Iron fertilization enhanced net community production but not downward particle flux during the Southern Ocean iron fertilization experiment LOHAFEX
International audience A closed eddy core in the Subantarctic Atlantic Ocean was fertilized twice with two tons of iron (as FeSO4), and the 300 km2 fertilized patch was studied for 39 days to test whether fertilization enhances downward particle flux into the deep ocean. Chlorophyll a and primary pr...
Published in: | Global Biogeochemical Cycles |
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Main Authors: | , , , , , , , , , , , , , , |
Other Authors: | , , , , , , , , , , , , , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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HAL CCSD
2013
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Online Access: | https://hal.science/hal-01445819 https://hal.science/hal-01445819/document https://hal.science/hal-01445819/file/Martin_et_al-2013-Global_Biogeochemical_Cycles.pdf https://doi.org/10.1002/gbc.20077 |
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Open Polar |
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Institut national des sciences de l'Univers: HAL-INSU |
op_collection_id |
ftinsu |
language |
English |
topic |
[SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography [SDE.BE]Environmental Sciences/Biodiversity and Ecology [SDE.IE]Environmental Sciences/Environmental Engineering |
spellingShingle |
[SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography [SDE.BE]Environmental Sciences/Biodiversity and Ecology [SDE.IE]Environmental Sciences/Environmental Engineering Martin, Patrick van Der Loeff, Michiel M. Rutgers Cassar, Nicolas Vandromme, Pieter d'Ovidio, Francesco Stemmann, Lars Rengarajan, R. Soares, Melena González, Humberto, E. Ebersbach, Friederike, E Lampitt, Richard S. Sanders, Richard Barnett, Bruce A. Smetacek, Victor Naqvi, S. Wajih A. Iron fertilization enhanced net community production but not downward particle flux during the Southern Ocean iron fertilization experiment LOHAFEX |
topic_facet |
[SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography [SDE.BE]Environmental Sciences/Biodiversity and Ecology [SDE.IE]Environmental Sciences/Environmental Engineering |
description |
International audience A closed eddy core in the Subantarctic Atlantic Ocean was fertilized twice with two tons of iron (as FeSO4), and the 300 km2 fertilized patch was studied for 39 days to test whether fertilization enhances downward particle flux into the deep ocean. Chlorophyll a and primary productivity doubled after fertilization, and photosynthetic quantum yield (FV/FM) increased from 0.33 to ≥0.40. Silicic acid (<2 µmol L −1 ) limited diatoms, which contributed <10% of phytoplankton biomass. Copepods exerted high grazing pressure. This is the first study of particle flux out of an artificially fertilized bloom with very low diatom biomass. Net community production (NCP) inside the patch, estimated from O2:Ar ratios, averaged 21 mmol POC m−2 d−1, probably ±20%. 234 Th profiles implied constant export of ~6.3 mmol POC m −2 d −1 in the patch, similar to unfertilized waters. The difference between NCP and 234 Th-derived export partly accumulated in the mixed layer and was partly remineralized between the mixed layer and 100 m. Neutrally buoyant sediment traps at 200 and 450 m inside and outside the patch caught mostly <1.1 mmol POC m −2 d −1 , predominantly of fecal origin; flux did not increase upon fertilization. Our data thus indicate intense flux attenuation between 100 and 200 m, and probably between the mixed layer and 100 m. We attribute the lack of fertilization-induced export to silicon limitation of diatoms and reprocessing of sinking particles by detritus feeders. Our data are consistent with the view that nitrate-rich but silicate-deficient waters are not poised for enhanced particle export upon iron addition. |
author2 |
