Sourcing the iron in the naturally fertilised bloom around the Kerguelen Plateau: particulate trace metal dynamics
The KEOPS2 project aims to elucidate the role of natural Fe fertilisation on biogeochemical cycles and ecosystem functioning, including quantifying the sources and processes by which iron is delivered in the vicinity of the Kerguelen Archipelago, Southern Ocean. The KEOPS2 process study used an upst...
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Copernicus Publications
2015
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Online Access: | https://doi.org/10.5194/bg-12-739-2015 https://doaj.org/article/ebdfc56767fe4a8b86ce2a8e20af5500 |
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ftdoajarticles:oai:doaj.org/article:ebdfc56767fe4a8b86ce2a8e20af5500 2023-05-15T18:25:17+02:00 Sourcing the iron in the naturally fertilised bloom around the Kerguelen Plateau: particulate trace metal dynamics P. van der Merwe A. R. Bowie F. Quéroué L. Armand S. Blain F. Chever D. Davies F. Dehairs F. Planchon G. Sarthou A. T. Townsend T. W. Trull 2015-02-01T00:00:00Z https://doi.org/10.5194/bg-12-739-2015 https://doaj.org/article/ebdfc56767fe4a8b86ce2a8e20af5500 EN eng Copernicus Publications http://www.biogeosciences.net/12/739/2015/bg-12-739-2015.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 1726-4170 1726-4189 doi:10.5194/bg-12-739-2015 https://doaj.org/article/ebdfc56767fe4a8b86ce2a8e20af5500 Biogeosciences, Vol 12, Iss 3, Pp 739-755 (2015) Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 article 2015 ftdoajarticles https://doi.org/10.5194/bg-12-739-2015 2022-12-31T13:32:11Z The KEOPS2 project aims to elucidate the role of natural Fe fertilisation on biogeochemical cycles and ecosystem functioning, including quantifying the sources and processes by which iron is delivered in the vicinity of the Kerguelen Archipelago, Southern Ocean. The KEOPS2 process study used an upstream high-nutrient, low-chlorophyll (HNLC), deep water (2500 m), reference station to compare with a shallow (500 m), strongly fertilised plateau station and continued the observations to a downstream, bathymetrically trapped recirculation of the Polar Front where eddies commonly form and persist for hundreds of kilometres into the Southern Ocean. Over the Kerguelen Plateau, mean particulate (1–53 μm) Fe and Al concentrations (pFe = 13.4 nM, pAl = 25.2 nM) were more than 20-fold higher than at an offshore (lower-productivity) reference station (pFe = 0.53 nM, pAl = 0.83 nM). In comparison, over the plateau dissolved Fe levels were only elevated by a factor of ~ 2. Over the Kerguelen Plateau, ratios of pMn / pAl and pFe / pAl resemble basalt, likely originating from glacial/fluvial inputs into shallow coastal waters. In downstream, offshore deep-waters, higher pFe / pAl, and pMn / pAl ratios were observed, suggesting loss of lithogenic material accompanied by retention of pFe and pMn. Biological uptake of dissolved Fe and Mn and conversion into the biogenic particulate fraction or aggregation of particulate metals onto bioaggregates also increased these ratios further in surface waters as the bloom developed within the recirculation structure. While resuspension of shelf sediments is likely to be one of the important mechanisms of Fe fertilisation over the plateau, fluvial and glacial sources appear to be important to areas downstream of the island. Vertical profiles within an offshore recirculation feature associated with the Polar Front show pFe and pMn levels that were 6-fold and 3.5-fold lower, respectively, than over the plateau in surface waters, though still 3.6-fold and 1.7-fold higher respectively than the ... Article in Journal/Newspaper Southern Ocean Directory of Open Access Journals: DOAJ Articles Southern Ocean Kerguelen Biogeosciences 12 3 739 755 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
spellingShingle |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 P. van der Merwe A. R. Bowie F. Quéroué L. Armand S. Blain F. Chever D. Davies F. Dehairs F. Planchon G. Sarthou A. T. Townsend T. W. Trull Sourcing the iron in the naturally fertilised bloom around the Kerguelen Plateau: particulate trace metal dynamics |
