Microbial ecosystem responses to alkalinity enhancement in the North Atlantic Subtropical Gyre
In addition to reducing carbon dioxide (CO2) emissions, actively removing CO2 from the atmosphere is widely considered necessary to keep global warming well below 2°C. Ocean Alkalinity Enhancement (OAE) describes a suite of such CO2 removal processes that all involve enhancing the buffering capacity...
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ftnerc:oai:nora.nerc.ac.uk:533205 2023-05-15T17:31:33+02:00 Microbial ecosystem responses to alkalinity enhancement in the North Atlantic Subtropical Gyre Subhas, Adam V. Marx, Lukas Reynolds, Sarah Flohr, Anita Mawji, Edward W. Brown, Peter J. Cael, B.B. 2022-07-25 text http://nora.nerc.ac.uk/id/eprint/533205/ https://nora.nerc.ac.uk/id/eprint/533205/1/fclim-04-784997.pdf https://doi.org/10.3389/fclim.2022.784997 en eng https://nora.nerc.ac.uk/id/eprint/533205/1/fclim-04-784997.pdf Subhas, Adam V.; Marx, Lukas; Reynolds, Sarah; Flohr, Anita orcid:0000-0002-5018-5379 Mawji, Edward W.; Brown, Peter J. orcid:0000-0002-1152-1114 Cael, B.B. orcid:0000-0003-1317-5718 . 2022 Microbial ecosystem responses to alkalinity enhancement in the North Atlantic Subtropical Gyre. Frontiers in Climate, 4. https://doi.org/10.3389/fclim.2022.784997 <https://doi.org/10.3389/fclim.2022.784997> cc_by_4 CC-BY Publication - Article PeerReviewed 2022 ftnerc https://doi.org/10.3389/fclim.2022.784997 2023-02-04T19:53:36Z In addition to reducing carbon dioxide (CO2) emissions, actively removing CO2 from the atmosphere is widely considered necessary to keep global warming well below 2°C. Ocean Alkalinity Enhancement (OAE) describes a suite of such CO2 removal processes that all involve enhancing the buffering capacity of seawater. In theory, OAE both stores carbon and offsets ocean acidification. In practice, the response of the marine biogeochemical system to OAE must be demonstrably negligible, or at least manageable, before it can be deployed at scale. We tested the OAE response of two natural seawater mixed layer microbial communities in the North Atlantic Subtropical Gyre, one at the Western gyre boundary, and one in the middle of the gyre. We conducted 4-day microcosm incubation experiments at sea, spiked with three increasing amounts of alkaline sodium salts and a 13C-bicarbonate tracer at constant pCO2. We then measured a suite of dissolved and particulate parameters to constrain the chemical and biological response to these additions. Microbial communities demonstrated occasionally measurable, but mostly negligible, responses to alkalinity enhancement. Neither site showed a significant increase in biologically produced CaCO3, even at extreme alkalinity loadings of +2,000 μmol kg−1. At the gyre boundary, alkalinity enhancement did not significantly impact net primary production rates. In contrast, net primary production in the central gyre decreased by ~30% in response to alkalinity enhancement. The central gyre incubations demonstrated a shift toward smaller particle size classes, suggesting that OAE may impact community composition and/or aggregation/disaggregation processes. In terms of chemical effects, we identify equilibration of seawater pCO2, inorganic CaCO3 precipitation, and immediate effects during mixing of alkaline solutions with seawater, as important considerations for developing experimental OAE methodologies, and for practical OAE deployment. These initial results underscore the importance of performing ... Article in Journal/Newspaper North Atlantic Ocean acidification Natural Environment Research Council: NERC Open Research Archive Frontiers in Climate 4 |
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Open Polar |
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Natural Environment Research Council: NERC Open Research Archive |
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ftnerc |
language |
English |
description |
