The role of iron as a micro-nutrient to the Antarctic sea-ice zone algal community
The values provided in temporal and spatial coverage are approximate only. In the 2007/2008 Season significant work on this project was carried out on the SPIEX voyage - (Sea Ice Physics and Ecosystems eXperiment). See the child metadata record for more information. Taken from the 2008-2009 Progress...
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Australian Ocean Data Network
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| Online Access: | https://researchdata.ands.org.au/role-iron-micro-algal-community/684530 https://data.aad.gov.au/metadata/records/ASAC_3026 https://secure3.aad.gov.au/proms/public/projects/report_project_public.cfm?project_no=3026 http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=ASAC_3026 |
| Summary: | The values provided in temporal and spatial coverage are approximate only. In the 2007/2008 Season significant work on this project was carried out on the SPIEX voyage - (Sea Ice Physics and Ecosystems eXperiment). See the child metadata record for more information. Taken from the 2008-2009 Progress Report: Laboratory activity/analysis: Laboratory activity included analysis of exopolysaccharides (EPS) using the PSA and alcian blue methods, and showed good agreement with previously published data. Dissolved iron (less than 0.2 microns) and total dissolvable iron (unfiltered) were measured using a FIA-CL method adapted to high gradients of salinity and concentrations. Polycarbonate (PC) filters (Nuclepore 0.2 micron pore size) retaining particulate metals were digested in a mixture of strong, ultrapure acids (750 micro litre 12N HCl, 250 micro litre 40% HF, 250 micro litre 14N HNO3) on a hotplate at 125 degrees C for 8 h. The procedure was successfully applied to plankton, estuarine and river sediment reference materials to verify the recovery of the digestion treatment. The concentrations of particulate iron (PFe) were determined by high resolution ICP-MS at the Central Science Laboratory at UTAS. All analytical milestones were successfully completed, data compiled and prepared for publication. Difficulties affecting project: The second part of the project (field sampling at Casey) was not achieved during austral spring 2008, due to unavailability of berths at Casey Station. Taken from the 2009-2010 progress report: Field work: The collection of a time series of Antarctic coastal sea ice was completed off the coast of Casey station Antarctica between Oct and Dec 2009. Two researchers, Pier van der Merwe and Delphine Lannuzel were flown into Casey station on FA02. Lab facilities were provided for sample processing and trained staff supplied to escort the researchers into the field via Hagglunds. Sample processing and analysis is 90% completed and the write up of the data is occurring currently and the first paper based on the Fe size fractionation and release during sea ice melt should be finished by early August. Metadata record for data from AAS (ASAC) project 3026. Public This project will assess the importance of the trace micro-nutrient element iron to Antarctic sea-ice algal communities during the International Polar Year (2007-2009). We will investigate the biogeochemistry of iron, including a comprehensive examination of its distribution, speciation, cycling and role in fuelling ice-edge phytoplankton blooms. A significant part of this research will concentrate on the the influence of organic exopolysaccharides on iron solubility, complexation and bioavailability, both within the ice and in surrounding snow and surface seawater. This innovative research will improve our understanding of key processes that control the productivity of the climatically-important Antarctic sea-ice zone. Project objectives: This project will assess the importance of the trace element iron (Fe) as a micro-nutrient to seasonal sea-ice algal communities in the Australian sector of Antarctica during the International Polar Year (2007-09). We will investigate the biogeochemistry of Fe, including a comprehensive examination of its distribution, speciation, cycling and role in fuelling ice-edge phytoplankton blooms. A significant part of this research will concentrate on the influence of organic exopolysaccharides (EPS) on Fe solubility and complexation (and hence bioavailability), both within the ice and in surrounding surface waters. This innovative research will improve our understanding of key processes that control the productivity of the climatically-important Antarctic sea-ice zone. Specifically, in this project: - The biogeochemical behaviour of Fe in sea-ice with regards to EPS complexation, and key physicochemical and biological data will be evaluated. - The bioavailability of Fe for phytoplankton growth during sea-ice melt will be investigated through laboratory-based experiments designed to mimic spring conditions. - The distribution of other bioactive trace elements in the Antarctic sea-ice environment will be examined as a means of fingerprinting the source(s) of Fe, as well as indicating their biological requirement. Taken from the 2008-2009 Progress Report: Progress against objectives: In the last twelve months we achieved all the objectives planned for the shore-based sample processing and analysis from the SIPEX voyage (fieldwork September-October 2007). An extensive and unique seasonal and spatial data set was put together including parameters such as ice texture, salinity, temperature, Chlorophyll a, particulate organic carbon (POC), dissolved organic carbon (DOC), macro-nutrients (silicate, phosphate and nitrate), and exoplysaccharides (EPS, using both alcian blue and PSA methods). Dissolved iron (dFe) and total dissolvable iron (TDFe) were analysed by flow injection - chemiluminescence (FIA-CL) analysis in Hobart. Polycarbonate (PC) filters (Nuclepore 0.2 micron pore size) retaining particulate metals were digested in a mixture of strong, ultrapure acids (750 micro litre 12N HCl, 250 micro litre 40% HF, 250 micro litre 14N HNO3) on a hotplate at 125 degrees C for 8 h. The procedure was successfully applied to plankton, estuarine and river sediment reference materials to verify the recovery of the digestion treatment. The concentrations of particulate iron (PFe) were determined by high resolution ICP-MS at the Central Science Laboratory at UTAS. This data has been quality-controlled, analysed, interpreted and published (see below). Due to the fact that logistical support was not possible for 2008/09 (insufficient berths at Casey Station) despite approval of our project, the field component of the project was delayed. Taken from the 2009-2010 Progress Report: Progress against objectives: Monthly Milestones of PhD student Pier van der Merwe: Successful Antarctic research expedition occurred in Oct-Dec 2009 at Casey Station Antarctica with logistical support from AAS project #3026 (flight on FA02 and berths at Casey station as well as field support of personnel). OCT-DEC 2009 - Antarctic time series data collection and processing successful. Data analysis scheduled for Jan - Mar. Write up of last paper(s) scheduled for Mar-June. Final completion of thesis due in August. DEC - Chlorophyll a data analysed JAN - FIA and CLECSV analyses start simultaneously FEB - Finish FIA analyses and attend Ocean science meeting in Portland Oregon. MAR - Finish CLECSV analyses and run POC and PFe digestions and analyses. Scheduled with Thomas Rodemann and Ashley Townsend at the CSL, UTAS. APR - MAY Data analysis and write up of 3rd paper, and possibly 4th based on field work at Casey station Oct-Dec 2009. See the child metadata records for more information about the data. |
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