Earth Observatory of Singapore (EOS) Nanyang Technological University Singapour National Oceanography Centre Southampton (NOC) University of Southampton Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung = Alfred Wegener Institute for Polar and Marine Research = Institut Alfred-Wegener pour la recherche polaire et marine (AWI) Helmholtz-Gemeinschaft = Helmholtz Association Division of Earth and Ocean Sciences Duke University Durham Laboratoire d'océanographie de Villefranche (LOV) Observatoire océanologique de Villefranche-sur-mer (OOVM) Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS) Processus de couplage à Petite Echelle, Ecosystèmes et Prédateurs Supérieurs (PEPS) Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN) Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)) École normale supérieure - Paris (ENS-PSL) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS) Physical Research Laboratory Ahmedabad (PRL) Indian Space Research Organisation (ISRO) CSIR National Institute of Oceanography India (NIO) Instituto de Ciencias Marinas y Limnológicas Universidad Austral de Chile |
format |
Article in Journal/Newspaper |
author |
Martin, Patrick van Der Loeff, Michiel M. Rutgers Cassar, Nicolas Vandromme, Pieter d'Ovidio, Francesco Stemmann, Lars Rengarajan, R. Soares, Melena González, Humberto, E. Ebersbach, Friederike, E Lampitt, Richard S. Sanders, Richard Barnett, Bruce A. Smetacek, Victor Naqvi, S. Wajih A. |
author_facet |
Martin, Patrick van Der Loeff, Michiel M. Rutgers Cassar, Nicolas Vandromme, Pieter d'Ovidio, Francesco Stemmann, Lars Rengarajan, R. Soares, Melena González, Humberto, E. Ebersbach, Friederike, E Lampitt, Richard S. Sanders, Richard Barnett, Bruce A. Smetacek, Victor Naqvi, S. Wajih A. |
author_sort |
Martin, Patrick |
title |
Iron fertilization enhanced net community production but not downward particle flux during the Southern Ocean iron fertilization experiment LOHAFEX |
title_short |
Iron fertilization enhanced net community production but not downward particle flux during the Southern Ocean iron fertilization experiment LOHAFEX |
title_full |
Iron fertilization enhanced net community production but not downward particle flux during the Southern Ocean iron fertilization experiment LOHAFEX |
title_fullStr |
Iron fertilization enhanced net community production but not downward particle flux during the Southern Ocean iron fertilization experiment LOHAFEX |
title_full_unstemmed |
Iron fertilization enhanced net community production but not downward particle flux during the Southern Ocean iron fertilization experiment LOHAFEX |
title_sort |
iron fertilization enhanced net community production but not downward particle flux during the southern ocean iron fertilization experiment lohafex |
publisher |
HAL CCSD |
publishDate |
2013 |
url |
https://hal.science/hal-01445819 https://hal.science/hal-01445819/document https://hal.science/hal-01445819/file/Martin_et_al-2013-Global_Biogeochemical_Cycles.pdf https://doi.org/10.1002/gbc.20077 |
genre |
Southern Ocean Copepods |
genre_facet |
Southern Ocean Copepods |
op_source |
ISSN: 0886-6236 EISSN: 1944-8224 Global Biogeochemical Cycles https://hal.science/hal-01445819 Global Biogeochemical Cycles, 2013, 27, pp.871-881. ⟨10.1002/gbc.20077⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1002/gbc.20077 hal-01445819 https://hal.science/hal-01445819 https://hal.science/hal-01445819/document https://hal.science/hal-01445819/file/Martin_et_al-2013-Global_Biogeochemical_Cycles.pdf doi:10.1002/gbc.20077 |
op_rights |
info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.1002/gbc.20077 |
container_title |
Global Biogeochemical Cycles |
container_volume |
27 |
container_issue |
3 |
container_start_page |
871 |
op_container_end_page |
881 |
_version_ |
1797570593578549248 |
spelling |
