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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Published in:Limnology and Oceanography
Main Authors: Piontek, Judith, Galgani, Luisa, Nöthig, Eva‐Maria, Peeken, Ilka, Engel, Anja
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2021
Subjects:
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
id ftoceanrep:oai:oceanrep.geomar.de:50970
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spelling 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
institution 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
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