Tight benthic-pelagic coupling drives seasonal and interannual changes in iron‑sulfur cycling in Arctic fjord sediments (Kongsfjorden, Svalbard)
Glaciated fjords are dynamic systems dominated by seasonal events such as spring phytoplankton blooms and pulses of glacial sediment-bearing meltwater delivery. These fjords are also characterized by strong spatial gradients in environmental factors such as sedimentation rate and primary productivit...
Published in: | Journal of Marine Systems |
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Language: | English |
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2022
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ftuniaarhuspubl:oai:pure.atira.dk:publications/6e81dd9d-4314-476c-8c68-38735ef1742a 2023-12-31T10:01:56+01:00 Tight benthic-pelagic coupling drives seasonal and interannual changes in iron‑sulfur cycling in Arctic fjord sediments (Kongsfjorden, Svalbard) Herbert, Lisa C. Michaud, Alexander B. Laufer-Meiser, Katja Hoppe, Clara J.M. Zhu, Qingzhi Aller, Robert C. Jørgensen, Bo Barker Wehrmann, Laura M. 2022-01 https://pure.au.dk/portal/da/publications/tight-benthicpelagic-coupling-drives-seasonal-and-interannual-changes-in-ironsulfur-cycling-in-arctic-fjord-sediments-kongsfjorden-svalbard(6e81dd9d-4314-476c-8c68-38735ef1742a).html https://doi.org/10.1016/j.jmarsys.2021.103645 http://www.scopus.com/inward/record.url?scp=85116901641&partnerID=8YFLogxK eng eng https://pure.au.dk/portal/da/publications/tight-benthicpelagic-coupling-drives-seasonal-and-interannual-changes-in-ironsulfur-cycling-in-arctic-fjord-sediments-kongsfjorden-svalbard(6e81dd9d-4314-476c-8c68-38735ef1742a).html info:eu-repo/semantics/restrictedAccess Herbert , L C , Michaud , A B , Laufer-Meiser , K , Hoppe , C J M , Zhu , Q , Aller , R C , Jørgensen , B B & Wehrmann , L M 2022 , ' Tight benthic-pelagic coupling drives seasonal and interannual changes in iron‑sulfur cycling in Arctic fjord sediments (Kongsfjorden, Svalbard) ' , Journal of Marine Systems , vol. 225 , 103645 . https://doi.org/10.1016/j.jmarsys.2021.103645 Arctic Benthic environment Biogeochemistry Fjord Iron Sulfur article 2022 ftuniaarhuspubl https://doi.org/10.1016/j.jmarsys.2021.103645 2023-12-07T00:05:15Z Glaciated fjords are dynamic systems dominated by seasonal events such as spring phytoplankton blooms and pulses of glacial sediment-bearing meltwater delivery. These fjords are also characterized by strong spatial gradients in environmental factors such as sedimentation rate and primary productivity from the glacier-influenced head to the marine-influenced mouth. Such seasonal variations and spatial gradients, combined with the ongoing influence of climate change, generate non-steady state conditions, which have a strong impact on the mineralization of organic carbon in the fjord sediments and the flux of nutrients from the seabed. In order to investigate the role of fjord seasonal events and variability on diagenetic cycling of iron (Fe) and sulfur (S), we sampled Kongsfjorden (Svalbard, 79°N) in the spring, mid-summer, and late summer. We investigated sediment structure and biogeochemistry, conducted laboratory experiments to determine reaction rates, and compared these findings to water column productivity and turbidity. We found that rapid sedimentation near the glacial input buried algal matter-rich layers that fueled sub-surface peaks in mineralization rates over multi-year timescales. Sulfate reduction rates were limited by organic carbon availability and competition with Fe-reducers, while Fe reduction was controlled by the availability of reactive Fe(III) oxides. Pore water Fe 2+ concentrations were influenced by sulfur cycling pathways and abiotic reactions such as carbonate precipitation and potentially reverse weathering. Seasonal changes in sedimentation and organic carbon supply caused lower sulfate reduction and sulfide production rates in spring, driving generally higher spring fluxes of Fe 2+ from the sediment. The results of this study reveal the potential for an increased benthic source of nutrients such as Fe with continued benthic remineralization over winter in Kongsfjorden. Interannual changes in primary productivity, which are likely to intensify with global warming, and shifts in ... Article in Journal/Newspaper Arctic Arctic Climate change glacier Global warming Kongsfjord* Kongsfjorden Phytoplankton Svalbard Aarhus University: Research Journal of Marine Systems 225 103645 |
institution |
Open Polar |
collection |
Aarhus University: Research |
op_collection_id |
ftuniaarhuspubl |
language |
English |
topic |
Arctic Benthic environment Biogeochemistry Fjord Iron Sulfur |
spellingShingle |
Arctic Benthic environment Biogeochemistry Fjord Iron Sulfur Herbert, Lisa C. Michaud, Alexander B. Laufer-Meiser, Katja Hoppe, Clara J.M. Zhu, Qingzhi Aller, Robert C. Jørgensen, Bo Barker Wehrmann, Laura M. Tight benthic-pelagic coupling drives seasonal and interannual changes in iron‑sulfur cycling in Arctic fjord sediments (Kongsfjorden, Svalbard) |
