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Fast repetition rate fluorometer (FRRF) study of sea ice algae in low iron conditions. Algae were grown in an ice tank and the measurements were made at the end with a Chelsea Insrtuments FRRF. Materials and Methods (see the download document for original formatting and formulas) 1. Ice tank incubation The polar pennate diatom Fragilariopsis cylindrus, isolated from Antarctic pack ice in 2015 (Davis station, East Antarctica) was incubated in a purpose designed ice tank (Island Research, Tasmania). The ice tank, which was contructed of titanium to minimise dissolved Fe, was placed into a freezer (–20 degrees C), and the ice thickness and temperature gradient controlled by interaction between a basal heater and the adjustable ambient freezer temperature (see Kennedy et al., 2012). This enabled an ice thickness of approximately 5.5 cm to be maintained during the experiment. The diatom F. cylindrus was incubated in Aquil media (Price et al. 1989) buffered with ethylenediaminetetraacetic acid (EDTA) at 150 micro mol photons m−2 s−1 (PAR), a salinity of 35, and a Fe concentration of 400 nM, where the concentration of total inorganic forms of Fe (Fe') was 1.54 nM, this being continuously supplied to the medium and the exact value calculated using the software Visual MINTEQ, ver. 3.1 (https://vminteq.lwr.kth.se). Before a freezing cycle started, the seawater temperature was maintained at 2.5 degrees C, and a sample was obtained to assess the original physiological state of the algae (Day−5, hereafter). After obtaining the sample, the seawater temperature was set to −1.8 degrees C to initiate ice formation in the ice tank. Once ice had formed at Day−2, the under-ice seawater was partially replaced with ultrapure water to reduce the salinity down to 35, because the salinity had increased (to approximately 38) as a result of brine rejection from the ice. After a 2-day acclimation to the new salinity, ice samples were obtained every 5 days for 20 days (i.e., Days 0, 5, 10, 15, and 20). To minimize the heterogeneity among ice cores, ice samples were randomly collected from the tank chamber with a trace metal-free hand drill (2 cm in diameter) from randomly annotated grids on the ice surface, following normal random sampling numbers generated by the software R (https://www.r-project.org/). To assess the effects of melting and high light exposure, the ice was melted at 2.5 degrees C for 2 days. After the ice had completely melted, the seawater was exposed to a high light level, which was adjusted to represent the likely summer light intensity at the surface in ice-edge regions (800 micro mol photons m−2 s−1; MODIS Aqua), Seawater samples were obtained both after the melting and light exposure events (Melt and Light, respectively, hereafter). 2. Fast repetition rate (FRR) fluorometry To monitor the photophysiology of F. cylindrus during the freezing and melting processes, variable chlorophyll a fluorescence (ChlF) measurements were conducted using a bench-top Fast Repetition Rate fluorometer (FRRf) (FastOcean Act2Run Systems, Chelsea Technologies) with Act2Run software (Chelsea Technologies). Ice samples were directly thawed at 2 degrees C in the dark for 30 min, and the slushily melted ice samples were placed in a quartz tube and their flouresence (ChlF) was measured. A single turnover protocol was applied for the ChlF measurements; 100 flashlets with 1 micro second duration at a wavelength 450 nm and 2 micro second intervals for excitation of reaction centres of photosystem II (PSII, hereafter), and 20 flahlets with 1 μs duration and 100 micro second intervals for relaxation. Eighteen light steps were applied to generate a rapid light curve (RLC) from 0 to 1800 μmol photons m−2 s−1, taking less than 5 min to complete one RLC. At each light step (~15 s), at least five induction and relaxation curves were averaged to obtain ChlF yields, described in Table, after calibrating the ChlF yields with filtered seawater. According to the models proposed by Kolber et al. (1998), photosynthetic parameters of chlorophyll a (chl a) induction and relaxation curves were calculated based on the ChlF yields as shown in Table. Electron transport rate though the reaction centres of PSII (RCII) (ETRRCII) was calculated as per the equation detailed in the download document.
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The productivity of Antarctic waters may be controlled by the amount of iron. Experiments have shown that this is probably the case for phytoplankton but as yet we do not know if iron limits the growth of sea ice algae. This study will assess whether iron limits sea ice algae production and will conduct experiments to work out how these algae use iron. Measurements have been made to determine whether sea ice algae are limited by Fe. Sea ice samples were taken and this spreadsheet refers to those ice cores Columns A-G are self explanatory Column G is the depth in the ice core from the bottom Column H is the chlorophyll concentration in mg Chl m-2 Column I is the phaeophytin concentration in mg m-2 J is the total amount of protein in the sample ng m-2 K is the total amount of the protein flavodoxin ng m-2 L is the total amount of ferrodoxin ng m-2 These last two enable the Fe limitation status to calculated (not completed).
