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EARTH SCIENCE > BIOLOGICAL CLASSIFICATION > ANIMALS/INVERTEBRATES > ARTHROPODS > CRUSTACEANS > COPEPODS

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  • Zooplankton were collected with a Rectangular Midwater Trawl (RMT 8+1 net) from 37 sampling sites on and near the Southern Kerguelen Plateau. The contents of each net were preserved in 5% buffered formaldehyde. This dataset covers the counts of the contents of the RMT1 net. The contents were split in the laboratory using a Motoda Box and then identified and counted under a Leica M165C stereo-microscope. A flow meter attached to the mouth of the RMT 8 was used to record the volume of seawater passing through the net, and this volume was converted to water passing through the RMT 1 by applying the conversion factor of 2.027357. The organisms in the samples were identified to the lowest taxonomic level possible. For copepods and euphausiids this level was to species, and generally to sex and/or development stage. For other groups, the identifications were to high levels such as Family or Order.

  • Zooplankton were collected during the winter-spring transition during two cruises of the Aurora Australis: SIPEX in 2007 and SIPEX II in 2012. To determine size and biomass, key species were measured. Measurements of Prosome, Urosome and Total length are provided. The zooplankton were taken from samples collected with umbrella nets, RMT1 net and sea ice cores. They were measured under a Leica M165C steromicroscope using an ocular micrometer. The ocular micrometer was calibrated against a stage micrometer (+/- 0.01 um).

  • This data record has been compiled for a statistical methods study, conducted by Abigael Proctor as part of her PhD research in 2018. The data in this record have been used to showcase a new statistical method for determining no effect concentration (NEC). The study uses the data in this record to compare NEC and LCx estimates for copper in four Antarctic marine invertebrate species. The data associated with this record are a subset of four existing larger datasets: 1. amphipod: AAS_2933_Orchomenella_pinguides_Sensitivity_metals_Davis_2010-11 2. copepod: AAS_4100_Toxicity_Copepods 3. gastropod: AAS_2933_MetaToxicityMarine_JuvenileGastropods_Kingston2007 4. ostracod: AAS_2933_MetalToxicityMarine_BrownOstracods_Kingston2007 Subset details are described in the excel file provided.

  • Zooplankton were collected during the winter-spring transition during two cruises of the Aurora Australis: SIPEX in 2007 and SIPEX II in 2012. As part of the collections sea ice cores were collected to describe the ice habitat during the period of zooplankton collections. Ice cores were taken with a 20 cm diameter SIPRE corer and sectioned in the field with an ice core. Temperature was measured in the section using a spike thermometer and slivers of each section were melted without filtered water to record salinity. The remainders of each section were melted at 4oC in filtered seawater and the melted water was used to measure chlorophyll a concentration, and meiofauna species and abundance. Meiofauna were counted and identified using a Leica M12 microscope: to species in most cases and down to stage during 2012.