topic_facet |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
description |
The KEOPS2 project aims to elucidate the role of natural Fe fertilisation on biogeochemical cycles and ecosystem functioning, including quantifying the sources and processes by which iron is delivered in the vicinity of the Kerguelen Archipelago, Southern Ocean. The KEOPS2 process study used an upstream high-nutrient, low-chlorophyll (HNLC), deep water (2500 m), reference station to compare with a shallow (500 m), strongly fertilised plateau station and continued the observations to a downstream, bathymetrically trapped recirculation of the Polar Front where eddies commonly form and persist for hundreds of kilometres into the Southern Ocean. Over the Kerguelen Plateau, mean particulate (1–53 μm) Fe and Al concentrations (pFe = 13.4 nM, pAl = 25.2 nM) were more than 20-fold higher than at an offshore (lower-productivity) reference station (pFe = 0.53 nM, pAl = 0.83 nM). In comparison, over the plateau dissolved Fe levels were only elevated by a factor of ~ 2. Over the Kerguelen Plateau, ratios of pMn / pAl and pFe / pAl resemble basalt, likely originating from glacial/fluvial inputs into shallow coastal waters. In downstream, offshore deep-waters, higher pFe / pAl, and pMn / pAl ratios were observed, suggesting loss of lithogenic material accompanied by retention of pFe and pMn. Biological uptake of dissolved Fe and Mn and conversion into the biogenic particulate fraction or aggregation of particulate metals onto bioaggregates also increased these ratios further in surface waters as the bloom developed within the recirculation structure. While resuspension of shelf sediments is likely to be one of the important mechanisms of Fe fertilisation over the plateau, fluvial and glacial sources appear to be important to areas downstream of the island. Vertical profiles within an offshore recirculation feature associated with the Polar Front show pFe and pMn levels that were 6-fold and 3.5-fold lower, respectively, than over the plateau in surface waters, though still 3.6-fold and 1.7-fold higher respectively than the ... |
format |
Article in Journal/Newspaper |
author |
P. van der Merwe A. R. Bowie F. Quéroué L. Armand S. Blain F. Chever D. Davies F. Dehairs F. Planchon G. Sarthou A. T. Townsend T. W. Trull |
author_facet |
P. van der Merwe A. R. Bowie F. Quéroué L. Armand S. Blain F. Chever D. Davies F. Dehairs F. Planchon G. Sarthou A. T. Townsend T. W. Trull |
author_sort |
P. van der Merwe |
title |
Sourcing the iron in the naturally fertilised bloom around the Kerguelen Plateau: particulate trace metal dynamics |
title_short |
Sourcing the iron in the naturally fertilised bloom around the Kerguelen Plateau: particulate trace metal dynamics |
title_full |
Sourcing the iron in the naturally fertilised bloom around the Kerguelen Plateau: particulate trace metal dynamics |
title_fullStr |
Sourcing the iron in the naturally fertilised bloom around the Kerguelen Plateau: particulate trace metal dynamics |
title_full_unstemmed |
Sourcing the iron in the naturally fertilised bloom around the Kerguelen Plateau: particulate trace metal dynamics |
title_sort |
sourcing the iron in the naturally fertilised bloom around the kerguelen plateau: particulate trace metal dynamics |
publisher |
Copernicus Publications |
publishDate |
2015 |
url |
https://doi.org/10.5194/bg-12-739-2015 https://doaj.org/article/ebdfc56767fe4a8b86ce2a8e20af5500 |
geographic |
Southern Ocean Kerguelen |
geographic_facet |
Southern Ocean Kerguelen |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
Biogeosciences, Vol 12, Iss 3, Pp 739-755 (2015) |
op_relation |
http://www.biogeosciences.net/12/739/2015/bg-12-739-2015.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 1726-4170 1726-4189 doi:10.5194/bg-12-739-2015 https://doaj.org/article/ebdfc56767fe4a8b86ce2a8e20af5500 |
op_doi |
https://doi.org/10.5194/bg-12-739-2015 |
container_title |
Biogeosciences |
container_volume |
12 |
container_issue |
3 |
container_start_page |
739 |
op_container_end_page |
755 |
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1766206601802285056 |