Seasonal dynamics of carbonate chemistry, nutrients and CO2 uptake in a sub-Arctic fjord
Environmental change can have a significant impact on biogeochemical cycles at high latitudes and be particularly important in ecologically valuable fjord ecosystems. Seasonality in biogeochemical cycling in a sub-Arctic fjord of northern Norway (Kaldfjorden) was investigated from October 2016 to Se...
Published in: | Elementa: Science of the Anthropocene |
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University of California Press
2020
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Online Access: | http://dx.doi.org/10.1525/elementa.438 https://online.ucpress.edu/elementa/article-pdf/doi/10.1525/elementa.438/789670/438-7444-1-pb.pdf |
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crunicaliforniap:10.1525/elementa.438 2024-09-30T14:30:53+00:00 Seasonal dynamics of carbonate chemistry, nutrients and CO2 uptake in a sub-Arctic fjord Jones, Elizabeth M. Renner, Angelika H. H. Chierici, Melissa Wiedmann, Ingrid Lødemel, Helene Hodal Biuw, Martin Deming, Jody W. Miller, Lisa A. 2020 http://dx.doi.org/10.1525/elementa.438 https://online.ucpress.edu/elementa/article-pdf/doi/10.1525/elementa.438/789670/438-7444-1-pb.pdf en eng University of California Press http://creativecommons.org/licenses/by/4.0/ Elem Sci Anth volume 8 ISSN 2325-1026 journal-article 2020 crunicaliforniap https://doi.org/10.1525/elementa.438 2024-09-05T05:01:58Z Environmental change can have a significant impact on biogeochemical cycles at high latitudes and be particularly important in ecologically valuable fjord ecosystems. Seasonality in biogeochemical cycling in a sub-Arctic fjord of northern Norway (Kaldfjorden) was investigated from October 2016 to September 2018. Monthly changes in total inorganic carbon (CT), alkalinity (AT), major nutrients and calcium carbonate saturation (Ω) were driven by freshwater discharge, biological production and mixing with subsurface carbon-rich coastal water. Stable oxygen isotope ratios indicated that meteoric water (snow melt, river runoff, precipitation) had stratified and freshened surface waters, contributing to 81% of the monthly CT deficit in the surface layer. The timing and magnitude of freshwater inputs played an important role in Ω variability, reducing AT and CT by dilution. This dilution effect was strongly counteracted by the opposing effect of primary production that dominated surface water Ω seasonality. The spring phytoplankton bloom rapidly depleted nitrate and CT to drive highest Ω (~2.3) in surface waters. Calcification reduced AT and CT, which accounted for 21% of the monthly decrease in Ω during a coccolithophore bloom. Freshwater runoff contributed CT, AT and silicates of terrestrial origin to the fjord. Lowest surface water Ω (~1.6) resulted from organic matter remineralisation and mixing into subsurface water during winter and spring. Surface waters were undersaturated with respect to atmospheric CO2, resulting in modest uptake of –0.32 ± 0.03 mol C m–2 yr–1. Net community production estimated from carbon drawdown was 14 ± 2 g C m–2 yr–1 during the productive season. Kaldfjorden currently functions as an atmospheric CO2 sink of 3.9 ± 0.3 g C m–2 yr–1. Time-series data are vital to better understand the processes and natural variability affecting biogeochemical cycling in dynamic coastal regions and thus better predict the impact of future changes on important fjord ecosystems. Article in Journal/Newspaper Arctic Northern Norway Phytoplankton University of California Press Arctic Norway Elementa: Science of the Anthropocene 8 |
institution |
Open Polar |
collection |
University of California Press |
op_collection_id |
crunicaliforniap |
language |
English |
description |