topic_facet |
Arctic Benthic environment Biogeochemistry Fjord Iron Sulfur |
description |
Glaciated fjords are dynamic systems dominated by seasonal events such as spring phytoplankton blooms and pulses of glacial sediment-bearing meltwater delivery. These fjords are also characterized by strong spatial gradients in environmental factors such as sedimentation rate and primary productivity from the glacier-influenced head to the marine-influenced mouth. Such seasonal variations and spatial gradients, combined with the ongoing influence of climate change, generate non-steady state conditions, which have a strong impact on the mineralization of organic carbon in the fjord sediments and the flux of nutrients from the seabed. In order to investigate the role of fjord seasonal events and variability on diagenetic cycling of iron (Fe) and sulfur (S), we sampled Kongsfjorden (Svalbard, 79°N) in the spring, mid-summer, and late summer. We investigated sediment structure and biogeochemistry, conducted laboratory experiments to determine reaction rates, and compared these findings to water column productivity and turbidity. We found that rapid sedimentation near the glacial input buried algal matter-rich layers that fueled sub-surface peaks in mineralization rates over multi-year timescales. Sulfate reduction rates were limited by organic carbon availability and competition with Fe-reducers, while Fe reduction was controlled by the availability of reactive Fe(III) oxides. Pore water Fe 2+ concentrations were influenced by sulfur cycling pathways and abiotic reactions such as carbonate precipitation and potentially reverse weathering. Seasonal changes in sedimentation and organic carbon supply caused lower sulfate reduction and sulfide production rates in spring, driving generally higher spring fluxes of Fe 2+ from the sediment. The results of this study reveal the potential for an increased benthic source of nutrients such as Fe with continued benthic remineralization over winter in Kongsfjorden. Interannual changes in primary productivity, which are likely to intensify with global warming, and shifts in ... |
format |
Article in Journal/Newspaper |
author |
Herbert, Lisa C. Michaud, Alexander B. Laufer-Meiser, Katja Hoppe, Clara J.M. Zhu, Qingzhi Aller, Robert C. Jørgensen, Bo Barker Wehrmann, Laura M. |
author_facet |
Herbert, Lisa C. Michaud, Alexander B. Laufer-Meiser, Katja Hoppe, Clara J.M. Zhu, Qingzhi Aller, Robert C. Jørgensen, Bo Barker Wehrmann, Laura M. |
author_sort |
Herbert, Lisa C. |
title |
Tight benthic-pelagic coupling drives seasonal and interannual changes in iron‑sulfur cycling in Arctic fjord sediments (Kongsfjorden, Svalbard) |
title_short |
Tight benthic-pelagic coupling drives seasonal and interannual changes in iron‑sulfur cycling in Arctic fjord sediments (Kongsfjorden, Svalbard) |
title_full |
Tight benthic-pelagic coupling drives seasonal and interannual changes in iron‑sulfur cycling in Arctic fjord sediments (Kongsfjorden, Svalbard) |
title_fullStr |
Tight benthic-pelagic coupling drives seasonal and interannual changes in iron‑sulfur cycling in Arctic fjord sediments (Kongsfjorden, Svalbard) |
title_full_unstemmed |
Tight benthic-pelagic coupling drives seasonal and interannual changes in iron‑sulfur cycling in Arctic fjord sediments (Kongsfjorden, Svalbard) |
title_sort |
tight benthic-pelagic coupling drives seasonal and interannual changes in iron‑sulfur cycling in arctic fjord sediments (kongsfjorden, svalbard) |
publishDate |
2022 |
url |
https://pure.au.dk/portal/da/publications/tight-benthicpelagic-coupling-drives-seasonal-and-interannual-changes-in-ironsulfur-cycling-in-arctic-fjord-sediments-kongsfjorden-svalbard(6e81dd9d-4314-476c-8c68-38735ef1742a).html https://doi.org/10.1016/j.jmarsys.2021.103645 http://www.scopus.com/inward/record.url?scp=85116901641&partnerID=8YFLogxK |
genre |
Arctic Arctic Climate change glacier Global warming Kongsfjord* Kongsfjorden Phytoplankton Svalbard |
genre_facet |
Arctic Arctic Climate change glacier Global warming Kongsfjord* Kongsfjorden Phytoplankton Svalbard |
op_source |
Herbert , L C , Michaud , A B , Laufer-Meiser , K , Hoppe , C J M , Zhu , Q , Aller , R C , Jørgensen , B B & Wehrmann , L M 2022 , ' Tight benthic-pelagic coupling drives seasonal and interannual changes in iron‑sulfur cycling in Arctic fjord sediments (Kongsfjorden, Svalbard) ' , Journal of Marine Systems , vol. 225 , 103645 . https://doi.org/10.1016/j.jmarsys.2021.103645 |
op_relation |
https://pure.au.dk/portal/da/publications/tight-benthicpelagic-coupling-drives-seasonal-and-interannual-changes-in-ironsulfur-cycling-in-arctic-fjord-sediments-kongsfjorden-svalbard(6e81dd9d-4314-476c-8c68-38735ef1742a).html |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1016/j.jmarsys.2021.103645 |
container_title |
Journal of Marine Systems |
container_volume |
225 |
container_start_page |
103645 |
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1786807905552433152 |