Investigating the Role of Iron and Light on Ecophysiology and Photophysiology in Southern Ocean Phytoplankton
The Southern Ocean (SO) is one of the most productive oceanic regions in the world. Despite a high abundance of macronutrients such as nitrate and phosphorus, some areas have a surprisingly low amount of phytoplankton biomass. These areas are known as high nutrient low chlorophyll regions (HNLC) and...
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Format: | Master Thesis |
Language: | English |
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Florida State University
2022
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ftfloridasu:oai:diginole.lib.fsu.edu:fsu_887513 2024-01-14T10:00:52+01:00 Investigating the Role of Iron and Light on Ecophysiology and Photophysiology in Southern Ocean Phytoplankton Rose, Jared Monsein (author) Kranz, Sven Alexander (professor directing thesis) Stukel, Michael R. (committee member) Knapp, Angela Noel, 1976- (committee member) Florida State University (degree granting institution) College of Arts and Sciences (degree granting college) Department of Earth, Ocean, and Atmospheric Science (degree granting department) 2022 computer online resource 1 online resource application/pdf https://diginole.lib.fsu.edu/islandora/object/fsu%3A887513/datastream/TN/view/Investigating%20the%20Role%20of%20Iron%20and%20Light%20on%20Ecophysiology%20and%20Photophysiology%20in%20Southern%20Ocean%20Phytoplankton.jpg English eng Florida State University fsu:887513 iid: Rose_fsu_0071N_17651 https://diginole.lib.fsu.edu/islandora/object/fsu%3A887513/datastream/TN/view/Investigating%20the%20Role%20of%20Iron%20and%20Light%20on%20Ecophysiology%20and%20Photophysiology%20in%20Southern%20Ocean%20Phytoplankton.jpg Chemical oceanography Text master thesis 2022 ftfloridasu 2023-12-17T17:17:58Z The Southern Ocean (SO) is one of the most productive oceanic regions in the world. Despite a high abundance of macronutrients such as nitrate and phosphorus, some areas have a surprisingly low amount of phytoplankton biomass. These areas are known as high nutrient low chlorophyll regions (HNLC) and are often limited by the micronutrient iron (Fe). The influx of Fe to the surface Southern Ocean has varied over geological timescales and is expected to change further in a future climate. Additionally, climate change will alter surface ocean mixing depth which can constrain phytoplankton productivity. To identify and understand the effects of Fe and light availability on phytoplankton, this study assessed ecophysiological and photophysiological responses of two SO phytoplankton species: the haptophyte Emiliania huxleyi (E. hux.) and the diatom Fragilariopsis cylindrus (F. cyl.). The species were grown under saturating and sub-saturating Fe conditions and different light conditions. A dynamic light treatment mimicked natural light variability in different mixed layer depths, inducing either light limitation, saturation and/or short-term high light stress while a continuous light environment for F. cyl. also simulated conditions in the Antarctic higher latitude summer. In all treatments, ecophysiological parameters such as growth, elemental ratios, and cellular chlorophyll a were measured. Photophysiology was examined using Fast Repetition Rate fluorometry (FRRf) over a diurnal cycle. For both species, the results indicated a clear reduction in chlorophyll a, growth rate and cellular POC under Fe limitation with weaker effects attributed to light intensity. Fe limitation reduced photochemical efficiency (photosynthetic quantum yield (Fv/Fm)) and resulted in a reduced reoxidation rate of the photosystem (τ). Light affected photophysiological parameters mainly during peak light in the dynamic lighting environment. Irrespective of Fe availability, light adaptation strategies differed between species. E.hux primarily ... Master Thesis Antarc* Antarctic Southern Ocean Florida State University: DigiNole Commons Antarctic Southern Ocean The Antarctic |
institution |
Open Polar |
collection |
Florida State University: DigiNole Commons |
op_collection_id |
ftfloridasu |
language |
English |
topic |
Chemical oceanography |
