Bacterial carbon cycling in a subarctic fjord:A seasonal study on microbial activity, growth efficiency, and virus-induced mortality in Kobbefjord, Greenland
In this seasonal study, we examined the environmental controls and quantitative importance of bacterial carbon consumption in the water column and the sediment in the subarctic Kobbefjord, Greenland. Depthintegrated bacterial production in the photic zone varied from 5.0 ± 2.7 mg C m d in February t...
Published in: | Limnology and Oceanography |
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2012
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Online Access: | https://pure.au.dk/portal/en/publications/de99bbed-18f2-4fc3-9c37-2b86758d3541 https://doi.org/10.4319/lo.2012.57.6.1732 http://www.scopus.com/inward/record.url?scp=84870383962&partnerID=8YFLogxK |
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ftuniaarhuspubl:oai:pure.atira.dk:publications/de99bbed-18f2-4fc3-9c37-2b86758d3541 2024-02-11T10:04:20+01:00 Bacterial carbon cycling in a subarctic fjord:A seasonal study on microbial activity, growth efficiency, and virus-induced mortality in Kobbefjord, Greenland Middelboe, Mathias Glud, Ronnie Nøhr Sejr, M.K. 2012-11-01 https://pure.au.dk/portal/en/publications/de99bbed-18f2-4fc3-9c37-2b86758d3541 https://doi.org/10.4319/lo.2012.57.6.1732 http://www.scopus.com/inward/record.url?scp=84870383962&partnerID=8YFLogxK eng eng https://pure.au.dk/portal/en/publications/de99bbed-18f2-4fc3-9c37-2b86758d3541 info:eu-repo/semantics/restrictedAccess Middelboe , M , Glud , R N & Sejr , M K 2012 , ' Bacterial carbon cycling in a subarctic fjord : A seasonal study on microbial activity, growth efficiency, and virus-induced mortality in Kobbefjord, Greenland ' , Limnology and Oceanography , vol. 57 , no. 6 , pp. 1732-1742 . https://doi.org/10.4319/lo.2012.57.6.1732 article 2012 ftuniaarhuspubl https://doi.org/10.4319/lo.2012.57.6.1732 2024-01-17T23:59:09Z In this seasonal study, we examined the environmental controls and quantitative importance of bacterial carbon consumption in the water column and the sediment in the subarctic Kobbefjord, Greenland. Depthintegrated bacterial production in the photic zone varied from 5.0 ± 2.7 mg C m d in February to 42 ± 28 mg C m d in May and 34 ± 7 mg C m d in September, corresponding to a bacterial production to primary production ratio of 0.34 6 0.14, 0.07 6 0.04, and 0.08 ± 0.06, respectively. Based on measured bacterial growth efficiencies (BGEs) of 0.09-0.10, pelagic bacterial carbon consumption was 54 ± 59 mg C m d, 1194 ± 329 mg C m d, and 689 ± 115 mg C m d in February, May, and September, respectively, which corresponded to 367%, 71%, and 87% of pelagic primary production. The average annual sediment respiration corresponded to 121 mg C m d and accounted for 17% of total microbial respiration in the system. Concentration of bioavailable dissolved organic carbon (BDOC) ranged from 144 ± 37 μg C L in the riverine input to the fjord to a maximum of 341 ± 37 μg C L in the surface waters in September. Parallel enrichment experiments showed that bacterial production and BGE were positively correlated with BDOC concentration, suggesting that organic carbon availability was limiting bacterial activity and carbon conversion efficiency. Viral production was low (0.8-1.8 × 10 viruses mL h ) as compared to low-latitude environments, suggesting a relatively small effect of viruses on bacterial mortality (4-36% of cell production) and carbon cycling. Heterotrophic bacterial consumption was closely coupled with autochthonous BDOC production, and the majority of the primary production was consumed by pelagic bacteria at all seasons. The relatively low measured BGE emphasized the importance of solid on-site BGE estimates for assessing carbon budgets in marine environments. Article in Journal/Newspaper Greenland Subarctic Aarhus University: Research Greenland Kobbefjord ENVELOPE(-51.527,-51.527,64.177,64.177) Limnology and Oceanography 57 6 1732 1742 |
institution |
Open Polar |
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Aarhus University: Research |
op_collection_id |
ftuniaarhuspubl |
language |
English |
description |
