Ecotoxicological tests were done at Davis and Casey Stations in 2009/10, 2010/11 and 2011/12 summer seasons under AAS Project 3054 to test the sensitivity of near-shore marine invertebrates to fuels in seawater. The three fuel types used in this project were: Special Antarctic Blend diesel (SAB), Marine Gas Oil diesel (MGO) and an intermediate grade (180) of marine bunker fuel oil (IFO). This dataset contains the results of tests with the near-shore amphipod species Paramoera walkeri exposed to WAFs of SAB, MGO and IFO 180 (specified below) conducted at Davis Station in 2009/10 summer (Season 1). Test treatments were obtained by experimentally mixing fuel and seawater in temperature control cabinets at -1°C to prepare a mixture of fuel hydrocarbons in filtered seawater (FSW) termed the water accommodated fraction (WAF). WAF was produced by adding fuel to seawater in 5 L or 10 L Pyrex glass bottles using a ratio of 1:40 fuel : FSW. This mixture was stirred at slow speed with minimal vortex on a magnetic stirrer. The water portion was then drawn from beneath the fuel. Test treatments consisted of undiluted 100% WAF and dilutions of 10% and 1% of WAFs in FSW. Toxicity tests were conducted in open glass vessels in temperature controlled cabinets. Mortality and/or sub-lethal effects were observed at endpoints of 24 h, 48 h, 96 h, 7 d, 14 d, and 21 d. Treatments were renewed at 7 d intervals. Water quality data was collected at each water change. Hydrocarbon concentrations in WAFs were determined from replicate experiments to measure THC in WAFs over time (Dataset AAS_3054_THC_WAF). WAF exposure concentrations for each test endpoint were derived from these hydrocarbon tests to account for depletion of hydrocarbons from test treatments and any renewal of treatments. An integrated concentration was calculated from measured hydrocarbon concentrations weighted to time. These integrated THC concentrations for endpoints from 24h to 21d are contained in dataset AAS_3054_THC_WAF_integrated_conc_09_10 and are the exposure concentrations used for analysis of sensitivity. Species tested; Paramoera walkeri amphipod; adults This dataset consists of Excel spreadsheets. The file name code for invertebrate tests is; Project number_Season_Taxa_Test name Eg AAS_3054_09_10_amphipod_1PWA1 Project number : AAS_3054 Season : 2009/10 season Taxa: amphipod Test name: 1 for Season 1, PW for genus and species, A for adult, 1 for Test 1 Spreadsheets contain the results of tests with this species. Where replicate tests were conducted, each experiment is on a separate spreadsheet. The worksheet labelled 'Test conditions' shows details of Test name, dates, animal collection details, laboratory holding conditions, details of water accommodated fractions (WAF), test conditions, scoring criteria and water quality data. The worksheet labelled 'Counts' has columns for Replicate number and columns with the Score for all the animals in that replicate at every time endpoint. A full description of the scoring criteria is on the 'Test conditions' worksheet. Totals, means and standard deviations are calculated for each treatment. The worksheet labelled 'Totals, means, percent, StDev' has calculations of Survival, Unaffected, including mean and standard deviation, Percent Survival and Unaffected including means and standard deviation. Amphipod tests also show the Total number of moults in each treatment. Samples were collected at the following locations: - Airport Beach, Davis, Vestfold Hills

Metadata record for data from AAS (ASAC) Project 2933. While it is generally thought that Antarctic organisms are highly sensitive to pollution, there is little data to support or disprove this. Such data is essential if realistic environmental guidelines, which take into account unique physical, biological and chemical characteristics of the Antarctic environment, are to be developed. Factors that modify bioavailability, and the effects of common contaminants on a range of Antarctic organisms from micro-algae to macro-invertebrates will be examined. Risk assessment techniques developed will provide the scientific basis for prioritising contaminated site remediation activities in marine environments, and will contribute to the development of guidelines specific to Antarctica. Amphipod and Isopod toxicity tests, Kingston 2007 Filename: Amphipod and Isopod test results.xls Test animals were collected from near shore environments at Casey Station, East Antarctica during Dec 2006 - Jan 2007, and