Vertical distribution and diel vertical migration of krill beneath snow-covered ice and in ice-free waters

Handle URI:
http://hdl.handle.net/10754/325458
Title:
Vertical distribution and diel vertical migration of krill beneath snow-covered ice and in ice-free waters
Authors:
Vestheim, Hege; Røstad, Anders ( 0000-0002-2512-9033 ) ; Klevjer, Thor A.; Solberg, Ingrid; Kaartvedt, Stein ( 0000-0002-8793-2948 )
Abstract:
A bottom mounted upward looking Simrad EK60 120-kHz echo sounder was used to study scattering layers (SLs) and individuals of the krill Meganyctiphanes norvegica. The mooring was situated at 150-m depth in the Oslofjord, connected with an onshore cable for power and transmission of digitized data. Records spanned 5 months from late autumn to spring. A current meter and CTD was associated with the acoustic mooring and a shore-based webcam monitored ice conditions in the fjord. The continuous measurements were supplemented with intermittent krill sampling campaigns and their physical and biological environment.The krill carried out diel vertical migration (DVM) throughout the winter, regardless of the distribution of potential prey. The fjord froze over in mid-winter and the daytime distribution of a mid-water SL of krill immediately became shallower associated with snow fall after freezing, likely related to reduction of light intensities. Still, a fraction of the population always descended all the way to the bottom, so that the krill population by day seemed to inhabit waters with light levels spanning up to six orders of magnitude. Deep-living krill ascended in synchrony with the rest of the population in the afternoon, but individuals consistently reappeared in near-bottom waters already? 1 h after the ascent. Thereafter, the krill appeared to undertake asynchronous migrations, with some krill always being present in near-bottom waters even though the entire population appeared to undertake DVM. The Author 2013. Published by Oxford University Press. All rights reserved.
KAUST Department:
Red Sea Research Center (RSRC)
Citation:
Vestheim H, Rostad A, Klevjer TA, Solberg I, Kaartvedt S (2013) Vertical distribution and diel vertical migration of krill beneath snow-covered ice and in ice-free waters. Journal of Plankton Research 36: 503-512. doi:10.1093/plankt/fbt112.
Publisher:
Oxford University Press (OUP)
Journal:
Journal of Plankton Research
Issue Date:
11-Nov-2013
DOI:
10.1093/plankt/fbt112
PubMed ID:
24616550
PubMed Central ID:
PMC3945875
Type:
Article
ISSN:
14643774
Appears in Collections:
Articles; Red Sea Research Center (RSRC)

Full metadata record

DC FieldValue Language
dc.contributor.authorVestheim, Hegeen
dc.contributor.authorRøstad, Andersen
dc.contributor.authorKlevjer, Thor A.en
dc.contributor.authorSolberg, Ingriden
dc.contributor.authorKaartvedt, Steinen
dc.date.accessioned2014-08-27T09:52:13Z-
dc.date.available2014-08-27T09:52:13Z-
dc.date.issued2013-11-11en
dc.identifier.citationVestheim H, Rostad A, Klevjer TA, Solberg I, Kaartvedt S (2013) Vertical distribution and diel vertical migration of krill beneath snow-covered ice and in ice-free waters. Journal of Plankton Research 36: 503-512. doi:10.1093/plankt/fbt112.en
dc.identifier.issn14643774en
dc.identifier.pmid24616550en
dc.identifier.doi10.1093/plankt/fbt112en
dc.identifier.urihttp://hdl.handle.net/10754/325458en
dc.description.abstractA bottom mounted upward looking Simrad EK60 120-kHz echo sounder was used to study scattering layers (SLs) and individuals of the krill Meganyctiphanes norvegica. The mooring was situated at 150-m depth in the Oslofjord, connected with an onshore cable for power and transmission of digitized data. Records spanned 5 months from late autumn to spring. A current meter and CTD was associated with the acoustic mooring and a shore-based webcam monitored ice conditions in the fjord. The continuous measurements were supplemented with intermittent krill sampling campaigns and their physical and biological environment.The krill carried out diel vertical migration (DVM) throughout the winter, regardless of the distribution of potential prey. The fjord froze over in mid-winter and the daytime distribution of a mid-water SL of krill immediately became shallower associated with snow fall after freezing, likely related to reduction of light intensities. Still, a fraction of the population always descended all the way to the bottom, so that the krill population by day seemed to inhabit waters with light levels spanning up to six orders of magnitude. Deep-living krill ascended in synchrony with the rest of the population in the afternoon, but individuals consistently reappeared in near-bottom waters already? 1 h after the ascent. Thereafter, the krill appeared to undertake asynchronous migrations, with some krill always being present in near-bottom waters even though the entire population appeared to undertake DVM. The Author 2013. Published by Oxford University Press. All rights reserved.en
dc.language.isoenen
dc.publisherOxford University Press (OUP)en
dc.rightsThis is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.en
dc.rights.urihttp://creativecommons.org/licenses/by/3.0/en
dc.subjectMeganyctiphanes norvegicaen
dc.subjectNorwayen
dc.subjectSea iceen
dc.subjectStationary acousticsen
dc.subjectSynchronous and asynchronous DVMen
dc.subjectbottom wateren
dc.subjectcrustaceanen
dc.subjectdiel migrationen
dc.subjectecho sounderen
dc.subjectfjorden
dc.subjectlight effecten
dc.subjectpopulation distributionen
dc.subjectseasonal variationen
dc.subjectsynchronyen
dc.subjectOslofjordenen
dc.titleVertical distribution and diel vertical migration of krill beneath snow-covered ice and in ice-free watersen
dc.typeArticleen
dc.contributor.departmentRed Sea Research Center (RSRC)en
dc.identifier.journalJournal of Plankton Researchen
dc.identifier.pmcidPMC3945875en
dc.eprint.versionPublisher's Version/PDFen
dc.contributor.institutionDepartment of Biosciences, University of Oslo, PO Box 1066 Blindern, 0316 Oslo, Norwayen
dc.contributor.institutionInstitute of Marine Research, PO Box 1870 Nordnes, 5817 Bergen, Norwayen
dc.contributor.affiliationKing Abdullah University of Science and Technology (KAUST)en
kaust.authorVestheim, Hegeen
kaust.authorRøstad, Andersen
kaust.authorSolberg, Ingriden
kaust.authorKaartvedt, Steinen

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