spellingShingle |
Chemical oceanography Investigating the Role of Iron and Light on Ecophysiology and Photophysiology in Southern Ocean Phytoplankton |
topic_facet |
Chemical oceanography |
description |
The Southern Ocean (SO) is one of the most productive oceanic regions in the world. Despite a high abundance of macronutrients such as nitrate and phosphorus, some areas have a surprisingly low amount of phytoplankton biomass. These areas are known as high nutrient low chlorophyll regions (HNLC) and are often limited by the micronutrient iron (Fe). The influx of Fe to the surface Southern Ocean has varied over geological timescales and is expected to change further in a future climate. Additionally, climate change will alter surface ocean mixing depth which can constrain phytoplankton productivity. To identify and understand the effects of Fe and light availability on phytoplankton, this study assessed ecophysiological and photophysiological responses of two SO phytoplankton species: the haptophyte Emiliania huxleyi (E. hux.) and the diatom Fragilariopsis cylindrus (F. cyl.). The species were grown under saturating and sub-saturating Fe conditions and different light conditions. A dynamic light treatment mimicked natural light variability in different mixed layer depths, inducing either light limitation, saturation and/or short-term high light stress while a continuous light environment for F. cyl. also simulated conditions in the Antarctic higher latitude summer. In all treatments, ecophysiological parameters such as growth, elemental ratios, and cellular chlorophyll a were measured. Photophysiology was examined using Fast Repetition Rate fluorometry (FRRf) over a diurnal cycle. For both species, the results indicated a clear reduction in chlorophyll a, growth rate and cellular POC under Fe limitation with weaker effects attributed to light intensity. Fe limitation reduced photochemical efficiency (photosynthetic quantum yield (Fv/Fm)) and resulted in a reduced reoxidation rate of the photosystem (τ). Light affected photophysiological parameters mainly during peak light in the dynamic lighting environment. Irrespective of Fe availability, light adaptation strategies differed between species. E.hux primarily ... |
author2 |
Rose, Jared Monsein (author) Kranz, Sven Alexander (professor directing thesis) Stukel, Michael R. (committee member) Knapp, Angela Noel, 1976- (committee member) Florida State University (degree granting institution) College of Arts and Sciences (degree granting college) Department of Earth, Ocean, and Atmospheric Science (degree granting department) |
format |
Master Thesis |
title |
Investigating the Role of Iron and Light on Ecophysiology and Photophysiology in Southern Ocean Phytoplankton |
title_short |
Investigating the Role of Iron and Light on Ecophysiology and Photophysiology in Southern Ocean Phytoplankton |
title_full |
Investigating the Role of Iron and Light on Ecophysiology and Photophysiology in Southern Ocean Phytoplankton |
title_fullStr |
Investigating the Role of Iron and Light on Ecophysiology and Photophysiology in Southern Ocean Phytoplankton |
title_full_unstemmed |
Investigating the Role of Iron and Light on Ecophysiology and Photophysiology in Southern Ocean Phytoplankton |
title_sort |
investigating the role of iron and light on ecophysiology and photophysiology in southern ocean phytoplankton |
publisher |
Florida State University |
publishDate |
2022 |
url |
https://diginole.lib.fsu.edu/islandora/object/fsu%3A887513/datastream/TN/view/Investigating%20the%20Role%20of%20Iron%20and%20Light%20on%20Ecophysiology%20and%20Photophysiology%20in%20Southern%20Ocean%20Phytoplankton.jpg |
geographic |
Antarctic Southern Ocean The Antarctic |
geographic_facet |
Antarctic Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Southern Ocean |
genre_facet |
Antarc* Antarctic Southern Ocean |
op_relation |
fsu:887513 iid: Rose_fsu_0071N_17651 https://diginole.lib.fsu.edu/islandora/object/fsu%3A887513/datastream/TN/view/Investigating%20the%20Role%20of%20Iron%20and%20Light%20on%20Ecophysiology%20and%20Photophysiology%20in%20Southern%20Ocean%20Phytoplankton.jpg |
_version_ |
1788066740277608448 |