Browsing NTNU Open by Author "Davidsen, Jan Grimsrud"
Now showing items 1-20 of 38
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An effective method for the recapture of escaped farmed salmon
Chittenden, Cedar; Rikardsen, Audun H.; Skilbrei, Ove Tommy; Davidsen, Jan Grimsrud; Halttunen, Elina; Skardhamar, Jofrid; McKinley, R. Scott (Journal article; Peer reviewed, 2011)ABSTRACT: The search for effective strategies to prevent and mitigate accidental releases of aquaculture fishes is on-going. To test a new recapture strategy and evaluate the individual dispersal behaviour of escaped farmed ... -
Bridging the Gap between Fisheries Science and Society: Exploring Fisheries Science as a Social Activity
Bailey, Jennifer L.; Liu, Yajie; Davidsen, Jan Grimsrud (Journal article; Peer reviewed, 2016)Much has been written about the poor relations between fisheries scientists and lay people, but the experience of two field biologists suggests that good relations can exist and have a positive impact on the exchange of ... -
Demographic and genetic description of Greenland´s only indigenous Atlantic salmon (Salmo salar) population
Arnekleiv, Jo Vegar; Davidsen, Jan Grimsrud; Sheehan, T. F.; Lehnert, s.j.; Bradbury, I.R.; Rønning, Lars; Sjursen, Aslak Darre; Kjærstad, Gaute; Nilssen, Kjell J. (Journal article; Peer reviewed, 2018)In Greenland, Atlantic salmon are known to reproduce in only one river, the Kapisillit River. Little is known about the population characteristics or the relationship to other salmon populations across the species range, ... -
Early marine migration of European silver eel (Anguilla anguilla) in Northern Norway
Davidsen, Jan Grimsrud; Finstad, Bengt; Økland, Finn; Thorstad, Eva Bonsak; Mo, Tor Atle; Rikardsen, Audun H. (Journal article; Peer reviewed, 2011) -
Effects of sound exposure from a seismic airgun on heart rate, acceleration and depth use in free-swimming Atlantic cod and saithe
Davidsen, Jan Grimsrud; Dong, Hefeng; Linne, Markus; Andersson, Mathias H.; Piper, Adam; Prystay, Tanya S.; Hvam, Eivind B.; Thorstad, Eva Bonsak; Whoriskey, Frederick G.; Cooke, Steven J.; Sjursen, Aslak Darre; Rønning, Lars; Netland, Tim Cato; Hawkins, Anthony D. (Journal article; Peer reviewed, 2019)Recent vegetation changes in arctic-alpine tundra ecosystems may affect several ecosystem processes that regulate microbe and soil functions. Such changes can alter ecosystem carbon (C) cycling with positive feedback to ... -
Effekter av økt vannuttak om sommeren fra Rovatnet i Hemne kommune på laks, sjøørret, bunndyr og elvemusling
Sjursen, Aslak Darre; Kjærstad, Gaute; Daverdin, Marc; Davidsen, Jan Grimsrud (NTNU Vitenskapsmuseet naturhistorisk notat;, Research report, 2018)Effekter av økt vannuttak fra Søavassdraget i Hemne kommune – NTNU Vitenskapsmuseet naturhistorisk notat 2018-8: 1-20. I forbindelse med AquaGen sin planlegging av oppgradering av anlegget på Kyrksæterøra med et nytt ... -
Environmental influences on life history strategies in partially anadromous brown trout (Salmo trutta, Salmonidae)
Nevoux, Marie; Finstad, Bengt; Davidsen, Jan Grimsrud; Finlay, Ross; Josset, Quentin; Poole, Rusell; Höjesjö, Johan; Aarestrup, Kim; Persson, Lo; Tolvanen, Oula; Jonsson, Bror (Journal article; Peer reviewed, 2019)This paper reviews the life history of brown trout and factors influencing decisions to migrate. Decisions that maximize fitness appear dependent on size at age. In partly anadromous populations, individuals that attain ... -
Ferskvannsbiologiske undersøkelser i Auretjørnelva i Namsos kommune - Vurdering av effekter av vannuttak på fisk og bunndyr
Sjursen, Aslak Darre; Rønning, Lars; Kjærstad, Gaute; Davidsen, Jan Grimsrud (NTNU Vitenskapsmuseet naturhistorisk notat;, Research report, 2019) -
