Qualitative and quantitative reconstructions of surface water characteristics and recent hydrographical changes in the Trondheimsfjord, central Norway
In the present study we investigated dinocyst assemblages in the Trondheimsfjord over the last 25 to 50 yr from three well-dated multi-cores (210Pb and 137Cs) retrieved along the fjord axis. The downcore distribution of the dinocysts is discussed in view of changes in key hydrographic parameters of...
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fttriple:oai:gotriple.eu:oai:doaj.org/article:ac0b25a2b09b467e81b25fb896e5c1bf 2023-05-15T17:36:24+02:00 Qualitative and quantitative reconstructions of surface water characteristics and recent hydrographical changes in the Trondheimsfjord, central Norway G. Milzer J. Giraudeau S. Schmidt F. Eynaud J. Faust 2014-02-01 https://doi.org/10.5194/cp-10-305-2014 http://www.clim-past.net/10/305/2014/cp-10-305-2014.pdf https://doaj.org/article/ac0b25a2b09b467e81b25fb896e5c1bf en eng Copernicus Publications 1814-9324 1814-9332 doi:10.5194/cp-10-305-2014 http://www.clim-past.net/10/305/2014/cp-10-305-2014.pdf https://doaj.org/article/ac0b25a2b09b467e81b25fb896e5c1bf undefined Climate of the Past, Vol 10, Iss 1, Pp 305-323 (2014) envir geo Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2014 fttriple https://doi.org/10.5194/cp-10-305-2014 2023-01-22T19:27:58Z In the present study we investigated dinocyst assemblages in the Trondheimsfjord over the last 25 to 50 yr from three well-dated multi-cores (210Pb and 137Cs) retrieved along the fjord axis. The downcore distribution of the dinocysts is discussed in view of changes in key hydrographic parameters of the surface waters (sea-surface temperatures (SSTs), sea-surface salinities (SSSs), and river discharges) monitored in the fjord. We examine the impact of the North Atlantic Oscillation pattern and of waste water supply from the local industry and agriculture on the fjord ecological state and thus dinocyst species diversity. Our results show that dinocyst production and diversity in the fjord is not evidently affected by human-induced eutrophication. Instead the assemblages appear to be mainly controlled by the NAO-related changes in nutrient availability and the physico-chemical characteristics of the surface mixed layer. Still, discharges of major rivers have been modulated since 1985 by the implementation of hydropower plants, which certainly influences the amounts of nutrients supplied to the fjord. The impact, however, is variable according to the local geographical setting, and barely differentiated from natural changes in river run off. We ultimately test the use of the modern analogue technique (MAT) for the reconstruction of winter and summer SSTs and SSSs and annual primary productivity (PP) in this particular fjord setting. The reconstructed data are compared with time series of summer and winter SSTs and SSSs measured at 10 m water depth, as well as with mean annual PPs along the Norwegian coast and in Scandinavian fjords. The reconstructions are generally in good agreement with the instrumental measurements and observations from other fjords. Major deviations can be attributed to peculiarities in the assemblages linked to the particular fjord setting and the related hydrological structure. Article in Journal/Newspaper North Atlantic North Atlantic oscillation Unknown Norway Climate of the Past 10 1 305 323 |
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envir geo G. Milzer J. Giraudeau S. Schmidt F. Eynaud J. Faust Qualitative and quantitative reconstructions of surface water characteristics and recent hydrographical changes in the Trondheimsfjord, central Norway |
topic_facet |
envir geo |
description |
In the present study we investigated dinocyst assemblages in the Trondheimsfjord over the last 25 to 50 yr from three well-dated multi-cores (210Pb and 137Cs) retrieved along the fjord axis. The downcore distribution of the dinocysts is discussed in view of changes in key hydrographic parameters of the surface waters (sea-surface temperatures (SSTs), sea-surface salinities (SSSs), and river discharges) monitored in the fjord. We examine the impact of the North Atlantic Oscillation pattern and of waste water supply from the local industry and agriculture on the fjord ecological state and thus dinocyst species diversity. Our results show that dinocyst production and diversity in the fjord is not evidently affected by human-induced eutrophication. Instead the assemblages appear to be mainly controlled by the NAO-related changes in nutrient availability and the physico-chemical characteristics of the surface mixed layer. Still, discharges of major rivers have been modulated since 1985 by the implementation of hydropower plants, which certainly influences the amounts of nutrients supplied to the fjord. The impact, however, is variable according to the local geographical setting, and barely differentiated from natural changes in river run off. We ultimately test the use of the modern analogue technique (MAT) for the reconstruction of winter and summer SSTs and SSSs and annual primary productivity (PP) in this particular fjord setting. The reconstructed data are compared with time series of summer and winter SSTs and SSSs measured at 10 m water depth, as well as with mean annual PPs along the Norwegian coast and in Scandinavian fjords. The reconstructions are generally in good agreement with the instrumental measurements and observations from other fjords. Major deviations can be attributed to peculiarities in the assemblages linked to the particular fjord setting and the related hydrological structure. |
format |
Article in Journal/Newspaper |
author |
G. Milzer J. Giraudeau S. Schmidt F. Eynaud J. Faust |
author_facet |
G. Milzer J. Giraudeau S. Schmidt F. Eynaud J. Faust |
author_sort |
G. Milzer |
title |
Qualitative and quantitative reconstructions of surface water characteristics and recent hydrographical changes in the Trondheimsfjord, central Norway |
title_short |
Qualitative and quantitative reconstructions of surface water characteristics and recent hydrographical changes in the Trondheimsfjord, central Norway |
title_full |
Qualitative and quantitative reconstructions of surface water characteristics and recent hydrographical changes in the Trondheimsfjord, central Norway |
title_fullStr |
Qualitative and quantitative reconstructions of surface water characteristics and recent hydrographical changes in the Trondheimsfjord, central Norway |
title_full_unstemmed |
Qualitative and quantitative reconstructions of surface water characteristics and recent hydrographical changes in the Trondheimsfjord, central Norway |
title_sort |
qualitative and quantitative reconstructions of surface water characteristics and recent hydrographical changes in the trondheimsfjord, central norway |
publisher |
Copernicus Publications |
publishDate |
2014 |
url |
https://doi.org/10.5194/cp-10-305-2014 http://www.clim-past.net/10/305/2014/cp-10-305-2014.pdf https://doaj.org/article/ac0b25a2b09b467e81b25fb896e5c1bf |
geographic |
Norway |
geographic_facet |
Norway |
genre |
North Atlantic North Atlantic oscillation |
genre_facet |
North Atlantic North Atlantic oscillation |
op_source |
Climate of the Past, Vol 10, Iss 1, Pp 305-323 (2014) |
op_relation |
1814-9324 1814-9332 doi:10.5194/cp-10-305-2014 http://www.clim-past.net/10/305/2014/cp-10-305-2014.pdf https://doaj.org/article/ac0b25a2b09b467e81b25fb896e5c1bf |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/cp-10-305-2014 |
container_title |
Climate of the Past |
container_volume |
10 |
container_issue |
1 |
container_start_page |
305 |
op_container_end_page |
323 |
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