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BENTHIC

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  • Ten sediment cores were collected from 3 marine bays in the Windmill Islands. Two cores were collected in Sparkes Bay, one in Shannon Bay, and seven in Brown Bay. Only diatom data are presented here, however Pb210 and metal analyses have also been undertaken - contact Ian Snape (ian.snape@aad.gov.au) for more information regarding this. The diatom spreadsheet (diatom_data) lists the relative abundance of benthic species. The abbreviation used to identify species are explained in the separate file called sp_list. Each core has been saved as a separate file. The STE cores were collected from within a couple of meters of each other. These cores were collected in close proximity to a tip site at one end of Brown Bay. BBMid was collected from the middle of the bay, while BB Outer 1 and 2 were collected from the outer regions of this bay, and thus represent the greatest distance from the tip site. Unless otherwise stated, the lowest number within each core represents the youngest sample. This work was completed as part of ASAC project 1130 (ASAC_1130) and project 2201 (ASAC_2201). Public summary from project 1130: Algal mats grow on sea floor in most shallow marine environments. They are thought to contribute more than half of the total primary production in many of these areas, making them a critical food source for invertebrates and some fish. We will establish how important they are in Antarctic marine environments and determine the effects of local sewerage and tip site pollution. We will also investigate the impact on the algal mats of the additional UV radiation which results from the ozone hole. Public summary from project 2201: As a signatory to the Protocol on Environmental Protection to the Antarctic Treaty Australia is committed to comprehensive protection of the Antarctic environment. This protocol requires that activities in the Antarctic shall be planned and conducted on the basis of information sufficient to make prior assessments of, and informed judgements about, their possible impacts on the Antarctic environment. Most of our activities in the Antarctic occur along the narrow fringe of ice-free rock adjacent to the sea and many of our activities have the potential to cause environmental harm to marine life. The Antarctic seas support the most complex and biologically diverse plant and animal communities of the region. However, very little is known about them and there is certainly not sufficient known to make informed judgements about possible environmental impacts. The animals and plants of the sea-bed are widely accepted as being the most appropriate part of the marine ecosystem for indicating disturbance caused by local sources. Attached sea-bed organisms have a fixed spatial relationship with a given place so they must either endure conditions or die. Once lost from a site recolonisation takes some time, as a consequence the structure of sea-bed communities reflect not only present conditions but they can also integrate conditions in the past. In contrast, fish and planktonic organisms can move freely so their site of capture does not indicate a long residence time at that location. Because sea-bed communities are particularly diverse they contain species with widely differing life strategies, as a result different species can have very different levels of tolerance to stress; this leads to a range of subtle changes in community structure as a response to gradually increasing disturbance, rather than an all or nothing response. This project will examine sea-bed communities near our stations to determine how seriously they are affected by human activities. This information will be used to set priorities for improving operational procedures to reduce the risk of further environmental damage. The fields in this dataset are: Species Site Abundance Benthic

