Significant mixed layer nitrification in a natural iron-fertilized bloom of the Southern Ocean
Nitrification, the microbially mediated oxidation of ammonium into nitrate, is generally expected to be low in the Southern Ocean mixed layer. This paradigm assumes that nitrate is mainly provided through vertical mixing and assimilated during the vegetative season, supporting the concept that nitra...
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ftunivbruxelles:oai:dipot.ulb.ac.be:2013/299513 2023-05-15T18:25:00+02:00 Significant mixed layer nitrification in a natural iron-fertilized bloom of the Southern Ocean Fripiat, François Elskens, M. Trull, Thomas W. Blain, S. Cavagna, A. -J. Fernandez, C. Fonseca-Batista, D. Planchon, Frédéric Raimbault, P. Roukaerts, Arnout Dehairs, F. 2015-11 1 full-text file(s): application/pdf http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/299513 https://dipot.ulb.ac.be/dspace/bitstream/2013/299513/3/Fripiat_et_al_2015GBC.pdf en eng uri/info:doi/10.1002/2014GB005051 https://dipot.ulb.ac.be/dspace/bitstream/2013/299513/3/Fripiat_et_al_2015GBC.pdf http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/299513 1 full-text file(s): info:eu-repo/semantics/restrictedAccess Global biogeochemical cycles, 29 (11 Sciences de la terre et du cosmos info:eu-repo/semantics/article info:ulb-repo/semantics/articlePeerReview info:ulb-repo/semantics/openurl/article 2015 ftunivbruxelles 2022-06-12T22:10:11Z Nitrification, the microbially mediated oxidation of ammonium into nitrate, is generally expected to be low in the Southern Ocean mixed layer. This paradigm assumes that nitrate is mainly provided through vertical mixing and assimilated during the vegetative season, supporting the concept that nitrate uptake is equivalent to the new primary production (i.e. primary production which is potentially available for export). Here we show that nitrification is significant (~40–80% of the seasonal nitrate uptake) in the naturally iron-fertilized bloom over the southeast Kerguelen Plateau. Hence, a large fraction of the nitrate-based primary production is regenerated, instead of being exported. It appears that nitrate assimilation (light dependent) and nitrification (partly light inhibited) are spatially separated between the upper and lower parts, respectively, of the deep surface mixed layers. These deep mixed layers, extending well below the euphotic layer, allow nitrifiers to compete with phytoplankton for the assimilation of ammonium. The high contributions of nitrification to nitrate uptake are in agreement with both low export efficiency (i.e. the percentage of primary production that is exported) and low seasonal nitrate drawdown despite high nitrate assimilation. info:eu-repo/semantics/published Article in Journal/Newspaper Southern Ocean DI-fusion : dépôt institutionnel de l'Université libre de Bruxelles (ULB) Southern Ocean Kerguelen |
institution |
Open Polar |
collection |
DI-fusion : dépôt institutionnel de l'Université libre de Bruxelles (ULB) |
op_collection_id |
ftunivbruxelles |
language |
English |
topic |
Sciences de la terre et du cosmos |
spellingShingle |
Sciences de la terre et du cosmos Fripiat, François Elskens, M. Trull, Thomas W. Blain, S. Cavagna, A. -J. Fernandez, C. Fonseca-Batista, D. Planchon, Frédéric Raimbault, P. Roukaerts, Arnout Dehairs, F. Significant mixed layer nitrification in a natural iron-fertilized bloom of the Southern Ocean |
topic_facet |
Sciences de la terre et du cosmos |
description |
Nitrification, the microbially mediated oxidation of ammonium into nitrate, is generally expected to be low in the Southern Ocean mixed layer. This paradigm assumes that nitrate is mainly provided through vertical mixing and assimilated during the vegetative season, supporting the concept that nitrate uptake is equivalent to the new primary production (i.e. primary production which is potentially available for export). Here we show that nitrification is significant (~40–80% of the seasonal nitrate uptake) in the naturally iron-fertilized bloom over the southeast Kerguelen Plateau. Hence, a large fraction of the nitrate-based primary production is regenerated, instead of being exported. It appears that nitrate assimilation (light dependent) and nitrification (partly light inhibited) are spatially separated between the upper and lower parts, respectively, of the deep surface mixed layers. These deep mixed layers, extending well below the euphotic layer, allow nitrifiers to compete with phytoplankton for the assimilation of ammonium. The high contributions of nitrification to nitrate uptake are in agreement with both low export efficiency (i.e. the percentage of primary production that is exported) and low seasonal nitrate drawdown despite high nitrate assimilation. info:eu-repo/semantics/published |
format |
Article in Journal/Newspaper |
author |
Fripiat, François Elskens, M. Trull, Thomas W. Blain, S. Cavagna, A. -J. Fernandez, C. Fonseca-Batista, D. Planchon, Frédéric Raimbault, P. Roukaerts, Arnout Dehairs, F. |
author_facet |
Fripiat, François Elskens, M. Trull, Thomas W. Blain, S. Cavagna, A. -J. Fernandez, C. Fonseca-Batista, D. Planchon, Frédéric Raimbault, P. Roukaerts, Arnout Dehairs, F. |
author_sort |
Fripiat, François |
title |
Significant mixed layer nitrification in a natural iron-fertilized bloom of the Southern Ocean |
title_short |
Significant mixed layer nitrification in a natural iron-fertilized bloom of the Southern Ocean |
title_full |
Significant mixed layer nitrification in a natural iron-fertilized bloom of the Southern Ocean |
title_fullStr |
Significant mixed layer nitrification in a natural iron-fertilized bloom of the Southern Ocean |
title_full_unstemmed |
Significant mixed layer nitrification in a natural iron-fertilized bloom of the Southern Ocean |
title_sort |
significant mixed layer nitrification in a natural iron-fertilized bloom of the southern ocean |
publishDate |
2015 |
url |
http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/299513 https://dipot.ulb.ac.be/dspace/bitstream/2013/299513/3/Fripiat_et_al_2015GBC.pdf |
geographic |
Southern Ocean Kerguelen |
geographic_facet |
Southern Ocean Kerguelen |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
Global biogeochemical cycles, 29 (11 |
op_relation |
uri/info:doi/10.1002/2014GB005051 https://dipot.ulb.ac.be/dspace/bitstream/2013/299513/3/Fripiat_et_al_2015GBC.pdf http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/299513 |
op_rights |
1 full-text file(s): info:eu-repo/semantics/restrictedAccess |
_version_ |
1766206101437546496 |