The Arctic picoeukaryote <i>Micromonas pusilla</i> benefits from ocean acidification under constant and dynamic light
<p>Compared to the rest of the globe, the Arctic Ocean is affected disproportionately by climate change. Despite these fast environmental changes, we currently know little about the effects of ocean acidification (OA) on marine key species in this area. Moreover, the existing studies typically...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2020-02-01
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| Series: | Biogeosciences |
| Online Access: | https://www.biogeosciences.net/17/635/2020/bg-17-635-2020.pdf |
| _version_ | 1830339792060022784 |
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| author | E. White C. J. M. Hoppe B. Rost B. Rost |
| author_facet | E. White C. J. M. Hoppe B. Rost B. Rost |
| author_sort | E. White |
| collection | DOAJ |
| description | <p>Compared to the rest of the globe, the Arctic Ocean is affected
disproportionately by climate change. Despite these fast environmental
changes, we currently know little about the effects of ocean acidification
(OA) on marine key species in this area. Moreover, the existing studies
typically test the effects of OA under constant, hence artificial, light
fields. In this study, the abundant Arctic picoeukaryote <i>Micromonas pusilla</i> was acclimated to
current (400 <span class="inline-formula">µ</span>atm) and future (1000 <span class="inline-formula">µ</span>atm) <span class="inline-formula"><i>p</i>CO<sub>2</sub></span> levels under a
constant as well as a dynamic light, simulating more realistic light fields as
experienced in the upper mixed layer. To describe and understand the
responses to these drivers, growth, particulate organic carbon (POC)
production, elemental composition, photophysiology and reactive oxygen
species (ROS) production were analysed. <i>M. pusilla </i>was able to benefit from OA on
various scales, ranging from an increase in growth rates to enhanced
photosynthetic capacity, irrespective of the light regime. These beneficial
effects were, however, not reflected in the POC production rates, which can
be explained by energy partitioning towards cell division rather than
biomass build-up. In the dynamic light regime, <i>M. pusilla</i> was able to optimize its
photophysiology for effective light usage during both low- and high-light
periods. This photoacclimative response, which was achieved by modifications
to photosystem II (PSII), imposed high metabolic costs leading to a
reduction in growth and POC production rates when compared to constant
light. There were no significant interactions observed between dynamic light
and OA, indicating that <i>M. pusilla</i> is able to maintain effective photoacclimation
without increased photoinactivation under high <span class="inline-formula"><i>p</i>CO<sub>2</sub></span>. Based on these
findings, <i>M. pusilla</i> is likely to cope well with future conditions in the Arctic
Ocean.</p> |
| first_indexed | 2024-12-19T21:03:38Z |
| format | Article |
| id | doaj.art-f2ba01b6b3ef4743a08e4e15b733cb0c |
| institution | Directory Open Access Journal |
| issn | 1726-4170 1726-4189 |
| language | English |
| last_indexed | 2024-12-19T21:03:38Z |
| publishDate | 2020-02-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Biogeosciences |
| spelling | doaj.art-f2ba01b6b3ef4743a08e4e15b733cb0c2022-12-21T20:05:44ZengCopernicus PublicationsBiogeosciences1726-41701726-41892020-02-011763564710.5194/bg-17-635-2020The Arctic picoeukaryote <i>Micromonas pusilla</i> benefits from ocean acidification under constant and dynamic lightE. White0C. J. M. Hoppe1B. Rost2B. Rost3Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, 27570 Bremerhaven, GermanyAlfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, 27570 Bremerhaven, GermanyAlfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, 27570 Bremerhaven, GermanyFachbereich Biologie/Chemie, Universität Bremen, Leobener Strasse, 28359 Bremen, Germany<p>Compared to the rest of the globe, the Arctic Ocean is affected disproportionately by climate change. Despite these fast environmental changes, we currently know little about the effects of ocean acidification (OA) on marine key species in this area. Moreover, the existing studies typically test the effects of OA under constant, hence artificial, light fields. In this study, the abundant Arctic picoeukaryote <i>Micromonas pusilla</i> was acclimated to current (400 <span class="inline-formula">µ</span>atm) and future (1000 <span class="inline-formula">µ</span>atm) <span class="inline-formula"><i>p</i>CO<sub>2</sub></span> levels under a constant as well as a dynamic light, simulating more realistic light fields as experienced in the upper mixed layer. To describe and understand the responses to these drivers, growth, particulate organic carbon (POC) production, elemental composition, photophysiology and reactive oxygen species (ROS) production were analysed. <i>M. pusilla </i>was able to benefit from OA on various scales, ranging from an increase in growth rates to enhanced photosynthetic capacity, irrespective of the light regime. These beneficial effects were, however, not reflected in the POC production rates, which can be explained by energy partitioning towards cell division rather than biomass build-up. In the dynamic light regime, <i>M. pusilla</i> was able to optimize its photophysiology for effective light usage during both low- and high-light periods. This photoacclimative response, which was achieved by modifications to photosystem II (PSII), imposed high metabolic costs leading to a reduction in growth and POC production rates when compared to constant light. There were no significant interactions observed between dynamic light and OA, indicating that <i>M. pusilla</i> is able to maintain effective photoacclimation without increased photoinactivation under high <span class="inline-formula"><i>p</i>CO<sub>2</sub></span>. Based on these findings, <i>M. pusilla</i> is likely to cope well with future conditions in the Arctic Ocean.</p>https://www.biogeosciences.net/17/635/2020/bg-17-635-2020.pdf |
| spellingShingle | E. White C. J. M. Hoppe B. Rost B. Rost The Arctic picoeukaryote <i>Micromonas pusilla</i> benefits from ocean acidification under constant and dynamic light Biogeosciences |
| title | The Arctic picoeukaryote <i>Micromonas pusilla</i> benefits from ocean acidification under constant and dynamic light |
| title_full | The Arctic picoeukaryote <i>Micromonas pusilla</i> benefits from ocean acidification under constant and dynamic light |
| title_fullStr | The Arctic picoeukaryote <i>Micromonas pusilla</i> benefits from ocean acidification under constant and dynamic light |
| title_full_unstemmed | The Arctic picoeukaryote <i>Micromonas pusilla</i> benefits from ocean acidification under constant and dynamic light |
| title_short | The Arctic picoeukaryote <i>Micromonas pusilla</i> benefits from ocean acidification under constant and dynamic light |
| title_sort | arctic picoeukaryote i micromonas pusilla i benefits from ocean acidification under constant and dynamic light |
| url | https://www.biogeosciences.net/17/635/2020/bg-17-635-2020.pdf |
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