  • A hierarchical, 3-level, nested design was used. The highest hierarchical level consisted of six locations. Two of these locations, Brown Bay and Shannon Bay, have been contaminated with heavy metals (Stark et al., 2003; Snape et al., 2001); Brown Bay has also been contaminated with petroleum hydrocarbons (Snape et al., 2001). The remaining four locations are more distant from Casey Station and were used as control locations. These locations were Denison Island, Odbert Island, O'Brien Bay and Sparkes Bay. A full description of these sites is given below. Within each location two sites were selected approximately 100 m apart. Within each site, two plots were sampled (~ 10 m apart). Although the sampling program had been designed for four replicates within each plot, the patchy distribution of bottom sediments in the Windmill Islands restricted this to two replicate samples (~ 1 m apart) per plot. Samples were collected using an Eckman grab sampler, deployed from a boat. To minimise the potential influence of water depth, all samples were collected from 8 m water depth. Samples were collected within a three day period in early February when no sea-ice was present. Diatom data are presented as the relative abundances of benthic species. Samples are identified xyz where x = first initial of sample location (or first 2 initials where 2 locations start with the same letter), y = plot number (plots 1 and 2 represent site 1, while plots 3 and 4 are from site 2), and z = replicate number (a or b). Abbreviations used for species are shown in the separate file sp_list. This work was completed as part of ASAC project 1130 (ASAC_1130) and project 2201 (ASAC_2201). Public summary from project 1130: Algal mats grow on sea floor in most shallow marine environments. They are thought to contribute more than half of the total primary production in many of these areas, making them a critical food source for invertebrates and some fish. We will establish how important they are in Antarctic marine environments and determine the effects of local sewerage and tip site pollution. We will also investigate the impact on the algal mats of the additional UV radiation which results from the ozone hole. Public summary from project 2201: As a signatory to the Protocol on Environmental Protection to the Antarctic Treaty Australia is committed to comprehensive protection of the Antarctic environment. This protocol requires that activities in the Antarctic shall be planned and conducted on the basis of information sufficient to make prior assessments of, and informed judgements about, their possible impacts on the Antarctic environment. Most of our activities in the Antarctic occur along the narrow fringe of ice-free rock adjacent to the sea and many of our activities have the potential to cause environmental harm to marine life. The Antarctic seas support the most complex and biologically diverse plant and animal communities of the region. However, very little is known about them and there is certainly not sufficient known to make informed judgements about possible environmental impacts The animals and plants of the sea-bed are widely accepted as being the most appropriate part of the marine ecosystem for indicating disturbance caused by local sources. Attached sea-bed organisms have a fixed spatial relationship with a given place so they must either endure conditions or die. Once lost from a site recolonisation takes some time, as a consequence the structure of sea-bed communities reflect not only present conditions but they can also integrate conditions in the past. In contrast, fish and planktonic organisms can move freely so their site of capture does not indicate a long residence time at that location. Because sea-bed communities are particularly diverse they contain species with widely differing life strategies, as a result different species can have very different levels of tolerance to stress; this leads to a range of subtle changes in community structure as a response to gradually increasing disturbance, rather than an all or nothing response. This project will examine sea-bed communities near our stations to determine how seriously they are affected by human activities. This information will be used to set priorities for improving operational procedures to reduce the risk of further environmental damage. The fields in this dataset are: Species Site Abundance Benthic

  • Sediment samples were collected with an Eckamn grab from four locations within the Windmill Islands (Herring Island, O'Connor Island, Shannon Bay and Brown Bay). A weekly sampling program was performed over a 10 week period, however not all locations could be accessed each time due to sea-ice conditions. All samples were collected at an 8 m water depth. Preliminary analysis of fortnightly samples are presented here. Diatom data are given as relative abundances of benthic diatom species. The abbreviations used to identify species are explained in the accompanying file sp_list. This work was completed as part of ASAC project 1130 (ASAC_1130) and project 2201 (ASAC_2201). Public summary from project 1130: Algal mats grow on sea floor in most shallow marine environments. They are thought to contribute more than half of the total primary production in many of these areas, making them a critical food source for invertebrates and some fish. We will establish how important they are in Antarctic marine environments and determine the effects of local sewerage and tip site pollution. We will also investigate the impact on the algal mats of the additional UV radiation which results from the ozone hole. Public summary from project 2201: As a signatory to the Protocol on Environmental Protection to the Antarctic Treaty Australia is committed to comprehensive protection of the Antarctic environment. This protocol requires that activities in the Antarctic shall be planned and conducted on the basis of information sufficient to make prior assessments of, and informed judgements about, their possible impacts on the Antarctic environment. Most of our activities in the Antarctic occur along the narrow fringe of ice-free rock adjacent to the sea and many of our activities have the potential to cause environmental harm to marine life. The Antarctic seas support the most complex and biologically diverse plant and animal communities of the region. However, very little is known about them and there is certainly not sufficient known to make informed judgements about possible environmental impacts. The animals and plants of the sea-bed are widely accepted as being the most appropriate part of the marine ecosystem for indicating disturbance caused by local sources. Attached sea-bed organisms have a fixed spatial relationship with a given place so they must either endure conditions or die. Once lost from a site recolonisation takes some time, as a consequence the structure of sea-bed communities reflect not only present conditions but they can also integrate conditions in the past. In contrast, fish and planktonic organisms can move freely so their site of capture does not indicate a long residence time at that location. Because sea-bed communities are particularly diverse they contain species with widely differing life strategies, as a result different species can have very different levels of tolerance to stress; this leads to a range of subtle changes in community structure as a response to gradually increasing disturbance, rather than an all or nothing response. This project will examine sea-bed communities near our stations to determine how seriously they are affected by human activities. This information will be used to set priorities for improving operational procedures to reduce the risk of further environmental damage. The fields in this dataset are: Species Site Abundance Benthic Date Location