transported to culturing facilities at the Australian Antarctic Division in Tasmania, where tests were conducted during 2007. The test animals were exposed to metals in non-renewable static tests in vials containing 50 mL of the test solution at ambient Antarctic coastal salinity of 34 ppt. Tests were held in temperature controlled cabinets (incubators) at a temperature of 0 degrees C (plus or minus approximately 1 degrees C). Five to eight test animals were introduced into each of 3 replicate vials per treatment at test commencement, and were exposed for 10 to 12 weeks during which periodic observations were made. Test solutions were renewed in weekly water changes. Periodic observations (time since start of test) are given in hr (hours), d (days) or w (weeks). At each observation time, test animals were scored in one of the Endpoint categories described on each worksheet. Each worksheet provides data for a particular test taxa (slater isopods, small red isopods, spider amphipods and Orange Long Antennae Amphipods - taxonomy to be verified) for a given test number (T01, T02) and a given metal contaminant (copper, zinc, cadmium). Test information is provided in the first 14 rows of each worksheet, e.g. Site of collection, Test start date, Endpoint categories etc. ASU = artificial settlement units (plastic scourers used by Sarah Richards, which had been deployed in Newcomb Bay in approximately the year 2000). Conc micrograms/L are nominal concentrations. Measured concentrations are provided in the worksheet: /Amph and Isop T01-02 CHEMISTRY SUMM Test temperature was 0 degrees C unless otherwise stated. Unit for all temperature data is degrees C. The file contains the following worksheets: Worksheet: /Amph and Isop T01-02 CHEMISTRY SUMM Chemistry data as provided also in Kingston 07 Chemistry_Amph and Iso.xls described below. Worksheet: /Slater isopods T01 Cu Test taxa: Slater isopod; Test ID: T01, Kingston 2007; Metal contaminant: copper Worksheet: /Slater isopods T01 Zn Test taxa: Slater isopod; Test ID: T01, Kingston 2007; Metal contaminant: zinc Worksheet: /Slater isopods T01 Cd Test taxa: Slater isopod; Test ID: T01, Kingston 2007; Metal contaminant: cadmium Worksheet: /Small red isopods T02 Cu Test taxa: Small red isopods; Test ID: T02, Kingston 2007; Metal contaminant: copper Worksheet: /Small red isopods T02 Zn Test taxa: Small red isopods; Test ID: T02, Kingston 2007; Metal contaminant: zinc Worksheet: /Spider Amphipods T01 Cu Test taxa: Spider Amphipods; Test ID: T01, Kingston 2007; Metal contaminant: copper Worksheet: /Orange LongAnt Amph T01 Cu Test taxa: Orange Long Antenae Amphipods; Test ID: T01, Kingston 2007; Metal contaminant: copper Filename:Kingston 07 Chemistry_Amph and Iso.xls Metal concentrations in test solutions were analysed using an ICP-AES, by Ashley Townsend at the Central Science Laboratory, University of Tasmania, Hobart. Worksheet: /Amph and Isop T01-02 Summary Summary of chemistry data for Amphipod and Isopod

Metadata record for data from AAS (ASAC) Project 2933. While it is generally thought that Antarctic organisms are highly sensitive to pollution, there is little data to support or disprove this. Such data is essential if realistic environmental guidelines, which take into account unique physical, biological and chemical characteristics of the Antarctic environment, are to be developed. Factors that modify bioavailability, and the effects of common contaminants on a range of Antarctic organisms from micro-algae to macro-invertebrates will be examined. Risk assessment techniques developed will provide the scientific basis for prioritising contaminated site remediation activities in marine environments, and will contribute to the development of guidelines specific to Antarctica. Juvenile Gastropod toxicity tests, Kingston 2007 During 2007 a series of toxicity tests, using Antarctic marine invertebrates, were conducted at Australian Antarctic Division laboratories in Kingston, Tasmania, to test the sensitivity of Antarctic nearshore biota to a range of common metal contaminants. This data record describes two such tests, using juveniles of the microgastropod Skenella paludionoides. The first test (T01) was a 14 day test (start date: 20/08/2007) using juveniles less than 7 days old. The second test (T02) was a 12 week test (start date: 10/09/2007) using juveniles of the same cohort, that were less than 28 days at the commencement of the test. A range of concentrations of three single metals (cadmium, copper and zinc) were applied as test treatments to determine this species sensitivity to these common metal contaminants. T01 included all three metals, T02 used copper and zinc only. Data are provided in the excel file: CaseyKingston0607_Microgastropod.xlsx This file includes descriptive test details, test data and measured metal concentrations of test solutions. Scanned copies of laboratory notebook and test scoresheets are provided in PDF files: - CKing_ Ecotox Kingston 0607.pdf - Kingston07-microgastropod-juv-T01.pdf

