Distributions and stoichiometry of dissolved nitrogen and phosphorus in the iron-fertilized region near Kerguelen (Southern Ocean)
During KEOPS2 (Kerguelen Ocean and Plateau Compared Study 2), we determined dissolved inorganic and organic nitrogen and phosphorus species in the naturally fertilized region of Kerguelen Island (Southern Ocean). Above 150 m, stations were clearly separated by the polar front (PF), with concentratio...
Published in: | Biogeosciences |
---|---|
Main Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Copernicus Gesellschaft Mbh
2015
|
Subjects: | |
Online Access: | https://archimer.ifremer.fr/doc/00292/40343/38883.pdf https://archimer.ifremer.fr/doc/00292/40343/38884.pdf https://archimer.ifremer.fr/doc/00292/40343/71315.pdf https://doi.org/10.5194/bg-12-623-2015 https://archimer.ifremer.fr/doc/00292/40343/ |
id |
ftarchimer:oai:archimer.ifremer.fr:40343 |
---|---|
record_format |
openpolar |
spelling |
ftarchimer:oai:archimer.ifremer.fr:40343 2023-05-15T18:25:12+02:00 Distributions and stoichiometry of dissolved nitrogen and phosphorus in the iron-fertilized region near Kerguelen (Southern Ocean) Blain, S. Capparos, J. Gueneugues, A. Obernosterer, I. Oriol, L. 2015-01-30 application/pdf https://archimer.ifremer.fr/doc/00292/40343/38883.pdf https://archimer.ifremer.fr/doc/00292/40343/38884.pdf https://archimer.ifremer.fr/doc/00292/40343/71315.pdf https://doi.org/10.5194/bg-12-623-2015 https://archimer.ifremer.fr/doc/00292/40343/ eng eng Copernicus Gesellschaft Mbh https://archimer.ifremer.fr/doc/00292/40343/38883.pdf https://archimer.ifremer.fr/doc/00292/40343/38884.pdf https://archimer.ifremer.fr/doc/00292/40343/71315.pdf doi:10.5194/bg-12-623-2015 https://archimer.ifremer.fr/doc/00292/40343/ Author(s) 2015. CC Attribution 3.0 License info:eu-repo/semantics/openAccess restricted use CC-BY Biogeosciences (1726-4170) (Copernicus Gesellschaft Mbh), 2015-01-30 , Vol. 12 , N. 2 , P. 623-635 text Publication info:eu-repo/semantics/article 2015 ftarchimer https://doi.org/10.5194/bg-12-623-2015 2021-09-23T20:26:57Z During KEOPS2 (Kerguelen Ocean and Plateau Compared Study 2), we determined dissolved inorganic and organic nitrogen and phosphorus species in the naturally fertilized region of Kerguelen Island (Southern Ocean). Above 150 m, stations were clearly separated by the polar front (PF), with concentrations of NO3-, NO2- and PO43- overall lower north of the PF than south. Though less pronounced, a similar trend was detectable for dissolved organic nitrogen (DON) and dissolved organic phosphorus (DOP). At all stations offshore and above the plateau, a subsurface maximum of NH4+ was observed between 50 and 150 m. We examined nutrient stoichiometry by calculating the linear combination N* = [NO3-]-16 [PO43-]. The majority of stations and depths revealed N* close to -3 mu M; however, for surface waters north of the PF, N* increased up to 6 mu M. This suggests a preferential uptake of PO43- versus NO3- by fast-growing diatoms. Using the tracer TNxs = [TDN]-16[TDP] (TDN, total dissolved nitrogen; TDP, total dissolved phosphorus) revealed that the dissolved organic fraction significantly contributed to changes in TNxs. TNxs values were negative for most stations and depths, and relatively constant in the 0-500m layer. As for N*, the stations north of the PF had higher TNxs in the 0-100m layer. We discuss this stoichiometric anomaly with respect to possible external sources and sinks of N and P. Additional data collected in February 2013 at two sites revealed the occurrence of a subsurface minimum of N* located just below the pycnocline, which denotes a layer where remineralization of particulate organic matter with low N: P ratio P, possibly associated with preferential remineralization of P versus N, persists throughout the season. Article in Journal/Newspaper Southern Ocean Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) Kerguelen Kerguelen Island ENVELOPE(69.500,69.500,-49.250,-49.250) Southern Ocean Biogeosciences 12 2 623 635 |
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 |
