and vector methods used in multivariate analysis. Biometrika, 53: 325 – 338. Gowlett-Holmes, K. (2008) A field guide to the marine invertebrates of South Australia. Notomares, Sandy Bay, Tasmania, Australia. Higgins, R.P. & Thiel, H. (1988) Introduction to the study of meiofauna. Smithsonian Institution Press, Washington D.C. Legendre, P. & Anderson, M.J. (1999) Distance-based redundancy analysis: testing multispecies responses in multifactorial ecological experiments. Ecological Monographs, 69: 1 – 24.

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 59

Loo, M.G.K. & Drabsch, S.L. (2008) Subtidal soft sediments of Gulf St Vincent. Chapter 16 in: S.A. Shepherd, S.Bryars, I. Kirkegaard, P. Harbison, & J.T. Jennings (eds.) Natural History of Gulf St Vincent. Royal Society of South Australia Inc. Adelaide, Australia, pp. 204 – 223. Loo, M.G.K., Mantila, L., Segade M-E., Wiltshire, K., & Sharma, S. (2008) Adelaide Desalination Project, Macroinfauna/Meiofauna Characterisation Study. SARDI Aquatic Sciences Publication No. F2008/000823-1. McArdle, B.H. & Anderson, M.J. (2001) Fitting multivariate models to community data: a comment on distance-based redundancy analysis. Ecology, 82: 290 – 297. Morrisey, D.J., Howitt, L., Underwood, A.J. & Stark, J.S. (1992a) Spatial variation in soft-sediment benthos. Marine Ecology-Progress Series, 81: 197 – 204. Morrisey, D.J., Underwood, A.J., Howitt, L., & Stark, J.S. (1992b) Temporal variation in soft-sediment benthos. Journal of Experimental Marine Biology and Ecology, 164: 233 – 245. Ramsdale, T.M., Keuning, J., Glavinic, A., and Dittmann, S. (2011) Adelaide Aqua Infauna Monitoring Summary Report on monitoring Winter 2009 – Summer 2011, Flinders University, Adelaide Roberts, D.A., Johnston, E.L. & Knott, N.A. (2010) Impacts of desalination plant discharges on the marine environment: a critical review of published studies. Water Research, 44: 5117 – 5128. SA Water (2008) Proposed Adelaide Desalination Plant Environmental Impact Statement. SA Water, Government of South Australia. Shepherd, S.A. & Davies, M. (eds.) (1997) Marine Invertebrates of Southern Australia Part 3. South Australian Research and Development Institute in conjunction with the Flora and Fauna of South Australian handbooks committee, Adelaide. Shepherd, S.A. & Thomas, I.M. (eds.) (1982) Marine Invertebrates of Southern Australia Part 1. South Australian Government Printer, Adelaide. Shepherd, S.A. & Thomas, I.M. (eds.) (1989) Marine Invertebrates of Southern Australia Part 2. South Australian Government Printer, Adelaide. Somerfield, P.J. & Warwick, R.M. (1996) Meiofauna in marine pollution monitoring programmes. A laboratory manual. Ministry of Agriculture, Fisheries and Food, Directorate of Fisheries Research, Lowerstoft, UK. Torgerson, W.S. (1958) Theory and methods of scaling. John Wiley & Sons, New York Turner, D.J. & Collings, G. (2008) Subtidal macroalgal communities of Gulf St Vincent. Chapter 20 in: S.A. Shepherd, S.Bryars, I. Kirkegaard, P. Harbison, & J.T. Jennings (eds.) Natural History of Gulf St Vincent. Royal Society of South Australia Inc. Adelaide, Australia, pp. 264 – 278. Underwood, A.J. (1991) Beyond BACI: Experimental designs for detecting human impacts on temporal variation in natural populations. Australian Journal of Marine and Freshwater Research, 42: 569 – 587. Underwood, A.J. (1992) Beyond BACI: The detection of environmental impacts on populations in the real but variable world. Journal of Experimental Marine Biology and Ecology, 161: 145 – 178. Warwick, R.M. (1981) The nematode/copepod ratio and its use in pollution ecology. Marine Pollution Bulletin 12: 329 – 333. Wentworth, C.K. (1922) A scale of grade and class terms for clastic sediments. Journal of Geology. 30: 377- 392.

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 60

Appendix A. Species list of macro-infaunal organisms found in samples at all sites.