ftinsu:oai:HAL:hal-01445819v1 2024-04-28T08:39:39+00:00 Iron fertilization enhanced net community production but not downward particle flux during the Southern Ocean iron fertilization experiment LOHAFEX Martin, Patrick van Der Loeff, Michiel M. Rutgers Cassar, Nicolas Vandromme, Pieter d'Ovidio, Francesco Stemmann, Lars Rengarajan, R. Soares, Melena González, Humberto, E. Ebersbach, Friederike, E Lampitt, Richard S. Sanders, Richard Barnett, Bruce A. Smetacek, Victor Naqvi, S. Wajih A. Earth Observatory of Singapore (EOS) Nanyang Technological University Singapour National Oceanography Centre Southampton (NOC) University of Southampton Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung = Alfred Wegener Institute for Polar and Marine Research = Institut Alfred-Wegener pour la recherche polaire et marine (AWI) Helmholtz-Gemeinschaft = Helmholtz Association Division of Earth and Ocean Sciences Duke University Durham Laboratoire d'océanographie de Villefranche (LOV) Observatoire océanologique de Villefranche-sur-mer (OOVM) Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS) Processus de couplage à Petite Echelle, Ecosystèmes et Prédateurs Supérieurs (PEPS) Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN) Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)) École normale supérieure - Paris (ENS-PSL) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS) Physical Research Laboratory Ahmedabad (PRL) Indian Space Research Organisation (ISRO) CSIR National Institute of Oceanography India (NIO) Instituto de Ciencias Marinas y Limnológicas Universidad Austral de Chile 2013 https://hal.science/hal-01445819 https://hal.science/hal-01445819/document https://hal.science/hal-01445819/file/Martin_et_al-2013-Global_Biogeochemical_Cycles.pdf https://doi.org/10.1002/gbc.20077 en eng HAL CCSD American Geophysical Union info:eu-repo/semantics/altIdentifier/doi/10.1002/gbc.20077 hal-01445819 https://hal.science/hal-01445819 https://hal.science/hal-01445819/document https://hal.science/hal-01445819/file/Martin_et_al-2013-Global_Biogeochemical_Cycles.pdf doi:10.1002/gbc.20077 info:eu-repo/semantics/OpenAccess ISSN: 0886-6236 EISSN: 1944-8224 Global Biogeochemical Cycles https://hal.science/hal-01445819 Global Biogeochemical Cycles, 2013, 27, pp.871-881. ⟨10.1002/gbc.20077⟩ [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography [SDE.BE]Environmental Sciences/Biodiversity and Ecology [SDE.IE]Environmental Sciences/Environmental Engineering info:eu-repo/semantics/article Journal articles 2013 ftinsu https://doi.org/10.1002/gbc.20077 2024-04-05T00:47:53Z International audience A closed eddy core in the Subantarctic Atlantic Ocean was fertilized twice with two tons of iron (as FeSO4), and the 300 km2 fertilized patch was studied for 39 days to test whether fertilization enhances downward particle flux into the deep ocean. Chlorophyll a and primary productivity doubled after fertilization, and photosynthetic quantum yield (FV/FM) increased from 0.33 to ≥0.40. Silicic acid (<2 µmol L −1 ) limited diatoms, which contributed <10% of phytoplankton biomass. Copepods exerted high grazing pressure. This is the first study of particle flux out of an artificially fertilized bloom with very low diatom biomass. Net community production (NCP) inside the patch, estimated from O2:Ar ratios, averaged 21 mmol POC m−2 d−1, probably ±20%. 234 Th profiles implied constant export of ~6.3 mmol POC m −2 d −1 in the patch, similar to unfertilized waters. The difference between NCP and 234 Th-derived export partly accumulated in the mixed layer and was partly remineralized between the mixed layer and 100 m. Neutrally buoyant sediment traps at 200 and 450 m inside and outside the patch caught mostly <1.1 mmol POC m −2 d −1 , predominantly of fecal origin; flux did not increase upon fertilization. Our data thus indicate intense flux attenuation between 100 and 200 m, and probably between the mixed layer and 100 m. We attribute the lack of fertilization-induced export to silicon limitation of diatoms and reprocessing of sinking particles by detritus feeders. Our data are consistent with the view that nitrate-rich but silicate-deficient waters are not poised for enhanced particle export upon iron addition. Article in Journal/Newspaper Southern Ocean Copepods Institut national des sciences de l'Univers: HAL-INSU Global Biogeochemical Cycles 27 3 871 881 |