Biogeochemical dynamics and the silicon cycle in the Atlantic sector of the Southern Ocean during austral spring 1992
High biogenic silica (BSi) concentrations (maximum: 11.7μmoll−1) were recorded during late November at the southern border of the Polar Frontal region (PFr). Position of the BSi maximum at depth suggested the occurrence of a sinking diatom population. By contrast, siliceous biomass was low (BSi <...
Published in: | Deep Sea Research Part II: Topical Studies in Oceanography |
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Format: | Article in Journal/Newspaper |
Language: | English |
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Elsevier
1997
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Online Access: | https://oceanrep.geomar.de/id/eprint/1620/ https://oceanrep.geomar.de/id/eprint/1620/1/1-s2.0-S0967064596000665-main.pdf https://doi.org/10.1016/S0967-0645(96)00066-5 |
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ftoceanrep:oai:oceanrep.geomar.de:1620 2023-05-15T18:18:49+02:00 Biogeochemical dynamics and the silicon cycle in the Atlantic sector of the Southern Ocean during austral spring 1992 Quéguiner, B. Treguér, P. Peeken, Ilka Scharek, R. 1997 text https://oceanrep.geomar.de/id/eprint/1620/ https://oceanrep.geomar.de/id/eprint/1620/1/1-s2.0-S0967064596000665-main.pdf https://doi.org/10.1016/S0967-0645(96)00066-5 en eng Elsevier https://oceanrep.geomar.de/id/eprint/1620/1/1-s2.0-S0967064596000665-main.pdf Quéguiner, B., Treguér, P., Peeken, I. and Scharek, R. (1997) Biogeochemical dynamics and the silicon cycle in the Atlantic sector of the Southern Ocean during austral spring 1992. Deep-Sea Research Part II-Topical Studies in Oceanography, 44 (1/2). pp. 69-90. DOI 10.1016/S0967-0645(96)00066-5 <https://doi.org/10.1016/S0967-0645%2896%2900066-5>. doi:10.1016/S0967-0645(96)00066-5 info:eu-repo/semantics/restrictedAccess Article PeerReviewed 1997 ftoceanrep https://doi.org/10.1016/S0967-0645(96)00066-5 2023-04-07T14:44:18Z High biogenic silica (BSi) concentrations (maximum: 11.7μmoll−1) were recorded during late November at the southern border of the Polar Frontal region (PFr). Position of the BSi maximum at depth suggested the occurrence of a sinking diatom population. By contrast, siliceous biomass was low (BSi <0.6 μmol l−1) in the Marginal Ice Zone (MIZ) despite a sea-ice retreat of 200 km during the study period. Diatoms released from the receding ice were not actively growing. The Permanently Open Ocean Zone also showed very low BSi biomass (<0.5μmol l−1) and appeared as an area where phytoplankton are not dominated by siliceous organisms, especially in its middle part where BSi/POC (particulate organic carbon) molar ratios ranged between 0.04 and 0.06 at 53°S, from surface to 200 m depth. At the southern border of the PFZ, the bloom coincided with an area of high lithogenic silica concentrations probably of aeolian origin. In addition, BSi/POC molar ratios measured in the PFZ were the highest ever recorded in the surface waters of the Southern Ocean (maximum: 1.75). This could be due to the presence of heavily silicified diatoms such as Fragilariopsis kerguelensis or also could reflect the more rapid recycling of POC as compared to BSi. Within the bloom area BSi concentrations were positively correlated to pyrophaeophytin pigments, possibly indicating the occurrence of a senescent diatom population. High concentrations of BSi (> 1.5 μmol Si 1−1) extended to 200 m between 49°S and 51°S. Numerous empty frustules also were observed, suggesting significant sedimentation of siliceous particles between 49°S and 51°S. Estimates of the BSi production of the Polar Frontal region are derived from 14C primary production and appropriate BSi/POC ratios, and implications for the total annual production of BSi for the Southern Ocean are discussed. Article in Journal/Newspaper Sea ice Southern Ocean OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Austral Southern Ocean Deep Sea Research Part II: Topical Studies in Oceanography 44 1-2 69 89 |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