Port Port Phylum Common Name Taxa Glenelg Stanvac Noarlunga Arthropoda Amphipod Gammaridae juvenile   Arthropoda Amphipod Eurystheus persetosus    Arthropoda Amphipod Photoidae sp. 2   Arthropoda Amphipod Haustorius sp. 1    Arthropoda Amphipod Haustorius sp. 2  Arthropoda Amphipod Leucothoidae sp. 1    Arthropoda Amphipod Leucothoidae sp. 2    Arthropoda Amphipod Gammaridae sp. 1    Arthropoda Amphipod Gammaridae sp. 2    Arthropoda Amphipod Gammaridae sp. 3    Arthropoda Amphipod Gammaridae sp. 4    Arthropoda Amphipod Gammaridae sp. 5    Arthropoda Amphipod Gammaridae sp.6    Arthropoda Amphipod Gammaridae sp.7    Arthropoda Amphipod Gammaridae sp. 9  Arthropoda Amphipod Gammaridae sp. 11    Arthropoda Amphipod Gammaridae sp. 13    Arthropoda Amphipod Gammaridae sp. 14   Arthropoda Amphipod Gammaridae sp. 16    Arthropoda Amphipod Gammaridae sp. 18    Arthropoda Amphipod Gammaridae sp. 21    Arthropoda Amphipod Gammaridae sp. 24    Arthropoda Amphipod Gammaridae sp. 26   Arthropoda Amphipod Gammaridae sp. 27    Arthropoda Amphipod Gammaridae sp. 29    Arthropoda Amphipod Gammaridae sp. 31    Arthropoda Amphipod Gammaridae sp. 32  Arthropoda Amphipod Gammaridae sp. 35   Arthropoda Amphipod Gammaridae sp. 36  Arthropoda Amphipod Gammaridae sp. 37   Arthropoda Amphipod Gammaridae sp. 38   Arthropoda Amphipod Gammaridae sp. 40  Arthropoda Amphipod Gammaridae sp. 41  Arthropoda Amphipod Gammaridae sp. 44  Arthropoda Amphipod Gammaridae sp. 45  Arthropoda Amphipod Gammaridae sp. 47  Arthropoda Amphipod Leucothoe sp. 1    Arthropoda Amphipod Dexaminidae sp. 1   

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 61

Port Port Phylum Common Name Taxa Glenelg Stanvac Noarlunga Arthropoda Amphipod Dexaminidae sp. 2    Arthropoda Amphipod Dexaminidae sp. 3    Arthropoda Amphipod Ampithoidae sp. 1    Arthropoda Amphipod Amphipoda sp. 1   Arthropoda Amphipod Cyproidea ornata    Arthropoda Amphipod Cerapus abditus  Arthropoda Amphipod Caprellidae sp. 1   Arthropoda Amphipod Caprellidae sp. 2    Arthropoda Amphipod Caprellidae sp. 3  Arthropoda Amphipod Caprellidae sp. 4   Arthropoda Amphipod Caprellidae sp. 5   Arthropoda Amphipod Caprellidae sp. 6  Arthropoda Isopod Anthuridae sp. 1  Arthropoda Isopod Crabyzos longicaudatus  Arthropoda Isopod Isopoda sp. 1    Arthropoda Isopod Isopoda sp. 2   Arthropoda Isopod Isopoda sp. 3  Arthropoda Isopod Isopoda sp. 4  Arthropoda Isopod Cirolana vieta   Arthropoda Isopod Flabbarifera sp. 1    Arthropoda Isopod Flabbarifera sp. 2  Arthropoda Isopod Cilicaea latreillei   Arthropoda Isopod Serolis bakeri    Arthropoda Isopod Parastacilla bakeri   Arthropoda Isopod Neastacilla deducta    Arthropoda Cumacean Cumacea sp. 1    Arthropoda Cumacean Cumacea sp. 2   Arthropoda Cumacean Cumacea sp. 3    Arthropoda Cumacean Cumacea sp. 4   Gynodiastylis Arthropoda Cumacean truncatifrons    Arthropoda Cumacean Gynodiastylis turgidus    Arthropoda Cumacean Cyclaspis tribulis    Arthropoda Tanaid Tanaidacea sp. 1    Arthropoda Tanaid Tanaidacea sp. 2    Arthropoda Tanaid Tanaidacea sp. 3    Arthropoda Tanaid Tanaidacea sp. 4  Arthropoda Tanaid Tanaidacea sp. 5  Arthropoda Tanaid Tanaidacea sp. 6  Arthropoda Copepod Calanoida sp. 1  Arthropoda Copepod Copepoda sp. 1 

