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dc.contributor.authorMoe, Karina
dc.contributor.authorNæsje, Tor
dc.contributor.authorHaugen, Thrond Oddvar
dc.contributor.authorUlvan, Eva Marita
dc.contributor.authorAronsen, Tonje
dc.contributor.authorSandnes, Tomas
dc.contributor.authorThorstad, Eva Bonsak
dc.identifier.citationAquaculture Environment Interactions 2016, 8:77-88nb_NO
dc.description.abstractWe compared the within-river movements and distribution of wild and escaped farmed Atlantic salmon Salmo salar before and during spawning in the Namsen river system of Central Norway. A total of 74 wild and 43 escaped farmed salmon were captured at sea, tagged with radio transmitters and released. Based on our examinations, most, if not all salmon (farmed and wild) entering the River Namsen were sexually mature. Farmed salmon entering the river system had a higher probability than wild individuals of reaching the migration barrier in the upper part of the river, 70 km from the sea. During the pre-spawning and spawning periods, farmed salmon were located mainly in the upper parts (50 to 70 km from the sea), whereas wild salmon were evenly distributed along the entire river during both periods. Consequently, the probability of farmed × wild inter-breeding varied among river sections. Our finding that the distribution of escaped farmed salmon may differ from that of wild salmon and among river sections in the prespawning and spawning periods—and that it may also vary over time—must be taken into consideration when (1) designing monitoring programs aimed at estimating the proportion of escaped farmed salmon in rivers and (2) when interpreting monitoring results. Furthermore, targeted fishing in the river aimed at reducing the number of farmed salmon prior to spawning may be more effective in upper rivers sections, and below major migration barriers.nb_NO
dc.rightsNavngivelse-Ikkekommersiell 3.0 Norge*
dc.subjectradio telemetrynb_NO
dc.subjectfarmed escapeesnb_NO
dc.subjectwithin-river movementsnb_NO
dc.subjectspawning periodnb_NO
dc.subjectintrogression risknb_NO
dc.subjectRiver Namsennb_NO
dc.titleArea use and movement patterns of wild and escaped farmed Atlantic salmon before and during spawning in a large Norwegian rivernb_NO
dc.typeJournal articlenb_NO
dc.source.journalAquaculture Environment Interactionsnb_NO

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Navngivelse-Ikkekommersiell 3.0 Norge
Except where otherwise noted, this item's license is described as Navngivelse-Ikkekommersiell 3.0 Norge