Seasonal microbial food web dynamics in contrasting Southern Ocean productivity regimes
Spatial and seasonal dynamics of microbial loop fluxes were investigated in contrasting productivity regimes in the Indian sector of the Southern Ocean. Observations carried out in late summer (February–March 2018; project MOBYDICK) revealed higher microbial biomasses and fluxes in the naturally iro...
Published in: | Limnology and Oceanography |
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Main Authors: | , , , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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ASLO
2021
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Online Access: | https://archimer.ifremer.fr/doc/00649/76109/77064.pdf https://archimer.ifremer.fr/doc/00649/76109/77065.tiff https://archimer.ifremer.fr/doc/00649/76109/77066.tif https://archimer.ifremer.fr/doc/00649/76109/77067.tif https://archimer.ifremer.fr/doc/00649/76109/77068.tif https://archimer.ifremer.fr/doc/00649/76109/77069.docx https://doi.org/10.1002/lno.11591 https://archimer.ifremer.fr/doc/00649/76109/ |
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ftarchimer:oai:archimer.ifremer.fr:76109 2023-09-05T13:23:27+02:00 Seasonal microbial food web dynamics in contrasting Southern Ocean productivity regimes Christaki, Urania Gueneugues, Audrey Liu, Yan Blain, Stéphane Catala, Philippe Colombet, Jonathan Debeljak, Pavla Jardillier, Ludwig Irion, Solène Planchon, Frederic Sassenhagen, Ingrid Sime Ngando, Telesphore Obernosterer, Ingrid 2021-01 application/pdf https://archimer.ifremer.fr/doc/00649/76109/77064.pdf https://archimer.ifremer.fr/doc/00649/76109/77065.tiff https://archimer.ifremer.fr/doc/00649/76109/77066.tif https://archimer.ifremer.fr/doc/00649/76109/77067.tif https://archimer.ifremer.fr/doc/00649/76109/77068.tif https://archimer.ifremer.fr/doc/00649/76109/77069.docx https://doi.org/10.1002/lno.11591 https://archimer.ifremer.fr/doc/00649/76109/ eng eng ASLO https://archimer.ifremer.fr/doc/00649/76109/77064.pdf https://archimer.ifremer.fr/doc/00649/76109/77065.tiff https://archimer.ifremer.fr/doc/00649/76109/77066.tif https://archimer.ifremer.fr/doc/00649/76109/77067.tif https://archimer.ifremer.fr/doc/00649/76109/77068.tif https://archimer.ifremer.fr/doc/00649/76109/77069.docx doi:10.1002/lno.11591 https://archimer.ifremer.fr/doc/00649/76109/ info:eu-repo/semantics/openAccess restricted use Limnology And Oceanography (0024-3590) (ASLO), 2021-01 , Vol. 66 , N. 1 , P. 108-122 text Article info:eu-repo/semantics/article 2021 ftarchimer https://doi.org/10.1002/lno.11591 2023-08-22T22:51:07Z Spatial and seasonal dynamics of microbial loop fluxes were investigated in contrasting productivity regimes in the Indian sector of the Southern Ocean. Observations carried out in late summer (February–March 2018; project MOBYDICK) revealed higher microbial biomasses and fluxes in the naturally iron‐fertilized surface waters of Kerguelen island in comparison to surrounding off‐plateau waters. Differences were most pronounced for bacterial heterotrophic production (2.3‐fold), the abundance of heterotrophic nanoflagellates (HNF; 2.7‐fold). Independent of site, grazing by HNF was the main loss process of bacterial production (80–100%), while virus‐induced mortality was low (< 9%). Combining these results with observations from previous investigations during early spring and summer allowed us to describe seasonal patterns in microbial food web fluxes and to compare these to carbon export in the iron‐fertilized and high‐nutrient, low‐chlorophyll (HNLC) Southern Ocean. Our data suggest an overall less efficient microbial food web during spring and summer, when respiration and viral lysis, respectively, represent important loss terms of bacterially‐mediated carbon. In late summer, primary production is more efficiently transferred to bacterial biomass and HNF and thus available for higher trophic levels. These results provide a new insight into the seasonal variability and the quantitative importance of microbial food web processes for the fate of primary production in the Southern Ocean Article in Journal/Newspaper Southern Ocean Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) Indian Kerguelen Kerguelen Island ENVELOPE(69.500,69.500,-49.250,-49.250) Southern Ocean Limnology and Oceanography 66 1 108 122 |
institution |
Open Polar |
collection |
Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) |
op_collection_id |
ftarchimer |
language |
English |
