Projected 21st-century changes in marine heterotrophic bacteria under climate change
Marine heterotrophic Bacteria (or referred to as bacteria) play an important role in the ocean carbon cycle by utilizing, respiring, and remineralizing organic matter exported from the surface to deep ocean. Here, we investigate the responses of bacteria to climate change using a three-dimensional c...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2023-02-01
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| Series: | Frontiers in Microbiology |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fmicb.2023.1049579/full |
| _version_ | 1797904938519494656 |
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| author | Heather H. Kim Charlotte Laufkötter Charlotte Laufkötter Tomas Lovato Scott C. Doney Hugh W. Ducklow |
| author_facet | Heather H. Kim Charlotte Laufkötter Charlotte Laufkötter Tomas Lovato Scott C. Doney Hugh W. Ducklow |
| author_sort | Heather H. Kim |
| collection | DOAJ |
| description | Marine heterotrophic Bacteria (or referred to as bacteria) play an important role in the ocean carbon cycle by utilizing, respiring, and remineralizing organic matter exported from the surface to deep ocean. Here, we investigate the responses of bacteria to climate change using a three-dimensional coupled ocean biogeochemical model with explicit bacterial dynamics as part of the Coupled Model Intercomparison Project Phase 6. First, we assess the credibility of the century-scale projections (2015–2099) of bacterial carbon stock and rates in the upper 100 m layer using skill scores and compilations of the measurements for the contemporary period (1988–2011). Second, we demonstrate that across different climate scenarios, the simulated bacterial biomass trends (2076–2099) are sensitive to the regional trends in temperature and organic carbon stocks. Bacterial carbon biomass declines by 5–10% globally, while it increases by 3–5% in the Southern Ocean where semi-labile dissolved organic carbon (DOC) stocks are relatively low and particle-attached bacteria dominate. While a full analysis of drivers underpinning the simulated changes in all bacterial stock and rates is not possible due to data constraints, we investigate the mechanisms of the changes in DOC uptake rates of free-living bacteria using the first-order Taylor decomposition. The results demonstrate that the increase in semi-labile DOC stocks drives the increase in DOC uptake rates in the Southern Ocean, while the increase in temperature drives the increase in DOC uptake rates in the northern high and low latitudes. Our study provides a systematic analysis of bacteria at global scale and a critical step toward a better understanding of how bacteria affect the functioning of the biological carbon pump and partitioning of organic carbon pools between surface and deep layers. |
| first_indexed | 2024-04-10T09:58:08Z |
| format | Article |
| id | doaj.art-cbaee6d329ae46db8e651fd702b82a1e |
| institution | Directory Open Access Journal |
| issn | 1664-302X |
| language | English |
| last_indexed | 2024-04-10T09:58:08Z |
| publishDate | 2023-02-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Microbiology |
| spelling | doaj.art-cbaee6d329ae46db8e651fd702b82a1e2023-02-16T12:09:39ZengFrontiers Media S.A.Frontiers in Microbiology1664-302X2023-02-011410.3389/fmicb.2023.10495791049579Projected 21st-century changes in marine heterotrophic bacteria under climate changeHeather H. Kim0Charlotte Laufkötter1Charlotte Laufkötter2Tomas Lovato3Scott C. Doney4Hugh W. Ducklow5Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, United StatesDivision of Climate and Environmental Physics, Physics Institute, University of Bern, Bern, SwitzerlandOeschger Centre for Climate Change Research, University of Bern, Bern, SwitzerlandOcean Modeling and Data Assimilation Division, Fondazione Centro Euro-Mediterraneo sui Cambiamenti Climatici - CMCC, Bologna, ItalyDepartment of Environmental Sciences, University of Virginia, Charlottesville, VA, United StatesDepartment of Earth and Environmental Sciences, Columbia University, New York, NY, United StatesMarine heterotrophic Bacteria (or referred to as bacteria) play an important role in the ocean carbon cycle by utilizing, respiring, and remineralizing organic matter exported from the surface to deep ocean. Here, we investigate the responses of bacteria to climate change using a three-dimensional coupled ocean biogeochemical model with explicit bacterial dynamics as part of the Coupled Model Intercomparison Project Phase 6. First, we assess the credibility of the century-scale projections (2015–2099) of bacterial carbon stock and rates in the upper 100 m layer using skill scores and compilations of the measurements for the contemporary period (1988–2011). Second, we demonstrate that across different climate scenarios, the simulated bacterial biomass trends (2076–2099) are sensitive to the regional trends in temperature and organic carbon stocks. Bacterial carbon biomass declines by 5–10% globally, while it increases by 3–5% in the Southern Ocean where semi-labile dissolved organic carbon (DOC) stocks are relatively low and particle-attached bacteria dominate. While a full analysis of drivers underpinning the simulated changes in all bacterial stock and rates is not possible due to data constraints, we investigate the mechanisms of the changes in DOC uptake rates of free-living bacteria using the first-order Taylor decomposition. The results demonstrate that the increase in semi-labile DOC stocks drives the increase in DOC uptake rates in the Southern Ocean, while the increase in temperature drives the increase in DOC uptake rates in the northern high and low latitudes. Our study provides a systematic analysis of bacteria at global scale and a critical step toward a better understanding of how bacteria affect the functioning of the biological carbon pump and partitioning of organic carbon pools between surface and deep layers.https://www.frontiersin.org/articles/10.3389/fmicb.2023.1049579/fullmarine heterotrophic bacteriabacteriamicrobesCoupled Model Intercomparison ProjectCMCC-ESMclimate change |
| spellingShingle | Heather H. Kim Charlotte Laufkötter Charlotte Laufkötter Tomas Lovato Scott C. Doney Hugh W. Ducklow Projected 21st-century changes in marine heterotrophic bacteria under climate change Frontiers in Microbiology marine heterotrophic bacteria bacteria microbes Coupled Model Intercomparison Project CMCC-ESM climate change |
| title | Projected 21st-century changes in marine heterotrophic bacteria under climate change |
| title_full | Projected 21st-century changes in marine heterotrophic bacteria under climate change |
| title_fullStr | Projected 21st-century changes in marine heterotrophic bacteria under climate change |
| title_full_unstemmed | Projected 21st-century changes in marine heterotrophic bacteria under climate change |
| title_short | Projected 21st-century changes in marine heterotrophic bacteria under climate change |
| title_sort | projected 21st century changes in marine heterotrophic bacteria under climate change |
| topic | marine heterotrophic bacteria bacteria microbes Coupled Model Intercomparison Project CMCC-ESM climate change |
| url | https://www.frontiersin.org/articles/10.3389/fmicb.2023.1049579/full |
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