  • We investigated the toxicity of copper, zinc and cadmium to the following taxa: copepods Tigriopus angulatus (Lang) and Harpacticus sp. (Order Harpacticoida, Family Harpacticidae); flatworm Obrimoposthia ohlini (Bergendal) (Order Seriata, Family Procerodidae); bivalve Gaimardia trapesina (Lamarck) (Order Veneroida, Family Gaimardiidae); sea cucumber Pseudopsolus macquariensis (Dendy) (Order Dendrochirotida, Family Cucumriidae); sea star Anasterias directa (Koeler) (Order Forcipulatida, Family Asteriidae). Sites chosen for the collection of invertebrates for this study were free of obvious signs of metal contamination, as verified by the analysis of seawater samples from collection sites by inductively coupled plasma optical emission spectrometry (ICP-OES). Six invertebrate species were selected for toxicity tests to represent a range of taxa and ecological niches. Individuals of the copepod Tigriopus angulatus were collected using fine mesh dip nets from rock pools high on the intertidal zone. Individuals of the flatworm Obrimoposthia ohlini were collected from the undersides of boulders, high in the intertidal zone. The copepod Harpacticus sp. and bivalve Gaimardia trapesina were collected from several macroalgae species at high energy locations in the intertidal zone. Individuals of the sea cucumber Pseudopsolus macquariensis were collected from rocks from high energy locations from the intertidal to subtidal zones. Juveniles of the sea star Anasterias directa were collected from rocks in deep pools, low in the intertidal zone. All experimental tests using O. ohlini, T. angulatus, P. macquariensis and A. directa were conducted at the AAD Kingston laboratories, while some tests with Harpacticus sp. and all tests with G. trapesina were conducted in the laboratory facilities on Macquarie Island. Adult life-stages were tested for all species except for P. macquairensis and A. directa in which juvenile stages were tested. Psedopsolus macquariensis released eggs in the aquarium which developed into juveniles prior to being used in tests, and juvenile A. directa were collected from the field. Each test involved exposure to copper, zinc or cadmium solution under a static non-renewal test regime over 14 days. Five metal concentrations plus a control were used for each test, with 3-5 replicates of each concentration. Where possible, tests were replicated. Concentrations used in replicate tests sometimes varied, as species sensitivity information accrued in tests was used to optimise subsequent tests. Metal test solutions in seawater were prepared 24 hours prior to the addition of animals, using 500 micrograms/L CuSO4, 500 micrograms/L ZnCl2 and 500 micrograms/L Cd SO4 MilliQ stock solutions. Seawater was filtered to 0.45 microns and water quality parameters were measured using a TPS 90-FL multimeter at the start and end of tests. Dissolved oxygen (DO) was greater than 80% saturation, salinity 35 ppt plus or minus 0.5, and pH was ~8.1-8.3 at the start of tests. All experimental vials and glassware were acid washed with 10% nitric acid and rinsed with MilliQ three times before use. Metal concentrations were determined using ICP-OES; samples of test solutions were taken at the start (day 0) and end of tests (day 14), filtered through a 0.45 microns syringe filter and acidified with 1% ultra-pure nitric acid. Measured concentrations at the start of tests were within 96% of nominal concentrations. In order to estimate exposure concentrations, the measured concentrations at days 0 and 14 were averaged. Tests were conducted in lidded plastic vials of varying sizes, depending on the size and number of individuals in the test. For both copepod species, there were 10 individuals per 50 mL in 70 mL vials; for P. macquariensis there were 8 individuals per 50 mL in 70 mL vials; and for O. ohlini, A. directa and G. trapesina, 10 individuals per 100 mL in 120 mL vials. Tests were conducted under a light-dark regime (at 2360 lux) of 18:6h light:dark in summer, 12:12 for tests for the rest of the year. Tests were kept in controlled temperature cabinets set at 6 degrees C, and temperatures within cabinets were monitored throughout the test using data loggers. Vials were checked daily and survival recorded on days 1, 2, 4, 7, 10 and 14. Individuals were considered dead, and removed from test vials, when for G. trapesina adductor muscles no longer closed shell; O. ohlini were inactive and covered in mucous; P. macquariensis and A. directa tube feet were no longer moving; T. angulatus and Harpacticus sp. urosomes were perpendicular to prosomes. Data are provided in a series of excel workbooks; one workbook per test species.

  • This metadata record contains the results of two bioassays testing the response of Antarctic marine copepods to both individual and combined metals via 14 day toxicity tests. The tests were conducted during the 2012-2013 season at Davis Station, East Antarctica. Three metals (cadmium, copper and zinc) were tested singularly and in metal mixture combinations. The concentrations used in the two tests are outlined in the excel spreadsheet (AAS4100_12-13_MixedMetalTox.xlsx). Tests were carried out in 70 mL plastic vials (exposure vials) that contained 50 mL of test solutions. Test solutions were prepared by mixing stock solutions with filtered (0.45 microns) sea water and were stored in a constant temperature cabinet at 0 plus or minus 1 degree C for at least 2 hours prior to the start of tests in order to get to the required test temperature. Each treatment included four replicates and each test included eight controls. Within each replicate vial, 9-12 copepods were carefully added. No additional air, food or water was provided over the test period. At five days a water change was completed by removing the old test solution and replacing it with freshly prepared test solution at the same concentration. The tests were carried out in a constant temperature cabinet set at 0 plus or minus 1 degree C on a 16:8 light:dark photoperiod over 14 days. The number of surviving copepods were counted in each test container, at the same time each day, for 10 days and then a final count was completed on day 14. Mortality was determined by observing the copepods over 20 seconds and if there was no movement they were considered dead. Test solutions were sampled four times during the tests for measurement of metal concentrations. Samples were collected at day 0, day 5 pre-water change, day 5 post-water change and at day 10. Concentrations of the three test metals were determined in theses samples using Inductively-Coupled Plasma Optical Emission Spectrometer (ICP-OES) with appropriate matrix matched standards and blanks to ensure quality control. For all analyses, measured metal concentrations (as opposed to nominal concentrations) were used. Point estimates, including LC10 and LC50 values, were determined using the maximum likelihood-probit method using the software ToxCalc (version 5.0.26 Tidepool Scientific Software). Point estimates were calculated at 4, 7, 10 and 14 days of exposure. Whenever the assumptions for the maximum likelihood-probit method were not met then the Trimmed Spearman-Karber Analysis was used. Data are provided in an Excel workbook (filename: AAS4100_12-13_MixedMetalTox.xlsx). The first worksheet ("/Test Conditions") provides descriptive details for the tests and a key to abbreviations and units. Each worksheet includes a "This worksheet provides..." statement to assist interpretation of the data. A second data file is provided (filename: AAS4100_12-13_ToxCalc.xlsx) containing relevant test data from AAS4100_12-13_MixedMetalTox.xlsx, for input to ToxCalc software for analysis. This file also contains subsequent ToxCalc outputs, with key data (LC10 and LC50 values) provided in a summary worksheet. Other support files provided are seven images of the test species (images by Frances Alexander) and two figures showing copepod response to test solutions (% survival) over the exposure period of the two tests. Copepod samples were collected from the nearshore environment of Prydz Bay, offshore from Davis Station, on two days: 20 December 2012 and 9 January 2013. The 20 December collection was composed of Tisbe sp., collected from benthic habitats and the 9 January collection was composed of Paralabidocera Antarctica, collected from surface waters. Two 14-day laboratory-based toxicity tests were conducted in the Davis laboratories. The test dates were: 2 - 16 January 2013 (test 01; using Tisbe sp., collected 20 December 2012) and 10 - 24 January 2013 (test 02; using P. Antarctica, collected 9 January 2013).

