Browsing NINA Brage by Author "Økland, Finn"
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Annual and diel activity cycles of a northern population of the large migratory cyprinid fish asp (Leuciscus aspius)
Kärgenberg, Einar; Sandlund, Odd Terje; Thorstad, Eva Bonsak; Thalfeldt, Mart; Økland, Finn; Kaasik, Ants; Tambets, Meelis (Peer reviewed; Journal article, 2022)Little is known about the exact movement parameters of migratory cyprinids listed as conservation priorities. A northern population of predatory asp, listed on the Bern Convention Appendix III, was studied in a near ... -
Atferd hos rømt oppdrettslaks i Sunndalsfjorden
Solem, Øyvind; Hedger, Richard; Urke, Henning Andre; Kristensen, Torstein; Økland, Finn; Ulvan, Eva Marita; Uglem, Ingebrigt (NINA rapport;805, Research report, 2012)Solem, Ø., Hedger, R., Urke, H.A, Kristensen, T., Økland, F., Ulvan, E. & Uglem, I. 2012. Atferd hos rømt oppdrettslaks i Sunndalsfjorden - NINA Rapport 805, 23 sider. Hensikten med prosjektet var å undersøke overlevelse, ... -
Atferd og spredning av rømt oppdrettslaks og villaks i Namsen og andre elver. Resultater fra merking av laks i Namsfjorden og Vikna
Næsje, Tor; Ulvan, Eva Marita; Sandnes, Tomas*; Jensen, Jenny; Staldvik, Frode; Holm, Ragnar*; Landstad, Jan Arild*; Økland, Finn; Moe, Karina; Fiske, Peder; Heggberget, Tor Gravråk; Thorstad, Eva Bonsak (NINA Rapport;931, Research report, 2013-04)Vi undersøkte atferd og spredning av rømt oppdrettslaks og villaks i Namsen og andre elver i Midt-Norge i 2012. Hovedmålsettingen var å skaffe kunnskap slik at man kan gjøre sikrere beregninger av den reelle andelen rømt ... -
Automatisk posisjonering av akustisk merket smolt i tre dimensjoner – utprøving og evaluering i Mandalsvassdraget.
Gjelland, Karl Øystein; Baktoft, Henrik; Økland, Finn; Hedger, Richard David; Forseth, Torbjørn (NINA rapport;1072, Research report, 2014)Et nytt system som kan gi tredimensjonal (3D) posisjonering av smolt ved hjelp av trådløs akustisk telemetri ble utprøvd og evaluert i Mandalsvassdraget sommeren 2014. I forsøkene ble signaler fra akustiske merker logget ... -
Behaviour and mortality of downstream migrating Atlantic salmon smolts at a small power station with multiple migration routes
Kärgenberg, Einar; Thorstad, Eva Bonsak; Järvekülg, Rein; Sandlund, Odd Terje; Saadre, Ene; Økland, Finn; Thalfeldt, Mart; Tambets, Meelis (Journal article; Peer reviewed, 2019)Salmon smolts were released upstream of a run‐of‐river hydropower site and recaptured downstream for inspection. Descending fish behaviour through three possible migration routes (turbines, fishway, spillway) was analysed ... -
Beskatning og bestandsstørrelse av laks i Namsenvassdraget
Thorstad, Eva Bonsak; Fiske, Peder; Staldvik, Frode; Økland, Finn (NINA rapport;747, Research report, 2011)Thorstad, E.B., Fiske, P., Staldvik, F. & Økland, F. 2011. Beskatning og bestandsstørrelse av laks i Namsenvassdraget 2010. - NINA Rapport 747: 1-32. Undersøkelser av beskatningsrater og bestandsstørrelse i Namsenvassdraget ... -
Biotic and abiotic determinants of the ascent behaviour of adult Atlantic salmon transiting passable waterfalls
Lennox, Robert J.; Thorstad, Eva Bonsak; Diserud, Ola Håvard; Økland, Finn; Cooke, Steven J.; Aasestad, Ingar; Forseth, Torbjørn (Journal article; Peer reviewed, 2018)The spawning migration of Atlantic salmon has been characterized by tracking salmon carrying electronic tags as they ascend rivers, but still little is known about how natural obstacles such as waterfalls influence migratory ... -
Can Energy Depletion of Wild Atlantic Salmon Kelts Negotiating Hydropower Facilities Lead to Reduced Survival?
