Identifying potential sources of iron-binding ligands in coastal Antarctic environments and the wider Southern Ocean
The availability of iron (Fe) to marine microbial communities is enhanced through complexation by ligands. In Fe limited environments, measuring the distribution and identifying the likely sources of ligands is therefore central to understanding the drivers of marine productivity. Antarctic coastal...
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ftunivbruxelles:oai:dipot.ulb.ac.be:2013/349543 2023-05-15T13:37:12+02:00 Identifying potential sources of iron-binding ligands in coastal Antarctic environments and the wider Southern Ocean Smith, Abigail A.M. Nelson, Talitha Ratnarajah, Lavenia Genovese, Cristina Westwood, Karen j Holmes, Thomas T.M. Corkill, Matthew Townsend, Ashley T Bell, Elanor Wuttig, Kathrin Lannuzel, Delphine 2022-08 1 full-text file(s): application/pdf http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/349543 https://dipot.ulb.ac.be/dspace/bitstream/2013/349543/1/doi_333187.pdf en eng uri/info:doi/10.3389/fmars.2022.948772 uri/info:scp/85136196815 https://dipot.ulb.ac.be/dspace/bitstream/2013/349543/1/doi_333187.pdf http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/349543 1 full-text file(s): info:eu-repo/semantics/openAccess Frontiers in marine science, 9 Généralités benthic nepheloid layers complexation Fe availability microbial productivity SOLt collection info:eu-repo/semantics/article info:ulb-repo/semantics/articlePeerReview info:ulb-repo/semantics/openurl/article 2022 ftunivbruxelles 2022-09-14T22:20:51Z The availability of iron (Fe) to marine microbial communities is enhanced through complexation by ligands. In Fe limited environments, measuring the distribution and identifying the likely sources of ligands is therefore central to understanding the drivers of marine productivity. Antarctic coastal marine environments support highly productive ecosystems and are influenced by numerous sources of ligands, the magnitude of which varies both spatially and seasonally. Using competitive ligand exchange adsorptive cathodic stripping voltammetry (CLE-AdCSV) with 2-(2-thiazolylazo)-p-cresol (TAC) as a competing artificial ligand, this study investigates Fe-binding ligands (FeL) across the continental shelf break in the Mertz Glacier Region, East Antarctica (64 - 67°S; 138 - 154°E) during austral summer of 2019. The average FeL concentration was 0.86 ± 0.5 nM Eq Fe, with strong conditional stability constants (Log KFeL) averaging 23.1 ± 1.0. The strongest binding ligands were observed in modified circumpolar deep water (CDW), thought to be linked to bacterial Fe remineralisation and potential siderophore release. High proportions of excess unbound ligands (L’) were observed in surface waters, as a result of phytoplankton Fe uptake in the mixed layer and euphotic zone. However, FeL and L’ concentrations were greater at depth, suggesting ligands were supplied with dissolved Fe from upwelled CDW and particle remineralisation in benthic nepheloid layers over the shelf. Recent sea-ice melt appeared to support bacterial production in areas where Fe and ligands were exhausted. This study is included within our newly compiled Southern Ocean Ligand (SOLt) Collection, a database of publicly available Fe-binding ligand surveys performed south of 50°S. A review of the SOLt Collection brings attention to the paucity of ligand data collected along the East Antarctic coast and the difficulties in pinpointing sources of Fe and ligands in coastal environments. Elucidating poorly understood ligand sources is essential to predicting future ... Article in Journal/Newspaper Antarc* Antarctic Antarctica East Antarctica Mertz Glacier Sea ice Southern Ocean DI-fusion : dépôt institutionnel de l'Université libre de Bruxelles (ULB) Antarctic Southern Ocean East Antarctica Austral Tac ENVELOPE(-59.517,-59.517,-62.500,-62.500) Mertz Glacier ENVELOPE(144.500,144.500,-67.667,-67.667) |
institution |
Open Polar |
collection |
DI-fusion : dépôt institutionnel de l'Université libre de Bruxelles (ULB) |
op_collection_id |
ftunivbruxelles |
language |
English |
topic |
Généralités benthic nepheloid layers complexation Fe availability microbial productivity SOLt collection |
spellingShingle |
Généralités benthic nepheloid layers complexation Fe availability microbial productivity SOLt collection Smith, Abigail A.M. Nelson, Talitha Ratnarajah, Lavenia Genovese, Cristina Westwood, Karen j Holmes, Thomas T.M. Corkill, Matthew Townsend, Ashley T Bell, Elanor Wuttig, Kathrin Lannuzel, Delphine Identifying potential sources of iron-binding ligands in coastal Antarctic environments and the wider Southern Ocean |
