Pelagic ecosystem dynamics between late autumn and the post spring bloom in a sub-Arctic fjord
Marine ecosystems, and particularly fjords, are experiencing an increasing level of human activity on a year-round basis, including the poorly studied winter period. To improve the knowledge base for environmentally sustainable management in all seasons, this study provides hydrographic and biologic...
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Online Access: | https://hdl.handle.net/11250/2999223 https://doi.org/10.1525/elementa.2021.00070 |
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ftimr:oai:imr.brage.unit.no:11250/2999223 2023-05-15T15:01:58+02:00 Pelagic ecosystem dynamics between late autumn and the post spring bloom in a sub-Arctic fjord Walker, Emily-Zoe Elizabeth Wiedmann, Ingrid Nikolopoulos, Anna Skardhamar, Jofrid Jones, Elizabeth Marie Renner, Angelika 2022 application/pdf https://hdl.handle.net/11250/2999223 https://doi.org/10.1525/elementa.2021.00070 eng eng Framsenteret: WHALE (#201914747042018) EC/H2020/ECOTIP (#869383) Norges forskningsråd: 228107 Norges forskningsråd: 299554 UiT Norges arktiske universitet: Publication fund urn:issn:2325-1026 https://hdl.handle.net/11250/2999223 https://doi.org/10.1525/elementa.2021.00070 cristin:2029144 Elementa: Science of the Anthropocene Peer reviewed Journal article 2022 ftimr https://doi.org/10.1525/elementa.2021.00070 2022-06-22T22:40:31Z Marine ecosystems, and particularly fjords, are experiencing an increasing level of human activity on a year-round basis, including the poorly studied winter period. To improve the knowledge base for environmentally sustainable management in all seasons, this study provides hydrographic and biological baseline data for the sub-Arctic fjord Kaldfjorden, Northern Norway (69.7° N, 18.7° E), between autumn 2017 and spring 2018. Field observations are integrated with results of a numerical ocean model simulation, illustrating how pelagic biomass, represented by chlorophyll a (Chl a), particulate organic carbon (POC), and zooplankton, is affected by stratification and circulation from October to May. We observed an unusually warm autumn that likely delayed the onset of cooling and may have supported the high abundances of holoplankton and meroplankton (5768 individuals m–3). With the onset of winter, the water column cooled and became vertically mixed, while suspended Chl a concentrations declined rapidly (< 0.12 mg Chl a m–3). In January and February, suspended POC concentrations and downward flux were elevated near the seafloor. The hydrodynamic model results indicate that the strongest currents at depth occurred in these months, potentially inducing resuspension events close to the seafloor. In spring (April), peak abundances of suspended biomass were observed (6.9–7.2 mg Chl a m–3 at 5–15 m; 9952 zooplankton ind. m–3 at 0–100 m), and field observations and model results suggest that zooplankton of Atlantic origin were probably advected into Kaldfjorden. During all investigated seasons, the model simulation suggests a complex circulation pattern, even in such a small fjord, which can have implications for environmental management of the fjord. We conclude that the pelagic system in Kaldfjorden changes continually from autumn to spring and that winter must be seen as a dynamic period, not a season where the fjord ecosystem is ‘at rest’. publishedVersion Article in Journal/Newspaper Arctic Northern Norway Zooplankton Institute for Marine Research: Brage IMR Arctic Norway Elementa: Science of the Anthropocene 10 1 |
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Open Polar |
collection |
Institute for Marine Research: Brage IMR |
op_collection_id |
ftimr |
language |
English |
description |