description |
Spatial and seasonal dynamics of microbial loop fluxes were investigated in contrasting productivity regimes in the Indian sector of the Southern Ocean. Observations carried out in late summer (February–March 2018; project MOBYDICK) revealed higher microbial biomasses and fluxes in the naturally iron‐fertilized surface waters of Kerguelen island in comparison to surrounding off‐plateau waters. Differences were most pronounced for bacterial heterotrophic production (2.3‐fold), the abundance of heterotrophic nanoflagellates (HNF; 2.7‐fold). Independent of site, grazing by HNF was the main loss process of bacterial production (80–100%), while virus‐induced mortality was low (< 9%). Combining these results with observations from previous investigations during early spring and summer allowed us to describe seasonal patterns in microbial food web fluxes and to compare these to carbon export in the iron‐fertilized and high‐nutrient, low‐chlorophyll (HNLC) Southern Ocean. Our data suggest an overall less efficient microbial food web during spring and summer, when respiration and viral lysis, respectively, represent important loss terms of bacterially‐mediated carbon. In late summer, primary production is more efficiently transferred to bacterial biomass and HNF and thus available for higher trophic levels. These results provide a new insight into the seasonal variability and the quantitative importance of microbial food web processes for the fate of primary production in the Southern Ocean |
format |
Article in Journal/Newspaper |
author |
Christaki, Urania Gueneugues, Audrey Liu, Yan Blain, Stéphane Catala, Philippe Colombet, Jonathan Debeljak, Pavla Jardillier, Ludwig Irion, Solène Planchon, Frederic Sassenhagen, Ingrid Sime Ngando, Telesphore Obernosterer, Ingrid |
spellingShingle |
Christaki, Urania Gueneugues, Audrey Liu, Yan Blain, Stéphane Catala, Philippe Colombet, Jonathan Debeljak, Pavla Jardillier, Ludwig Irion, Solène Planchon, Frederic Sassenhagen, Ingrid Sime Ngando, Telesphore Obernosterer, Ingrid Seasonal microbial food web dynamics in contrasting Southern Ocean productivity regimes |
author_facet |
Christaki, Urania Gueneugues, Audrey Liu, Yan Blain, Stéphane Catala, Philippe Colombet, Jonathan Debeljak, Pavla Jardillier, Ludwig Irion, Solène Planchon, Frederic Sassenhagen, Ingrid Sime Ngando, Telesphore Obernosterer, Ingrid |
author_sort |
Christaki, Urania |
title |
Seasonal microbial food web dynamics in contrasting Southern Ocean productivity regimes |
title_short |
Seasonal microbial food web dynamics in contrasting Southern Ocean productivity regimes |
title_full |
Seasonal microbial food web dynamics in contrasting Southern Ocean productivity regimes |
title_fullStr |
Seasonal microbial food web dynamics in contrasting Southern Ocean productivity regimes |
title_full_unstemmed |
Seasonal microbial food web dynamics in contrasting Southern Ocean productivity regimes |
title_sort |
seasonal microbial food web dynamics in contrasting southern ocean productivity regimes |
publisher |
ASLO |
publishDate |
2021 |
url |
https://archimer.ifremer.fr/doc/00649/76109/77064.pdf https://archimer.ifremer.fr/doc/00649/76109/77065.tiff https://archimer.ifremer.fr/doc/00649/76109/77066.tif https://archimer.ifremer.fr/doc/00649/76109/77067.tif https://archimer.ifremer.fr/doc/00649/76109/77068.tif https://archimer.ifremer.fr/doc/00649/76109/77069.docx https://doi.org/10.1002/lno.11591 https://archimer.ifremer.fr/doc/00649/76109/ |
long_lat |
ENVELOPE(69.500,69.500,-49.250,-49.250) |
geographic |
Indian Kerguelen Kerguelen Island Southern Ocean |
geographic_facet |
Indian Kerguelen Kerguelen Island Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
Limnology And Oceanography (0024-3590) (ASLO), 2021-01 , Vol. 66 , N. 1 , P. 108-122 |
op_relation |
https://archimer.ifremer.fr/doc/00649/76109/77064.pdf https://archimer.ifremer.fr/doc/00649/76109/77065.tiff https://archimer.ifremer.fr/doc/00649/76109/77066.tif https://archimer.ifremer.fr/doc/00649/76109/77067.tif https://archimer.ifremer.fr/doc/00649/76109/77068.tif https://archimer.ifremer.fr/doc/00649/76109/77069.docx doi:10.1002/lno.11591 https://archimer.ifremer.fr/doc/00649/76109/ |
op_rights |
info:eu-repo/semantics/openAccess restricted use |
op_doi |
https://doi.org/10.1002/lno.11591 |
container_title |
Limnology and Oceanography |
container_volume |
66 |
container_issue |
1 |
container_start_page |
108 |
op_container_end_page |
122 |
_version_ |
1776204028241248256 |