Baktoft, Henrik; Gjelland, Karl Øystein; Szabo-Meszaros, Marcell; Silva, Ana T.; Riha, Milan; Økland, Finn; Alfredsen, Knut; Forseth, Torbjørn (Peer reviewed; Journal article, 2020)Repeat spawners constitute an important component of Atlantic salmon populations, but survival of post-spawning individuals (kelts) are often compromised by anthropogenic structures such as hydropower plants (HPPs). Potential ... -
Comparing dominance relationships and movement of native marble trout (Salmo marmoratus) and introduced rainbow trout (Oncorhynchus mykiss)
Pengal, Polona; Cokan, Blaz; Økland, Finn; Höjesjö, Johan; Tambets, Meelis; Thorstad, Eva Bonsak (Peer reviewed; Journal article, 2023) -
Contrasting structural complexity diferentiate hunting strategy in an ambush apex predator
Říha, Milan; Gjelland, Karl Øystein; Děd, Vilém; Eloranta, Antti; Rabaneda-Bueno, Ruben; Baktoft, Henrik; Vejřík, Lukáš; Vejříková, Ivana; Drastik, Vladislav; Šmejkal, Marek; Holubová, Michaela; Jůza, Tomáš; Rosten, Carolyn; Sajdlová, Zuzana; Økland, Finn; Peterka, Jiří (Peer reviewed; Journal article, 2021)Structural complexity is known to influence prey behaviour, mortality and population structure, but the effects on predators have received less attention. We tested whether contrasting structural complexity in two newly ... -
Development and testing of attachment methods for pop-up satellite archival transmitters in European eel
Økland, Finn; Thorstad, Eva Bonsak; Westerberg, Håkan; Aarestrup, Kim; Metcalfe, Julian D. (Peer reviewed, 2013)Background: Four methods for attaching pop-up satellite transmitters to European eel were tested in the laboratory by recording long-term tag retention, growth and survival; short-term behavioral responses; and physical ... -
Downstream migration of Atlantic salmon smolt at three German hydropower stations
Økland, Finn; Teichert, Maxim A.K.; Thorstad, Eva B.; Havn, Torgeir B.; Heermann, Lisa; Sæther, Stein Are; Diserud, Ola H.; Tambets, Meelis; Hedger, Richard D.; Borcherding, Jost (NINA Rapport;1203, Research report, 2016-10-04)Økland, F., Teichert, M.A.K., Thorstad, E.B., Havn, T.B., Heermann, L., Sæther, S.A., Diserud, O.H., Tambets, M., Hedger, R.D. & Borcherding, J. 2016. Downstream migration of Atlantic salmon smolt at three German hydropower ... -
Downstream migration of Atlantic salmon smolts at Unkelmühle power station and Buisdorf dam in 2016
Havn, Torgeir B.; Økland, Finn; Heermann, Lisa; Thorstad, Eva B.; Teichert, Maxim A.K.; Sæther, Stein Are; Tambets, Meelis; Borcherding, Jost (NINA Report;1412, Research report, 2018)Havn, T.B., Økland, F., Heermann, L., Thorstad, E.B., Teichert, M.A.K., Sæther, S.A., Tam-bets, M. & Borcherding, J. 2018. Downstream migration of Atlantic salmon smolts at Unkelmühle power station and Buisdorf dam in 2016. ... -
Downstream migration of European eel at three German hydropower stations
Økland, Finn; Teichert, Maxim A.K.; Havn, Torgeir B.; Thorstad, Eva B.; Heermann, Lisa; Sæther, Stein Are; Tambets, Meelis; Borcherding, Jost (NINA Report;1355, Research report, 2017)Økland, F., Teichert, M.A.K., Havn, T.B., Thorstad, E.B., Heermann, L., Sæther, S.A., Tambets, M. & Borcherding, J. 2017. Downstream migration of European eel at three German hydropower stations. NINA Report 1355: 53 pages, ... -