topic_facet |
Généralités benthic nepheloid layers complexation Fe availability microbial productivity SOLt collection |
description |
The availability of iron (Fe) to marine microbial communities is enhanced through complexation by ligands. In Fe limited environments, measuring the distribution and identifying the likely sources of ligands is therefore central to understanding the drivers of marine productivity. Antarctic coastal marine environments support highly productive ecosystems and are influenced by numerous sources of ligands, the magnitude of which varies both spatially and seasonally. Using competitive ligand exchange adsorptive cathodic stripping voltammetry (CLE-AdCSV) with 2-(2-thiazolylazo)-p-cresol (TAC) as a competing artificial ligand, this study investigates Fe-binding ligands (FeL) across the continental shelf break in the Mertz Glacier Region, East Antarctica (64 - 67°S; 138 - 154°E) during austral summer of 2019. The average FeL concentration was 0.86 ± 0.5 nM Eq Fe, with strong conditional stability constants (Log KFeL) averaging 23.1 ± 1.0. The strongest binding ligands were observed in modified circumpolar deep water (CDW), thought to be linked to bacterial Fe remineralisation and potential siderophore release. High proportions of excess unbound ligands (L’) were observed in surface waters, as a result of phytoplankton Fe uptake in the mixed layer and euphotic zone. However, FeL and L’ concentrations were greater at depth, suggesting ligands were supplied with dissolved Fe from upwelled CDW and particle remineralisation in benthic nepheloid layers over the shelf. Recent sea-ice melt appeared to support bacterial production in areas where Fe and ligands were exhausted. This study is included within our newly compiled Southern Ocean Ligand (SOLt) Collection, a database of publicly available Fe-binding ligand surveys performed south of 50°S. A review of the SOLt Collection brings attention to the paucity of ligand data collected along the East Antarctic coast and the difficulties in pinpointing sources of Fe and ligands in coastal environments. Elucidating poorly understood ligand sources is essential to predicting future ... |
format |
Article in Journal/Newspaper |
author |
Smith, Abigail A.M. Nelson, Talitha Ratnarajah, Lavenia Genovese, Cristina Westwood, Karen j Holmes, Thomas T.M. Corkill, Matthew Townsend, Ashley T Bell, Elanor Wuttig, Kathrin Lannuzel, Delphine |
author_facet |
Smith, Abigail A.M. Nelson, Talitha Ratnarajah, Lavenia Genovese, Cristina Westwood, Karen j Holmes, Thomas T.M. Corkill, Matthew Townsend, Ashley T Bell, Elanor Wuttig, Kathrin Lannuzel, Delphine |
author_sort |
Smith, Abigail A.M. |
title |
Identifying potential sources of iron-binding ligands in coastal Antarctic environments and the wider Southern Ocean |
title_short |
Identifying potential sources of iron-binding ligands in coastal Antarctic environments and the wider Southern Ocean |
title_full |
Identifying potential sources of iron-binding ligands in coastal Antarctic environments and the wider Southern Ocean |
title_fullStr |
Identifying potential sources of iron-binding ligands in coastal Antarctic environments and the wider Southern Ocean |
title_full_unstemmed |
Identifying potential sources of iron-binding ligands in coastal Antarctic environments and the wider Southern Ocean |
title_sort |
identifying potential sources of iron-binding ligands in coastal antarctic environments and the wider southern ocean |
publishDate |
2022 |
url |
http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/349543 https://dipot.ulb.ac.be/dspace/bitstream/2013/349543/1/doi_333187.pdf |
long_lat |
ENVELOPE(-59.517,-59.517,-62.500,-62.500) ENVELOPE(144.500,144.500,-67.667,-67.667) |
geographic |
Antarctic Southern Ocean East Antarctica Austral Tac Mertz Glacier |
geographic_facet |
Antarctic Southern Ocean East Antarctica Austral Tac Mertz Glacier |
genre |
Antarc* Antarctic Antarctica East Antarctica Mertz Glacier Sea ice Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica Mertz Glacier Sea ice Southern Ocean |
op_source |
Frontiers in marine science, 9 |
op_relation |
uri/info:doi/10.3389/fmars.2022.948772 uri/info:scp/85136196815 https://dipot.ulb.ac.be/dspace/bitstream/2013/349543/1/doi_333187.pdf http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/349543 |
op_rights |
1 full-text file(s): info:eu-repo/semantics/openAccess |
_version_ |
1766089174674309120 |