Phytoplankton Responses to Bacterially Regenerated Iron in a Southern Ocean Eddy
International audience In the Subantarctic sector of the Southern Ocean, vertical entrainment of iron (Fe) triggers the seasonal productivity cycle but diminishing physical supply during the spring to summer transition forces microbial assemblages to rapidly acclimate. Here, we tested how phytoplank...
Published in: | Microorganisms |
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Online Access: | https://cnrs.hal.science/hal-03831160 https://cnrs.hal.science/hal-03831160/document https://cnrs.hal.science/hal-03831160/file/Fourquez%20et%20al.%202022.pdf https://doi.org/10.3390/microorganisms10081655 |
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ftccsdartic:oai:HAL:hal-03831160v1 2024-02-11T10:08:48+01:00 Phytoplankton Responses to Bacterially Regenerated Iron in a Southern Ocean Eddy Fourquez, Marion Strzepek, Robert, F Ellwood, Michael, J Hassler, Christel Cabanes, Damien Eggins, Sam Pearce, Imojen Deppeler, Stacy Trull, Thomas, W Boyd, Philip, W Bressac, Matthieu University of Tasmania Hobart, Australia (UTAS) Australian National University (ANU) Université de Genève = University of Geneva (UNIGE) Université de Lausanne = University of Lausanne (UNIL) 2022 https://cnrs.hal.science/hal-03831160 https://cnrs.hal.science/hal-03831160/document https://cnrs.hal.science/hal-03831160/file/Fourquez%20et%20al.%202022.pdf https://doi.org/10.3390/microorganisms10081655 en eng HAL CCSD MDPI info:eu-repo/semantics/altIdentifier/doi/10.3390/microorganisms10081655 hal-03831160 https://cnrs.hal.science/hal-03831160 https://cnrs.hal.science/hal-03831160/document https://cnrs.hal.science/hal-03831160/file/Fourquez%20et%20al.%202022.pdf doi:10.3390/microorganisms10081655 info:eu-repo/semantics/OpenAccess ISSN: 2076-2607 Microorganisms https://cnrs.hal.science/hal-03831160 Microorganisms, 2022, 10 (8), pp.1655. ⟨10.3390/microorganisms10081655⟩ particles Southern Ocean eddies vertical supply Subantarctic iron regeneration [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography info:eu-repo/semantics/article Journal articles 2022 ftccsdartic https://doi.org/10.3390/microorganisms10081655 2024-01-14T00:06:06Z International audience In the Subantarctic sector of the Southern Ocean, vertical entrainment of iron (Fe) triggers the seasonal productivity cycle but diminishing physical supply during the spring to summer transition forces microbial assemblages to rapidly acclimate. Here, we tested how phytoplankton and bacteria within an isolated eddy respond to different dissolved Fe (DFe)/ligand inputs. We used three treatments: one that mimicked the entrainment of new DFe (Fe-NEW), another in which DFe was supplied from bacterial regeneration of particles (Fe-REG), and a control with no addition of DFe (Fe-NO). After 6 days, 3.5 (Fe-NO, Fe-NEW) to 5-fold (Fe-REG) increases in Chlorophyll a were observed. These responses of the phytoplankton community were best explained by the differences between the treatments in the amount of DFe recycled during the incubation (Fe-REG, 15% recycled c.f. 40% Fe-NEW, 60% Fe-NO). This additional recycling was more likely mediated by bacteria. By day 6, bacterial production was comparable between Fe-NO and Fe-NEW but was approximately two-fold higher in Fe-REG. A preferential response of phytoplankton (haptophyte-dominated) relative to high nucleic acid (HNA) bacteria was also found in the Fe-REG treatment while the relative proportion of diatoms increased faster in the Fe-NEW and Fe-NO treatments. Comparisons between light and dark incubations further confirmed the competition between picophytoplankton and HNA for DFe. Overall, our results demonstrate great versatility by microorganisms to use different Fe sourcesthat results in highly efficient Fe recycling within surface waters. This study also encourages future research to further investigate the interactions between functional groups of microbes (e.g. HNA and cyanobacteria) to better constraint modeling in Fe and carbon biogeochemical cycles. Article in Journal/Newspaper Southern Ocean Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Southern Ocean Microorganisms 10 8 1655 |
institution |
Open Polar |
collection |
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
op_collection_id |
ftccsdartic |
language |
English |
topic |
particles Southern Ocean eddies vertical supply Subantarctic iron regeneration [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography |
spellingShingle |