Effects of a dispersal barrier on freshwater migration of the vimba bream (Vimba vimba)
Tambets, Meelis; Kärgenberg, Einar; Thorstad, Eva Bonsak; Sandlund, Odd Terje; Økland, Finn; Thalfeldt, Mart (Journal article; Peer reviewed, 2018)To study the effects of a dispersal barrier on migration of the semi-anadromous vimba bream in the Pärnu River, Estonia, we tagged thirty fish with acoustic transmitters and released above the barrier. Tagged fish showed ... -
Empirical observations of the spawning migrationof European eels: The long and dangerous roadto the Sargasso Sea
Righton, David; Westerberg, Håkan; Feunteun, Eric; Økland, Finn; Gargan, Patrick G.; Amilhat, Elsa; Metcalfe, Julian; Lobon-Cervia, Javier; Sjöberg, Niklas; Simon, Janek; Acou, Anthony; Vedor, Marisa; Walker, Alan; Trancart, Thomas; Brämick, Uwe; Aarestrup, Kim (Journal article; Peer reviewed, 2016)The spawning migration of the European eel (Anguilla anguilla L.) to the Sargasso Sea is one of the greatest animal migrations. However, the duration and route of the migration remain uncertain. Using fishery data from ... -
Escaped farmed Atlantic salmon in Norwegian rivers during 1989–2013
Diserud, Ola Håvard; Fiske, Peder; Sægrov, Harald; Urdal, K.; Aronsen, Tonje; Lo, Håvard; Barlaup, Bjørn Torgeir; Niemela, Eero; Orell, P.; Erkinaro, J.; Lund, Roar A.; Økland, Finn; Østborg, Gunnel Marie; Hansen, Lars Petter; Hindar, Kjetil (Journal article; Peer reviewed, 2019)We report on the data from an extensive monitoring programme for the occurrence of escaped farmed Atlantic salmon (Salmo salar) in Norwegian rivers for 25 years. This monitoring started as a 3-year research programme in ... -
European eel Anguilla anguilla compromise speed for safety in the early marine spawning migration
Lennox, Robert J.; Økland, Finn; Mitamura, Hiromichi; Cooke, Steven J.; Thorstad, Eva Bonsak (Journal article; Peer reviewed, 2018)There are substantial benefits to potential fitness conferred to animals that undertake migrations. However, animals must make compromises to maximize survival and compensate for the risks associated with long-distance ... -
Forekomsten av havniøye i norske elver
Hesthagen, Trygve; Vøllestad, Asbjørn; Økland, Finn (NINA Rapport;1965, Research report, 2021)Hesthagen, T., Vøllestad, A. & Økland, F. 2021. Forekomsten av havniøye i norske elver. NINA Rapport 1965. Norsk institutt for naturforskning. I denne rapporten er det gjort en sammenstilling av forekomsten av havniøye i ... -
Forslag til overvåkingssystem for sjøørret
Finstad, Bengt; Ulvan, Eva Marita; Jonsson, Bror; Ugedal, Ola; Thorstad, Eva Bonsak; Hvidsten, Nils Arne; Hindar, Kjetil; Karlsson, Sten; Uglem, Ingebrigt; Økland, Finn (NINA rapport;689, Research report, 2011)Finstad, B., Ulvan, E.M., Jonsson, B., Ugedal, O., Thorstad, E.B., Hvidsten, N.A., Hindar, K., Karlsson, S., Uglem, I. & Økland, F. 2011. Forslag til overvåkingssystem for sjøørret. - NINA Rapport 689. 53 s. Prosjektets ...