Export fluxes in a naturally iron-fertilized area of the Southern Ocean - Part 2: Importance of diatom resting spores and faecal pellets for export
The biological composition of the material exported to a moored sediment trap located under the winter mixed layer of the naturally fertilized Kerguelen Plateau in the Southern Ocean was studied over an annual cycle. Despite iron availability in spring, the annual particulate organic carbon (POC) ex...
Published in: | Biogeosciences |
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Language: | English |
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Copernicus Gesellschaft Mbh
2015
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Online Access: | https://archimer.ifremer.fr/doc/00295/40579/39498.pdf https://archimer.ifremer.fr/doc/00295/40579/39499.pdf https://archimer.ifremer.fr/doc/00295/40579/71317.pdf https://doi.org/10.5194/bg-12-3171-2015 https://archimer.ifremer.fr/doc/00295/40579/ |
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ftarchimer:oai:archimer.ifremer.fr:40579 2023-05-15T13:50:50+02:00 Export fluxes in a naturally iron-fertilized area of the Southern Ocean - Part 2: Importance of diatom resting spores and faecal pellets for export Rembauville, M. Blain, S. Armand, L. Queguiner, B. Salter, I. 2015-06-02 application/pdf https://archimer.ifremer.fr/doc/00295/40579/39498.pdf https://archimer.ifremer.fr/doc/00295/40579/39499.pdf https://archimer.ifremer.fr/doc/00295/40579/71317.pdf https://doi.org/10.5194/bg-12-3171-2015 https://archimer.ifremer.fr/doc/00295/40579/ eng eng Copernicus Gesellschaft Mbh https://archimer.ifremer.fr/doc/00295/40579/39498.pdf https://archimer.ifremer.fr/doc/00295/40579/39499.pdf https://archimer.ifremer.fr/doc/00295/40579/71317.pdf doi:10.5194/bg-12-3171-2015 https://archimer.ifremer.fr/doc/00295/40579/ Author(s) 2015. CC Attribution 3.0 License info:eu-repo/semantics/openAccess restricted use CC-BY Biogeosciences (1726-4170) (Copernicus Gesellschaft Mbh), 2015-06-02 , Vol. 12 , N. 11 , P. 3171-3195 text Publication info:eu-repo/semantics/article 2015 ftarchimer https://doi.org/10.5194/bg-12-3171-2015 2021-09-23T20:27:02Z The biological composition of the material exported to a moored sediment trap located under the winter mixed layer of the naturally fertilized Kerguelen Plateau in the Southern Ocean was studied over an annual cycle. Despite iron availability in spring, the annual particulate organic carbon (POC) export (98.2 mmol m(-2)) at 289m was low, but annual biogenic silica export was significant (114 mmol m(-2)). This feature was related to the abundance of empty diatom cells and the ratio of full to empty cells exerted a first-order control in BSi : POC export stoichiometry of the biological pump. Chaetoceros Hyalochaete spp. and Thalassiosira antarctica resting spores were responsible for more than 60% of the annual POC flux that occurred during two very short export events of < 14 days in spring-summer. Relatively low diatom fluxes were observed over the remainder of the year. Faecal pellet contribution to annual carbon flux was lower (34 %) and reached its seasonal maximum in autumn and winter (> 80 %). The seasonal progression of faecal pellet types revealed a clear transition from small spherical shapes (small copepods) in spring, to larger cylindrical and ellipsoid shapes in summer (euphausiids and large copepods) and finally to large tabular shapes (salps) in autumn and winter. We propose in this high-biomass, low-export (HBLE) environment that small but highly silicified and fast-sinking resting spores are able to bypass the intense grazing pressure and efficient carbon transfer to higher trophic levels that are responsible for the low fluxes observed the during the remainder of the year. More generally our study also provides a statistical framework linking the ecological succession of diatom and zooplankton communities to the seasonality of carbon and silicon export within an iron-fertilized bloom region in the Southern Ocean. Article in Journal/Newspaper Antarc* Antarctica Southern Ocean Copepods Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) Kerguelen Southern Ocean Biogeosciences 12 11 3171 3195 |
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 |
