• 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 ...
    • Big-data approaches lead to an increased understanding of the ecology of animal movement 

      Ran, Nathan; Monk, Christopher T.; Arlinghaus, Robert; Adam, Timo; Alós, Josep; Assaf, Michael; Baktoft, Henrik; Beardsworth, Christine E.; Bertram, Michael G.; Bijleveld, Allert I.; Brodin, Tomas; Brooks, Jill L.; Campos-Candela, Andrea; Cooke, Steven J.; Gjelland, Karl Øystein; Gupte, Pratik R.; Harel, Roi; Hellstrom, Gustav; Jeltsch, Florian; Killen, Shaun S.; Klefoth, Thomas; Langrock, Roland; Lennox, Robert; Lourie, Emmanuel; Madden, Joah R.; Orchan, Yotam; Pauwels, Ine S.; Říha, Milan; Roeleke, Manuel; Schlägel, