The structure of diatom communities constrains biogeochemical properties in surface waters of the Southern Ocean (Kerguelen Plateau)
International audience In the context of climate change, understanding the ecological processes controlling the functioning and the efficiency of the biological pump is of primary importance. Plankton community structure and species-specific properties are often invoked as likely to affect biogeoche...
Published in: | Journal of Marine Systems |
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Format: | Article in Journal/Newspaper |
Language: | English |
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2020
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Online Access: | https://doi.org/10.1016/j.jmarsys.2020.103458 https://hal.archives-ouvertes.fr/hal-03035828/file/Lafond,2020-subm.pdf https://hal.archives-ouvertes.fr/hal-03035828 |
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fttriple:oai:gotriple.eu:0wd49VPUm7LgPOdaSkTXj 2023-05-15T17:02:07+02:00 The structure of diatom communities constrains biogeochemical properties in surface waters of the Southern Ocean (Kerguelen Plateau) Lafond, Augustin Leblanc, Karine Legras, Justine Cornet, Veronique QUEGUINER, Bernard Institut méditerranéen d'océanologie (MIO) Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Toulon (UTLN) 2020-01-01 https://doi.org/10.1016/j.jmarsys.2020.103458 https://hal.archives-ouvertes.fr/hal-03035828/file/Lafond,2020-subm.pdf https://hal.archives-ouvertes.fr/hal-03035828 en eng HAL CCSD Elsevier hal-03035828 10670/1.wzmw7p hal-03129381 doi:10.1016/j.jmarsys.2020.103458 10670/1.ftylxu https://hal.archives-ouvertes.fr/hal-03035828/file/Lafond,2020-subm.pdf https://hal.archives-ouvertes.fr/hal-03035828 other Hyper Article en Ligne - Sciences de l'Homme et de la Société ISSN: 0924-7963 Journal of Marine Systems Journal of Marine Systems, Elsevier, 2020, 212, pp.103458 deep particle stocks diversity mortality modes diatoms Biological carbon pump Biological pump Community structure Kerguelen Plateau Southern Ocean envir geo Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2020 fttriple https://doi.org/10.1016/j.jmarsys.2020.103458 2023-01-22T17:34:31Z International audience In the context of climate change, understanding the ecological processes controlling the functioning and the efficiency of the biological pump is of primary importance. Plankton community structure and species-specific properties are often invoked as likely to affect biogeochemistry and the export of organic and biogenic material to the ocean interior. Although a major player in this respect, diatoms are still viewed as a single functional type whose diversity is generally overlooked. Here we examine that question, building on the results achieved during the MOBYDICK expedition, which occurred in the vicinity of the Kerguelen Islands (Southern Ocean) in late summer, a time window corresponding to the demise of the annually recurrent phytoplankton blooms already known to be controlled by iron availability. The Si/C/N stoichiometry of the particulate matter was studied in conjunction with the different diatom community structures, their physiological states, as well as their species-specific carbon contents and silicification degrees. Our results show that diatoms outside the ironfertilized plateau were more heavily silicified, due to the combined effects of both taxonomic composition of the resident community and a direct physiological response to iron stress, resulting in higher Si:C elemental ratios in diatoms as well as in the bulk particulate matter. Despite low silicic acid concentrations, large chains of weakly silicified Corethron inerme were able to grow in the upper mixed layer above the plateau, while in adjacent high nutrient low chlorophyll (HNLC) waters, communities were dominated by Fragilariopsis spp., Cylindrotheca closterium and the centric genera Actinocyclus/Thalassiosira spp. Depth was also an important factor shaping diatom communities, with the presence of a deep and inactive assemblage located within the pycnocline gradient, both on-and off-plateau, which likely resulted from the differential sinking and accumulation of species previously grown at the surface. In HNLC ... Article in Journal/Newspaper Kerguelen Islands Southern Ocean Unknown Southern Ocean Kerguelen Kerguelen Islands Journal of Marine Systems 212 103458 |
institution |
Open Polar |
collection |
Unknown |
op_collection_id |
fttriple |
language |
English |
topic |
deep particle stocks diversity mortality modes diatoms Biological carbon pump Biological pump Community structure Kerguelen Plateau Southern Ocean envir geo |
spellingShingle |