particles Southern Ocean eddies vertical supply Subantarctic iron regeneration [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography Fourquez, Marion Strzepek, Robert, F Ellwood, Michael, J Hassler, Christel Cabanes, Damien Eggins, Sam Pearce, Imojen Deppeler, Stacy Trull, Thomas, W Boyd, Philip, W Bressac, Matthieu Phytoplankton Responses to Bacterially Regenerated Iron in a Southern Ocean Eddy |
topic_facet |
particles Southern Ocean eddies vertical supply Subantarctic iron regeneration [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography |
description |
International audience In the Subantarctic sector of the Southern Ocean, vertical entrainment of iron (Fe) triggers the seasonal productivity cycle but diminishing physical supply during the spring to summer transition forces microbial assemblages to rapidly acclimate. Here, we tested how phytoplankton and bacteria within an isolated eddy respond to different dissolved Fe (DFe)/ligand inputs. We used three treatments: one that mimicked the entrainment of new DFe (Fe-NEW), another in which DFe was supplied from bacterial regeneration of particles (Fe-REG), and a control with no addition of DFe (Fe-NO). After 6 days, 3.5 (Fe-NO, Fe-NEW) to 5-fold (Fe-REG) increases in Chlorophyll a were observed. These responses of the phytoplankton community were best explained by the differences between the treatments in the amount of DFe recycled during the incubation (Fe-REG, 15% recycled c.f. 40% Fe-NEW, 60% Fe-NO). This additional recycling was more likely mediated by bacteria. By day 6, bacterial production was comparable between Fe-NO and Fe-NEW but was approximately two-fold higher in Fe-REG. A preferential response of phytoplankton (haptophyte-dominated) relative to high nucleic acid (HNA) bacteria was also found in the Fe-REG treatment while the relative proportion of diatoms increased faster in the Fe-NEW and Fe-NO treatments. Comparisons between light and dark incubations further confirmed the competition between picophytoplankton and HNA for DFe. Overall, our results demonstrate great versatility by microorganisms to use different Fe sourcesthat results in highly efficient Fe recycling within surface waters. This study also encourages future research to further investigate the interactions between functional groups of microbes (e.g. HNA and cyanobacteria) to better constraint modeling in Fe and carbon biogeochemical cycles. |
author2 |
University of Tasmania Hobart, Australia (UTAS) Australian National University (ANU) Université de Genève = University of Geneva (UNIGE) Université de Lausanne = University of Lausanne (UNIL) |
format |
Article in Journal/Newspaper |
author |
Fourquez, Marion Strzepek, Robert, F Ellwood, Michael, J Hassler, Christel Cabanes, Damien Eggins, Sam Pearce, Imojen Deppeler, Stacy Trull, Thomas, W Boyd, Philip, W Bressac, Matthieu |
author_facet |
Fourquez, Marion Strzepek, Robert, F Ellwood, Michael, J Hassler, Christel Cabanes, Damien Eggins, Sam Pearce, Imojen Deppeler, Stacy Trull, Thomas, W Boyd, Philip, W Bressac, Matthieu |
author_sort |
Fourquez, Marion |
title |
Phytoplankton Responses to Bacterially Regenerated Iron in a Southern Ocean Eddy |
title_short |
Phytoplankton Responses to Bacterially Regenerated Iron in a Southern Ocean Eddy |
title_full |
Phytoplankton Responses to Bacterially Regenerated Iron in a Southern Ocean Eddy |
title_fullStr |
Phytoplankton Responses to Bacterially Regenerated Iron in a Southern Ocean Eddy |
title_full_unstemmed |
Phytoplankton Responses to Bacterially Regenerated Iron in a Southern Ocean Eddy |
title_sort |
phytoplankton responses to bacterially regenerated iron in a southern ocean eddy |
publisher |
HAL CCSD |
publishDate |
2022 |
url |
https://cnrs.hal.science/hal-03831160 https://cnrs.hal.science/hal-03831160/document https://cnrs.hal.science/hal-03831160/file/Fourquez%20et%20al.%202022.pdf https://doi.org/10.3390/microorganisms10081655 |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
ISSN: 2076-2607 Microorganisms https://cnrs.hal.science/hal-03831160 Microorganisms, 2022, 10 (8), pp.1655. ⟨10.3390/microorganisms10081655⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.3390/microorganisms10081655 hal-03831160 https://cnrs.hal.science/hal-03831160 https://cnrs.hal.science/hal-03831160/document https://cnrs.hal.science/hal-03831160/file/Fourquez%20et%20al.%202022.pdf doi:10.3390/microorganisms10081655 |
op_rights |
info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.3390/microorganisms10081655 |
container_title |
Microorganisms |
container_volume |
10 |
container_issue |
8 |
container_start_page |
1655 |
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1790608410817855488 |