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dc.contributor.advisorPedersen, Torstein
dc.contributor.authorMichaelsen, Christer
dc.date.accessioned2012-12-17T15:17:01Z
dc.date.available2012-12-17T15:17:01Z
dc.date.issued2012-11-15
dc.description.abstractHabitat choice of small juvenile coastal cod (Gadus morhua L. 1758) was investigated in a field study in Porsangerfjorden and Ullsfjorden in Northern Norway. A towed video rig was used to record video along depth transects in the subtidal zone. Depth, algae cover and occurrence of 0- group, 1-group and 2+ group cod was registered. Beach seine and angling was used to estimate relative abundances of cod and sample fish for length measurement and diet analysis. The occurrence of juvenile cod was significantly higher in areas with algae cover of 20% or more. In addition there seemed to be a depth preference for depths between 10-20 m. There was a difference in the degree of association to macroalgae between the various age groups of cod. The diet analysis showed variations in between the various age groups of cod. My findings suggest that macroalgae habitats play a vital role as nursing grounds for juvenile coastal cod by providing refuge from predators and lucrative feeding opportunities. There was observed an ontogenic shift in diet composition among juvenile coastal cod, which suggests that the role of macroalgae habitats is different for various age groups of juvnile cod. 0-group seemed more closely associated with the macroalgae than older individuals. Overgrazing of macroalgae by sea urchins may affect the survival of juvenile coastal cod by limiting the extent of nursing grounds. The recruiment of norwegian coastal cod north of 62°N is probably affected by the condition and extent of macroalgae habitats along the coast of Norway.en
dc.identifier.urihttps://hdl.handle.net/10037/4692
dc.identifier.urnURN:NBN:no-uit_munin_4406
dc.language.isoengen
dc.publisherUniversity of Tromsøen
dc.publisherUniversitetet i Tromsøen
dc.rights.accessRightsopenAccess
dc.rights.holderCopyright 2012 The Author(s)
dc.rights.urihttps://creativecommons.org/licenses/by-nc-sa/3.0en_US
dc.rightsAttribution-NonCommercial-ShareAlike 3.0 Unported (CC BY-NC-SA 3.0)en_US
dc.subject.courseIDFSK-3960en
dc.subjectVDP::Landbruks- og Fiskerifag: 900::Fiskerifag: 920::Ressursbiologi: 921en
dc.subjectVDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Resource biology: 921en
dc.titleHabitat choice of juvenile coastal cod : the role of macroalgae habitats for juvenile coastal cod (Gadus morhua L.) in Porsangerfjorden and Ullsfjorden in Northern Norwayen
dc.typeMaster thesisen
dc.typeMastergradsoppgaveen


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Attribution-NonCommercial-ShareAlike 3.0 Unported (CC BY-NC-SA 3.0)
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