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dc.contributor.authorWeidberg, Nicholas
dc.contributor.authorBasedow, Sünnje Linnéa
dc.date.accessioned2019-08-02T08:54:17Z
dc.date.available2019-08-02T08:54:17Z
dc.date.issued2019-04-08
dc.description.abstractCritical 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 <i>Calanus finmarchicus</i> 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 (<i>Clupea harengus</i>), 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.en_US
dc.description.sponsorshipTOTAL E&Pen_US
dc.descriptionSource at <a href=https://doi.org/10.1002/lno.11168>https://doi.org/10.1002/lno.11168. </a>en_US
dc.identifier.citationWeidberg, 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. <i>Limnology and Oceanography</i>. https://doi.org/10.1002/lno.11168en_US
dc.identifier.cristinIDFRIDAID 1712425
dc.identifier.doi10.1002/lno.11168
dc.identifier.issn0024-3590
dc.identifier.issn1939-5590
dc.identifier.urihttps://hdl.handle.net/10037/15827
dc.language.isoengen_US
dc.publisherWileyen_US
dc.relation.journalLimnology and Oceanography
dc.relation.projectIDinfo:eu-repo/grantAgreement/RCN/HAVKYST/153070/Norway/Plankton climatology in North Norwegian waters - concepts, mechanisms and monitoring//en_US
dc.relation.projectIDinfo:eu-repo/grantAgreement/RCN/?/133904/Norway/?//en_US
dc.relation.projectIDinfo:eu-repo/grantAgreement/RCN/MARINFORSK/268391/Norway/Sustainable harvesting of a patchy resource: aggregation mechanisms and implications for stock size estimates/Sea Patches/en_US
dc.rights.accessRightsopenAccessen_US
dc.subjectVDP::Agriculture and fishery disciplines: 900::Fisheries science: 920en_US
dc.subjectVDP::Landbruks- og Fiskerifag: 900::Fiskerifag: 920en_US
dc.titleLong-term variability in overwintering copepod populations in the Lofoten Basin: The role of the North Atlantic oscillation and trophic effectsen_US
dc.typeJournal articleen_US
dc.typeTidsskriftartikkelen_US
dc.typePeer revieweden_US


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