---- Public Summary from Project ---- Heard Island offers scientists a unique subantarctic laboratory for investigating climate change. We will establish a reference set of microalgal floras from lakes and lagoons and ultimately use the microalgal floras of today to investigate changes in fossil microalgal communities of Heard Island lake and lagoonal ecosystems to better understand regional subantarctic climate changes. Sediments were sampled with hand corers. Water samples were collected with a Niskin bottle. The dataset contains a summary of the locations data were sampled from, as well as average isotope concentrations from each sampling location. The fields in this dataset are: Date Location Salinity pH GPS Isotopes Concentration (ppb)

These data sets describe the toxicity of lead, coppyer, zinc and cadmium spiked seawater to the juveniles of Abatus ingens and Abatus nimrodi. Metals were tested separately over exposure periods of 96 and 240 hours. The experimental endpoint was mortality as defined by cessation of observable movement. The coding system for the data files is J(juvenile)_An (Abatus nimrodi) or Ai (Abatus ingens) - Metal name_Dates of the experiment_ the period of the observation (96 hour or 240 hour). This work falls under the umbrella project ASAC_2201. The fields in this dataset are: Species Toxicant Date Replicate Concentration Moving pH Salinity Dissolved Oxygen

This data set describes the concentrations of copper, lead and iron in the calcareous tests of heart urchins that were exposed to spiked sediments for 60 days. Porewater is the water extracted from between sand grains. Filtered porewater has been filtered. DGT stands for Diffuse Gel Transfer. The HCl extraction listed in one of the excel spreadsheets is an extraction from the actual sediment. The fields in this dataset are: Isotope Concentration Porewater Filtered Porewater DGT Porewater

This data set describes the toxicity of marine sediment spiked with undispersed diesel and diesel dispersed with Dasic Slickgone to the Antarctic ophiuroid Ophiura crassa. In 4 experiment ophiuroids were exposed for 10 days with daily observations of the movement of the animals as an indication of health. This work falls under the umbrella project ASAC_2201. The fields in this dataset are: Concentration SAB Time Animals Moving

These results are for the time trial extraction of HCl. See also the metadata records for the 0.5 and 4 hour extractions of HCl. A regional survey of potential contaminants in marine or estuarine sediments is often one of the first steps in a post-disturbance environmental impact assessment. Of the many different chemical extraction or digestion procedures that have been proposed to quantify metal contamination, partial acid extractions are probably the best overall compromise between selectivity, sensitivity, precision, cost and expediency. The extent to which measured metal concentrations relate to the anthropogenic fraction that is bioavailable is contentious, but is one of the desired outcomes of an assessment or prediction of biological impact. As part of a regional survey of metal contamination associated with Australia's past waste management activities in Antarctica, we wanted to identify an acid type and extraction protocol that would allow a reasonable definition of the anthropogenic bioavailable fraction for a large number of samples. From a kinetic study of the 1 M HCl extraction of two certified Certified Reference Materials (MESS-2 and PACS-2) and two Antarctic marine sediments, we concluded that a 4 hour extraction time allows the equilibrium dissolution of relatively labile metal contaminants, but does not favour the extraction of natural geogenic metals. In a regional survey of 88 marine samples from the Casey Station area of East Antarctica, the 4 h extraction procedure correlated best with biological data, and most clearly identified those sediments thought to be contaminated by runoff from abandoned waste disposal sites. Most importantly the 4 hour extraction provided better definition of the low to moderately contaminated locations by picking up small differences in anthropogenic metal concentrations. For the purposes of inter-regional comparison, we recommend a 4 hour 1 M HCl acid extraction as a standard method for assessing metal contamination in Antarctica. The fields in this dataset are Concentration Extraction Time Antimony Arsenic Cadmium Chromium Copper Iron Lead Manganese Nickel Silver Tin Zinc

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