Influence of Irradiance and Iron on the Growth of Colonial Phaeocystic antarctica: Implications for Seasonal Bloom Dynamics in the Ross Sea, Antarctica
Laboratory culture experiments were used to investigate the growth rate of colonial Phaeocystis anarctica as a function of irradiance and dissolved iron concentration. The experiments were conducted with a P. antarctica strain isolated from the southern Ross Sea, Antarctica, and made use of natural,...
Published in: | Aquatic Microbial Ecology |
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ODU Digital Commons
2009
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ftolddominionuni:oai:digitalcommons.odu.edu:oeas_fac_pubs-1114 2023-06-11T04:07:05+02:00 Influence of Irradiance and Iron on the Growth of Colonial Phaeocystic antarctica: Implications for Seasonal Bloom Dynamics in the Ross Sea, Antarctica Garcia, Nathan S. Sedwick, Peter N. DiTullio, Giacomo R. 2009-01-01T08:00:00Z application/pdf https://digitalcommons.odu.edu/oeas_fac_pubs/82 https://doi.org/10.3354/ame01334 https://digitalcommons.odu.edu/context/oeas_fac_pubs/article/1114/viewcontent/SedwickInfluenceofIrradiance.pdf unknown ODU Digital Commons https://digitalcommons.odu.edu/oeas_fac_pubs/82 doi:10.3354/ame01334 https://digitalcommons.odu.edu/context/oeas_fac_pubs/article/1114/viewcontent/SedwickInfluenceofIrradiance.pdf OES Faculty Publications Phaeocystis antarctica Growth Iron Light Ross Sea Bloom dynamics Southern ocean Phytoplankton growth Biochemical composition Pigment Concentrations Environmental factors Circumpolar current Dissolved iron Pacific Ocean Biochemistry Marine Biology Oceanography article 2009 ftolddominionuni https://doi.org/10.3354/ame01334 2023-05-08T17:59:38Z Laboratory culture experiments were used to investigate the growth rate of colonial Phaeocystis anarctica as a function of irradiance and dissolved iron concentration. The experiments were conducted with a P. antarctica strain isolated from the southern Ross Sea, Antarctica, and made use of natural, low-iron (P. antarctica attained an average maximum cell-specific growth rate of 0.37 d-1at an irradiance of 68 μE m-2s-1, above which growth rates decreased to 0.27 d-1 at an irradiance of 314 μE m-2s-1. The dependence of growth rate on ambient dissolved iron concentration was examined in dose-response type bioassay experiments using realistic subnanomolar additions of dissolved iron. The experimental results indicate significant changes in the iron requirements for growth of colonial P. antarctica as a function of irradiance, with our estimates of the half-saturation constant for growth with respect to dissolved iron (Kμ) ranging from 0.26 nM at ~20 μE m-2s-1, to 0.045 nM at similar to 40 μE m-2s-1 and to 0.19 nM at ~ 90 μE m-2 s-1. We interpret these variations in K, as reflecting an increase in the cellular iron requirements of colonial P. antarctica at suboptimal and supraoptimal irradiance, such that the cells require higher ambient dissolved iron concentrations to attain maximum growth rates under Such irradiance conditions. The experiments also provide evidence of a relationship between iron availability and the relative proportion of colonial versus solitary P. antarctica cells, whereby the colonial form appears to be favored by higher dissolved iron concentrations. Our experimental results suggest that the initiation and termination of colonial P. antarctica blooms in the Ross Sea are determined by the combined effects of irradiance-driven changes in cellular iron requirements and a seasonal decrease in dissolved iron availability. Article in Journal/Newspaper Antarc* Antarctica Ross Sea Southern Ocean Old Dominion University: ODU Digital Commons Southern Ocean Ross Sea Pacific Aquatic Microbial Ecology 57 203 220 |
institution |
Open Polar |
collection |
Old Dominion University: ODU Digital Commons |
op_collection_id |
ftolddominionuni |
language |
unknown |
topic |
Phaeocystis antarctica Growth Iron Light Ross Sea Bloom dynamics Southern ocean Phytoplankton growth Biochemical composition Pigment Concentrations Environmental factors Circumpolar current Dissolved iron Pacific Ocean Biochemistry Marine Biology Oceanography |
spellingShingle |
Phaeocystis antarctica Growth Iron Light Ross Sea Bloom dynamics Southern ocean Phytoplankton growth Biochemical composition Pigment Concentrations Environmental factors Circumpolar current Dissolved iron Pacific Ocean Biochemistry Marine Biology Oceanography Garcia, Nathan S. Sedwick, Peter N. DiTullio, Giacomo R. Influence of Irradiance and Iron on the Growth of Colonial Phaeocystic antarctica: Implications for Seasonal Bloom Dynamics in the Ross Sea, Antarctica |
