Long-term variability in overwintering copepod populations in the Lofoten Basin: The role of the North Atlantic oscillation and trophic effects
Source at https://doi.org/10.1002/lno.11168. Critical gaps in knowledge hinder our ability to infer spatiotemporal dynamics in pelagic ecosystems. In particular, environmental changes affecting key copepod species while overwintering in deep waters are still not well understood. Here, we analyzed an...
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Online Access: | https://hdl.handle.net/10037/15827 https://doi.org/10.1002/lno.11168 |
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ftunivtroemsoe:oai:munin.uit.no:10037/15827 2023-05-15T15:48:03+02:00 Long-term variability in overwintering copepod populations in the Lofoten Basin: The role of the North Atlantic oscillation and trophic effects Weidberg, Nicholas Basedow, Sünnje Linnéa 2019-04-08 https://hdl.handle.net/10037/15827 https://doi.org/10.1002/lno.11168 eng eng Wiley Limnology and Oceanography info:eu-repo/grantAgreement/RCN/HAVKYST/153070/Norway/Plankton climatology in North Norwegian waters - concepts, mechanisms and monitoring// info:eu-repo/grantAgreement/RCN/?/133904/Norway/?// info:eu-repo/grantAgreement/RCN/MARINFORSK/268391/Norway/Sustainable harvesting of a patchy resource: aggregation mechanisms and implications for stock size estimates/Sea Patches/ Weidberg, N. & Basedow, S.L. (2019). Long-term variability in overwintering copepod populations in theLofoten Basin: The role of the North Atlantic oscillation and trophic effects. Limnology and Oceanography . https://doi.org/10.1002/lno.11168 FRIDAID 1712425 doi:10.1002/lno.11168 0024-3590 1939-5590 https://hdl.handle.net/10037/15827 openAccess VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920 VDP::Landbruks- og Fiskerifag: 900::Fiskerifag: 920 Journal article Tidsskriftartikkel Peer reviewed 2019 ftunivtroemsoe https://doi.org/10.1002/lno.11168 2021-06-25T17:56:42Z Source at https://doi.org/10.1002/lno.11168. Critical gaps in knowledge hinder our ability to infer spatiotemporal dynamics in pelagic ecosystems. In particular, environmental changes affecting key copepod species while overwintering in deep waters are still not well understood. Here, we analyzed an 11 yr time series (2000–2010) of winter (January/February) samplings in the Lofoten Basin to characterize the spatial distribution of Calanus finmarchicus overwintering abundances and to infer their long‐term temporal trends. The spatial structure of populations at depths between 700 and 900 m corresponded to mesoscale aggregations consistent with eddies in the region. Over time, increased abundances of copepods and of one of its main predators, the herring ( Clupea harengus ), matched a negative trend in the 7 yr lagged winter NAO index. However, this progressive climatic shift did not affect surface conditions in the region or southward but corresponded to an increase in salinity and a deepening of the vertical extension of the Atlantic Water layer. We hypothesized that this change in salinity structure across the water column increased the density contrast between copepods and ambient water masses and facilitates the ascent rates during seasonal vertical migration. We suggest a step‐wise mechanism from NAO large‐scale forcing to copepod and herring populations mediated by hydrographical changes in intermediate water masses to explain the observed trends in abundances. Thus, large‐scale, lagged climatic patterns affecting overwintering copepods might scale up to succesive trophic levels in the pelagic ecosystem. Article in Journal/Newspaper Calanus finmarchicus Lofoten North Atlantic North Atlantic oscillation Copepods University of Tromsø: Munin Open Research Archive Lofoten Lofoten Basin ENVELOPE(4.000,4.000,70.000,70.000) Limnology and Oceanography 64 5 2044 2058 |
institution |
Open Polar |
collection |
University of Tromsø: Munin Open Research Archive |
op_collection_id |
ftunivtroemsoe |
language |
English |
topic |
VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920 VDP::Landbruks- og Fiskerifag: 900::Fiskerifag: 920 |
spellingShingle |
VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920 VDP::Landbruks- og Fiskerifag: 900::Fiskerifag: 920 Weidberg, Nicholas Basedow, Sünnje Linnéa Long-term variability in overwintering copepod populations in the Lofoten Basin: The role of the North Atlantic oscillation and trophic effects |
