Mesoscale surface distribution of biogeochemical characteristics in the Crozet Basin frontal zones (South Indian Ocean)
peer reviewed A mesoscale study was conducted in January and February 1999 in the Crozet Basin frontal zones (43degrees50' to 45degrees20'S, 61degrees00' to 64degrees30'E) within the southernmost and easternmost convergence area of the Antarctic Circumpolar Current (ACC) and the...
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Online Access: | https://orbi.uliege.be/handle/2268/1239 https://doi.org/10.3354/meps249001 |
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ftorbi:oai:orbi.ulg.ac.be:2268/1239 2024-04-21T07:46:47+00:00 Mesoscale surface distribution of biogeochemical characteristics in the Crozet Basin frontal zones (South Indian Ocean) Fiala, M. Delille, Bruno Dubreuil, C. Kopczynska, E. Leblanc, K. Morvan, J. Queguiner, B. Blain, S. Cailliau, C. Conan, P. Corvaisier, R. Denis, M. Frankignoulle, Michel Oriol, L. Roy, S. Unité d'Océanographie Chimique 2003 https://orbi.uliege.be/handle/2268/1239 https://doi.org/10.3354/meps249001 en eng Inter-Research urn:issn:0171-8630 urn:issn:1616-1599 https://orbi.uliege.be/handle/2268/1239 info:hdl:2268/1239 doi:10.3354/meps249001 scopus-id:2-s2.0-0242515753 restricted access http://purl.org/coar/access_right/c_16ec info:eu-repo/semantics/restrictedAccess Marine Ecology. Progress Series, 249, 1-14 (2003) frontal zones nutrients biogenic silica chlorophyll a pCO(2) phytoplankton bacteria Life sciences Aquatic sciences & oceanology Environmental sciences & ecology Physical chemical mathematical & earth Sciences Earth sciences & physical geography Sciences du vivant Sciences aquatiques & océanologie Sciences de l’environnement & écologie Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique journal article http://purl.org/coar/resource_type/c_6501 info:eu-repo/semantics/article peer reviewed 2003 ftorbi https://doi.org/10.3354/meps249001 2024-03-27T14:59:59Z peer reviewed A mesoscale study was conducted in January and February 1999 in the Crozet Basin frontal zones (43degrees50' to 45degrees20'S, 61degrees00' to 64degrees30'E) within the southernmost and easternmost convergence area of the Antarctic Circumpolar Current (ACC) and the Agulhas Return Current (ARC). Distribution of biogeochemical parameters was strongly linked to the merged Subtropical (STF) and Subantarctic (SAF) Fronts which mark the border between the cold and less saline subantarctic waters and the warm and more saline subtropical waters. This survey took place during a post-bloom period. Chlorophyll a concentrations were low throughout the study area ranging from 0.2 mug l(-1) in the Polar Frontal Zone (PFZ) to 0.4 mug l(-1) in the Subtropical Zone (STZ). Maximum chlorophyll a values (0.8 mug l(-1)) associated with an increase in biogenic silica concentration (from 0.03 to 0.34 muM) and a diatom peak (1.2 x 10(5) cells l(-1)) were encountered in the northeastern part of the STF edge. Despite northwardly decreasing concentrations of nitrates from 14 muM in the PFZ to 6 PM in the STZ, they were not the main factor limiting phytoplankton growth. Low silicic acid (mean = 0.6 muM) could have limited diatom development in the PFZ and the STZ where diatom numbers were low. In STZ waters, where average diatom numbers were highest, various species of Nitzschia and Thalassiothrix were common, but Pseudonitzschia spp. were dominant. Throughout the survey area, pico- and nano-sized cells dominated the phytoplankton assemblage, and their number was the highest in the STZ. Cyanobacteria, only present in subtropical waters >12.5degreesC, were the major component of the picoplankton size-fraction. While dinoflagellate numbers were low in the Subantarctic Zone (SAZ), their abundance and species numbers increased in the STZ, where Oxytoxum laticeps became dominant and several further large-size species of Prorocentrum, Ceratium and Gymnodinium appeared in addition to those at the STF. The distribution of ... Article in Journal/Newspaper Antarc* Antarctic University of Liège: ORBi (Open Repository and Bibliography) Marine Ecology Progress Series 249 1 14 |
institution |
Open Polar |
collection |
University of Liège: ORBi (Open Repository and Bibliography) |
op_collection_id |
ftorbi |
language |
English |
topic |
frontal zones nutrients biogenic silica chlorophyll a pCO(2) phytoplankton bacteria Life sciences Aquatic sciences & oceanology Environmental sciences & ecology Physical chemical mathematical & earth Sciences Earth sciences & physical geography Sciences du vivant Sciences aquatiques & océanologie Sciences de l’environnement & écologie Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique |
spellingShingle |