This metadata record contains the results from bioassays conducted to show the response of the common Antarctic amphipod, Paramoera walkeri to contamination from combinations of Special Antarctic Blend (SAB) diesel, Marine Gas Oil (MGO) and Intermediate Fuel Oil (IFO 180), chemically dispersed with fuel dispersants Ardrox 6120 and Slickgone NS. Fuel only water accommodated fractions (WAF), chemically enhanced water accommodated fractions (CEWAF) and dispersant only treatments were prepared following the methods in Singer et al. (2000) with adaptations from Barron and Ka’aihue (2003). WAF was made using the ratio of 1: 25 (v/v), fuel to filtered seawater (FSW) following the methods of Brown et al. (in prep). Ratios for chemically dispersed treatments were 1: 100 (v/v), fuel to FSW and 1: 20 (v/v) dispersant to fuel. Dispersant only treatments were made using ratios for CEWAF, substituting the fuel component with FSW. Mixes were made in 5 L or 10 L glass aspirator bottles using a magnetic stirrer to achieve a vortex of 20-25% in the FSW before the addition of test media. The same mixing energy was used to prepare all WAFs for enhanced reproducibility and comparability of results (Barron and Ka’aihue, 2003). Mixes were stirred in darkness to prevent bacterial growth for 42 h with an additional settling time of 6 h at 0 plus or minus 1 oC. Extended stirring times were used following the recommendations determined as part of the hydrocarbon chemistry component of this project (Kotzakoulakis, unpublished data). A dilution series of four concentrations were made from the full strength aqueous phase of each mix using serial dilution. WAF test concentrations were 100%, 50%, 20% and 10% while CEWAF concentrations were 10%, 5%, 1% and 0.1%. These concentrations were chosen in order to quantify the mortality curve and allow statistical calculation of LC50 values. To facilitate comparisons of dispersant toxicity in the presence and absence of fuel, dispersant only test concentrations reflected those of CEWAF treatments. WAF was sealed in airtight glass bottles stored at 0 plus or minus 1 oC for a maximum of 3 h before use. Fresh test solutions were prepared every four days to ensure consistent water quality and replace hydrocarbons that adsorbed or evaporated into the atmosphere. Each test concentration was represented by five replicates with five FSW control beakers, with 10 P. walkeri individuals per replicate. Only healthy and active individuals were chosen with a size range of 7.9 plus or minus 0.7 mm for adults and 2.5 plus or minus 0.2 for juveniles measured from the base of the antennae to the widest part of the dorsal curve. Larger individuals and brooding females were not used to avoid unrelated deaths related to age or reproductive state (Sagar, 1980). Beakers were filled to 200 ml and were left open to allow the natural evaporation of lighter monoaromatic hydrocarbon components that would occur during a real spill. A small square of plankton mesh was placed in each jar to provide a substratum to reduce the stress of laboratory conditions and to help to stem cannibalism. Animals were not fed during experiments to avoid hydrocarbons adsorbed onto food pellets being ingested by the amphipods, thereby introducing an additional exposure pathway. Experiments ran for a total of 12 d exposure duration. Experiments were run in cold temperature-controlled cabinets maintained at a temperature of 0 plus or minus 1 oC, fluorescent lights in the cabinets were set to a light regime of 18 h light, 6 h darkness, following the methods in Brown et al. (2017) to reflect Antarctic summer environmental conditions. Lethal and sublethal observations were made at standard ecotoxicology test times of 24 h, 48 h, 96 h, 7 d, 10 d and 12 d, with an additional observation at 8 d coinciding with one of the 4-day water changes. The health status of each individual was classified on a scale of one to four; one showing no effect up to four being mortality.