topic_facet |
Phaeocystis antarctica Growth Iron Light Ross Sea Bloom dynamics Southern ocean Phytoplankton growth Biochemical composition Pigment Concentrations Environmental factors Circumpolar current Dissolved iron Pacific Ocean Biochemistry Marine Biology Oceanography |
description |
Laboratory culture experiments were used to investigate the growth rate of colonial Phaeocystis anarctica as a function of irradiance and dissolved iron concentration. The experiments were conducted with a P. antarctica strain isolated from the southern Ross Sea, Antarctica, and made use of natural, low-iron (P. antarctica attained an average maximum cell-specific growth rate of 0.37 d-1at an irradiance of 68 μE m-2s-1, above which growth rates decreased to 0.27 d-1 at an irradiance of 314 μE m-2s-1. The dependence of growth rate on ambient dissolved iron concentration was examined in dose-response type bioassay experiments using realistic subnanomolar additions of dissolved iron. The experimental results indicate significant changes in the iron requirements for growth of colonial P. antarctica as a function of irradiance, with our estimates of the half-saturation constant for growth with respect to dissolved iron (Kμ) ranging from 0.26 nM at ~20 μE m-2s-1, to 0.045 nM at similar to 40 μE m-2s-1 and to 0.19 nM at ~ 90 μE m-2 s-1. We interpret these variations in K, as reflecting an increase in the cellular iron requirements of colonial P. antarctica at suboptimal and supraoptimal irradiance, such that the cells require higher ambient dissolved iron concentrations to attain maximum growth rates under Such irradiance conditions. The experiments also provide evidence of a relationship between iron availability and the relative proportion of colonial versus solitary P. antarctica cells, whereby the colonial form appears to be favored by higher dissolved iron concentrations. Our experimental results suggest that the initiation and termination of colonial P. antarctica blooms in the Ross Sea are determined by the combined effects of irradiance-driven changes in cellular iron requirements and a seasonal decrease in dissolved iron availability. |
format |
Article in Journal/Newspaper |
author |
Garcia, Nathan S. Sedwick, Peter N. DiTullio, Giacomo R. |
author_facet |
Garcia, Nathan S. Sedwick, Peter N. DiTullio, Giacomo R. |
author_sort |
Garcia, Nathan S. |
title |
Influence of Irradiance and Iron on the Growth of Colonial Phaeocystic antarctica: Implications for Seasonal Bloom Dynamics in the Ross Sea, Antarctica |
title_short |
Influence of Irradiance and Iron on the Growth of Colonial Phaeocystic antarctica: Implications for Seasonal Bloom Dynamics in the Ross Sea, Antarctica |
title_full |
Influence of Irradiance and Iron on the Growth of Colonial Phaeocystic antarctica: Implications for Seasonal Bloom Dynamics in the Ross Sea, Antarctica |
title_fullStr |
Influence of Irradiance and Iron on the Growth of Colonial Phaeocystic antarctica: Implications for Seasonal Bloom Dynamics in the Ross Sea, Antarctica |
title_full_unstemmed |
Influence of Irradiance and Iron on the Growth of Colonial Phaeocystic antarctica: Implications for Seasonal Bloom Dynamics in the Ross Sea, Antarctica |
title_sort |
influence of irradiance and iron on the growth of colonial phaeocystic antarctica: implications for seasonal bloom dynamics in the ross sea, antarctica |
publisher |
ODU Digital Commons |
publishDate |
2009 |
url |
https://digitalcommons.odu.edu/oeas_fac_pubs/82 https://doi.org/10.3354/ame01334 https://digitalcommons.odu.edu/context/oeas_fac_pubs/article/1114/viewcontent/SedwickInfluenceofIrradiance.pdf |
geographic |
Southern Ocean Ross Sea Pacific |
geographic_facet |
Southern Ocean Ross Sea Pacific |
genre |
Antarc* Antarctica Ross Sea Southern Ocean |
genre_facet |
Antarc* Antarctica Ross Sea Southern Ocean |
op_source |
OES Faculty Publications |
op_relation |
https://digitalcommons.odu.edu/oeas_fac_pubs/82 doi:10.3354/ame01334 https://digitalcommons.odu.edu/context/oeas_fac_pubs/article/1114/viewcontent/SedwickInfluenceofIrradiance.pdf |
op_doi |
https://doi.org/10.3354/ame01334 |
container_title |
Aquatic Microbial Ecology |
container_volume |
57 |
container_start_page |
203 |
op_container_end_page |
220 |
_version_ |
1768379679219122176 |