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...
Published in: | Frontiers in Marine Science |
---|---|
Main Authors: | , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Frontiers Research Foundation
2022
|
Subjects: | |
Online Access: | https://doi.org/10.3389/fmars.2022.948772 http://ecite.utas.edu.au/152968 |
id |
ftunivtasecite:oai:ecite.utas.edu.au:152968 |
---|---|
record_format |
openpolar |
spelling |
ftunivtasecite:oai:ecite.utas.edu.au:152968 2023-05-15T13:42:41+02:00 Identifying potential sources of iron-binding ligands in coastal Antarctic environments and the wider Southern Ocean Smith, AJR Nelson, T Ratnarajah, L Genovese, C Westwood, K Holmes, TM Corkill, M Townsend, AT Bell, E Wuttig, K Lannuzel, D 2022 application/pdf https://doi.org/10.3389/fmars.2022.948772 http://ecite.utas.edu.au/152968 en eng Frontiers Research Foundation http://ecite.utas.edu.au/152968/1/152968 - Identifying potential sources of iron-binding ligands.pdf http://dx.doi.org/10.3389/fmars.2022.948772 Smith, AJR and Nelson, T and Ratnarajah, L and Genovese, C and Westwood, K and Holmes, TM and Corkill, M and Townsend, AT and Bell, E and Wuttig, K and Lannuzel, D, Identifying potential sources of iron-binding ligands in coastal Antarctic environments and the wider Southern Ocean, Frontiers in Marine Science, 9 Article 948772. ISSN 2296-7745 (2022) [Refereed Article] http://ecite.utas.edu.au/152968 Earth Sciences Oceanography Chemical oceanography Refereed Article PeerReviewed 2022 ftunivtasecite https://doi.org/10.3389/fmars.2022.948772 2022-11-28T23:17:13Z 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 degree S; 138 - 154 degree E) during austral summer of 2019. The average FeL concentration was 0.86 +- 0.5 nM Eq Fe, with strong conditional stability constants (Log K FeL ) 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 degree 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 ... Article in Journal/Newspaper Antarc* Antarctic Antarctica East Antarctica Mertz Glacier Sea ice Southern Ocean eCite UTAS (University of Tasmania) Antarctic Austral East Antarctica Mertz Glacier ENVELOPE(144.500,144.500,-67.667,-67.667) Southern Ocean Tac ENVELOPE(-59.517,-59.517,-62.500,-62.500) Frontiers in Marine Science 9 |
institution |
Open Polar |
collection |
eCite UTAS (University of Tasmania) |
op_collection_id |
ftunivtasecite |
language |
English |
topic |
Earth Sciences Oceanography Chemical oceanography |
spellingShingle |
Earth Sciences Oceanography Chemical oceanography Smith, AJR Nelson, T Ratnarajah, L Genovese, C Westwood, K Holmes, TM Corkill, M Townsend, AT Bell, E Wuttig, K Lannuzel, D Identifying potential sources of iron-binding ligands in coastal Antarctic environments and the wider Southern Ocean |
topic_facet |
Earth Sciences Oceanography Chemical oceanography |
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 degree S; 138 - 154 degree E) during austral summer of 2019. The average FeL concentration was 0.86 +- 0.5 nM Eq Fe, with strong conditional stability constants (Log K FeL ) 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 degree 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 ... |
format |
Article in Journal/Newspaper |
author |
Smith, AJR Nelson, T Ratnarajah, L Genovese, C Westwood, K Holmes, TM Corkill, M Townsend, AT Bell, E Wuttig, K Lannuzel, D |
author_facet |
Smith, AJR Nelson, T Ratnarajah, L Genovese, C Westwood, K Holmes, TM Corkill, M Townsend, AT Bell, E Wuttig, K Lannuzel, D |
author_sort |
Smith, AJR |
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 |
publisher |
Frontiers Research Foundation |
publishDate |
2022 |
url |
https://doi.org/10.3389/fmars.2022.948772 http://ecite.utas.edu.au/152968 |
long_lat |
ENVELOPE(144.500,144.500,-67.667,-67.667) ENVELOPE(-59.517,-59.517,-62.500,-62.500) |
geographic |
Antarctic Austral East Antarctica Mertz Glacier Southern Ocean Tac |
geographic_facet |
Antarctic Austral East Antarctica Mertz Glacier Southern Ocean Tac |
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_relation |
http://ecite.utas.edu.au/152968/1/152968 - Identifying potential sources of iron-binding ligands.pdf http://dx.doi.org/10.3389/fmars.2022.948772 Smith, AJR and Nelson, T and Ratnarajah, L and Genovese, C and Westwood, K and Holmes, TM and Corkill, M and Townsend, AT and Bell, E and Wuttig, K and Lannuzel, D, Identifying potential sources of iron-binding ligands in coastal Antarctic environments and the wider Southern Ocean, Frontiers in Marine Science, 9 Article 948772. ISSN 2296-7745 (2022) [Refereed Article] http://ecite.utas.edu.au/152968 |
op_doi |
https://doi.org/10.3389/fmars.2022.948772 |
container_title |
Frontiers in Marine Science |
container_volume |
9 |
_version_ |
1766171597594427392 |