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A survey of macrobenthic assemblages in soft-sediments was done at Casey Station, East Antarctica. Samples were taken by divers using hand-held corers (core size - 10 cm diameter by 10 cm deep). The aims were: 1) To examine spatial variation at several scales in these assemblages; 2) To determine if there were differences between potentially impacted areas and control areas; 3) To determine the level of replication, taxonomic resolution and data transformation that are appropriate to studies of human impacts in Antarctic soft-sediment assemblages. Cores were collected by divers in a hierarchical, spatially nested design incorporating 4 scales: Locations (1000s of metres apart), Sites (100s of metres), Plots (10s of metres) and among replicates within plots (~1 metre). Four replicates for infaunal analysis were collected from each plot. Variation at the whole assemblage level was most significant at the largest scale: between Locations; but significant differences were also found between Plots within Sites, and between Sites within Locations. The impacted locations, near two waste tips, a sewage outfall and a wharf, as a group were significantly different to control locations. Impacted locations had less variable assemblages but more variable populations of dominant species than control locations. Control locations had greater richness and diversity than impacted locations. Patterns of assemblage structure were similar at fine (species and family) and medium (family to order) levels of taxonomic resolution but changed at coarse (phylum) levels of resolution. Assemblage patterns were similar between untransformed, square root and fourth root transformations but often different in presence/absence transformations. Concentrations of metals in sediments were also analysed and other environmental variables such as grain size and water depth were measured (two replicates from each plot). Multivariate correlations between the biological and environmental datasets were examined. Links to ASAC 1100. The fields in this dataset are: Location Site/Plot Replicate Antimony Arsenic Cadmium Chromium Copper Iron Lead Manganese Mercury Nickel Silver Tin Zinc Weight Toxicity
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A survey of macrobenthic assemblages in soft-sediments was done at Casey Station, East Antarctica. Samples were taken by divers using hand-held corers (core size - 10 cm diameter by 10 cm deep). This was the final component of a large nested sampling survey extending over a three year periods with samples taken in three summers and one winter period. The aims were: 1) To examine spatial variation at several scales in these assemblages; 2) To determine if there were differences between potentially impacted areas and control areas; 3) To determine the level of replication, taxonomic resolution and data transformation that are appropriate to studies of human impacts in Antarctic soft-sediment assemblages. Cores were collected by divers in a hierarchical, spatially nested design incorporating 4 scales: Locations (1000s of metres apart), Sites (100s of metres), Plots (10s of metres) and among replicates within plots (~1 metre). This data set consists of 48 core samples from three locations, O'Brien Bay, Sparkes Bay and Wilkes. Samples are sorted mainly to species. Links to ASAC 1100. The fields in this dataset are: Location Site/Rep Species
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Increased ultraviolet radiation (UV-A and/or UV-B) may impact on the establishment and structure of a shallow water benthic invertebrate assemblages. A global experiment in more than 8 countries, using an identical methodology (transparent UV filters) will add significantly to our understanding of the impacts of anthropogenically induced global change on natural systems. To appraise the effects of increased UVR on shallow marine benthic assemblages, five experimental rafts were deployed in protected bays west of Shirley Island near Casey Station, Antarctica (66.16oS 110.30oE). Each raft consisted of eight experimental units, each of which contained a colonization panel (ceramic tile) positioned horizontally and submerged 4-6 cm underwater. Irradiation treatments were randomly assigned to each unit with the use of UV cut-off filters. The treatments were as follows: No UVR (transmits photosynthetically active radiation or PAR, 400-700nm), No UVB (transmits PAR + UVA, 320-700nm), Perspex (full spectrum, 280-700nm, procedural control), or No filter (full spectrum, treatment control). In addition there were three levels of consumer treatments: With consumption (container sides removed), without consumption (container sides perforated with 4 mm holes), and a control (3 sides perforated, 1 side removed). After seven weeks tiles were removed to the laboratory for examination. All tiles were dominated by diatoms and no sessile invertebrates were apparent. The first trial has been completed, but several other panels are still in place. A conference will be held in early 2002 between participating countries to discuss results and findings. The 2001\2002 summer season consisted of experimental designs divided up into three separate projects. The aims were all to provide a corrollary to the previous seasons data. Project 1 consisted of the extraction and redeployment of settlement depth arrays situated in Geoffrey's Bay and Hollin Island Channel. Due to prevailing weather conditions resulting in limited boating hours and diving program, only one array was retrieved. On inspection of the array it was decided to deploy further replicates to gain a better temporal understanding of the communities. Projects 2 and 3 consisted of a