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 62

Port Port Phylum Common Name Taxa Glenelg Stanvac Noarlunga Arthropoda Slender-legged Sea flea Paranebalia longipes    Arthropoda Leaf-legged Sea flea Leptostraca sp. 1  Arthropoda Leaf-legged Sea flea Nabalia sp. 1  Arthropoda Crab Halicarcinus rostratus    Arthropoda Crab Halicarcinus ovatus    Arthropoda Crab Litocheira bispinosa  Arthropoda Crab Ebalia intermedia   Arthropoda Crab Stimdromia lateralis  Arthropoda Crab Decopoda sp. 1   Arthropoda Crab Decopoda sp. 2  Arthropoda Crab Decopoda sp. 3  Arthropoda Crab Decopoda sp. 4  Arthropoda Crab Decopoda sp. 5  Arthropoda Crab Zoea (Crab larvae)   Arthropoda Crab Megalopa (Crab larvae)   Arthropoda Hermit crab Paguridae sp. 1  Arthropoda Hermit crab Paguridae sp. 2  Arthropoda Hermit crab Paguridae sp. 3  Arthropoda Hermit crab Paguridae sp. 4  Arthropoda Hermit crab Paguridae sp. 5  Arthropoda Hermit crab Paguridae sp. 6  Arthropoda Hermit crab Paguridae sp. 7  Arthropoda Squat lobster Galathea australiensis  Arthropoda Shrimp Pasiphaeidae sp. 1    Arthropoda Shrimp Caridea sp. 1    Arthropoda Shrimp Caridea sp. 2    Arthropoda Shrimp Caridea sp. 3   Arthropoda Shrimp Caridea sp. 4  Arthropoda Shrimp Caridea sp. 5  Arthropoda Shrimp Caridea juvenile    Arthropoda Mysid Mysidacea sp. 1    Arthropoda Mysid Mysidacea sp. 2    Arthropoda Mysid Mysidacea juvenile    Arthropoda Ostracod Ostracoda sp. 1    Arthropoda Ostracod Ostracoda sp. 2   Arthropoda Ostracod Ostracod sp. 4  Arthropoda Ostracod Ostracod sp. 5    Arthropoda Ostracod Ostracod sp. 6 Arthropoda Ostracod Ostracod sp. 7  Arthropoda Sea spider Pycnogonida sp. 1  Arthropoda Sea spider Pycnogonida sp. 2  Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 63

Port Port Phylum Common Name Taxa Glenelg Stanvac Noarlunga Mollusca Gastropod Electoma georgiana   Mollusca Gastropod Notogibbula lehmanni    Mollusca Gastropod Notogibbula bicarinata  Mollusca Gastropod Ethalia sp.    Mollusca Gastropod Notocochlis sagittate    Mollusca Gastropod Gastropod sp. 1  Mollusca Gastropod Gastropod sp. 2  Mollusca Gastropod Gastropod sp. 3  Mollusca Gastropod Gastropod sp. 5  Mollusca Gastropod Thalotia conica  Mollusca Gastropod Thalotia chlorostoma  Mollusca Gastropod Phasianella ventricosa  Mollusca Gastropod Nassarius mobilis   Mollusca Gastropod Mitrella acuminata    Mollusca Gastropod Anachis atkinsoni  Mollusca Tusk shell Scaphopoda sp. 1    Mollusca Limpet Limpet sp. 1  Mollusca Limpet Limpet sp. 2  Hemitoma Mollusca Keyhole limpet subemarginata  Mollusca Chiton Leptochiton liratus    Mollusca Sea slug Haminoea brevis    Mollusca Sea slug Dendrodoris peculiaris  Mollusca Sea slug Berthellina citrina  Mollusca Sea slug Philine angasi  Mollusca Nudibranch Nudibrancha sp. 1  Mollusca Bivalve Mactra sp.    Mollusca Bivalve Nunculanidae crassa   Mollusca Bivalve Tellinid sp.    Mollusca Bivalve Limaria orientalis    Mollusca Bivalve Musculus nanus    Mollusca Bivalve Modiolus areolatus    Mollusca Bivalve Trichlomusculus barbatus   Mollusca Bivalve Venerupis anomala  Mollusca Bivalve Mussell sp.  Mollusca Bivalve Fulvia tenicostata  Mollusca Bivalve Semele ada  Mollusca Bivalve Bivalve sp. 1  Mollusca Bivalve Myochamidae sp. 1  Mollusca Bivalve Acrosterigma cygnorum 

