The influence of iron and light on net community production in the Subantarctic and Polar Frontal Zones
The roles of iron and light in controlling biomass and primary productivity are clearly established in the Southern Ocean. However, their influence on net community production (NCP) and carbon export remains to be quantified. To improve our understanding of NCP and carbon export production in the Su...
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ftdoajarticles:oai:doaj.org/article:2c7fafc4c0e5430c80f233b3187a2c10 2023-05-15T13:43:21+02:00 The influence of iron and light on net community production in the Subantarctic and Polar Frontal Zones N. Cassar P. J. DiFiore B. A. Barnett M. L. Bender A. R. Bowie B. Tilbrook K. Petrou K. J. Westwood S. W. Wright D. Lefevre 2011-02-01T00:00:00Z https://doi.org/10.5194/bg-8-227-2011 https://doaj.org/article/2c7fafc4c0e5430c80f233b3187a2c10 EN eng Copernicus Publications http://www.biogeosciences.net/8/227/2011/bg-8-227-2011.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-8-227-2011 1726-4170 1726-4189 https://doaj.org/article/2c7fafc4c0e5430c80f233b3187a2c10 Biogeosciences, Vol 8, Iss 2, Pp 227-237 (2011) Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 article 2011 ftdoajarticles https://doi.org/10.5194/bg-8-227-2011 2022-12-31T08:12:32Z The roles of iron and light in controlling biomass and primary productivity are clearly established in the Southern Ocean. However, their influence on net community production (NCP) and carbon export remains to be quantified. To improve our understanding of NCP and carbon export production in the Subantarctic Zone (SAZ) and the northern reaches of the Polar Frontal Zone (PFZ), we conducted continuous onboard determinations of NCP as part of the Sub-Antarctic Sensitivity to Environmental Change (SAZ-Sense) study, which occurred in January–February 2007. Biological O 2 supersaturation was derived from measuring O 2 /Ar ratios by equilibrator inlet mass spectrometry. Based on these continuous measurements, NCP during the austral summer 2007 in the Australian SAZ was approximately 43 mmol O 2 m −2 d −1 . NCP showed significant spatial variability, with larger values near the Subtropical front, and a general southward decrease. For shallower mixed layers (<50 m), dissolved Fe concentrations and Fe sufficiency, estimated from variable fluorescence, correlated strongly with NCP. The strong correlation between NCP and dissolved Fe may be difficult to interpret because of the correlation of dissolved Fe to MLD and because the concentration of iron may not be a good indicator of its availability. At stations with deeper mixed layers, NCP was consistently low, regardless of iron sufficiency, consistent with light availability also being an important control of NCP. Our new observations provide independent evidence for the critical roles of iron and light in mediating carbon export from the Southern Ocean mixed layer. Article in Journal/Newspaper Antarc* Antarctic Southern Ocean Directory of Open Access Journals: DOAJ Articles Antarctic Austral Southern Ocean Biogeosciences 8 2 227 237 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
spellingShingle |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 N. Cassar P. J. DiFiore B. A. Barnett M. L. Bender A. R. Bowie B. Tilbrook K. Petrou K. J. Westwood S. W. Wright D. Lefevre The influence of iron and light on net community production in the Subantarctic and Polar Frontal Zones |
topic_facet |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
description |
The roles of iron and light in controlling biomass and primary productivity are clearly established in the Southern Ocean. However, their influence on net community production (NCP) and carbon export remains to be quantified. To improve our understanding of NCP and carbon export production in the Subantarctic Zone (SAZ) and the northern reaches of the Polar Frontal Zone (PFZ), we conducted continuous onboard determinations of NCP as part of the Sub-Antarctic Sensitivity to Environmental Change (SAZ-Sense) study, which occurred in January–February 2007. Biological O 2 supersaturation was derived from measuring O 2 /Ar ratios by equilibrator inlet mass spectrometry. Based on these continuous measurements, NCP during the austral summer 2007 in the Australian SAZ was approximately 43 mmol O 2 m −2 d −1 . NCP showed significant spatial variability, with larger values near the Subtropical front, and a general southward decrease. For shallower mixed layers (<50 m), dissolved Fe concentrations and Fe sufficiency, estimated from variable fluorescence, correlated strongly with NCP. The strong correlation between NCP and dissolved Fe may be difficult to interpret because of the correlation of dissolved Fe to MLD and because the concentration of iron may not be a good indicator of its availability. At stations with deeper mixed layers, NCP was consistently low, regardless of iron sufficiency, consistent with light availability also being an important control of NCP. Our new observations provide independent evidence for the critical roles of iron and light in mediating carbon export from the Southern Ocean mixed layer. |
format |
Article in Journal/Newspaper |
author |
N. Cassar P. J. DiFiore B. A. Barnett M. L. Bender A. R. Bowie B. Tilbrook K. Petrou K. J. Westwood S. W. Wright D. Lefevre |
author_facet |
N. Cassar P. J. DiFiore B. A. Barnett M. L. Bender A. R. Bowie B. Tilbrook K. Petrou K. J. Westwood S. W. Wright D. Lefevre |
author_sort |
N. Cassar |
title |
The influence of iron and light on net community production in the Subantarctic and Polar Frontal Zones |
title_short |
The influence of iron and light on net community production in the Subantarctic and Polar Frontal Zones |
title_full |
The influence of iron and light on net community production in the Subantarctic and Polar Frontal Zones |
title_fullStr |
The influence of iron and light on net community production in the Subantarctic and Polar Frontal Zones |
title_full_unstemmed |
The influence of iron and light on net community production in the Subantarctic and Polar Frontal Zones |
title_sort |
influence of iron and light on net community production in the subantarctic and polar frontal zones |
publisher |
Copernicus Publications |
publishDate |
2011 |
url |
https://doi.org/10.5194/bg-8-227-2011 https://doaj.org/article/2c7fafc4c0e5430c80f233b3187a2c10 |
geographic |
Antarctic Austral Southern Ocean |
geographic_facet |
Antarctic Austral Southern Ocean |
genre |
Antarc* Antarctic Southern Ocean |
genre_facet |
Antarc* Antarctic Southern Ocean |
op_source |
Biogeosciences, Vol 8, Iss 2, Pp 227-237 (2011) |
op_relation |
http://www.biogeosciences.net/8/227/2011/bg-8-227-2011.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-8-227-2011 1726-4170 1726-4189 https://doaj.org/article/2c7fafc4c0e5430c80f233b3187a2c10 |
op_doi |
https://doi.org/10.5194/bg-8-227-2011 |
container_title |
Biogeosciences |
container_volume |
8 |
container_issue |
2 |
container_start_page |
227 |
op_container_end_page |
237 |
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1766187857372774400 |