Environmental change can have a significant impact on biogeochemical cycles at high latitudes and be particularly important in ecologically valuable fjord ecosystems. Seasonality in biogeochemical cycling in a sub-Arctic fjord of northern Norway (Kaldfjorden) was investigated from October 2016 to September 2018. Monthly changes in total inorganic carbon (CT), alkalinity (AT), major nutrients and calcium carbonate saturation (Ω) were driven by freshwater discharge, biological production and mixing with subsurface carbon-rich coastal water. Stable oxygen isotope ratios indicated that meteoric water (snow melt, river runoff, precipitation) had stratified and freshened surface waters, contributing to 81% of the monthly CT deficit in the surface layer. The timing and magnitude of freshwater inputs played an important role in Ω variability, reducing AT and CT by dilution. This dilution effect was strongly counteracted by the opposing effect of primary production that dominated surface water Ω seasonality. The spring phytoplankton bloom rapidly depleted nitrate and CT to drive highest Ω (~2.3) in surface waters. Calcification reduced AT and CT, which accounted for 21% of the monthly decrease in Ω during a coccolithophore bloom. Freshwater runoff contributed CT, AT and silicates of terrestrial origin to the fjord. Lowest surface water Ω (~1.6) resulted from organic matter remineralisation and mixing into subsurface water during winter and spring. Surface waters were undersaturated with respect to atmospheric CO2, resulting in modest uptake of –0.32 ± 0.03 mol C m–2 yr–1. Net community production estimated from carbon drawdown was 14 ± 2 g C m–2 yr–1 during the productive season. Kaldfjorden currently functions as an atmospheric CO2 sink of 3.9 ± 0.3 g C m–2 yr–1. Time-series data are vital to better understand the processes and natural variability affecting biogeochemical cycling in dynamic coastal regions and thus better predict the impact of future changes on important fjord ecosystems. |
author2 |
Deming, Jody W. Miller, Lisa A. |
format |
Article in Journal/Newspaper |
author |
Jones, Elizabeth M. Renner, Angelika H. H. Chierici, Melissa Wiedmann, Ingrid Lødemel, Helene Hodal Biuw, Martin |
spellingShingle |
Jones, Elizabeth M. Renner, Angelika H. H. Chierici, Melissa Wiedmann, Ingrid Lødemel, Helene Hodal Biuw, Martin Seasonal dynamics of carbonate chemistry, nutrients and CO2 uptake in a sub-Arctic fjord |
author_facet |
Jones, Elizabeth M. Renner, Angelika H. H. Chierici, Melissa Wiedmann, Ingrid Lødemel, Helene Hodal Biuw, Martin |
author_sort |
Jones, Elizabeth M. |
title |
Seasonal dynamics of carbonate chemistry, nutrients and CO2 uptake in a sub-Arctic fjord |
title_short |
Seasonal dynamics of carbonate chemistry, nutrients and CO2 uptake in a sub-Arctic fjord |
title_full |
Seasonal dynamics of carbonate chemistry, nutrients and CO2 uptake in a sub-Arctic fjord |
title_fullStr |
Seasonal dynamics of carbonate chemistry, nutrients and CO2 uptake in a sub-Arctic fjord |
title_full_unstemmed |
Seasonal dynamics of carbonate chemistry, nutrients and CO2 uptake in a sub-Arctic fjord |
title_sort |
seasonal dynamics of carbonate chemistry, nutrients and co2 uptake in a sub-arctic fjord |
publisher |
University of California Press |
publishDate |
2020 |
url |
http://dx.doi.org/10.1525/elementa.438 https://online.ucpress.edu/elementa/article-pdf/doi/10.1525/elementa.438/789670/438-7444-1-pb.pdf |
geographic |
Arctic Norway |
geographic_facet |
Arctic Norway |
genre |
Arctic Northern Norway Phytoplankton |
genre_facet |
Arctic Northern Norway Phytoplankton |
op_source |
Elem Sci Anth volume 8 ISSN 2325-1026 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1525/elementa.438 |
container_title |
Elementa: Science of the Anthropocene |
container_volume |
8 |
_version_ |
1811635635114475520 |