Metadata record for data from AAS (ASAC) Project 2933. While it is generally thought that Antarctic organisms are highly sensitive to pollution, there is little data to support or disprove this. Such data is essential if realistic environmental guidelines, which take into account unique physical, biological and chemical characteristics of the Antarctic environment, are to be developed. Factors that modify bioavailability, and the effects of common contaminants on a range of Antarctic organisms from micro-algae to macro-invertebrates will be examined. Risk assessment techniques developed will provide the scientific basis for prioritising contaminated site remediation activities in marine environments, and will contribute to the development of guidelines specific to Antarctica. Brown Ostracod toxicity tests, Kingston 2007 Test animals were collected from near shore environments at Casey Station, East Antarctica during Dec 2006 - Jan 2007, and transported to culturing facilities at the Australian Antarctic Division in Tasmania, where tests were conducted during 2007. The test animals were exposed to metals in non-renewable static tests in vials containing 50 mL of the test solution at ambient Antarctic coastal salinity of 34 ppt. Tests were held in temperature controlled cabinets (incubators) at a temperature of 0, 2 or 4 degrees C (+/- approximately 1 degrees C). Ten test animals were introduced into each of 3 to 5 replicate vials per treatment at test commencement, and were exposed for 10 weeks during which periodic observations were made. Test solutions were renewed in weekly water changes. Periodic observations (time since start of test) are given in hr (hours), d (days) or w (weeks). At each observation time, test animals were scored in one of the Endpoint categories described on each worksheet. Each worksheet provides data for a particular test taxa (Brown Ostracods - taxonomy to be verified) for a given test number (T01, T02, T03, T04, T05,) and a given metal contaminant (copper, zinc, cadmium and lead). Test information is provided in the first 14 rows of each worksheet, e.g. Site of collection, Test start date, Endpoint categories etc. ASU = artificial settlement units (plastic scourers used by Sarah Richards, which had been deployed in Newcomb Bay in approximately the year 2000). Concentration micro grams per litre are nominal concentrations. Measured concentrations are provided in the file: Brown Ostracod_chemistry.xls, as described below. Test temperature was 0 degrees C unless otherwise stated. Unit for all temperature data are degrees C. See the readme file in the download for more information.