frontal zones nutrients biogenic silica chlorophyll a pCO(2) phytoplankton bacteria Life sciences Aquatic sciences & oceanology Environmental sciences & ecology Physical chemical mathematical & earth Sciences Earth sciences & physical geography Sciences du vivant Sciences aquatiques & océanologie Sciences de l’environnement & écologie Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique Fiala, M. Delille, Bruno Dubreuil, C. Kopczynska, E. Leblanc, K. Morvan, J. Queguiner, B. Blain, S. Cailliau, C. Conan, P. Corvaisier, R. Denis, M. Frankignoulle, Michel Oriol, L. Roy, S. Mesoscale surface distribution of biogeochemical characteristics in the Crozet Basin frontal zones (South Indian Ocean) |
topic_facet |
frontal zones nutrients biogenic silica chlorophyll a pCO(2) phytoplankton bacteria Life sciences Aquatic sciences & oceanology Environmental sciences & ecology Physical chemical mathematical & earth Sciences Earth sciences & physical geography Sciences du vivant Sciences aquatiques & océanologie Sciences de l’environnement & écologie Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique |
description |
peer reviewed A mesoscale study was conducted in January and February 1999 in the Crozet Basin frontal zones (43degrees50' to 45degrees20'S, 61degrees00' to 64degrees30'E) within the southernmost and easternmost convergence area of the Antarctic Circumpolar Current (ACC) and the Agulhas Return Current (ARC). Distribution of biogeochemical parameters was strongly linked to the merged Subtropical (STF) and Subantarctic (SAF) Fronts which mark the border between the cold and less saline subantarctic waters and the warm and more saline subtropical waters. This survey took place during a post-bloom period. Chlorophyll a concentrations were low throughout the study area ranging from 0.2 mug l(-1) in the Polar Frontal Zone (PFZ) to 0.4 mug l(-1) in the Subtropical Zone (STZ). Maximum chlorophyll a values (0.8 mug l(-1)) associated with an increase in biogenic silica concentration (from 0.03 to 0.34 muM) and a diatom peak (1.2 x 10(5) cells l(-1)) were encountered in the northeastern part of the STF edge. Despite northwardly decreasing concentrations of nitrates from 14 muM in the PFZ to 6 PM in the STZ, they were not the main factor limiting phytoplankton growth. Low silicic acid (mean = 0.6 muM) could have limited diatom development in the PFZ and the STZ where diatom numbers were low. In STZ waters, where average diatom numbers were highest, various species of Nitzschia and Thalassiothrix were common, but Pseudonitzschia spp. were dominant. Throughout the survey area, pico- and nano-sized cells dominated the phytoplankton assemblage, and their number was the highest in the STZ. Cyanobacteria, only present in subtropical waters >12.5degreesC, were the major component of the picoplankton size-fraction. While dinoflagellate numbers were low in the Subantarctic Zone (SAZ), their abundance and species numbers increased in the STZ, where Oxytoxum laticeps became dominant and several further large-size species of Prorocentrum, Ceratium and Gymnodinium appeared in addition to those at the STF. The distribution of ... |
author2 |
Unité d'Océanographie Chimique |
format |
Article in Journal/Newspaper |
author |
Fiala, M. Delille, Bruno Dubreuil, C. Kopczynska, E. Leblanc, K. Morvan, J. Queguiner, B. Blain, S. Cailliau, C. Conan, P. Corvaisier, R. Denis, M. Frankignoulle, Michel Oriol, L. Roy, S. |
author_facet |
Fiala, M. Delille, Bruno Dubreuil, C. Kopczynska, E. Leblanc, K. Morvan, J. Queguiner, B. Blain, S. Cailliau, C. Conan, P. Corvaisier, R. Denis, M. Frankignoulle, Michel Oriol, L. Roy, S. |
author_sort |
Fiala, M. |
title |
Mesoscale surface distribution of biogeochemical characteristics in the Crozet Basin frontal zones (South Indian Ocean) |
title_short |
Mesoscale surface distribution of biogeochemical characteristics in the Crozet Basin frontal zones (South Indian Ocean) |
title_full |
Mesoscale surface distribution of biogeochemical characteristics in the Crozet Basin frontal zones (South Indian Ocean) |
title_fullStr |
Mesoscale surface distribution of biogeochemical characteristics in the Crozet Basin frontal zones (South Indian Ocean) |
title_full_unstemmed |
Mesoscale surface distribution of biogeochemical characteristics in the Crozet Basin frontal zones (South Indian Ocean) |
title_sort |
mesoscale surface distribution of biogeochemical characteristics in the crozet basin frontal zones (south indian ocean) |
publisher |
Inter-Research |
publishDate |
2003 |
url |
https://orbi.uliege.be/handle/2268/1239 https://doi.org/10.3354/meps249001 |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
Marine Ecology. Progress Series, 249, 1-14 (2003) |
op_relation |
urn:issn:0171-8630 urn:issn:1616-1599 https://orbi.uliege.be/handle/2268/1239 info:hdl:2268/1239 doi:10.3354/meps249001 scopus-id:2-s2.0-0242515753 |
op_rights |
restricted access http://purl.org/coar/access_right/c_16ec info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.3354/meps249001 |
container_title |
Marine Ecology Progress Series |
container_volume |
249 |
container_start_page |
1 |
op_container_end_page |
14 |
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1796944530270846976 |