Microbial ecosystem responses to alkalinity enhancement in the North Atlantic Subtropical Gyre
In addition to reducing carbon dioxide (CO 2 ) emissions, actively removing CO 2 from the atmosphere is widely considered necessary to keep global warming well below 2°C. Ocean Alkalinity Enhancement (OAE) describes a suite of such CO 2 removal processes that all involve enhancing the buffering capa...
Published in: | Frontiers in Climate |
---|---|
Main Authors: | , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
Frontiers Media SA
2022
|
Subjects: | |
Online Access: | http://dx.doi.org/10.3389/fclim.2022.784997 https://www.frontiersin.org/articles/10.3389/fclim.2022.784997/full |
id |
crfrontiers:10.3389/fclim.2022.784997 |
---|---|
record_format |
openpolar |
spelling |
crfrontiers:10.3389/fclim.2022.784997 2024-05-19T07:44:59+00:00 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 http://dx.doi.org/10.3389/fclim.2022.784997 https://www.frontiersin.org/articles/10.3389/fclim.2022.784997/full unknown Frontiers Media SA https://creativecommons.org/licenses/by/4.0/ Frontiers in Climate volume 4 ISSN 2624-9553 journal-article 2022 crfrontiers https://doi.org/10.3389/fclim.2022.784997 2024-04-24T07:12:49Z In addition to reducing carbon dioxide (CO 2 ) emissions, actively removing CO 2 from the atmosphere is widely considered necessary to keep global warming well below 2°C. Ocean Alkalinity Enhancement (OAE) describes a suite of such CO 2 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 13 C-bicarbonate tracer at constant pCO 2 . 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 CaCO 3 , 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 pCO 2 , inorganic CaCO 3 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 ... Article in Journal/Newspaper North Atlantic Ocean acidification Frontiers (Publisher) Frontiers in Climate 4 |
institution |
Open Polar |
collection |
Frontiers (Publisher) |
op_collection_id |
crfrontiers |
language |
unknown |
description |
In addition to reducing carbon dioxide (CO 2 ) emissions, actively removing CO 2 from the atmosphere is widely considered necessary to keep global warming well below 2°C. Ocean Alkalinity Enhancement (OAE) describes a suite of such CO 2 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 13 C-bicarbonate tracer at constant pCO 2 . 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 CaCO 3 , 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 pCO 2 , inorganic CaCO 3 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 ... |
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 |
publisher |
Frontiers Media SA |
publishDate |
2022 |
url |
http://dx.doi.org/10.3389/fclim.2022.784997 https://www.frontiersin.org/articles/10.3389/fclim.2022.784997/full |
genre |
North Atlantic Ocean acidification |
genre_facet |
North Atlantic Ocean acidification |
op_source |
Frontiers in Climate volume 4 ISSN 2624-9553 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.3389/fclim.2022.784997 |
container_title |
Frontiers in Climate |
container_volume |
4 |
_version_ |
1799484892558393344 |