In this seasonal study, we examined the environmental controls and quantitative importance of bacterial carbon consumption in the water column and the sediment in the subarctic Kobbefjord, Greenland. Depthintegrated bacterial production in the photic zone varied from 5.0 ± 2.7 mg C m d in February to 42 ± 28 mg C m d in May and 34 ± 7 mg C m d in September, corresponding to a bacterial production to primary production ratio of 0.34 6 0.14, 0.07 6 0.04, and 0.08 ± 0.06, respectively. Based on measured bacterial growth efficiencies (BGEs) of 0.09-0.10, pelagic bacterial carbon consumption was 54 ± 59 mg C m d, 1194 ± 329 mg C m d, and 689 ± 115 mg C m d in February, May, and September, respectively, which corresponded to 367%, 71%, and 87% of pelagic primary production. The average annual sediment respiration corresponded to 121 mg C m d and accounted for 17% of total microbial respiration in the system. Concentration of bioavailable dissolved organic carbon (BDOC) ranged from 144 ± 37 μg C L in the riverine input to the fjord to a maximum of 341 ± 37 μg C L in the surface waters in September. Parallel enrichment experiments showed that bacterial production and BGE were positively correlated with BDOC concentration, suggesting that organic carbon availability was limiting bacterial activity and carbon conversion efficiency. Viral production was low (0.8-1.8 × 10 viruses mL h ) as compared to low-latitude environments, suggesting a relatively small effect of viruses on bacterial mortality (4-36% of cell production) and carbon cycling. Heterotrophic bacterial consumption was closely coupled with autochthonous BDOC production, and the majority of the primary production was consumed by pelagic bacteria at all seasons. The relatively low measured BGE emphasized the importance of solid on-site BGE estimates for assessing carbon budgets in marine environments. |
format |
Article in Journal/Newspaper |
author |
Middelboe, Mathias Glud, Ronnie Nøhr Sejr, M.K. |
spellingShingle |
Middelboe, Mathias Glud, Ronnie Nøhr Sejr, M.K. Bacterial carbon cycling in a subarctic fjord:A seasonal study on microbial activity, growth efficiency, and virus-induced mortality in Kobbefjord, Greenland |
author_facet |
Middelboe, Mathias Glud, Ronnie Nøhr Sejr, M.K. |
author_sort |
Middelboe, Mathias |
title |
Bacterial carbon cycling in a subarctic fjord:A seasonal study on microbial activity, growth efficiency, and virus-induced mortality in Kobbefjord, Greenland |
title_short |
Bacterial carbon cycling in a subarctic fjord:A seasonal study on microbial activity, growth efficiency, and virus-induced mortality in Kobbefjord, Greenland |
title_full |
Bacterial carbon cycling in a subarctic fjord:A seasonal study on microbial activity, growth efficiency, and virus-induced mortality in Kobbefjord, Greenland |
title_fullStr |
Bacterial carbon cycling in a subarctic fjord:A seasonal study on microbial activity, growth efficiency, and virus-induced mortality in Kobbefjord, Greenland |
title_full_unstemmed |
Bacterial carbon cycling in a subarctic fjord:A seasonal study on microbial activity, growth efficiency, and virus-induced mortality in Kobbefjord, Greenland |
title_sort |
bacterial carbon cycling in a subarctic fjord:a seasonal study on microbial activity, growth efficiency, and virus-induced mortality in kobbefjord, greenland |
publishDate |
2012 |
url |
https://pure.au.dk/portal/en/publications/de99bbed-18f2-4fc3-9c37-2b86758d3541 https://doi.org/10.4319/lo.2012.57.6.1732 http://www.scopus.com/inward/record.url?scp=84870383962&partnerID=8YFLogxK |
long_lat |
ENVELOPE(-51.527,-51.527,64.177,64.177) |
geographic |
Greenland Kobbefjord |
geographic_facet |
Greenland Kobbefjord |
genre |
Greenland Subarctic |
genre_facet |
Greenland Subarctic |
op_source |
Middelboe , M , Glud , R N & Sejr , M K 2012 , ' Bacterial carbon cycling in a subarctic fjord : A seasonal study on microbial activity, growth efficiency, and virus-induced mortality in Kobbefjord, Greenland ' , Limnology and Oceanography , vol. 57 , no. 6 , pp. 1732-1742 . https://doi.org/10.4319/lo.2012.57.6.1732 |
op_relation |
https://pure.au.dk/portal/en/publications/de99bbed-18f2-4fc3-9c37-2b86758d3541 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.4319/lo.2012.57.6.1732 |
container_title |
Limnology and Oceanography |
container_volume |
57 |
container_issue |
6 |
container_start_page |
1732 |
op_container_end_page |
1742 |
_version_ |
1790600922365165568 |