Photosynthetic maximum quantum yield increases are an essential component of the Southern Ocean phytoplankton response to iron
It is well established that an increase in iron supply causes an increase in total oceanic primary production in many regions, but the physiological mechanism driving the observed increases has not been clearly identified. The Southern Ocean iron enrichment experiment, an iron fertilization experime...
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ftwilliammarycol:oai:scholarworks.wm.edu:vimsarticles-1990 2023-06-11T04:07:01+02:00 Photosynthetic maximum quantum yield increases are an essential component of the Southern Ocean phytoplankton response to iron Hiscock, MR Lance, VP Apprill, AM Bidigare, RR Johnson, ZI Smith, WO, Jr. 2008-01-01T08:00:00Z application/pdf https://scholarworks.wm.edu/vimsarticles/990 doi: 10.1073/pnas.0705006105 https://scholarworks.wm.edu/context/vimsarticles/article/1990/viewcontent/4775.full.pdf unknown W&M ScholarWorks https://scholarworks.wm.edu/vimsarticles/990 doi: 10.1073/pnas.0705006105 https://scholarworks.wm.edu/context/vimsarticles/article/1990/viewcontent/4775.full.pdf VIMS Articles Equatorial Pacific-Ocean Primary Productivity Enrichment Experiment Atlantic Sector Light Fertilization Size Models Color Water Biological Sciences Peer-Reviewed Articles Aquaculture and Fisheries text 2008 ftwilliammarycol https://doi.org/10.1073/pnas.0705006105 2023-05-04T17:43:38Z It is well established that an increase in iron supply causes an increase in total oceanic primary production in many regions, but the physiological mechanism driving the observed increases has not been clearly identified. The Southern Ocean iron enrichment experiment, an iron fertilization experiment in the waters closest to Antarctica, resulted in a 9-fold increase in chlorophyll (Chl) concentration and a 5-fold increase in integrated primary production. Upon iron addition, the maximum quantum yield of photosynthesis (phi(m)) rapidly doubled, from 0.011 to 0.025 mol C.mol quanta(-1). Paradoxically, this increase in light-limited productivity was not accompanied by a significant increase in light-saturated productivity (P-max(b)). P-max(b) maximum Chl normalized productivity, was 1.34 mg C.mg Chl(-1).h(-1) outside and 1.49 mg C.mg Chl(-1)-h(-1) inside the iron-enriched patch. The importance of phi(m) as compared with P-max(b) in controlling the biological response to iron addition has vast implications for understanding the ecological response to iron. We show that an iron-driven increase in phi(m) is the proximate physiological mechanism affected by iron addition and can account for most of the increases in primary production. The relative importance of phi(m) over P-max(b) in this iron-fertilized bloom highlights the limitations of often-used primary productivity algorithms that are driven by estimates of P-max(b) but largely ignore variability in phi(m) and light-limited productivity. To use primary productivity models that include variability in iron supply in prediction or forecasting, the variability of light-limited productivity must be resolved. Text Antarc* Antarctica Southern Ocean W&M ScholarWorks Southern Ocean Pacific Proceedings of the National Academy of Sciences 105 12 4775 4780 |
institution |
Open Polar |
collection |
W&M ScholarWorks |
op_collection_id |
ftwilliammarycol |
language |
unknown |
topic |
Equatorial Pacific-Ocean Primary Productivity Enrichment Experiment Atlantic Sector Light Fertilization Size Models Color Water Biological Sciences Peer-Reviewed Articles Aquaculture and Fisheries |
spellingShingle |
Equatorial Pacific-Ocean Primary Productivity Enrichment Experiment Atlantic Sector Light Fertilization Size Models Color Water Biological Sciences Peer-Reviewed Articles Aquaculture and Fisheries Hiscock, MR Lance, VP Apprill, AM Bidigare, RR Johnson, ZI Smith, WO, Jr. Photosynthetic maximum quantum yield increases are an essential component of the Southern Ocean phytoplankton response to iron |
topic_facet |
Equatorial Pacific-Ocean Primary Productivity Enrichment Experiment Atlantic Sector Light Fertilization Size Models Color Water Biological Sciences Peer-Reviewed Articles Aquaculture and Fisheries |
description |
It is well established that an increase in iron supply causes an increase in total oceanic primary production in many regions, but the physiological mechanism driving the observed increases has not been clearly identified. The Southern Ocean iron enrichment experiment, an iron fertilization experiment in the waters closest to Antarctica, resulted in a 9-fold increase in chlorophyll (Chl) concentration and a 5-fold increase in integrated primary production. Upon iron addition, the maximum quantum yield of photosynthesis (phi(m)) rapidly doubled, from 0.011 to 0.025 mol C.mol quanta(-1). Paradoxically, this increase in light-limited productivity was not accompanied by a significant increase in light-saturated productivity (P-max(b)). P-max(b) maximum Chl normalized productivity, was 1.34 mg C.mg Chl(-1).h(-1) outside and 1.49 mg C.mg Chl(-1)-h(-1) inside the iron-enriched patch. The importance of phi(m) as compared with P-max(b) in controlling the biological response to iron addition has vast implications for understanding the ecological response to iron. We show that an iron-driven increase in phi(m) is the proximate physiological mechanism affected by iron addition and can account for most of the increases in primary production. The relative importance of phi(m) over P-max(b) in this iron-fertilized bloom highlights the limitations of often-used primary productivity algorithms that are driven by estimates of P-max(b) but largely ignore variability in phi(m) and light-limited productivity. To use primary productivity models that include variability in iron supply in prediction or forecasting, the variability of light-limited productivity must be resolved. |
format |
Text |
author |
Hiscock, MR Lance, VP Apprill, AM Bidigare, RR Johnson, ZI Smith, WO, Jr. |
author_facet |
Hiscock, MR Lance, VP Apprill, AM Bidigare, RR Johnson, ZI Smith, WO, Jr. |
author_sort |
Hiscock, MR |
title |
Photosynthetic maximum quantum yield increases are an essential component of the Southern Ocean phytoplankton response to iron |
title_short |
Photosynthetic maximum quantum yield increases are an essential component of the Southern Ocean phytoplankton response to iron |
title_full |
Photosynthetic maximum quantum yield increases are an essential component of the Southern Ocean phytoplankton response to iron |
title_fullStr |
Photosynthetic maximum quantum yield increases are an essential component of the Southern Ocean phytoplankton response to iron |
title_full_unstemmed |
Photosynthetic maximum quantum yield increases are an essential component of the Southern Ocean phytoplankton response to iron |
title_sort |
photosynthetic maximum quantum yield increases are an essential component of the southern ocean phytoplankton response to iron |
publisher |
W&M ScholarWorks |
publishDate |
2008 |
url |
https://scholarworks.wm.edu/vimsarticles/990 https://scholarworks.wm.edu/context/vimsarticles/article/1990/viewcontent/4775.full.pdf |
geographic |
Southern Ocean Pacific |
geographic_facet |
Southern Ocean Pacific |
genre |
Antarc* Antarctica Southern Ocean |
genre_facet |
Antarc* Antarctica Southern Ocean |
op_source |
VIMS Articles |
op_relation |
https://scholarworks.wm.edu/vimsarticles/990 doi: 10.1073/pnas.0705006105 https://scholarworks.wm.edu/context/vimsarticles/article/1990/viewcontent/4775.full.pdf |
op_doi |
https://doi.org/10.1073/pnas.0705006105 |
container_title |
Proceedings of the National Academy of Sciences |
container_volume |
105 |
container_issue |
12 |
container_start_page |
4775 |
op_container_end_page |
4780 |
_version_ |
1768379442193760256 |