Organic ligands control the concentrations of dissolved iron in Antarctic sea ice
The organic complexation of dissolved iron (DFe) was assessed in 5 snow, 34 sea ice, 12 brine and 24 under-ice seawater samples collected during a 22day time series in the East Antarctic sector in austral summer 2009. Similar to seawater, over 99% of DFe was bound to organic ligands in snow, sea ice...
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ftunivtasecite:oai:ecite.utas.edu.au:103854 2023-05-15T14:03:25+02:00 Organic ligands control the concentrations of dissolved iron in Antarctic sea ice Lannuzel, D Grotti, M Abelmoschi, ML Van Der Merwe, P 2015 https://doi.org/10.1016/j.marchem.2015.05.005 http://ecite.utas.edu.au/103854 en eng Elsevier Science Bv http://dx.doi.org/10.1016/j.marchem.2015.05.005 Lannuzel, D and Grotti, M and Abelmoschi, ML and Van Der Merwe, P, Organic ligands control the concentrations of dissolved iron in Antarctic sea ice, Marine Chemistry, 174 pp. 120-130. ISSN 0304-4203 (2015) [Refereed Article] http://ecite.utas.edu.au/103854 Earth Sciences Oceanography Chemical Oceanography Refereed Article PeerReviewed 2015 ftunivtasecite https://doi.org/10.1016/j.marchem.2015.05.005 2019-12-13T22:05:13Z The organic complexation of dissolved iron (DFe) was assessed in 5 snow, 34 sea ice, 12 brine and 24 under-ice seawater samples collected during a 22day time series in the East Antarctic sector in austral summer 2009. Similar to seawater, over 99% of DFe was bound to organic ligands in snow, sea ice and brines throughout the study. Dissolved organic ligand and Fe concentrations were higher in the brines and sea ice than in snow and seawater samples. In sea ice, [DFe] ranged from 2.1 to 81.0nM and organic Fe complexing ligands ([Lt]) ranged from 4.5 to 72.1nM, with complex stability log K FeL =21.023.0. Estimated concentrations of inorganic Fe ([Fe′]) in sea ice ranged from 0.1 to 98.2pM. In brines, [DFe] ranged from 0.3 to 34.6nM and [Lt] ranged from 5.9 to 41.4nM, with complex stability log K FeL =21.022.0. Estimated concentrations of inorganic Fe (Fe′) in brines ranged from 0.70 to 7.2pM. Organic ligands were nearly saturated with Fe in both sea ice and brines, with positive linear relationships observed between [DFe] and [Lt]: [Lt]=0.90 [DFe]+4.24 (R 2 =0.93, n=34) in sea ice and [Lt]=1.08[DFe]+4.86 (R 2 =0.98, n=12) in brines. Our results therefore suggest that the organic ligands produced by sea ice algae and bacteria keep Fe in the dissolved phase therefore enhancing its availability for the sea ice algal community. When DFe concentrations become higher than the ligand concentrations, non-organically bound Fe is transferred into the particulate phase by scavenging, biological uptake or precipitation processes. As sea ice starts to melt, DFe is released into seawater together with organic ligands, potentially increasing the residence time of Fe in Antarctic surface waters and its bio-availability for the phytoplankton community. Article in Journal/Newspaper Antarc* Antarctic ice algae Sea ice eCite UTAS (University of Tasmania) Antarctic Austral Marine Chemistry 174 120 130 |
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eCite UTAS (University of Tasmania) |
op_collection_id |
ftunivtasecite |
language |
English |
topic |
Earth Sciences Oceanography Chemical Oceanography |
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Earth Sciences Oceanography Chemical Oceanography Lannuzel, D Grotti, M Abelmoschi, ML Van Der Merwe, P Organic ligands control the concentrations of dissolved iron in Antarctic sea ice |
topic_facet |
Earth Sciences Oceanography Chemical Oceanography |
description |
The organic complexation of dissolved iron (DFe) was assessed in 5 snow, 34 sea ice, 12 brine and 24 under-ice seawater samples collected during a 22day time series in the East Antarctic sector in austral summer 2009. Similar to seawater, over 99% of DFe was bound to organic ligands in snow, sea ice and brines throughout the study. Dissolved organic ligand and Fe concentrations were higher in the brines and sea ice than in snow and seawater samples. In sea ice, [DFe] ranged from 2.1 to 81.0nM and organic Fe complexing ligands ([Lt]) ranged from 4.5 to 72.1nM, with complex stability log K FeL =21.023.0. Estimated concentrations of inorganic Fe ([Fe′]) in sea ice ranged from 0.1 to 98.2pM. In brines, [DFe] ranged from 0.3 to 34.6nM and [Lt] ranged from 5.9 to 41.4nM, with complex stability log K FeL =21.022.0. Estimated concentrations of inorganic Fe (Fe′) in brines ranged from 0.70 to 7.2pM. Organic ligands were nearly saturated with Fe in both sea ice and brines, with positive linear relationships observed between [DFe] and [Lt]: [Lt]=0.90 [DFe]+4.24 (R 2 =0.93, n=34) in sea ice and [Lt]=1.08[DFe]+4.86 (R 2 =0.98, n=12) in brines. Our results therefore suggest that the organic ligands produced by sea ice algae and bacteria keep Fe in the dissolved phase therefore enhancing its availability for the sea ice algal community. When DFe concentrations become higher than the ligand concentrations, non-organically bound Fe is transferred into the particulate phase by scavenging, biological uptake or precipitation processes. As sea ice starts to melt, DFe is released into seawater together with organic ligands, potentially increasing the residence time of Fe in Antarctic surface waters and its bio-availability for the phytoplankton community. |
format |
Article in Journal/Newspaper |
author |
Lannuzel, D Grotti, M Abelmoschi, ML Van Der Merwe, P |
author_facet |
Lannuzel, D Grotti, M Abelmoschi, ML Van Der Merwe, P |
author_sort |
Lannuzel, D |
title |
Organic ligands control the concentrations of dissolved iron in Antarctic sea ice |
title_short |
Organic ligands control the concentrations of dissolved iron in Antarctic sea ice |
title_full |
Organic ligands control the concentrations of dissolved iron in Antarctic sea ice |
title_fullStr |
Organic ligands control the concentrations of dissolved iron in Antarctic sea ice |
title_full_unstemmed |
Organic ligands control the concentrations of dissolved iron in Antarctic sea ice |
title_sort |
organic ligands control the concentrations of dissolved iron in antarctic sea ice |
publisher |
Elsevier Science Bv |
publishDate |
2015 |
url |
https://doi.org/10.1016/j.marchem.2015.05.005 http://ecite.utas.edu.au/103854 |
geographic |
Antarctic Austral |
geographic_facet |
Antarctic Austral |
genre |
Antarc* Antarctic ice algae Sea ice |
genre_facet |
Antarc* Antarctic ice algae Sea ice |
op_relation |
http://dx.doi.org/10.1016/j.marchem.2015.05.005 Lannuzel, D and Grotti, M and Abelmoschi, ML and Van Der Merwe, P, Organic ligands control the concentrations of dissolved iron in Antarctic sea ice, Marine Chemistry, 174 pp. 120-130. ISSN 0304-4203 (2015) [Refereed Article] http://ecite.utas.edu.au/103854 |
op_doi |
https://doi.org/10.1016/j.marchem.2015.05.005 |
container_title |
Marine Chemistry |
container_volume |
174 |
container_start_page |
120 |
op_container_end_page |
130 |
_version_ |
1766274071246405632 |