In addition to reducing carbon dioxide (CO2) emissions, actively removing CO2 from the atmosphere is widely considered necessary to keep global warming well below 2°C. Ocean Alkalinity Enhancement (OAE) describes a suite of such CO2 removal processes that all involve enhancing the buffering capacity of seawater. In theory, OAE both stores carbon and offsets ocean acidification. In practice, the response of the marine biogeochemical system to OAE must be demonstrably negligible, or at least manageable, before it can be deployed at scale. We tested the OAE response of two natural seawater mixed layer microbial communities in the North Atlantic Subtropical Gyre, one at the Western gyre boundary, and one in the middle of the gyre. We conducted 4-day microcosm incubation experiments at sea, spiked with three increasing amounts of alkaline sodium salts and a 13C-bicarbonate tracer at constant pCO2. We then measured a suite of dissolved and particulate parameters to constrain the chemical and biological response to these additions. Microbial communities demonstrated occasionally measurable, but mostly negligible, responses to alkalinity enhancement. Neither site showed a significant increase in biologically produced CaCO3, even at extreme alkalinity loadings of +2,000 μmol kg−1. At the gyre boundary, alkalinity enhancement did not significantly impact net primary production rates. In contrast, net primary production in the central gyre decreased by ~30% in response to alkalinity enhancement. The central gyre incubations demonstrated a shift toward smaller particle size classes, suggesting that OAE may impact community composition and/or aggregation/disaggregation processes. In terms of chemical effects, we identify equilibration of seawater pCO2, inorganic CaCO3 precipitation, and immediate effects during mixing of alkaline solutions with seawater, as important considerations for developing experimental OAE methodologies, and for practical OAE deployment. These initial results underscore the importance of performing ... |
format |
Article in Journal/Newspaper |
author |
Subhas, Adam V. Marx, Lukas Reynolds, Sarah Flohr, Anita Mawji, Edward W. Brown, Peter J. Cael, B.B. |
spellingShingle |
Subhas, Adam V. Marx, Lukas Reynolds, Sarah Flohr, Anita Mawji, Edward W. Brown, Peter J. Cael, B.B. Microbial ecosystem responses to alkalinity enhancement in the North Atlantic Subtropical Gyre |
author_facet |
Subhas, Adam V. Marx, Lukas Reynolds, Sarah Flohr, Anita Mawji, Edward W. Brown, Peter J. Cael, B.B. |
author_sort |
Subhas, Adam V. |
title |
Microbial ecosystem responses to alkalinity enhancement in the North Atlantic Subtropical Gyre |
title_short |
Microbial ecosystem responses to alkalinity enhancement in the North Atlantic Subtropical Gyre |
title_full |
Microbial ecosystem responses to alkalinity enhancement in the North Atlantic Subtropical Gyre |
title_fullStr |
Microbial ecosystem responses to alkalinity enhancement in the North Atlantic Subtropical Gyre |
title_full_unstemmed |
Microbial ecosystem responses to alkalinity enhancement in the North Atlantic Subtropical Gyre |
title_sort |
microbial ecosystem responses to alkalinity enhancement in the north atlantic subtropical gyre |
publishDate |
2022 |
url |
http://nora.nerc.ac.uk/id/eprint/533205/ https://nora.nerc.ac.uk/id/eprint/533205/1/fclim-04-784997.pdf https://doi.org/10.3389/fclim.2022.784997 |
genre |
North Atlantic Ocean acidification |
genre_facet |
North Atlantic Ocean acidification |
op_relation |
https://nora.nerc.ac.uk/id/eprint/533205/1/fclim-04-784997.pdf Subhas, Adam V.; Marx, Lukas; Reynolds, Sarah; Flohr, Anita orcid:0000-0002-5018-5379 Mawji, Edward W.; Brown, Peter J. orcid:0000-0002-1152-1114 Cael, B.B. orcid:0000-0003-1317-5718 . 2022 Microbial ecosystem responses to alkalinity enhancement in the North Atlantic Subtropical Gyre. Frontiers in Climate, 4. https://doi.org/10.3389/fclim.2022.784997 <https://doi.org/10.3389/fclim.2022.784997> |
op_rights |
cc_by_4 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.3389/fclim.2022.784997 |
container_title |
Frontiers in Climate |
container_volume |
4 |
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1766129198243512320 |