  • Underwater footage was taken with a Sony digital Handycam mounted in a pressure case on a roll cage, and then trawled off the back of the Aurora Australis. The footage was taken primarily of benthic habitats, and was done on an opportunistic basis, rather than part of a systematic trawling survey. Most of the footage was taken within the Heard Island Exclusive Economic Zone (EEZ), but some footage was also taken between Mawson and Davis off the Antarctic continent. Footage of both areas (highlights of Heard Island, and of Prydz Bay) are available at the provided URL. The footage was collected by: Tony Veness Bryan Scott Andrew Tabor Kelvin Cope Andrew Cawthorn Stuart Crapper

  • A sediment core was collected from the western side of Pidgeon Island, (66.3216 S, 110.445 E) at a water depth of 82.0 m. This sediment core (PG 1411-2) was recovered using a release-controlled piston corer, with a length of 3 m, using the coring technique described in Melles et al., (1994). The total core length was 240 cm. This core was stored in the dark, at 0 degrees C until required. Samples were taken for diatom analyses and radiocarbon (14C) dating. Prior to sub-sampling the core was split in half, along its length. One half was used for sampling, the other kept intact and stored at IASOS (University of Tasmania). To reduce potential contamination, resulting from the disturbance of sediments during the core-splitting procedure, a thin layer of sediment was removed from the exposed surface immediately prior to sampling. In order to obtain samples for diatom analysis, a toothpick was inserted into the core segment, and used to gouge a small amount of sediment from the middle of the core. Samples for diatom analyses were initially collected every 5 mm, however, sampling frequency progressively decreased down the core. Samples for radiocarbon data consisted of at least 1 cm 3 of sediment, collected from the middle of the core. These samples were collected from between 0-1 cm, 12-13 cm, 59-60 cm, 77-78 cm, 117-118 cm, and 229-230 cm depth. Diatom data are presented as raw counts, benthic abundances, the ratio of benthic to plankton species, and as the benthic index. Calculated ages (in years) are also given for all samples. The sedimentological core log is given as a powerpoint presentation. This work was completed as part of ASAC project 1130 (ASAC_1130) and project 2201 (ASAC_2201). Public summary from project 1130: Algal mats grow on sea floor in most shallow marine environments. They are thought to contribute more than half of the total primary production in many of these areas, making them a critical food source for invertebrates and some fish. We will establish how important they are in Antarctic marine environments and determine the effects of local sewerage and tip site pollution. We will also investigate the impact on the algal mats of the additional UV radiation which results from the ozone hole. Public summary from project 2201: As a signatory to the Protocol on Environmental Protection to the Antarctic Treaty Australia is committed to comprehensive protection of the Antarctic environment. This protocol requires that activities in the Antarctic shall be planned and conducted on the basis of information sufficient to make prior assessments of, and informed judgements about, their possible impacts on the Antarctic environment. Most of our activities in the Antarctic occur along the narrow fringe of ice-free rock adjacent to the sea and many of our activities have the potential to cause environmental harm to marine life. The Antarctic seas support the most complex and biologically diverse plant and animal communities of the region. However, very little is known about them and there is certainly not sufficient known to make informed judgements about possible environmental impacts. The animals and plants of the sea-bed are widely accepted as being the most appropriate part of the marine ecosystem for indicating disturbance caused by local sources. Attached sea-bed organisms have a fixed spatial relationship with a given place so they must either endure conditions or die. Once lost from a site recolonisation takes some time, as a consequence the structure of sea-bed communities reflect not only present conditions but they can also integrate conditions in the past. In contrast, fish and planktonic organisms can move freely so their site of capture does not indicate a long residence time at that location. Because sea-bed communities are particularly diverse they contain species with widely differing life strategies, as a result different species can have very different levels of tolerance to stress; this leads to a range of subtle changes in community structure as a response to gradually increasing disturbance, rather than an all or nothing response. This project will examine sea-bed communities near our stations to determine how seriously they are affected by human activities. This information will be used to set priorities for improving operational procedures to reduce the risk of further environmental damage. The fields in this dataset are: Species Site Benthic % Planktonic % Depth (cm) Age (years) Radiocarbon Age Corrected Age Benthic Index

