Chemometric perspectives on plankton community responses to natural iron fertilisation over and downstream of the Kerguelen Plateau in the Southern Ocean
International audience We examined phytoplankton community responses to natural iron fertilisation at 32 sites over and downstream from the Kerguelen Plateau in the Southern Ocean during the austral spring bloom in October-November 2011. The community structure was estimated from chemical and isotop...
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Format: | Article in Journal/Newspaper |
Language: | English |
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HAL CCSD
2015
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Online Access: | https://hal.science/hal-04115552 https://doi.org/10.5194/bg-12-1029-201510.5194/bgd-11-13841-2014 |
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openpolar |
institution |
Open Polar |
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Institut national des sciences de l'Univers: HAL-INSU |
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language |
English |
topic |
Earth Science [SDU]Sciences of the Universe [physics] |
spellingShingle |
Earth Science [SDU]Sciences of the Universe [physics] Trull, T. W. Davies, D. M. Dehairs, F. Cavagna, A. -J. Lasbleiz, M. Laurenceau-Cornec, E. C. d'Ovidio, F. Planchon, F. Leblanc, K. Quéguiner, B. Blain, S. Chemometric perspectives on plankton community responses to natural iron fertilisation over and downstream of the Kerguelen Plateau in the Southern Ocean |
topic_facet |
Earth Science [SDU]Sciences of the Universe [physics] |
description |
International audience We examined phytoplankton community responses to natural iron fertilisation at 32 sites over and downstream from the Kerguelen Plateau in the Southern Ocean during the austral spring bloom in October-November 2011. The community structure was estimated from chemical and isotopic measurements (particulate organic carbon - POC; 13 C-POC; particulate nitrogen - PN; 15 N-PN; and biogenic silica - BSi) on size-fractionated samples from surface waters (300, 210, 50, 20, 5, and 1 μm fractions). Higher values of 13 C-POC (vs. co-located 13 C values for dissolved inorganic carbon - DIC) were taken as indicative of faster growth rates and higher values of 15 N-PN (vs. co-located 15 N-NO 3 source values) as indicative of greater nitrate use (rather than ammonium use, i.e. higher f ratios). Community responses varied in relation to both regional circulation and the advance of the bloom. Iron-fertilised waters over the plateau developed dominance by very large diatoms (50-210 μm) with high BSi / POC ratios, high growth rates, and significant ammonium recycling (lower f ratios) as biomass built up. In contrast, downstream polar frontal waters with a similar or higher iron supply were dominated by smaller diatoms (20-50 μm) and exhibited greater ammonium recycling. Stations in a deep-water bathymetrically trapped recirculation south of the polar front with lower iron levels showed the large-cell dominance observed on the plateau but much less biomass. Comparison of these communities to surface water nitrate (and silicate) depletions as a proxy for export shows that the low-biomass recirculation feature had exported similar amounts of nitrogen to the high-biomass blooms over the plateau and north of the polar front. This suggests that early spring trophodynamic and export responses differed between regions with persistent low levels vs. intermittent high levels of iron fertilisation. |
author2 |
Aix Marseille Université (AMU) 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) |
format |
Article in Journal/Newspaper |
author |
Trull, T. W. Davies, D. M. Dehairs, F. Cavagna, A. -J. Lasbleiz, M. Laurenceau-Cornec, E. C. d'Ovidio, F. Planchon, F. Leblanc, K. Quéguiner, B. Blain, S. |
author_facet |
Trull, T. W. Davies, D. M. Dehairs, F. Cavagna, A. -J. Lasbleiz, M. Laurenceau-Cornec, E. C. d'Ovidio, F. Planchon, F. Leblanc, K. Quéguiner, B. Blain, S. |
author_sort |
Trull, T. W. |
title |
Chemometric perspectives on plankton community responses to natural iron fertilisation over and downstream of the Kerguelen Plateau in the Southern Ocean |
title_short |
Chemometric perspectives on plankton community responses to natural iron fertilisation over and downstream of the Kerguelen Plateau in the Southern Ocean |
title_full |
Chemometric perspectives on plankton community responses to natural iron fertilisation over and downstream of the Kerguelen Plateau in the Southern Ocean |