  • Zooplankton were collected during the winter-spring transition with an RMT8+1 net during the SIPEX voyage in 2007. Only the RMT1 data are presented here. The net was deployed on an oblique tow from the surface to 200 m. The catch in each cod-end was preserved in 5% borax-buffered formaldehyde. The samples were subsplit in the laboratory with a Folsom splitter if needed and examined under a Leica M12. Species were examined to the lowest taxon possible - to species for copepods and euphausiids and to higher levels for other taxa.

  • Study location and test species Subantarctic Macquarie Island lies in the Southern Ocean, just north of the Antarctic Convergence at 54 degrees 30' S, 158 degrees 57' E. Its climate is driven by oceanic processes, resulting in highly stable daily and inter-seasonal air and sea temperatures (Pendlebury and Barnes-Keoghan, 2007). Temperatures in intertidal rock pools (0.5 to 2 m deep) were logged with Thermochron ibuttons over two consecutive summers and averaged 6.5 (plus or minus 0.5) degrees C. The island is relatively pristine and in many areas there has been no past exposure to contamination. To confirm sites used for invertebrate collections were free from metal contamination, seawater samples were taken and analysed by inductively coupled plasma optical emission spectrometry (ICP-OES; Varian 720-ES; S1) The four invertebrate species used in this study were drawn from a range of taxa and ecological niches (Figure 1). The isopod Limnoria stephenseni was collected from floating fronds of the kelp Macrosystis pyrifera, which occurs several hundred meters offshore. The copepod Harpacticus sp. and bivalve Gaimardia trapesina were collected from algal species in the high energy shallow, subtidal zone. Finally, the flatworm Obrimoposthia ohlini was collected from the undersides of boulders throughout the intertidal zone. We hypothesised L. stephenseni would be particularly sensitive to changes in salinity and temperature due to its distribution in the deeper and relatively stable subtidal areas, while O. ohlini would be less sensitive due to its distribution high in the intertidal zone and exposure to naturally variable conditions. We reasoned that the remaining two species, G. trapesina, and Harpacticus sp. were intermediate in the conditions to which they are naturally exposed and hence would likely be intermediate in their response. Test procedure The combined effect of salinity, temperature and copper on biota was determined using a multi-factorial design. A range of copper concentrations were tested with each combination of temperatures and salinities, so that there were up to 9 copper toxicity tests simultaneously conducted per species (Table 1). Experiments on L. stephenseni and Harpacticus sp. were done on Macquarie Island within 2 to 3 days of collection, during which they were acclimated to laboratory conditions. While, G. trapesina and O. ohlini were transported by ship to Australia in a recirculating aquarium system and maintained in a recirculating aquarium at the Australian Antarctic Division in Hobart, both at 6 degreesC. These two taxa were used in experiments within 3 months of their collection. A limited number of G. trapesina and O. ohlini were available, resulting in fewer combinations of stressors tested. Controls for the temperature and salinity treatments were set at ambient levels of 35 plus or minus 0.1 ppt and 5.5 to 6 degreesC for all species. The lowered control temperature for the bivalve reflected the cooler seasonal temperatures at time of testing and lower position within the intertidal. Previous tests conducted under these ambient conditions provided information on the ranges of relevant copper concentrations, appropriate test durations, and water change regimes for each taxon (Holan et al., 2017, Holan et al., 2016b). From these previous studies, we determined that a test duration of 14 d was sometimes required with 7 d often being the best outcome for most species due to high control survival and sufficient response across concentrations. The bivalve G. trapesina was an exception to this due to unfavourable water quality after 3 days in previous work (Holan et al., 2016). For the other three species, this longer duration for acute tests, compared to tests with tropical and temperature species (24 to 96 h) was consistent with previous Antarctic studies that have required longer durations in order to elicit an acute response in biota (King and Riddle, 2001, Marcus Zamora et al., 2015, Sfiligoj et al., 2015). Experimental variables (volume of water, density of test organisms, copper concentrations, temperatures and salinities) differed for each experiment due to differences between each species (Table 1). The temperature increases