Phytoplankton in deep convection : an experimental approach on the effect of temperature and short light conditions on growth and physiology
The phytoplankton spring bloom of the North Atlantic is one of the largest biological events on earth. It strongly affects the biogeochemical cycle and the entire marine food web. Previous winter conditions strongly affect the timing and composition of the spring bloom Low light availability during...
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Staats- und Universitätsbibliothek Hamburg Carl von Ossietzky
2013
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ftsubhamburg:oai:ediss.sub.uni-hamburg.de:ediss/5574 2023-05-15T17:36:09+02:00 Phytoplankton in deep convection : an experimental approach on the effect of temperature and short light conditions on growth and physiology Phytoplankton in Tiefendurchmischung : ein experimenteller Ansatz des Effektes von Temperatur und Kurzlichtbedingungen auf Wachstum und Physiologie Walter, Bettina Beusekom, Justus van (Vertr.-Prof. Dr.) 2013-01-01 http://nbn-resolving.de/urn:nbn:de:gbv:18-69483 https://ediss.sub.uni-hamburg.de/handle/ediss/5574 eng eng Staats- und Universitätsbibliothek Hamburg Carl von Ossietzky http://nbn-resolving.de/urn:nbn:de:gbv:18-69483 https://ediss.sub.uni-hamburg.de/handle/ediss/5574 http://purl.org/coar/access_right/c_abf2 info:eu-repo/semantics/openAccess No license Phytoplankton Tiefendurchmischung Lichtakklimatisierung Temperature deep convection light acclimation 500 Naturwissenschaften 42.94 Meeresbiologie ddc:500 doctoralThesis doc-type:doctoralThesis 2013 ftsubhamburg 2022-11-09T07:11:03Z The phytoplankton spring bloom of the North Atlantic is one of the largest biological events on earth. It strongly affects the biogeochemical cycle and the entire marine food web. Previous winter conditions strongly affect the timing and composition of the spring bloom Low light availability during deep convection was assumed to prevent phytoplankton growth in winter. However, noticeable chlorophyll a concentration were determined in a convective mixed layer and phytoplankton cells are transported via convection through the entire convective cell and thereby visit frequently the euphotic zone for short periods. These short periods of light availability may allow phytoplankton productivity in winter. Yet, very little is known about algae growth and physiology in a deep convection situation. In this thesis different laboratory experiments were carried out to test the growth of the diatom Thalassiosira weisflogii under different light and temperature conditions, simulating deep convection. Oxygen development, biochemical compounds and photosynthetic efficiency were measured to study surviving strategies and acclimation processes to low light availability. Furthermore, the effect of different over-wintering conditions (complete darkness and deep convection) on the onset of a spring bloom were addressed by comparing differences in surviving strategies and possible competition between two different phytoplankton species (Thalassiosira weisflogii and Rhodomonas sp.). T. weissflogii showed positive growth rates under two hours light per day at temperatures above 8°C. Under comparable experimental conditions positive net primary production was calculated from continuous oxygen measurements explaining these positive growth rates. The comparison of two different light intensities with the same daily light dose indicated much higher growth rates for the low light scenario under non-limiting temperature conditions. This strongly emphazises that compensation irradiance may not be the correct tool to describe the limit of ... Doctoral or Postdoctoral Thesis North Atlantic ediss.sub.hamburg (Staats- und Universitätsbibliothek Hamburg, Carl von Ossietzky) |
institution |
Open Polar |
collection |
ediss.sub.hamburg (Staats- und Universitätsbibliothek Hamburg, Carl von Ossietzky) |
op_collection_id |
ftsubhamburg |
language |
English |
topic |
Phytoplankton Tiefendurchmischung Lichtakklimatisierung Temperature deep convection light acclimation 500 Naturwissenschaften 42.94 Meeresbiologie ddc:500 |
spellingShingle |
Phytoplankton Tiefendurchmischung Lichtakklimatisierung Temperature deep convection light acclimation 500 Naturwissenschaften 42.94 Meeresbiologie ddc:500 Walter, Bettina Phytoplankton in deep convection : an experimental approach on the effect of temperature and short light conditions on growth and physiology |
topic_facet |
Phytoplankton Tiefendurchmischung Lichtakklimatisierung Temperature deep convection light acclimation 500 Naturwissenschaften 42.94 Meeresbiologie ddc:500 |
description |
The phytoplankton spring bloom of the North Atlantic is one of the largest biological events on earth. It strongly affects the biogeochemical cycle and the entire marine food web. Previous winter conditions strongly affect the timing and composition of the spring bloom Low light availability during deep convection was assumed to prevent phytoplankton growth in winter. However, noticeable chlorophyll a concentration were determined in a convective mixed layer and phytoplankton cells are transported via convection through the entire convective cell and thereby visit frequently the euphotic zone for short periods. These short periods of light availability may allow phytoplankton productivity in winter. Yet, very little is known about algae growth and physiology in a deep convection situation. In this thesis different laboratory experiments were carried out to test the growth of the diatom Thalassiosira weisflogii under different light and temperature conditions, simulating deep convection. Oxygen development, biochemical compounds and photosynthetic efficiency were measured to study surviving strategies and acclimation processes to low light availability. Furthermore, the effect of different over-wintering conditions (complete darkness and deep convection) on the onset of a spring bloom were addressed by comparing differences in surviving strategies and possible competition between two different phytoplankton species (Thalassiosira weisflogii and Rhodomonas sp.). T. weissflogii showed positive growth rates under two hours light per day at temperatures above 8°C. Under comparable experimental conditions positive net primary production was calculated from continuous oxygen measurements explaining these positive growth rates. The comparison of two different light intensities with the same daily light dose indicated much higher growth rates for the low light scenario under non-limiting temperature conditions. This strongly emphazises that compensation irradiance may not be the correct tool to describe the limit of ... |
author2 |
Beusekom, Justus van (Vertr.-Prof. Dr.) |
format |
Doctoral or Postdoctoral Thesis |
author |
Walter, Bettina |
author_facet |
Walter, Bettina |
author_sort |
Walter, Bettina |
title |
Phytoplankton in deep convection : an experimental approach on the effect of temperature and short light conditions on growth and physiology |
title_short |
Phytoplankton in deep convection : an experimental approach on the effect of temperature and short light conditions on growth and physiology |
title_full |
Phytoplankton in deep convection : an experimental approach on the effect of temperature and short light conditions on growth and physiology |
title_fullStr |
Phytoplankton in deep convection : an experimental approach on the effect of temperature and short light conditions on growth and physiology |
title_full_unstemmed |
Phytoplankton in deep convection : an experimental approach on the effect of temperature and short light conditions on growth and physiology |
title_sort |
phytoplankton in deep convection : an experimental approach on the effect of temperature and short light conditions on growth and physiology |
publisher |
Staats- und Universitätsbibliothek Hamburg Carl von Ossietzky |
publishDate |
2013 |
url |
http://nbn-resolving.de/urn:nbn:de:gbv:18-69483 https://ediss.sub.uni-hamburg.de/handle/ediss/5574 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
http://nbn-resolving.de/urn:nbn:de:gbv:18-69483 https://ediss.sub.uni-hamburg.de/handle/ediss/5574 |
op_rights |
http://purl.org/coar/access_right/c_abf2 info:eu-repo/semantics/openAccess No license |
_version_ |
1766135546905624576 |