Marine ecosystems, and particularly fjords, are experiencing an increasing level of human activity on a year-round basis, including the poorly studied winter period. To improve the knowledge base for environmentally sustainable management in all seasons, this study provides hydrographic and biological baseline data for the sub-Arctic fjord Kaldfjorden, Northern Norway (69.7° N, 18.7° E), between autumn 2017 and spring 2018. Field observations are integrated with results of a numerical ocean model simulation, illustrating how pelagic biomass, represented by chlorophyll a (Chl a), particulate organic carbon (POC), and zooplankton, is affected by stratification and circulation from October to May. We observed an unusually warm autumn that likely delayed the onset of cooling and may have supported the high abundances of holoplankton and meroplankton (5768 individuals m–3). With the onset of winter, the water column cooled and became vertically mixed, while suspended Chl a concentrations declined rapidly (< 0.12 mg Chl a m–3). In January and February, suspended POC concentrations and downward flux were elevated near the seafloor. The hydrodynamic model results indicate that the strongest currents at depth occurred in these months, potentially inducing resuspension events close to the seafloor. In spring (April), peak abundances of suspended biomass were observed (6.9–7.2 mg Chl a m–3 at 5–15 m; 9952 zooplankton ind. m–3 at 0–100 m), and field observations and model results suggest that zooplankton of Atlantic origin were probably advected into Kaldfjorden. During all investigated seasons, the model simulation suggests a complex circulation pattern, even in such a small fjord, which can have implications for environmental management of the fjord. We conclude that the pelagic system in Kaldfjorden changes continually from autumn to spring and that winter must be seen as a dynamic period, not a season where the fjord ecosystem is ‘at rest’. publishedVersion |
format |
Article in Journal/Newspaper |
author |
Walker, Emily-Zoe Elizabeth Wiedmann, Ingrid Nikolopoulos, Anna Skardhamar, Jofrid Jones, Elizabeth Marie Renner, Angelika |
spellingShingle |
Walker, Emily-Zoe Elizabeth Wiedmann, Ingrid Nikolopoulos, Anna Skardhamar, Jofrid Jones, Elizabeth Marie Renner, Angelika Pelagic ecosystem dynamics between late autumn and the post spring bloom in a sub-Arctic fjord |
author_facet |
Walker, Emily-Zoe Elizabeth Wiedmann, Ingrid Nikolopoulos, Anna Skardhamar, Jofrid Jones, Elizabeth Marie Renner, Angelika |
author_sort |
Walker, Emily-Zoe Elizabeth |
title |
Pelagic ecosystem dynamics between late autumn and the post spring bloom in a sub-Arctic fjord |
title_short |
Pelagic ecosystem dynamics between late autumn and the post spring bloom in a sub-Arctic fjord |
title_full |
Pelagic ecosystem dynamics between late autumn and the post spring bloom in a sub-Arctic fjord |
title_fullStr |
Pelagic ecosystem dynamics between late autumn and the post spring bloom in a sub-Arctic fjord |
title_full_unstemmed |
Pelagic ecosystem dynamics between late autumn and the post spring bloom in a sub-Arctic fjord |
title_sort |
pelagic ecosystem dynamics between late autumn and the post spring bloom in a sub-arctic fjord |
publishDate |
2022 |
url |
https://hdl.handle.net/11250/2999223 https://doi.org/10.1525/elementa.2021.00070 |
geographic |
Arctic Norway |
geographic_facet |
Arctic Norway |
genre |
Arctic Northern Norway Zooplankton |
genre_facet |
Arctic Northern Norway Zooplankton |
op_source |
Elementa: Science of the Anthropocene |
op_relation |
Framsenteret: WHALE (#201914747042018) EC/H2020/ECOTIP (#869383) Norges forskningsråd: 228107 Norges forskningsråd: 299554 UiT Norges arktiske universitet: Publication fund urn:issn:2325-1026 https://hdl.handle.net/11250/2999223 https://doi.org/10.1525/elementa.2021.00070 cristin:2029144 |
op_doi |
https://doi.org/10.1525/elementa.2021.00070 |
container_title |
Elementa: Science of the Anthropocene |
container_volume |
10 |
container_issue |
1 |
_version_ |
1766333963963465728 |