Browsing NTNU Open by Author "Næsje, Tor"
Now showing items 1-10 of 10
-
Changes in growth and migration patterns of sea trout before and after the introduction of Atlantic salmon farming
Eldøy, Sindre Håvarstein; Ryan, Diarmuid; Roche, William; Thorstad, Eva Bonsak; Næsje, Tor; Sjursen, Aslak Darre; Gargan, Paddy; Davidsen, Jan Grimsrud (Peer reviewed; Journal article, 2020)Marine growth has strong implications for reproductive potential and ultimate fitness of sea trout. Hence, the effects of anthropogenic factors on marine growth are important when evaluating population responses and ... -
The effect of surveillance fishing on migration distance of Atlantic Salmon during the spawning period
Munkeby, Johan; Davidsen, Jan Grimsrud; Havn, Torgeir Børresen; Ulvan, Eva Marita; Næsje, Tor; Karlsen, Dag H.; Solem, Øyvind; Lennox, Robert J. (Peer reviewed; Journal article, 2024)Objective Surveillance fishing surveys can be performed to estimate the proportion of farmed salmon represented in the spawning stock of native Atlantic Salmon Salmo salar populations. These surveys take place after the ... -
Factors influencing return rate and marine residence durationin sea trout populations in Central Norway
Paterson, Rachel; Berntsen, Johan Henrik Hårdensson; Næsje, Tor; Berg, Marius; Finstad, Bengt (Peer reviewed; Journal article, 2021)Brown trout (Salmo trutta) display extensive plasticity in marine migratory behaviours, with marine migrations considered to be an adaptive strategy which enables sea trout to maximize growth and reproductive potential. ... -
Femti år etter utsettingene av mysis (Mysis relicta) og firetornet istidskreps (Pallasiola quadrispinosa) i norske innsjøer: til gagn eller skade?
Sandlund, Odd Terje; Arnekleiv, Jo Vegar; Hesthagen, Trygve H.; Koksvik, Jan Ivar; Næsje, Tor (Journal article; Peer reviewed, 2022)Krepsdyra Mysis relicta (mysis, pungreke) og Pallasiola quadrispinosa (firetornet istidskreps, heretter kalt pallasea) forekommer i Norge naturlig i noen innsjøer på Østlandet. Etter utsettinger i regulerte innsjøer i ... -
Homing behaviour of Atlantic salmon (Salmo salar) during final phase of marine migration and river entry
Davidsen, Jan Grimsrud; Rikardsen, Audun H.; Thorstad, Eva Bonsak; Halttunen, Elina; Mitamura, Hiromichi; Præbel, Kim; Skardhamar, Jofrid; Næsje, Tor (Journal article; Peer reviewed, 2013-03-11)Little is known about Atlantic salmon behaviour during the last phase of the marine homing migration and subsequent river entry. In this study, 56 adult Atlantic salmon in the Alta Fjord in northern Norway were equipped ... -
Marine depth use of sea trout Salmo trutta in fjord areas of Central Norway
Eldøy, Sindre Håvarstein; Davidsen, Jan Grimsrud; Thorstad, Eva Bonsak; Whoriskey, Frederick G.; Aarestrup, Kim; Næsje, Tor; Rønning, Lars; Sjursen, Aslak Darre; Rikardsen, Audun H.; Arnekleiv, Jo Vegar (Journal article; Peer reviewed, 2017)The vertical behaviour of 44 veteran sea trout Salmo trutta (275–580 mm) in different marine fjord habitats (estuary, pelagic, near shore with and without steep cliffs) was documented during May–February by acoustic ... -
Marine migration and habitat use of anadromous brown trout Salmo trutta
Eldøy, Sindre Håvarstein; Davidsen, Jan Grimsrud; Thorstad, Eva Bonsak; Whoriskey, F.; Aarestrup, K.; Næsje, Tor; Rønning, Lars; Sjursen, Aslak Darre; Rikardsen, Audun H.; Arnekleiv, Jo Vegar (Journal article, 2015)The biology and ecology of anadromous brown trout (Salmo trutta) at sea is poorly understood. This study provided information on spatial and temporal distribution of sea trout in the ocean. The behaviour of 115 individuals ... -
Modeling salmon lice effects on sea trout population dynamics using an individual-based approach
Hedger, Richard David; Diserud, Ola Håvard; Finstad, Bengt; Jensen, Arne Johan; Hendrichsen, Ditte Katrine; Ugedal, Ola; Næsje, Tor (Peer reviewed; Journal article, 2021)Salmon lice Lepeophtheirus salmonis infestation of sea trout Salmo trutta results in both additional marine mortality and behavioral changes which may contribute to sea trout population decline. For effective management ... -
Redefining the oceanic distribution of Atlantic salmon
Rikardsen, Audun H.; Righton, David; Strøm, John Fredrik; Thorstad, Eva Bonsak; Gargan, Patrick G.; Sheehan, Timothy F.; Økland, Finn; Chittenden, Cedar; Hedger, Richard David; Næsje, Tor; Renkawitz, Mark; Sturlaugsson, Johannes; Caballero, Pablo; Baktoft, Henrik; Davidsen, Jan Grimsrud; Halttunen, Elina; Wright, Serena; Finstad, Bengt; Aarestrup, Kim (Peer reviewed; Journal article, 2021)Determining the mechanisms driving range-wide reductions in Atlantic salmon marine survival is hindered by an insufcient understanding of their oceanic ecology and distribution. We attached 204 pop-up satellite archival ... -
Trophic niche similarity among sea trout Salmo trutta in Central Norway investigated using different time-integrated trophic tracers
Davidsen, Jan Grimsrud; Knudsen, Rune; Power, Michael; Sjursen, Aslak Darre; Rønning, Lars; Hårsaker, Karstein; Næsje, Tor; Arnekleiv, Jo Vegar (Journal article; Peer reviewed, 2017)From 2011 to 2013, anadromous brown trout Salmo trutta (213−730 mm, total body length, LT) were collected during or shortly after their marine feeding migration at 7 different localities in central Norway. The mean volume ...