Zooplankton grazing experiments using the dilution method have been conducted for 2 months at Davis station and on a weekly basis in order to investigate the relationship between zooplankton grazing rates and DMS production in surface water during the blooming season. Regular water sampling in conjunction with these experiments has been conducted to quantify pigments and phytoplankton populations in the same waters. This work was completed as part of ASAC project 2100 (ASAC_2100). The dataset also includes methods used to obtain the data. The fields in this dataset are: chlorophyll DMS DMSP Pigment Dilution

This metadata record will contain the results of bioassays conducted to characterise the response of Antarctic near-shore marine zooplankton to hydrocarbon contaminants in Special Antarctic Blend (SAB) diesel fuels commonly used in Antarctica. The results from one summer season (2010-11) are in this record. This was conducted under the AAS Project 3054: Ecological risks from oil products used in Antarctica: characterising hydrocarbon behaviour and assessing toxicity on sensitive early life stages of Antarctic marine invertebrates. Exposure solutions of fuel were experimentally mixed by slow stir of fuel and seawater in temperature control cabinets at -1 degree C to prepare a mixture of fuel hydrocarbons in filtered seawater (FSW) termed the Water Accommodated Fraction (WAF). WAF was produced by adding fuel to seawater in 5 L or 10 L Pyrex glass bottles using a ratio of 1:24 Fuel : FSW. This mixture was stirred at slow speed with minimal vortex for 18 h on a magnetic stirrer. The mixture was settled for 6 h before the water portion was drawn from beneath the fuel. Ecotoxicological bioassays were conducted at Davis Stations in the 2010/11 summer season using SAB WAF to prepare experimental treatments consisting of WAF dilution series. For each bioassay, treatments consisted of undiluted 100% WAF and dilutions of 10%, 17%, 25% and 50% of WAFs in FSW, to test the toxicity of water accommodated fractions of these three fuels on Antarctic both the zooplankton community and single copepod species. Bioassays were conducted in open vessels (glass jars or beakers) in temperature controlled cabinets. Mortality was observed at endpoints of 24 hrs, 48 hrs, 96 hrs, 7 days, 8 days, 9 days, 10 days, 11days, 12 days, 14 days, 15 days, and 16 days. New WAF solutions were prepared at the 7 day interval to replenish the experimental treatments. Deionised water was added to test solutions as required to maintain test solution volume and salinity. Water quality data was collected at each water change. Samples of test treatments for chemical analysis of hydrocarbon concentration were taken at each water change. Results of these analyses are not included as delayed progress with HC analyses impacted on quality of samples and these data were not used. This dataset consists of Excel spreadsheets. The file name code for zooplankton bioassays is; Project number_Season_Taxa_Test name Eg AAS_3054_10-11_zooplankton_m1 Project number : AAS_3054 Season : 2010/11 season Taxa: Zooplankton Community Test name: M1 =Multi-species test 1 Bioassay spreadsheets contain the results of bioassays for a species or the zooplankton community. Where replicate tests were conducted, each experiment is on a separate worksheet. The worksheet labelled "Test conditions" shows details of Test name, dates, animal collection details, laboratory holding conditions, details of water accommodated fractions (WAF), and bioassay conditions. The worksheet labelled "Counts" has a table for each of the replicates, arranged into a column for each treatment type. These tables show the number or dead individuals which were found and removed at each of the observation days. The worksheet labelled "Totals" has calculations of total number of individuals (of all species) which were found dead at each observation day in each replicate. It also gives the mean and standard deviation for each of the treatments. Further information on the zooplankton community structure in the 6 samples taken across the summer, based on the community in the toxicity tests and trials, is also included in the spreadsheet "AAS_3054_10-11_zooplankton_CommStructure". Sampling locations were near-shore from Davis Station, Vestfold Hills and from O'Gorman Rocks, southwest of Anchorage Island and northwest of Plough Island.

Metadata record for data expected ASAC Project 11 See the link below for public details on this project. From the abstract of the referenced paper: The Australian Antarctic Division carried out an extensive sampling program for pelagic and benthic fauna in Prydz Bay, Antarctica (Indian Ocean sector) in January to March 1991. A total of 341 cephalopod specimens comprising 256 squids and 85 octopods were captured for study. This preliminary report presents capture records of eight species of squids: Brachioteuthis sp., Kondakovia longimena, Bathyteuthis abyssicola, Mastigoteuthis psychophila, Psychroteuthis glacialis, Alluroteuthis antarcticus, Mesonychoteuthis hamiltoni and Galiteuthis glacialis. The Octopods captured are Megalehedone senei and several species of Pareledone. Psychoteuthis glacialis is reported to congregate on the bottom near the shelf edge at the depth of 400-600 metres. No distinctive pattern in diel vertical movement was found for any of the species captured. Evidence suggests the existence of ontogenetic descent in Galiteuthis glacialis. Cephalopod catches from the extensive sampling program for fishes and zooplankton were studied. For the pelagic fauna, half-hour duration IYGPT hauls were taken at three depths at 63 stations evenly distributed over Prydz Bay area. The three depths fished by the IYGPT at each station were near the surface, near the bottom or 800 m whichever was less, and the midpoint between those two depths. The 63 stations coincided with most of the stations used in the zooplankton sampling program which employed an RMT 1 + 8 net and sampled from 0-200 metres. Additionally 21 benthic samples were taken using bottom trawl, fished for half hour duration on the shelf of Prydz Bay.