During KEOPS2 (Kerguelen Ocean and Plateau Compared Study 2), we determined dissolved inorganic and organic nitrogen and phosphorus species in the naturally fertilized region of Kerguelen Island (Southern Ocean). Above 150 m, stations were clearly separated by the polar front (PF), with concentrations of NO3-, NO2- and PO43- overall lower north of the PF than south. Though less pronounced, a similar trend was detectable for dissolved organic nitrogen (DON) and dissolved organic phosphorus (DOP). At all stations offshore and above the plateau, a subsurface maximum of NH4+ was observed between 50 and 150 m. We examined nutrient stoichiometry by calculating the linear combination N* = [NO3-]-16 [PO43-]. The majority of stations and depths revealed N* close to -3 mu M; however, for surface waters north of the PF, N* increased up to 6 mu M. This suggests a preferential uptake of PO43- versus NO3- by fast-growing diatoms. Using the tracer TNxs = [TDN]-16[TDP] (TDN, total dissolved nitrogen; TDP, total dissolved phosphorus) revealed that the dissolved organic fraction significantly contributed to changes in TNxs. TNxs values were negative for most stations and depths, and relatively constant in the 0-500m layer. As for N*, the stations north of the PF had higher TNxs in the 0-100m layer. We discuss this stoichiometric anomaly with respect to possible external sources and sinks of N and P. Additional data collected in February 2013 at two sites revealed the occurrence of a subsurface minimum of N* located just below the pycnocline, which denotes a layer where remineralization of particulate organic matter with low N: P ratio P, possibly associated with preferential remineralization of P versus N, persists throughout the season. |
format |
Article in Journal/Newspaper |
author |
Blain, S. Capparos, J. Gueneugues, A. Obernosterer, I. Oriol, L. |
spellingShingle |
Blain, S. Capparos, J. Gueneugues, A. Obernosterer, I. Oriol, L. Distributions and stoichiometry of dissolved nitrogen and phosphorus in the iron-fertilized region near Kerguelen (Southern Ocean) |
author_facet |
Blain, S. Capparos, J. Gueneugues, A. Obernosterer, I. Oriol, L. |
author_sort |
Blain, S. |
title |
Distributions and stoichiometry of dissolved nitrogen and phosphorus in the iron-fertilized region near Kerguelen (Southern Ocean) |
title_short |
Distributions and stoichiometry of dissolved nitrogen and phosphorus in the iron-fertilized region near Kerguelen (Southern Ocean) |
title_full |
Distributions and stoichiometry of dissolved nitrogen and phosphorus in the iron-fertilized region near Kerguelen (Southern Ocean) |
title_fullStr |
Distributions and stoichiometry of dissolved nitrogen and phosphorus in the iron-fertilized region near Kerguelen (Southern Ocean) |
title_full_unstemmed |
Distributions and stoichiometry of dissolved nitrogen and phosphorus in the iron-fertilized region near Kerguelen (Southern Ocean) |
title_sort |
distributions and stoichiometry of dissolved nitrogen and phosphorus in the iron-fertilized region near kerguelen (southern ocean) |
publisher |
Copernicus Gesellschaft Mbh |
publishDate |
2015 |
url |
https://archimer.ifremer.fr/doc/00292/40343/38883.pdf https://archimer.ifremer.fr/doc/00292/40343/38884.pdf https://archimer.ifremer.fr/doc/00292/40343/71315.pdf https://doi.org/10.5194/bg-12-623-2015 https://archimer.ifremer.fr/doc/00292/40343/ |
long_lat |
ENVELOPE(69.500,69.500,-49.250,-49.250) |
geographic |
Kerguelen Kerguelen Island Southern Ocean |
geographic_facet |
Kerguelen Kerguelen Island Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
Biogeosciences (1726-4170) (Copernicus Gesellschaft Mbh), 2015-01-30 , Vol. 12 , N. 2 , P. 623-635 |
op_relation |
https://archimer.ifremer.fr/doc/00292/40343/38883.pdf https://archimer.ifremer.fr/doc/00292/40343/38884.pdf https://archimer.ifremer.fr/doc/00292/40343/71315.pdf doi:10.5194/bg-12-623-2015 https://archimer.ifremer.fr/doc/00292/40343/ |
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-12-623-2015 |
container_title |
Biogeosciences |
container_volume |
12 |
container_issue |
2 |
container_start_page |
623 |
op_container_end_page |
635 |
_version_ |
1766206478232846336 |