The biological composition of the material exported to a moored sediment trap located under the winter mixed layer of the naturally fertilized Kerguelen Plateau in the Southern Ocean was studied over an annual cycle. Despite iron availability in spring, the annual particulate organic carbon (POC) export (98.2 mmol m(-2)) at 289m was low, but annual biogenic silica export was significant (114 mmol m(-2)). This feature was related to the abundance of empty diatom cells and the ratio of full to empty cells exerted a first-order control in BSi : POC export stoichiometry of the biological pump. Chaetoceros Hyalochaete spp. and Thalassiosira antarctica resting spores were responsible for more than 60% of the annual POC flux that occurred during two very short export events of < 14 days in spring-summer. Relatively low diatom fluxes were observed over the remainder of the year. Faecal pellet contribution to annual carbon flux was lower (34 %) and reached its seasonal maximum in autumn and winter (> 80 %). The seasonal progression of faecal pellet types revealed a clear transition from small spherical shapes (small copepods) in spring, to larger cylindrical and ellipsoid shapes in summer (euphausiids and large copepods) and finally to large tabular shapes (salps) in autumn and winter. We propose in this high-biomass, low-export (HBLE) environment that small but highly silicified and fast-sinking resting spores are able to bypass the intense grazing pressure and efficient carbon transfer to higher trophic levels that are responsible for the low fluxes observed the during the remainder of the year. More generally our study also provides a statistical framework linking the ecological succession of diatom and zooplankton communities to the seasonality of carbon and silicon export within an iron-fertilized bloom region in the Southern Ocean. |
format |
Article in Journal/Newspaper |
author |
Rembauville, M. Blain, S. Armand, L. Queguiner, B. Salter, I. |
spellingShingle |
Rembauville, M. Blain, S. Armand, L. Queguiner, B. Salter, I. Export fluxes in a naturally iron-fertilized area of the Southern Ocean - Part 2: Importance of diatom resting spores and faecal pellets for export |
author_facet |
Rembauville, M. Blain, S. Armand, L. Queguiner, B. Salter, I. |
author_sort |
Rembauville, M. |
title |
Export fluxes in a naturally iron-fertilized area of the Southern Ocean - Part 2: Importance of diatom resting spores and faecal pellets for export |
title_short |
Export fluxes in a naturally iron-fertilized area of the Southern Ocean - Part 2: Importance of diatom resting spores and faecal pellets for export |
title_full |
Export fluxes in a naturally iron-fertilized area of the Southern Ocean - Part 2: Importance of diatom resting spores and faecal pellets for export |
title_fullStr |
Export fluxes in a naturally iron-fertilized area of the Southern Ocean - Part 2: Importance of diatom resting spores and faecal pellets for export |
title_full_unstemmed |
Export fluxes in a naturally iron-fertilized area of the Southern Ocean - Part 2: Importance of diatom resting spores and faecal pellets for export |
title_sort |
export fluxes in a naturally iron-fertilized area of the southern ocean - part 2: importance of diatom resting spores and faecal pellets for export |
publisher |
Copernicus Gesellschaft Mbh |
publishDate |
2015 |
url |
https://archimer.ifremer.fr/doc/00295/40579/39498.pdf https://archimer.ifremer.fr/doc/00295/40579/39499.pdf https://archimer.ifremer.fr/doc/00295/40579/71317.pdf https://doi.org/10.5194/bg-12-3171-2015 https://archimer.ifremer.fr/doc/00295/40579/ |
geographic |
Kerguelen Southern Ocean |
geographic_facet |
Kerguelen Southern Ocean |
genre |
Antarc* Antarctica Southern Ocean Copepods |
genre_facet |
Antarc* Antarctica Southern Ocean Copepods |
op_source |
Biogeosciences (1726-4170) (Copernicus Gesellschaft Mbh), 2015-06-02 , Vol. 12 , N. 11 , P. 3171-3195 |
op_relation |
https://archimer.ifremer.fr/doc/00295/40579/39498.pdf https://archimer.ifremer.fr/doc/00295/40579/39499.pdf https://archimer.ifremer.fr/doc/00295/40579/71317.pdf doi:10.5194/bg-12-3171-2015 https://archimer.ifremer.fr/doc/00295/40579/ |
op_rights |
Author(s) 2015. CC Attribution 3.0 License info:eu-repo/semantics/openAccess restricted use |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5194/bg-12-3171-2015 |
container_title |
Biogeosciences |
container_volume |
12 |
container_issue |
11 |
container_start_page |
3171 |
op_container_end_page |
3195 |
_version_ |
1766254148322328576 |