Live O. orensanzi were found in the AAD's Marine Research Facility emerging from sediments during feeding on 3 July 2014. It is likely that live specimens were included in samples collected for another species, Antarctonemertes sp. from intertidal rocky areas at Beall Island near Casey station (66 30.4265 degree S, 110 45.851 degrees E), East Antarctica in January and February 2014. It is also possible that the O. orensanzi were collected from southeast Newcomb Bay, adjacent to Casey station on 2 and 3 of February 2012 (Figure 4), and survived in the Marine Research Facility's aquarium, but this is considered less likely. Experiments were conducted at the AAD's quarantine facility in Kingston, Tasmania, between 19 July and 2 September 2014. This metadata record contains the results from bioassays conducted to show the response of Antarctic Polychaetes Ophryotrocha orensanzi to contamination from combinations if IFO 180 fuel and the fuel dispersants Ardrox 6129, Slickgone LTSW and Slickgone NS. Test solutions were prepared following the methods of Singer et al. (2000) with modifications by Barron and Ka'aihue (2003) and others. Water accommodated fractions of fuel in water (WAF) were produced using a 1:25 (v/v) fuel to FSW ratio in accordance with studies by Payne et al. (2014) and Brown et al., (2016) to facilitate comparability of results. Chemically enhanced water accommodated fractions (CEWAF) were made following a lower 1:100 (v/v) fuel to FSW ratio. A 1:20 (v/v) dispersant to fuel ratio was used for all three dispersants, an application rate of 1:20 dispersant to fuel rate was used both because this is the standard default application rate used in the field and to increase comparability to previous studies. Dispersant only mixes were made according to CEWAF specifications, substituting FSW for fuel. Test mixes were prepared in dark temperature-controlled cabinets at 0 plus or minus 1 degree C. Mixes were made in two L or five L glass aspirator bottles using a magnetic stirrer. Mix preparation followed the pre-vortex method in which a 20 - 25 % vortex was achieved in 0 plus or minus 1 degree C FSW before addition of the test materials. Once added, fuel was allowed to cool for a further 10 minutes before subsequent addition of dispersants during CEWAF preparation. Mixes were stirred for a total of 42 h with an additional settling time of 6 h following the recommendations determined as part of the hydrocarbon chemistry component of this project (Kotzakoulakis, unpublished data). The mixture was subsequently serially diluted to achieve the desired concentrations. Test concentrations were 100%, 50%, 20% and 10% for WAF and 10%, 5%, 1% and 0.1% for CEWAF. Concentrations for dispersant only treatments mimicked CEWAF in order to be directly comparable. Test solutions were kept in sealed glass bottles with minimal headspace at 0 plus or minus 1 degree C for a maximum of 3 h before use. Test dilutions were remade each four day period to replenish hydrocarbons lost through evaporation and absorption to simulate a repeated pulse exposure to the contaminant. Ninety percent of the test solution volume was replaced for each beaker during each water change by gently tipping out the solution with minimal disturbance to the test organisms. Replacement solutions were chilled to the correct temperature and replenished immediately to avoid any temperature shock to test animals. Beakers were topped up with deionized water between water changes to maintain water quality and solution volume. Bioassays were conducted in cold temperature cabinets at 0 plus or minus 1 degree C and light regimes were set to 18 h light and 6 h dark to mimic Antarctic conditions used by Brown et al. (2017). Exposure vessels were 100 ml glass beakers containing 80 ml of test solution. Beakers were left open to allow for the evaporation of lighter fuel components. Each experiment consisted of four replicates per treatment concentration, with eight to 10 individuals per