High biogenic silica (BSi) concentrations (maximum: 11.7μmoll−1) were recorded during late November at the southern border of the Polar Frontal region (PFr). Position of the BSi maximum at depth suggested the occurrence of a sinking diatom population. By contrast, siliceous biomass was low (BSi <0.6 μmol l−1) in the Marginal Ice Zone (MIZ) despite a sea-ice retreat of 200 km during the study period. Diatoms released from the receding ice were not actively growing. The Permanently Open Ocean Zone also showed very low BSi biomass (<0.5μmol l−1) and appeared as an area where phytoplankton are not dominated by siliceous organisms, especially in its middle part where BSi/POC (particulate organic carbon) molar ratios ranged between 0.04 and 0.06 at 53°S, from surface to 200 m depth. At the southern border of the PFZ, the bloom coincided with an area of high lithogenic silica concentrations probably of aeolian origin. In addition, BSi/POC molar ratios measured in the PFZ were the highest ever recorded in the surface waters of the Southern Ocean (maximum: 1.75). This could be due to the presence of heavily silicified diatoms such as Fragilariopsis kerguelensis or also could reflect the more rapid recycling of POC as compared to BSi. Within the bloom area BSi concentrations were positively correlated to pyrophaeophytin pigments, possibly indicating the occurrence of a senescent diatom population. High concentrations of BSi (> 1.5 μmol Si 1−1) extended to 200 m between 49°S and 51°S. Numerous empty frustules also were observed, suggesting significant sedimentation of siliceous particles between 49°S and 51°S. Estimates of the BSi production of the Polar Frontal region are derived from 14C primary production and appropriate BSi/POC ratios, and implications for the total annual production of BSi for the Southern Ocean are discussed. |
format |
Article in Journal/Newspaper |
author |
Quéguiner, B. Treguér, P. Peeken, Ilka Scharek, R. |
spellingShingle |
Quéguiner, B. Treguér, P. Peeken, Ilka Scharek, R. Biogeochemical dynamics and the silicon cycle in the Atlantic sector of the Southern Ocean during austral spring 1992 |
author_facet |
Quéguiner, B. Treguér, P. Peeken, Ilka Scharek, R. |
author_sort |
Quéguiner, B. |
title |
Biogeochemical dynamics and the silicon cycle in the Atlantic sector of the Southern Ocean during austral spring 1992 |
title_short |
Biogeochemical dynamics and the silicon cycle in the Atlantic sector of the Southern Ocean during austral spring 1992 |
title_full |
Biogeochemical dynamics and the silicon cycle in the Atlantic sector of the Southern Ocean during austral spring 1992 |
title_fullStr |
Biogeochemical dynamics and the silicon cycle in the Atlantic sector of the Southern Ocean during austral spring 1992 |
title_full_unstemmed |
Biogeochemical dynamics and the silicon cycle in the Atlantic sector of the Southern Ocean during austral spring 1992 |
title_sort |
biogeochemical dynamics and the silicon cycle in the atlantic sector of the southern ocean during austral spring 1992 |
publisher |
Elsevier |
publishDate |
1997 |
url |
https://oceanrep.geomar.de/id/eprint/1620/ https://oceanrep.geomar.de/id/eprint/1620/1/1-s2.0-S0967064596000665-main.pdf https://doi.org/10.1016/S0967-0645(96)00066-5 |
geographic |
Austral Southern Ocean |
geographic_facet |
Austral Southern Ocean |
genre |
Sea ice Southern Ocean |
genre_facet |
Sea ice Southern Ocean |
op_relation |
https://oceanrep.geomar.de/id/eprint/1620/1/1-s2.0-S0967064596000665-main.pdf Quéguiner, B., Treguér, P., Peeken, I. and Scharek, R. (1997) Biogeochemical dynamics and the silicon cycle in the Atlantic sector of the Southern Ocean during austral spring 1992. Deep-Sea Research Part II-Topical Studies in Oceanography, 44 (1/2). pp. 69-90. DOI 10.1016/S0967-0645(96)00066-5 <https://doi.org/10.1016/S0967-0645%2896%2900066-5>. doi:10.1016/S0967-0645(96)00066-5 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1016/S0967-0645(96)00066-5 |
container_title |
Deep Sea Research Part II: Topical Studies in Oceanography |
container_volume |
44 |
container_issue |
1-2 |
container_start_page |
69 |
op_container_end_page |
89 |
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1766195521469284352 |