similar experimental design, however monitoring the shallower depths of settlement (depths of 1m and 2m below sea level) for a period of one month. Project 2 consisted of arrays with two depths and 2 panels per depth, triple replicated, under the icesheet in O'Brien Bay and Shirley Channel, with a substrate depth of 20m. Diatom samples are to be analyzed in Australia. Project 3 was of a similar design to project 2 though it was measuring recruitment in shallow open water. The two sites consisted of Noonan Cove and Geoffrey's Bay at substrate depths of 5m. These tiles are also to be analyzed on return to Australia. There were 5 rafts used in this study - they are listed as R1 to R5 there were two factors in the design -(i) predator access: Caged (C) Half caged (H) and Open (O) and ii) UV exposure: Perspex (P), Macrolon (M), No filter (N) and Film + perspex (F). A list of the diatoms found on the settlement panels is provided at the URL below. The fields in this dataset are: Species Sample
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Marine soft-sediment assemblages were sampled from shallow (5 - 35m) nearshore regions around Casey Station, Windmill Islands, East Antarctica in late summer (Feb-March) 1997, using a van-Veen grab (surface area 20 x 25 cm). Samples were sieved through a 1 mm mesh and sorted to species where possible. A hierarchical, spatially nested sampling design was used with locations (km's apart), sites (100s of metres apart), and plots (10s of m). Two potentially impacted, polluted locations (adjacent to a sewage outfall and an old garbage tip) were compared with two control locations. Data was analysed using both multivariate and univariate statistical methods. Significant differences in assemblages were found between locations and between sites within locations. Significant differences in the abundances of taxa at several taxonomic levels (species, family, order, phylum) were found at all three spatial scales. Significant differences were also detected between the polluted and control locations. Compared with other Antarctic locations, the assemblages were dominated by crustaceans (90 to 97 % of individuals) and there was a paucity of polychaete fauna at the locations sampled. This study represents the first description of benthic assemblages from this region. A total of 70 samples are included in this data set. Also links to ASAC 1100. The fields in this dataset are: Location Site Plot/replicate Weight Volume Species
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The recruitment of epifauna (sessile and mobile) on hard-substratum was examined in a field experiment using tiles. A total of 160 tiles were deployed at five locations, with 32 tiles at each location, arranged in a spatially nested design. There were three potentially impacted locations locations (two in Brown Bay and one in Shannon Bay) and two control locations (in O'Brien Bay). This metadata record describes data from the first sampling time only. Eight tiles were collected from each location 15 months after the initial deployment. The experiment was setup so that recruitment of sessile epifauna to both the upper and lower sides of the tiles could be examined. The mobile epifauna on the tiles were also collected and are described in a separate metadata record. Heavy recruitment was observed on the underside of the tile and only light recruitment was observed on the upper surface. Also links to ASAC 1100.
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Marine soft-sediment assemblages were sampled from shallow (5 - 35m) nearshore regions around Casey Station, Windmill Islands, East Antarctica in winter 1998, using a van-Veen grab (surface area 20 x 25 cm). Samples were sieved through a 1 mm mesh and sorted to species where possible. A hierarchical, spatially nested sampling design was used with locations (km's apart), sites (100s of metres apart). Two potentially impacted, polluted locations (Shannon Bay - adjacent to a sewage outfall; and Brown Bay - adjacent to an old garbage tip) were compared with a control location in O'Brien Bay. Data were analysed using both multivariate and univariate statistical methods. Significant differences in assemblages were found between locations and between sites within locations. Significant differences in the abundances of taxa at several taxonomic levels (species, family, order, phylum) were also found at both spatial scales. Significant differences were also detected between the polluted and control locations. These samples were collected as part of a larger program examining human impacts in marine benthic assemblages at Casey Station. These samples were used in an analysis of temporal changes in soft-sediment assemblages at Casey. A total of 30 grab samples were collected in this survey. The fields in this dataset are: Location Site Date Site/Replicate Species
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A survey of the epibenthic fauna of hard-substrata was made around Casey Station, using a camera mounted on a frame to take photoquadrats. A nested sampling design was used with several spatial scales. At each location there were two sites, approximately 50-100 m apart. At each site there were three by 15 m long transects, approximately 5 m apart. On each transect there were 2 plots, 5 m long by 2 m wide. Six photoquadrats were taken in each plot. This metadata record describes one component of this survey, photoquadrats taken in and around boulders and boulder fields. One of the aims of this survey was to determine if there is any evidence of human impacts in these assemblages. There were several control and several potentially impacted locations. The data have yet to be analysed. Also links to ASAC 1100.