  • 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

  • Full title: Diatom and associated data for a manipulative field experiment which translocated control and contaminated sediments between locations within the Windmill Islands, Antarctica. A manipulative field experiment was performed to assess the effects of heavy metals and petroleum hydrocarbons on benthic diatom communities in the Windmill Islands. Three treatments were used (control, metal contaminated, and petroleum hydrocarbon contaminated), with replicates of each treatment deployed at three locations (Sparkes Bay, Brown Bay and O'Brien Bay). The datasets associated with this experiment include the concentrations of metals within the sediments as well as diatom data (raw counts, and the relative abundance of benthic species). This work was completed as part of ASAC project 1130 (ASAC_1130) and project 2201 (ASAC_2201). Public summary from project 1130: Algal mats grow on sea floor in most shallow marine environments. They are thought to contribute more than half of the total primary production in many of these areas, making them a critical food source for invertebrates and some fish. We will establish how important they are in Antarctic marine environments and determine the effects of local sewerage and tip-site pollution. We will also investigate the impact on the algal mats of the additional UV radiation which results from the ozone hole. Public summary from project 2201: As a signatory to the Protocol on Environmental Protection to the Antarctic Treaty Australia is committed to comprehensive protection of the Antarctic environment. This protocol requires that activities in the Antarctic shall be planned and conducted on the basis of information sufficient to make prior assessments of, and informed judgements about, their possible impacts on the Antarctic environment. Most of our activities in the Antarctic occur along the narrow fringe of ice-free rock adjacent to the sea and many of our activities have the potential to cause environmental harm to marine life. The Antarctic seas support the most complex and biologically diverse plant and animal communities of the region. However, very little is known about them and there is certainly not sufficient known to make informed judgements about possible environmental impacts. The animals and plants of the sea-bed are widely accepted as being the most appropriate part of the marine ecosystem for indicating disturbance caused by local sources. Attached sea-bed organisms have a fixed spatial relationship with a given place so they must either endure conditions or die. Once lost from a site recolonisation takes some time, as a consequence the structure of sea-bed communities reflect not only present conditions but they can also integrate conditions in the past. In contrast, fish and planktonic organisms can move freely so their site of capture does not indicate a long residence time at that location. Because sea-bed communities are particularly diverse they contain species with widely differing life strategies, as a result different species can have very different levels of tolerance to stress; this leads to a range of subtle changes in community structure as a response to gradually increasing disturbance, rather than an all or nothing response. This project will examine sea-bed communities near our stations to determine how seriously they are affected by human activities. This information will be used to set priorities for improving operational procedures to reduce the risk of further environmental damage. The fields in this dataset are: Species Arsenic Cadmium Copper Lead Silver Zinc Concentration Location Treatment Abundance Benthic Site

  • 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

  • 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

  • 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