Blar i forfatter "Nilsen, Rune"

Viser treff 1-8 av 8

    • Area protection may reduce salmon louse infection risk to wild salmonids 

      Bjørn, Pål Arne; Sivertsgård, Rolf; Finstad, Bengt; Nilsen, Rune; Serra-Llinares, Rosa Maria; Kristoffersen, Roar (Journal article; Tidsskriftartikkel; Peer reviewed, 2011-05-30)
      ABSTRACT: Salmon louse <i>Lepeophtheirus salmonis</i> Krøyer infection levels in both wild sea trout <i>Salmo trutta</i> L. and sentinel Atlantic salmon <i>Salmo salar</i> L. smolts were investigated inside and outside a temporary protected zone with limits on fish farming in the intensively farmed Romsdalsfjord system. Wild sea trout outside the protected zone had higher prevalence and significantly ...

    • Behaviour and habitat use of first-time migrant Arctic charr: novel insights from a subarctic marine area 

      Nordli, Eivind; Strøm, John Fredrik; Bøhn, Thomas; Thorstad, Eva Bonsak; Serra Llinares, Rosa Maria; Nilsen, Rune; Bjørn, Pål Arne (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-04-13)
      Anadromous Arctic charr Salvelinus alpinus is a cold-adapted salmonid that is vulnerable to climate warming and anthropogenic activities including salmon farming, hydropower regulation, and pollution, which poses a multiple-stressor scenario that influences or threatens populations. We studied the horizontal and vertical behaviour of Arctic charr tagged with acoustic transmitters (n = 45, mean ...

    • Impacts of salmon lice on mortality, marine migration distance and premature return in sea trout 

      Serra Llinares, Rosa Maria; Bøhn, Thomas; Karlsen, Ørjan; Nilsen, Rune; Freitas, Carla; Albretsen, Jon; Haraldstad, Tormod; Thorstad, Eva Bonsak; Elvik, Kristine Marit Schrøder; Bjørn, Pål Arne (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-02-06)
      Brown trout <i>Salmo trutta</i> (L.) is a facultative anadromous species, where a portion of individuals in populations with access to the sea perform migrations to use the richer feeding resources. We investigated the effect of salmon lice <i>Lepeophtheirus salmonis</i> (Krøyer 1837) infestation on the survival and behaviour of wild trout post-smolts (average fork length = 180 mm) during their ...

    • Lakselusinfestasjon på vill laksefisk langs Norskekysten i 2020 Sluttrapport til Mattilsynet 

      Nilsen, Rune; Serra Llinares, Rosa Maria; Sandvik, Anne Dagrun; Johnsen, Ingrid Askeland; Mohn, Agnes Marie; Karlsen, Ørjan; Lehmann, Gunnar Bekke; Birkeland, Ina Bakke; Stöger, Elisabeth; Lennox, Robert J.; Uglem, Ingebrigt; Berg, Marius (Research report; Forskningsrapport, 2020-12-10)
      Overvåkingsprogrammet for lakselus på vill laksefisk (NALO) er i 2020 gjennomført på oppdrag fra Mattilsynet (MT) og Nærings- og Fiskeridepartementet (NFD). En hydrodynamisk spredningsmodell som beregner tetthet av infektive lakseluskopepoditter i vannmassene ble som tidligere år kjørt ukentlig for hele Norskekysten. Innsatsen på overvåking av utvandrende postsmolt laks er holdt på samme nivå som i ...

    • Parasitter som biologiske markører på interaktiv segregering mellom stasjonær sympatrisk ørret og røye 

      Nilsen, Rune (Master thesis; Mastergradsoppgave, 2006)
      Allopatrisk ørret og røye i innsjøer er økologisk svært like med hensyn på nærings- og habitatpreferanser. I allopatri foretrekker begge artene å beite bunndyr i de littorale delene av innsjøen. I sympatri observeres ofte en segregering i nærings- og habitatvalg mellom ørret og røye, der røya skifter fra det prefererte habitatet, og går over til å beite mer zooplankton i de pelagiale delene av ...

    • Salmon louse infestation levels on sea trout can be predicted from a hydrodynamic lice dispersal model 

      Bøhn, Thomas; Nilsen, Rune; Gjelland, Karl Øystein; Biuw, Martin; Primicerio, Raul; Karlsen, Ørjan; Serra Llinares, Rosa Maria (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-13)
      1. The abundance of the parasitic salmon louse has increased with the growth in aquaculture of salmonids in open net pens. This represents a threat to wild salmonid populations as well as a key limiting factor for salmon farming. The Norwegian ‘traffic light’ management system for salmon farming aims to increase aquaculture production while securing sustainable wild salmonid populations. However, ...

    • Sea trout adapt their migratory behaviour in response to high salmon lice concentrations 

      Halttunen, Elina; Gjelland, Karl Øystein; Hamel, Sandra; Serra-Llinares, Rosa Maria; Nilsen, Rune; Arechavala-Lopez, Pablo; Skardhamar, Jofrid; Asplin, Lars; Karlsen, Ørjan; Bjørn, Pål Arne; Finstad, Bengt (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-11-21)
      Sea trout face growth–mortality trade-offs when entering the sea to feed. Salmon lice epizootics resulting from aquaculture have shifted these trade-offs, as salmon lice might both increase mortality and reduce growth of sea trout. We studied mortality and behavioural adaptations of wild sea trout in a large-scale experiment with acoustic telemetry in an aquaculture intensive area that was fallowed ...

    • Timing is everything: Survival of Atlantic salmon Salmo salar postsmolts during events of high salmon lice densities 

      Bøhn, Thomas; Gjelland, Karl Øystein; Serra Llinares, Rosa Maria; Finstad, Bengt; Primicerio, Raul; Nilsen, Rune; Karlsen, Ørjan; Sandvik, Anne Dagrun; Skilbrei, Ove Tommy; Elvik, Kristine Marit Schrøder; Skaala, Øystein; Bjørn, Pål Arne (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-04-07)
      <ol> <li>Atlantic salmon in aquaculture act as reservoir hosts and vectors of parasites like salmon lice and this parasite is shown to harm wild salmonid populations.</li> <li>In this study, <i>n</i> = 29,817 tagged Atlantic salmon were studied in four release trials. Half of the released fish were given prophylactic treatment against lice, the other half represented sham control fish. We used ...