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The effect of location and sediment contamination on recruitment of soft-sediment assemblages were examined in field experiment at Casey Station, East Antarctica. Four locations were used, a polluted bay adjacent to an old disused tip site (Brown Bay), a bay adjacent to the Casey Station sewage outfall, and two undisturbed control locations in O'Brien Bay. At each location two types of defaunated sediment (polluted and control) were placed 12 - 18 m, in experimental trays. Half of the experimental sediments were left in place over the Austral winter, from March - November, and the remaining sediments were collected after a total of one year, in February 1999. There were large differences in recruitment between the two locations and significant differences between the polluted and control sediment. There were not only differences in abundance of taxa and assemblage structure but also in spatial variability and variability of populations of certain taxa, with recruitment to the control locations more variable than polluted locations, and recruitment in the control sediment more variable than the polluted sediment. The majority of fauna recruiting to the experiment were highly motile colonizing species with non-pelagic lecithotrophic larvae, usually brooded and released as dispersing juveniles, such as gammarids, tanaids, isopods and gastropods. A total of 64 recruitment samples were collected after 9 months and 52 samples after one year. Samples were sieved at 500 micro m and sorted mainly to species. Samples are rows in data sheet. Site codes include place name (e.g. BB2) and experimental treatment (e.g. C1 - control 1). See accompanying sheet for full details of codes, including species names. Sediment chemistry data are means (and standard errors) for each treatment (averaged over 2 trays). Also links to ASAC 1100. The fields in this dataset are: Species Site Sample Abundance Toxicity Arsenic Cadmium Copper Lead Silver Zinc
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The effects of hyrdocarbon and heavy metal contamination of marine sediments on recruitment of soft-sediment assemblages were examined in a field experiment at Casey Station, East Antarctica. Three locations were used, a polluted bay adjacent to an old disused tip site (Brown Bay) and two control locations (O'Brien Bay and Sparkes Bay). At each location three types of defaunated sediment (hydrocarbon treated, heavy metal treated and control) were placed at approximately 15 m depth and left in place for 3 months, from December to February. Sediments were artificially contaminated with hydrocarbons and metals at concentrations which were representative of levels found in sediments at contaminated sites around Casey Station. There were large differences in recruitment between the three locations and significant differences between the control and contaminated sediment. Sediments in the experiment were also examined for evidence of degradation and attenuation of hydrocarbons and heavy metals. A total of 104 recruitment samples were collected. Samples were sieved at 500 micro m and sorted mainly to species. Other work to arise from this experiment includes examination of the effects on diatom communities and microbial communities. Data includes fauna, metals and hydrocarbon concentrations in experiment. Pre-deployment concentrations (before experiment was deployed in water) are indicated as 'pre-deployment'. Concentrations of contaminants in sediments surrounding the experiment (within several metres) are indicated as 'surrounding'. This project also links to ASAC 1100. The fields in this dataset are: Location Site Treatment (tmt) Site and replicate Species Toxicity Arsenic Cadmium Copper Lead Silver Zinc Special Antarctic Blend Fuel (SAB) Lube TPH
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A survey of the epibenthic fauna of hard-substrata was made around Casey Station, using a camera mounted on a frame to take photoquadrats. A nested sampling design was used with several spatial scales. At each location there were two sites, approximately 50-100 m apart. At each site there were three by 15 m long transects, approximately 5 m apart. On each transect there were 2 plots, 5 m long by 2 m wide. Six photoquadrats were taken in each plot. This metadata record describes one component of this survey, photoquadrats taken in flat or gently sloping rocky areas, where the bottom consisted of flat bedrock, gravel or cobbles. A separate survey was done in and around boulders and boulder fields. One of the aims of this survey was to determine if there is any evidence of human impacts in these assemblages. There were several control and several potentially impacted locations. The data have yet to be analysed. Also links to ASAC 1100.