Organic matter composition and heterotrophic bacterial activity at declining summer sea ice in the central Arctic Ocean
The Arctic Ocean is highly susceptible to climate change as evidenced by rapid warming and the drastic loss of sea ice during summer. The consequences of these environmental changes for the microbial cycling of organic matter are largely unexplored. Here, we investigated the distribution and composi...
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Online Access: | https://oceanrep.geomar.de/id/eprint/50970/ https://oceanrep.geomar.de/id/eprint/50970/1/lno.11639.pdf https://doi.org/10.1002/lno.11639 |
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ftoceanrep:oai:oceanrep.geomar.de:50970 2024-02-11T09:59:34+01:00 Organic matter composition and heterotrophic bacterial activity at declining summer sea ice in the central Arctic Ocean Piontek, Judith Galgani, Luisa Nöthig, Eva‐Maria Peeken, Ilka Engel, Anja 2021-02 text https://oceanrep.geomar.de/id/eprint/50970/ https://oceanrep.geomar.de/id/eprint/50970/1/lno.11639.pdf https://doi.org/10.1002/lno.11639 en eng Wiley ASLO (Association for the Sciences of Limnology and Oceanography) https://oceanrep.geomar.de/id/eprint/50970/1/lno.11639.pdf Piontek, J., Galgani, L. , Nöthig, E., Peeken, I. and Engel, A. (2021) Organic matter composition and heterotrophic bacterial activity at declining summer sea ice in the central Arctic Ocean. Open Access Limnology and Oceanography, 66 (S1). S343-S362. DOI 10.1002/lno.11639 <https://doi.org/10.1002/lno.11639>. doi:10.1002/lno.11639 cc_by_4.0 info:eu-repo/semantics/openAccess Article PeerReviewed 2021 ftoceanrep https://doi.org/10.1002/lno.11639 2024-01-15T00:22:42Z The Arctic Ocean is highly susceptible to climate change as evidenced by rapid warming and the drastic loss of sea ice during summer. The consequences of these environmental changes for the microbial cycling of organic matter are largely unexplored. Here, we investigated the distribution and composition of dissolved organic matter (DOM) along with heterotrophic bacterial activity in seawater and sea ice of the Eurasian Basin at the time of the record ice minimum in 2012. Bacteria in seawater were highly responsive to fresh organic matter and remineralized on average 55% of primary production in the upper mixed layer. Correlation analysis showed that the accumulation of dissolved combined carbohydrates (DCCHO) and dissolved amino acids (DAA), two major components of fresh organic matter, was related to the drawdown of nitrate. Nitrate‐depleted surface waters at stations adjacent to the Laptev Sea showed about 25% higher concentrations of DAA than stations adjacent to the Barents Sea and in the central Arctic basin. Carbohydrate concentration was the best predictor of heterotrophic bacterial activity in sea ice. In contrast, variability in sea‐ice bacterial biomass was largely driven by differences in ice thickness. This decoupling of bacterial biomass and activity may mitigate the negative effects of biomass loss due to ice melting on heterotrophic bacterial functions. Overall, our results reveal that changes in DOM production and inventories induced by sea‐ice loss have a high potential to enhance the bacterial remineralization of organic matter in seawater and sea ice of the Arctic Ocean. Article in Journal/Newspaper Arctic Arctic Basin Arctic Arctic Ocean Barents Sea Climate change laptev Laptev Sea Sea ice OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Arctic Arctic Ocean Barents Sea Laptev Sea Limnology and Oceanography 66 S1 |
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Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
The Arctic Ocean is highly susceptible to climate change as evidenced by rapid warming and the drastic loss of sea ice during summer. The consequences of these environmental changes for the microbial cycling of organic matter are largely unexplored. Here, we investigated the distribution and composition of dissolved organic matter (DOM) along with heterotrophic bacterial activity in seawater and sea ice of the Eurasian Basin at the time of the record ice minimum in 2012. Bacteria in seawater were highly responsive to fresh organic matter and remineralized on average 55% of primary production in the upper mixed layer. Correlation analysis showed that the accumulation of dissolved combined carbohydrates (DCCHO) and dissolved amino acids (DAA), two major components of fresh organic matter, was related to the drawdown of nitrate. Nitrate‐depleted surface waters at stations adjacent to the Laptev Sea showed about 25% higher concentrations of DAA than stations adjacent to the Barents Sea and in the central Arctic basin. Carbohydrate concentration was the best predictor of heterotrophic bacterial activity in sea ice. In contrast, variability in sea‐ice bacterial biomass was largely driven by differences in ice thickness. This decoupling of bacterial biomass and activity may mitigate the negative effects of biomass loss due to ice melting on heterotrophic bacterial functions. Overall, our results reveal that changes in DOM production and inventories induced by sea‐ice loss have a high potential to enhance the bacterial remineralization of organic matter in seawater and sea ice of the Arctic Ocean. |
format |
Article in Journal/Newspaper |
author |
Piontek, Judith Galgani, Luisa Nöthig, Eva‐Maria Peeken, Ilka Engel, Anja |
spellingShingle |
Piontek, Judith Galgani, Luisa Nöthig, Eva‐Maria Peeken, Ilka Engel, Anja Organic matter composition and heterotrophic bacterial activity at declining summer sea ice in the central Arctic Ocean |
author_facet |
Piontek, Judith Galgani, Luisa Nöthig, Eva‐Maria Peeken, Ilka Engel, Anja |
author_sort |
Piontek, Judith |
title |
Organic matter composition and heterotrophic bacterial activity at declining summer sea ice in the central Arctic Ocean |
title_short |
Organic matter composition and heterotrophic bacterial activity at declining summer sea ice in the central Arctic Ocean |
title_full |
Organic matter composition and heterotrophic bacterial activity at declining summer sea ice in the central Arctic Ocean |
title_fullStr |
Organic matter composition and heterotrophic bacterial activity at declining summer sea ice in the central Arctic Ocean |
title_full_unstemmed |
Organic matter composition and heterotrophic bacterial activity at declining summer sea ice in the central Arctic Ocean |
title_sort |
organic matter composition and heterotrophic bacterial activity at declining summer sea ice in the central arctic ocean |
publisher |
Wiley |
publishDate |
2021 |
url |
https://oceanrep.geomar.de/id/eprint/50970/ https://oceanrep.geomar.de/id/eprint/50970/1/lno.11639.pdf https://doi.org/10.1002/lno.11639 |
geographic |
Arctic Arctic Ocean Barents Sea Laptev Sea |
geographic_facet |
Arctic Arctic Ocean Barents Sea Laptev Sea |
genre |
Arctic Arctic Basin Arctic Arctic Ocean Barents Sea Climate change laptev Laptev Sea Sea ice |
genre_facet |
Arctic Arctic Basin Arctic Arctic Ocean Barents Sea Climate change laptev Laptev Sea Sea ice |
op_relation |
https://oceanrep.geomar.de/id/eprint/50970/1/lno.11639.pdf Piontek, J., Galgani, L. , Nöthig, E., Peeken, I. and Engel, A. (2021) Organic matter composition and heterotrophic bacterial activity at declining summer sea ice in the central Arctic Ocean. Open Access Limnology and Oceanography, 66 (S1). S343-S362. DOI 10.1002/lno.11639 <https://doi.org/10.1002/lno.11639>. doi:10.1002/lno.11639 |
op_rights |
cc_by_4.0 info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1002/lno.11639 |
container_title |
Limnology and Oceanography |
container_volume |
66 |
container_issue |
S1 |
_version_ |
1790595407586263040 |