that were tested (2 to 4 degreesC) reflected the increased sea and air temperatures predicted for the region tested by 2100 (Collins et al., 2013). Treatments were prepared 24 h prior to the addition of animals. Seawater was filtered to 0.45 microns and water quality was measured using a TPS 90-FL multimeter at the start and end of tests. Dissolved oxygen was greater than 80% saturation and pH was 8.1 to 8.3 at the start of tests. All experimental vials and glassware were washed with 10% nitric acid and rinsed with MilliQ water three times before use. Salinity of test solutions was prepared by dilution through the addition of MilliQ water. Copper treatments using the filtered seawater at altered salinities were prepared using 500mg/L CuSO4 (Analytical grade, Univar) in MilliQ water stock solution. Samples of test solutions for metal analysis by ICP-OES were taken at the start and end of tests (on days 0 and 14). Details of ICP-OES procedures are described in the Supplemental material (S4). Samples were taken using a 0.45 µm syringe filter that had been acid and Milli-Q rinsed. Samples were then acidified with 1% diluted ultra-pure nitric acid (65% Merck Suprapur). Measured concentrations at the start of tests were within 96% of nominal concentrations. In order to determine approximate exposure concentrations for each treatment, we averaged the 0 d and 14 d measured concentrations (Table 1). Tests were conducted in temperature controlled cabinets at a light intensity of 2360 lux. At the Macquarie Island station a light-dark regime of 16:8 h was used to mimic summer conditions. In the laboratories in Kingston, Australia, a 12:12 h regime was used to simulate Autum light conditions (as appropriate for the time of testing). Test individuals were slowly acclimated to treatment temperatures over 1 to 2 h before being added to treatments. Temperatures were monitored using Thermochron ibutton data loggers within the cabinets for the duration of the tests. Determination of mortality of individuals differed for each taxon. Mortality was recorded for Gaimardia trapesina when shells were open due to dysfunctional adductor muscles; for Obrimoposthia ohlini when individuals were inactive and covered in mucous; for Limnoria stephenseni when individuals were inactive after gentle stimulation with a stream of water from a pipette; and for Harpacticus sp. when urosomes were perpendicular to prosomes (as used in other studies with copepods; see Kwok and Leung, 2005). All dead individuals were removed from test vials.

  • High-throughput DNA-sequencing data for mesopelagic fish stomach contents sampled during the Kerguelen Axis voyage (January-Februay 2016). Mesopelagic fish form an important link between zooplankton and higher trophic levels in Southern Ocean food webs, however their diets are poorly known. Most of the dietary information available comes from morphological analysis of stomach contents and to a lesser extent fatty acid and stable isotopes. DNA sequencing could substantially improve our knowledge of mesopelagic fish diets, but has not previously been applied. We used high-throughput DNA sequencing (HTS) of the 18S ribosomal DNA and mitochondrial cytochrome oxidase I (COI) to characterise stomach contents of four myctophid and one bathylagid species collected at the southern extension of the Kerguelen Plateau (southern Kerguelen Axis), one of the most productive regions in the Indian sector of the Southern Ocean. Diets of the four myctophid species were dominated by amphipods, euphausiids and copepods, whereas radiolarians and siphonophores contributed a much greater proportion of HTS reads for Bathylagus sp. Analysis of mitochondrial COI showed that all species preyed on Thysanoessa macrura, but Euphausia superba was only detected in the stomach contents of myctophids. Size-based shifts in diet were apparent, with larger individuals of both bathylagid and myctophid species more likely to consume euphausiids, but we found little evidence for regional differences in diet composition for each species over the survey area. The presence of DNA from coelenterates and other gelatinous prey in the stomach contents of all five species suggests the importance of these taxa in the diet of Southern Ocean mesopelagics has been underestimated to date. Our study demonstrates the use of DNA-based diet assessment to determine the role of mesopelagic fish and their trophic position in the Southern Ocean and inform the development of ecosystem models. For more detail, see Clarke LJ, Trebilco R, Walters A, Polanowski AM, Deagle BE (2018). DNA-based diet analysis of mesopelagic fish from the southern Kerguelen Axis. Deep Sea Research Part II: Topical Studies in Oceanography. DOI: 10.1016/j.dsr2.2018.09.001.