Marine sediment meiofauna community composition and sediment environmental data collected in 2005 and published in Stark, J. S., M. Mohammad, A. McMinn, and J. Ingels. 2020. Diversity, abundance, spatial variation and human impacts in marine meiobenthic nematode and copepod communities at Casey station, East Antarctica. Frontiers in Marine Science 7:480. From the abstract: The composition, spatial structure, diversity and abundance of Antarctic nematode and copepod meiobenthic communities was examined in shallow (5 – 25 m) marine coastal sediments at Casey Station, East Antarctica. The sampling design incorporated spatial scales ranging from 10 meters to kilometres and included testing for human impacts by comparing disturbed (metal and hydrocarbon contaminated sediments adjacent to old waste disposal sites) and control areas. A total of 38 nematode genera and 20 copepod families were recorded with nematodes being dominant, comprising up to 95% of the total abundance. Variation was greatest at the largest scale (km’s) but each location had distinct assemblages. At smaller scales there were different patterns of variation for nematodes and copepods. There were significant differences between communities at control and disturbed locations. Community patterns had strong correlations with concentrations of anthropogenic metals in sediments as well as sediment grain size and total organic content. Given the strong association with environmental patterns, particularly anthropogenic disturbance, meiofauna may be seen as very useful indicators of natural and anthropogenic environmental changes in Antarctica. Methods derived from: Stark, J. S., M. Mohammad, A. McMinn, and J. Ingels. 2020. Diversity, abundance, spatial variation and human impacts in marine meiobenthic nematode and copepod communities at Casey station, East Antarctica. Frontiers in Marine Science 7:480. Sampling design Sampling was undertaken using a hierarchical, nested design with three spatial scales, Locations (separated by kms); within each location there were two sites (~ 100 m apart) and at each site there were two plots (~10m apart). Within each plot (1m diameter), two replicate cores were taken for meiofauna and two for environmental analysis, making a total of 8 meiofauna and 8 environmental cores per location, except at O’Brien Bay-5 where one meiofauna core was lost during sampling. Six locations were sampled around Casey Station. There were three control locations, two of which were within O’Brien Bay to the south of Casey (O’Brien Bay-1 (OB-1) and O’Brien Bay-5 (OB-5)); and one within Newcomb Bay, in McGrady Cove (Fig. 1). There were three locations adjacent to waste disposal sites: two locations were situated along a gradient of pollution within Brown Bay (Inner and Middle)(Stark et al. 2004, Stark 2008); and a third location was at Wilkes, adjacent to the abandoned waste disposal site at the derelict Wilkes station (Stark et al. 2003a), all within Newcomb Bay (Fig. 1). These waste disposal sites were used historically to dispose of all waste and rubbish generated on station and included used oil, building materials, electronics and batteries, food, clothing and chemicals (Snape et al. 2001, Stark et al. 2006). Both waste disposal sites are contaminated with metals and hydrocarbons above background levels (Stark et al. 2008, Stark et al. 2014b, Fryirs et al. 2015). Sample collection, meiofauna preparation and identification Sediment samples were collected by divers using modified 60 ml syringes with their intake end cut off to form a small core tube (28mm internal diameter). Cores were pushed into the sediment to a depth of 10 cm, extracted, and the bottom end was capped. In a few cases samples were only taken down to 5-7 cm, where sediments were less than 10 cm deep due to underlying rock. No sediments less than 5 cm deep were sampled. Cores were transported to Casey Station laboratories where they were emptied into sample jars and 4% formalin was added