title_fullStr |
Chemometric perspectives on plankton community responses to natural iron fertilisation over and downstream of the Kerguelen Plateau in the Southern Ocean |
title_full_unstemmed |
Chemometric perspectives on plankton community responses to natural iron fertilisation over and downstream of the Kerguelen Plateau in the Southern Ocean |
title_sort |
chemometric perspectives on plankton community responses to natural iron fertilisation over and downstream of the kerguelen plateau in the southern ocean |
publisher |
HAL CCSD |
publishDate |
2015 |
url |
https://hal.science/hal-04115552 https://doi.org/10.5194/bg-12-1029-201510.5194/bgd-11-13841-2014 |
geographic |
Austral Kerguelen Southern Ocean |
geographic_facet |
Austral Kerguelen Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
Biogeosciences https://hal.science/hal-04115552 Biogeosciences, 2015, 12, pp.1029-1056. ⟨10.5194/bg-12-1029-201510.5194/bgd-11-13841-2014⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/bg-12-1029-201510.5194/bgd-11-13841-2014 hal-04115552 https://hal.science/hal-04115552 BIBCODE: 2015BGeo.12.1029T doi:10.5194/bg-12-1029-201510.5194/bgd-11-13841-2014 |
op_doi |
https://doi.org/10.5194/bg-12-1029-201510.5194/bgd-11-13841-2014 |
_version_ |
1769009468487499776 |
spelling |
ftinsu:oai:HAL:hal-04115552v1 2023-06-18T03:43:11+02:00 Chemometric perspectives on plankton community responses to natural iron fertilisation over and downstream of the Kerguelen Plateau in the Southern Ocean Trull, T. W. Davies, D. M. Dehairs, F. Cavagna, A. -J. Lasbleiz, M. Laurenceau-Cornec, E. C. d'Ovidio, F. Planchon, F. Leblanc, K. Quéguiner, B. Blain, S. Aix Marseille Université (AMU) 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) 2015 https://hal.science/hal-04115552 https://doi.org/10.5194/bg-12-1029-201510.5194/bgd-11-13841-2014 en eng HAL CCSD info:eu-repo/semantics/altIdentifier/doi/10.5194/bg-12-1029-201510.5194/bgd-11-13841-2014 hal-04115552 https://hal.science/hal-04115552 BIBCODE: 2015BGeo.12.1029T doi:10.5194/bg-12-1029-201510.5194/bgd-11-13841-2014 Biogeosciences https://hal.science/hal-04115552 Biogeosciences, 2015, 12, pp.1029-1056. ⟨10.5194/bg-12-1029-201510.5194/bgd-11-13841-2014⟩ Earth Science [SDU]Sciences of the Universe [physics] info:eu-repo/semantics/article Journal articles 2015 ftinsu https://doi.org/10.5194/bg-12-1029-201510.5194/bgd-11-13841-2014 2023-06-05T19:25:43Z International audience We examined phytoplankton community responses to natural iron fertilisation at 32 sites over and downstream from the Kerguelen Plateau in the Southern Ocean during the austral spring bloom in October-November 2011. The community structure was estimated from chemical and isotopic measurements (particulate organic carbon - POC; 13 C-POC; particulate nitrogen - PN; 15 N-PN; and biogenic silica - BSi) on size-fractionated samples from surface waters (300, 210, 50, 20, 5, and 1 μm fractions). Higher values of 13 C-POC (vs. co-located 13 C values for dissolved inorganic carbon - DIC) were taken as indicative of faster growth rates and higher values of 15 N-PN (vs. co-located 15 N-NO 3 source values) as indicative of greater nitrate use (rather than ammonium use, i.e. higher f ratios). Community responses varied in relation to both regional circulation and the advance of the bloom. Iron-fertilised waters over the plateau developed dominance by very large diatoms (50-210 μm) with high BSi / POC ratios, high growth rates, and significant ammonium recycling (lower f ratios) as biomass built up. In contrast, downstream polar frontal waters with a similar or higher iron supply were dominated by smaller diatoms (20-50 μm) and exhibited greater ammonium recycling. Stations in a deep-water bathymetrically trapped recirculation south of the polar front with lower iron levels showed the large-cell dominance observed on the plateau but much less biomass. Comparison of these communities to surface water nitrate (and silicate) depletions as a proxy for export shows that the low-biomass recirculation feature had exported similar amounts of nitrogen to the high-biomass blooms over the plateau and north of the polar front. This suggests that early spring trophodynamic and export responses differed between regions with persistent low levels vs. intermittent high levels of iron fertilisation. Article in Journal/Newspaper Southern Ocean Institut national des sciences de l'Univers: HAL-INSU Austral Kerguelen Southern Ocean |