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 64

Port Port Phylum Common Name Taxa Glenelg Stanvac Noarlunga Mollusca Bivalve Limopsis tenisoni  Bryozoa Bryozoan Hornera ramosa    Bryozoa Bryozoan Reteporella granulata    Bryozoa Bryozoan Iodictym phoeniceum    Bryozoa Bryozoan Plagioecia sarniensis    Bryozoa Bryozoan Tubulipora sp.   Bryozoa Bryozoan Cheilostomata sp. 1  Bryozoa Bryozoan Celleporaria sp.  Bryozoa Bryozoan Bryozoan sp. 1  Bryozoa Bryozoan Bryozoan sp. 2  Bryozoa Bryozoan Bryozoan sp. 3   Bryozoa Bryozoan Bryozoan sp. 4  Bryozoa Bryozoan Bryozoan sp. 5  Bryozoa Bryozoan Tricellaria monotypa   Bryozoa Bryozoan Cheilostomata sp. 2  Enchinodermata Brittle star Amphiura constricta   Enchinodermata Brittle star Ophiothrix caespitosa    Enchinodermata Brittle star Ophiomyxa australis    Enchinodermata Brittle star Ophionereis schayeri   Enchinodermata Brittle star Echinoderm sp. 1  Enchinodermata Brittle star Echinoderm sp. 2   Enchinodermata Brittle star Echinoderm sp. 3   Enchinodermata Brittle star Echinoderm sp. 4  Enchinodermata Sea urchin Amblypneustes ovum    Enchinodermata Sea star Asteroidea sp.  Chordata Sea squirt Pyura sp. 2  Chordata Sea squirt Pyura sp. 1  Chordata Sea squirt Ascidian sp. 1  Chordata Sea squirt Ascidian sp. 2  Chordata Sea squirt Ascidian sp. 3  Chordata Sea squirt Ascidian sp. 4  Hemichordata Hemichordate Hemichordata sp. 1   Porifera Sponge Poriferan sp. 1  Porifera Sponge Leucosolenia sp.   Porifera Sponge Psammolinia sp. 1  Porifera Sponge Tethya sp.  Porifera Sponge Poriferan sp. 2  Porifera Sponge Thorecta sp.  Nemertea Nemertean Nemertea sp. 1    Sipuncula Sipuncula Sipuncula sp.    Echiura Echiran Echiura sp.  Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 65

Port Port Phylum Common Name Taxa Glenelg Stanvac Noarlunga Annelida Annelid Ogliochaeta sp.   Annelida Polychaete Eunicidae sp.   Annelida Polychaete Dorvilleidae sp.   Annelida Polychaete Terebellidae sp.    Annelida Polychaete Polynoidae sp.    Annelida Polychaete Aphroditidae sp.  Annelida Polychaete Paraonidae sp.   Annelida Polychaete Opheliidae sp.    Annelida Polychaete Capitellidae sp.    Annelida Polychaete Spionidae sp.    Annelida Polychaete Syllidae sp.    Annelida Polychaete Phyllodocidae sp.    Annelida Polychaete Nereididae sp.    Annelida Polychaete Nephtyidae sp.   Annelida Polychaete Chrysopetalidae sp.  Annelida Polychaete Trichobranchidae sp.   Annelida Polychaete Cirratulidae sp.  Annelida Polychaete Lumbrineridae sp.   Annelida Polychaete Ampharetidae sp.  Annelida Polychaete Pisionidae sp.  Annelida Polychaete Sigalionidae sp.    Annelida Polychaete Oweniidae sp.   Annelida Polychaete Flabelligardiae sp.   Annelida Polychaete Maldanidae sp.  Annelida Polychaete Pectinariidae sp.  Annelida Polychaete Sabellariidae sp.  Annelida Polychaete Glyceridae sp. 

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 66

Appendix B. Species list of meiofauna organisms found in samples at all sites, showing the different levels of taxonomic classification of each taxa group identified in samples during this study (taxa names included in this study are listed in the final column, ‘Taxa Group’).

Kingdom Phylum Sub-phylum Class Sub-class Order Taxa Group Rhizaria Foraminifera Foraminifera Sarcomastigophora

Animalia Nematoda Nematoda Platyhelminthes Turbellaria Turbellaria

Annelida Polychaeta Polychaeta

Tardigrada Tardigrada

Arthropod Crustacea Maxillopoda Copepoda Copepoda

Ostracoda Ostracoda

Malacostraca Amphipoda Amphipoda

Isopoda Isopoda

Cumacea Cumacea

Tanaidacea Tanaidacea

Chelicerata Arachnida Acari Acari

Hexapoda Hexapoda

Mollusca Bivalvia Bivalvia

Gastropoda Gastropoda

Rotifera Rotifera

Port Stanvac Desalination Plant Benthic Infauna Monitoring Program Winter 2011 67