deep particle stocks diversity mortality modes diatoms Biological carbon pump Biological pump Community structure Kerguelen Plateau Southern Ocean envir geo Lafond, Augustin Leblanc, Karine Legras, Justine Cornet, Veronique QUEGUINER, Bernard The structure of diatom communities constrains biogeochemical properties in surface waters of the Southern Ocean (Kerguelen Plateau) |
topic_facet |
deep particle stocks diversity mortality modes diatoms Biological carbon pump Biological pump Community structure Kerguelen Plateau Southern Ocean envir geo |
description |
International audience In the context of climate change, understanding the ecological processes controlling the functioning and the efficiency of the biological pump is of primary importance. Plankton community structure and species-specific properties are often invoked as likely to affect biogeochemistry and the export of organic and biogenic material to the ocean interior. Although a major player in this respect, diatoms are still viewed as a single functional type whose diversity is generally overlooked. Here we examine that question, building on the results achieved during the MOBYDICK expedition, which occurred in the vicinity of the Kerguelen Islands (Southern Ocean) in late summer, a time window corresponding to the demise of the annually recurrent phytoplankton blooms already known to be controlled by iron availability. The Si/C/N stoichiometry of the particulate matter was studied in conjunction with the different diatom community structures, their physiological states, as well as their species-specific carbon contents and silicification degrees. Our results show that diatoms outside the ironfertilized plateau were more heavily silicified, due to the combined effects of both taxonomic composition of the resident community and a direct physiological response to iron stress, resulting in higher Si:C elemental ratios in diatoms as well as in the bulk particulate matter. Despite low silicic acid concentrations, large chains of weakly silicified Corethron inerme were able to grow in the upper mixed layer above the plateau, while in adjacent high nutrient low chlorophyll (HNLC) waters, communities were dominated by Fragilariopsis spp., Cylindrotheca closterium and the centric genera Actinocyclus/Thalassiosira spp. Depth was also an important factor shaping diatom communities, with the presence of a deep and inactive assemblage located within the pycnocline gradient, both on-and off-plateau, which likely resulted from the differential sinking and accumulation of species previously grown at the surface. In HNLC ... |
author2 |
Institut méditerranéen d'océanologie (MIO) Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Toulon (UTLN) |
format |
Article in Journal/Newspaper |
author |
Lafond, Augustin Leblanc, Karine Legras, Justine Cornet, Veronique QUEGUINER, Bernard |
author_facet |
Lafond, Augustin Leblanc, Karine Legras, Justine Cornet, Veronique QUEGUINER, Bernard |
author_sort |
Lafond, Augustin |
title |
The structure of diatom communities constrains biogeochemical properties in surface waters of the Southern Ocean (Kerguelen Plateau) |
title_short |
The structure of diatom communities constrains biogeochemical properties in surface waters of the Southern Ocean (Kerguelen Plateau) |
title_full |
The structure of diatom communities constrains biogeochemical properties in surface waters of the Southern Ocean (Kerguelen Plateau) |
title_fullStr |
The structure of diatom communities constrains biogeochemical properties in surface waters of the Southern Ocean (Kerguelen Plateau) |
title_full_unstemmed |
The structure of diatom communities constrains biogeochemical properties in surface waters of the Southern Ocean (Kerguelen Plateau) |
title_sort |
structure of diatom communities constrains biogeochemical properties in surface waters of the southern ocean (kerguelen plateau) |
publisher |
HAL CCSD |
publishDate |
2020 |
url |
https://doi.org/10.1016/j.jmarsys.2020.103458 https://hal.archives-ouvertes.fr/hal-03035828/file/Lafond,2020-subm.pdf https://hal.archives-ouvertes.fr/hal-03035828 |
geographic |
Southern Ocean Kerguelen Kerguelen Islands |
geographic_facet |
Southern Ocean Kerguelen Kerguelen Islands |
genre |
Kerguelen Islands Southern Ocean |
genre_facet |
Kerguelen Islands Southern Ocean |
op_source |
Hyper Article en Ligne - Sciences de l'Homme et de la Société ISSN: 0924-7963 Journal of Marine Systems Journal of Marine Systems, Elsevier, 2020, 212, pp.103458 |
op_relation |
hal-03035828 10670/1.wzmw7p hal-03129381 doi:10.1016/j.jmarsys.2020.103458 10670/1.ftylxu https://hal.archives-ouvertes.fr/hal-03035828/file/Lafond,2020-subm.pdf https://hal.archives-ouvertes.fr/hal-03035828 |
op_rights |
other |
op_doi |
https://doi.org/10.1016/j.jmarsys.2020.103458 |
container_title |
Journal of Marine Systems |
container_volume |
212 |
container_start_page |
103458 |
_version_ |
1766055371838849024 |