Blar i NTNU Open på forfatter "Davidsen, Jan Grimsrud"
-
A dynamic state modelling approach to partial migration in brown trout
Solvåg, Christianne Dalsbotten (Master thesis, 2022)Partiell migrasjon, fenomenet der ein populasjon har både individ som migrerer og individ som let vere, er observert i store delar av dyreriket. Mekanismane bak kan vere komplekse, og kan inkludere både genetikk og miljø ... -
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 ... -
The Biology and feeding Ecology of Arctic charr in the Kerguelen Islands
Eldøy, Sindre Håvarstein; Davidsen, Jan Grimsrud; Vignon, Matthias; Power, Michael (Peer reviewed; Journal article, 2020)Subsequent to their introduction in the 1950s, Arctic charr Salvelinus alpinus have been able to establish a self‐sustaining population that has adapted to the unique conditions of the sub‐Antarctic Kerguelen Islands. Here, ... -
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 ... -
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 ... -
A dated volcano-tectonic deformation event in Jan Mayen causing landlocking of Arctic charr
Larsen, Eiliv; Lyså, Astrid; Höskuldsson, Ármann; Davidsen, Jan Grimsrud; Nadeau, Marie-Josée; Power, Michael; Tassis, Georgios; Wastegård, Stefan (Peer reviewed; Journal article, 2021)We provide the first documentation of tectonic deformation resulting from a volcanic eruption on the island of Jan Mayen. Vertical displacement of about 14 m southwest of the stratovolcano Beerenberg is associated with an ... -
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, ... -
Development of a risk assessment for sea trout in coastal areas exploited for aquaculture
Finstad, Bengt; Sandvik, Anne Dagrun; Ugedal, Ola; Vollset, Knut; Karlsen, Ørjan; Davidsen, Jan Grimsrud; Sægrov, Harald; Lennox, Robert J. (Peer reviewed; Journal article, 2021)ABSTRACT: The regulation of aquaculture production in Norway considers the potential impact of salmon lice on wild fish. However, most attention has been focused on impacts on wild Atlantic salmon, despite the fact that ... -
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) -
The effects of nutritional state, sex and body size on the marine migration behaviour of sea trout
Eldøy, Sindre Håvarstein; Bordeleau, Xavier; Lawrence, M. J.; Thorstad, Eva B.; Finstad, Anders Gravbrøt; Whoriskey, Frederick G.; Crossin, Glenn T; Cooke, Steven J.; Aarestrup, Kim; Rønning, Lars; Sjursen, Aslak Darre; Davidsen, Jan Grimsrud (Peer reviewed; Journal article, 2021)The sea trout (anadromous brown trout Salmo trutta) displays extensive among-individual variation in marine migration behaviour. We studied the migration behaviour of 286 sea trout (27-89 cm) tagged with acoustic transmitters ... -
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 Fuglevågvassdraget, Smøla kommune. Vurdering av effekter av økt vannuttak fra Storvatnet på fisk og bunndyr
Sjursen, Aslak Darre; Rønning, Lars; Kjærstad, Gaute; Davidsen, Jan Grimsrud (NTNU Vitenskapsmuseet naturhistorisk notat;, Research report, 2020)Sjursen, A.D., Kjærstad, G., Rønning, L. & Davidsen, J.G. 2020. Ferskvannsbiologiske undersøkelser i Fuglevågvassdraget, Smøla kommune. Vurdering av effekter av økt vannuttak fra Storvatnet på fisk og bunndyr – NTNU ... -
Ferskvannsbiologiske undersøkelser i Grøa, Sunndal kommune. Årsrapport for 2020
Kielland, Øystein Nordeide; Davidsen, Jan Grimsrud; Davidsen, Anette Sophie Grimsrud; Rønning, Lars; Kjærstad, Gaute (NTNU Vitenskapsmuseet naturhistorisk notat;, Research report, 2021) -
Ferskvannsbiologiske undersøkelser i Jonsvatnet 2020
Hårsaker, Karstein; Davidsen, Anette Sophie Grimsrud; Kielland, Øystein Nordeide; Kjærstad, Gaute; Rønning, Lars; Sjursen, Aslak Darre; Davidsen, Jan Grimsrud (NTNU Vitenskapsmuseet naturhistorisk rapport;, Research report, 2021) -
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 ...