topic_facet |
VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920 VDP::Landbruks- og Fiskerifag: 900::Fiskerifag: 920 |
description |
Source at https://doi.org/10.1002/lno.11168. Critical gaps in knowledge hinder our ability to infer spatiotemporal dynamics in pelagic ecosystems. In particular, environmental changes affecting key copepod species while overwintering in deep waters are still not well understood. Here, we analyzed an 11 yr time series (2000–2010) of winter (January/February) samplings in the Lofoten Basin to characterize the spatial distribution of Calanus finmarchicus overwintering abundances and to infer their long‐term temporal trends. The spatial structure of populations at depths between 700 and 900 m corresponded to mesoscale aggregations consistent with eddies in the region. Over time, increased abundances of copepods and of one of its main predators, the herring ( Clupea harengus ), matched a negative trend in the 7 yr lagged winter NAO index. However, this progressive climatic shift did not affect surface conditions in the region or southward but corresponded to an increase in salinity and a deepening of the vertical extension of the Atlantic Water layer. We hypothesized that this change in salinity structure across the water column increased the density contrast between copepods and ambient water masses and facilitates the ascent rates during seasonal vertical migration. We suggest a step‐wise mechanism from NAO large‐scale forcing to copepod and herring populations mediated by hydrographical changes in intermediate water masses to explain the observed trends in abundances. Thus, large‐scale, lagged climatic patterns affecting overwintering copepods might scale up to succesive trophic levels in the pelagic ecosystem. |
format |
Article in Journal/Newspaper |
author |
Weidberg, Nicholas Basedow, Sünnje Linnéa |
author_facet |
Weidberg, Nicholas Basedow, Sünnje Linnéa |
author_sort |
Weidberg, Nicholas |
title |
Long-term variability in overwintering copepod populations in the Lofoten Basin: The role of the North Atlantic oscillation and trophic effects |
title_short |
Long-term variability in overwintering copepod populations in the Lofoten Basin: The role of the North Atlantic oscillation and trophic effects |
title_full |
Long-term variability in overwintering copepod populations in the Lofoten Basin: The role of the North Atlantic oscillation and trophic effects |
title_fullStr |
Long-term variability in overwintering copepod populations in the Lofoten Basin: The role of the North Atlantic oscillation and trophic effects |
title_full_unstemmed |
Long-term variability in overwintering copepod populations in the Lofoten Basin: The role of the North Atlantic oscillation and trophic effects |
title_sort |
long-term variability in overwintering copepod populations in the lofoten basin: the role of the north atlantic oscillation and trophic effects |
publisher |
Wiley |
publishDate |
2019 |
url |
https://hdl.handle.net/10037/15827 https://doi.org/10.1002/lno.11168 |
long_lat |
ENVELOPE(4.000,4.000,70.000,70.000) |
geographic |
Lofoten Lofoten Basin |
geographic_facet |
Lofoten Lofoten Basin |
genre |
Calanus finmarchicus Lofoten North Atlantic North Atlantic oscillation Copepods |
genre_facet |
Calanus finmarchicus Lofoten North Atlantic North Atlantic oscillation Copepods |
op_relation |
Limnology and Oceanography info:eu-repo/grantAgreement/RCN/HAVKYST/153070/Norway/Plankton climatology in North Norwegian waters - concepts, mechanisms and monitoring// info:eu-repo/grantAgreement/RCN/?/133904/Norway/?// info:eu-repo/grantAgreement/RCN/MARINFORSK/268391/Norway/Sustainable harvesting of a patchy resource: aggregation mechanisms and implications for stock size estimates/Sea Patches/ Weidberg, N. & Basedow, S.L. (2019). Long-term variability in overwintering copepod populations in theLofoten Basin: The role of the North Atlantic oscillation and trophic effects. Limnology and Oceanography . https://doi.org/10.1002/lno.11168 FRIDAID 1712425 doi:10.1002/lno.11168 0024-3590 1939-5590 https://hdl.handle.net/10037/15827 |
op_rights |
openAccess |
op_doi |
https://doi.org/10.1002/lno.11168 |
container_title |
Limnology and Oceanography |
container_volume |
64 |
container_issue |
5 |
container_start_page |
2044 |
op_container_end_page |
2058 |
_version_ |
1766383049517301760 |