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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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Metadata record for data from ASAC Project 2297: Iron content of Southern Ocean phytoplankton: implications for carbon transfer to the deep sea. Data on size-fractionated distribution of suspended trace elements (including iron) in marine particles taken from the surface Southern Ocean south of Australia. Data for 4 size-fractions at 4 stations along ~142 degrees E are included. Explanation of codes used in the dataset: The isotope of the element of interest is listed down column A. LR refers to low resolution and MR medium resolution (that is the resolution of the ICPMS analytical instrument). So Mn55(LR) is the manganese isotope 55 ran in low resolution. SFP1_2um_B2_1: SFP=size-fractionated particles 1=station 1 2um=2micron filter size B2=blank 2 1=replicate 1 RSD%=relative standard deviation in % Blank=field blank Blk/sample%=blank-to-sample ratio in % CRMs_261102=certified reference materials (ran on 26 Nov 2002) Scaled up=previous column times multiplication factor (a serial dilution was used) Blk=blank subtracted certified=the value certified by the manufacturer of the reference material SLRS_1in25_1= the CRM 'SLRS', ran with a 1 in 25 dilution factor, replicate 1 DigBlk1_1=digestion blank 1, replicate 1 See the link below for public details on this project.
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These results are for the 0.5 hour extraction of HCl. See also the metadata records for the 4 hour extraction of HCl, and the time trial data for 1 M HCl extractions. 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 Location Site Replicate Antimony Arsenic Cadmium Chromium Copper Iron Lead Manganese Nickel Silver Tin Zinc
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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
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Full title: Diatom and associated data for a manipulative field experiment examining the effects of heavy metal and petroleum hydrocarbon contamination on benthic diatom communities in 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 and hydrocarbons within samples, 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 Site Abundance Treatment Type Antimony Arsenic Cadmium Chromium Copper Iron Lead Manganese Mercury Nickel Silver Tin Zinc Special Antarctic Blend Lube
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These results are for the 4 hour extraction of HCl. See also the metadata records for the 0.5 hour extraction of HCl, and the time trial data for 1 M HCl extractions. 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 Location Site Replicate Antimony Arsenic Cadmium Chromium Copper Iron Lead Manganese Nickel Silver Tin Zinc
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Exopolysaccharide (EPS) is complex sugar made by many microbes in the Antarctic marine environment. This project seeks to understand the ecological role of microbial EPS in the Southern Ocean, where it is known to strongly influence primary production. We will investigate the chemical composition and structure of EPS obtained from Antarctic microbes, which will improve our knowledge of its ecological significance and biotechnological potential. Dataset includes the following: 1) Information on Exopolysaccharide-producing bacterial isolates, isolation sites, media used and growth conditions. 2) 16S rRNA gene sequence and fatty acid data of isolates for strain identification. 3) Exopolysaccharide chemistry data including EPS carbohydrate composition, organic acid composition, sulfate content, molecular weight. 4) Physiology of exopolysaccharide synthesis. Effects of temperature and other factors on EPS yield and glucose conversion efficiency. 5) Iron binding properties. The download file includes: 11 files File 1. Bacterial isolate 16S rRNA gene sequences obtained from Southern Ocean seawater or ice samples. The sequences are all deposited on the GenBank nucleotide (NCBI) database. Sequences are in FASTA format. File 2. Seawater and sea-ice sample information including sites samples, sample type. File 3. Data for exopolysaccharide (EPS)-producing bacteria isolated and subsequently selected for further studied. Information indicates special treatments used to obtain strains including plankton towing, filtration method, and enrichment. Identification to species level was determined by 16S rRNA gene sequence analysis. File 4. EPS-producing bacterial isolate fatty acid content determined using GC/MS procedures. File 5. Basic chemical data for EPS from Antarctic isolates including protein, sulfate, and sugar type relative content (determined by chemical procedures), molecular weight in kilodaltons and polydispersity (determined by gel-based molecular seiving). File 6 Monosaccharide unit composition determined by GC/MS of EPS from Antarctic isolates. File 7. Effect of temperature on culture viscosity and growth of EPS-producing bacterium Pseudoalteromonas sp. CAM025 as affected by temperature. File 8. Effect of temperature on EPS and cell yields and EPS synthesis efficiency (as indicated by glucose consumption) of EPS-producing bacterium Pseudoalteromonas sp. CAM025 as affected by temperature. File 9. Efficiency of copper and cadmium metal ion adsorption onto EPS from EPS-producing bacterium Pseudoalteromonas sp. CAM025. File 10. Phenotypic characteristics data for novel EPS-producing Antarctic strain CAM030. Represents type strain of Olleya marilimosa. File 11. Effect of temperature on chemical make up of EPS from EPS-producing bacterium Pseudoalteromonas sp. CAM025.
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Sediment samples were collected from nine points along 3 parallel transects within the contaminated Brown Bay. The diatom spreadsheet (diatom_data) contains both initial diatom counts and the relative abundance of benthic species. The abbreviation used to identify species are explained in the separate file called sp_list. Metal, Total Purgeable Hydrocarbons (TPH), and grain-size data are all presented as separate files. 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: bbg_lat spreadsheet Site Latitude Longitude Easting Northing Diatoms spreadsheet Species Site Abundance Transect Metals Spreadsheet Sample Antimony Arsenic Cadmium Chromium Copper Iron Lead Manganese Mercury Nickel Silver Tin Zinc Total Organic Carbon Easting Northing TPH Spreadsheet Site Total Purgeable Hydrocarbons Fraction of Purgeable Hydrocarbons