  • 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 to each sample. Prior to processing, each sample was washed through a 500 μm sieve to remove the macrofauna and the coarser sediment fraction. A 32 μm sieve was used to retain the meiofauna size fraction. Meiofauna were extracted through a modified gravity gradient centrifugation technique (Heip et al. 1985, Pfannkuche et al. 1988) using a % solution of Ludox HS40 and Ludox AS in distilled water (Witthoft-Muhlmann et al. 2005). Ludox is a silicasol (a colloidal solution of Si02) which causes no plasmolysis. Samples were rinsed thoroughly over a sieve of 32 µm with tap water to prevent flocculation of Ludox. The samples were then transferred from the sieve to a large centrifuge tube. Ludox was diluted with water to specific gravity 1.18 g/ml (60% Ludox and 40% water; density = 1.18) and added to each tube until the level of the mixture was balanced for centrifuging. The sample was then centrifuged at 2800 rpm for 10 min. The supernatant was decanted and collected, and the remaining sediment pellet was resuspended. This process was repeated three times. All supernatants were filtered on a 32 µm sieve, which was rinsed with tap water to avoid a reaction between the Ludox and formalin. After the extraction, 4% formalin and 1% of Rose Bengal (to facilitate counting) was added to preserve meiofauna before identification. Nematodes and copepods retained on the 32 µm sieve were counted and sorted using a dissecting microscope at 25X magnification (Zeiss Stemi 2000; Zeiss Inc., Germany). Two hundred nematodes per sample were picked out at random and mounted on slides in glycerine after a slow evaporation procedure (modified after Riemann, 1988) and identified to genus level using Platt and Warwick (1983, 1988) and Warwick et al. (1998) and NeMys online identification (Steyaert et al. 2005). All copepods were picked out and mounted on slides in glycerine without evaporation for identification to family level using THAO: the Taxonomische Harpacticoida Archiv Oldenburg 2005 and Bodin (1997). The identification of nematodes and copepods was conducted on a compound microscope (1000 x magnification). Environmental variables Sediment samples were taken for analysis of grain size, metals and total organic matter (TOM) using a 5 cm diameter core pushed 10 cm into the sediment. Cores were frozen at -20°C until analysis. Each core was subsampled from the top 5 cm of the frozen core, which was then homogenized by stirring and then subsampled further for separate analysis of grain size, metals and TOM. Full details of analytical methods can be found in Stark et al. (2014a) and are briefly summarised below. Total organic matter was calculated by mass-loss on ignition at 550 ° for four hours to determine ash free dry weight following Heiri et al. (2001), on a on a 2 g homogenised wet sub-sample, from 2 replicate cores in each plot for a total of 4 cores per location. Grain size analysis: The outer 5 mm edge of the top 5 cm of the core was removed with a scalpel blade and dried at 45 °C, then sieved through a 2mm sieve. The less than 2 mm fraction and the greater than 2 mm fraction were weighed separately. A 5 g sample of the less than 2mm fraction was analysed using a Mastersizer 2000 Particle Size Analyser with Hydro 2000MU accessory at the Department of Physical Geography, Macquarie University, Sydney. Analysis of metals in sediments were done on a 3 g sub-sample of homogenised wet sediment. A 1:10 w/v 1 M HCl digest was used as recommended by (Scouller et al. 2006), which gives an estimate of bioavailable elements and those more likely to have an anthropogenic source. Samples were analysed by ICP-MS at the Central Science Laboratories (CSL), University of Tasmania for a suite of ions which included: Sr, Mo, Ag, Cd, Sn, Sb, Pb, Mg, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Al, Ba.