Ferskvannsbiologiske undersøkelser i Samsjøen, Holtsjøen, Samaelva og Søavassdraget, Sør-Trøndelag, i 2017
Davidsen, Jan Grimsrud; Sjursen, Aslak Darre; Davidsen, Anette Sophie Grimsrud; Kjærstad, Gaute; Rønning, Lars; Daverdin, Marc; Værnes, Einar; Hårsaker, Karstein; Arnekleiv, Jo Vegar (NTNU Vitenskapsmuseet naturhistorisk rapport;, Research report, 2018) -
Fiskebiologiske undersøkelser i Beiarelva 2017-19. Årsrapport for 2017
Sjursen, Aslak Darre; Hansen, Øyvind Kanstad; Rønning, Lars; Arnekleiv, Jo Vegar; Davidsen, Jan Grimsrud (NTNU Vitenskapsmuseet naturhistorisk rapport;, Research report, 2018) -
Fiskebiologiske undersøkelser i Beiarelva 2017-19. Årsrapport for 2018
Sjursen, Aslak Darre; Rønning, Lars; Arnekleiv, Jo Vegar; Davidsen, Jan Grimsrud (NTNU Vitenskapsmuseet naturhistorisk rapport;, Research report, 2019)Med bakgrunn i pålegg fra Miljødirektoratet har Statkraft Energi AS gitt NTNU Vitenskapsmuseet og Fersk -vannsbiologen AS i oppdrag å gjennomføre fiskebiologiske undersøkelser i Beiarelva i perioden 2017 -19 med ... -
Habitat use and depth preferences of sea trout (Salmo trutta) in a Norwegian estuary
Omholt, Vilde (Master thesis, 2020)Brunørreten (Salmo trutta) er en ferskvannsfisk som lever i bekker, elver, innsjøer og marine kystområder. Anadrome individer, ofte kalt sjøørret, har stor variasjon i migrasjonsstrategi og habitatbruk. De fleste større ... -
Home ranges and habitat utilisation of the river-resident Atlantic salmon, Salmo salar, småblank
Eikaas, Linda (Master thesis, 2016)Home ranges and habitat utilisation of the river resident Atlantic salmon, småblank, Salmo salar, in Nord Trøndelag, Norway, were studied by the use of radio telemetry during the period August 2014 to January 2016. The aim ... -
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 ... -
Individual repeatability in marine migratory behaviour: A multi-population assessment of anadromous brown trout tracked through consecutive feeding migrations
Eldøy, Sindre Håvarstein; Bordeleau, Xavier; Crossin, Glenn T; Davidsen, Jan Grimsrud (Journal article; Peer reviewed, 2019)Despite that the study of individual repeatability is a common topic in behavioral ecology, virtually nothing is known about inter-annual variability in the marine migratory behavior of iteroparous salmonids that can ... -
Interactions Between Sea trout and Farmed Salmonids: Risk of pathogen exchange with special emphasis on Piscine orthoreovirus (PRV)
Bårdsen, Marthe Tangvold (Master thesis, 2019)Forståelse av patogenutveksling mellom oppdrettet og ville laksefisker er viktig for å stadfeste økologiske påvirkninger fra akvakultur på ville populasjoner. En risikovurdering av patogenutveksling ble derfor utført ved ... -
Kartlegging av sjøørret i habitatområde ved utløpet av Stjørdalselva, Nord-Trøndelag og konsekvensanalyse av tre utfyllingsalternativer
Davidsen, Jan Grimsrud; Sjursen, Aslak Darre; Rønning, Lars; Davidsen, Anette Sophie Grimsrud; Daverdin, Marc (NTNU Vitenskapsmuseet naturhistorisk rapport;, Research report, 2017)Avinor ønsker å ta i bruk Langøra Sør (Stjørdal kommune, Nord-Trøndelag) og vannmiljøet rundt for flyplass-formål. Området omfatter det meste av gjenværende elvedelta og strandområder i Stjørdalsvassdraget, dvs. utløpet ... -
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 ... -
Marine Migration Behaviour of Brown Trout from Five Watercourses Flowing into a Common Fjord System in Northern Norway
Meyer, Ingegjerd (Master thesis, 2018)Brown trout is a freshwater fish which exhibits a wide array of life history and migration strategies. These different strategies result in great morphological variation both among and within populations. The aim of the ...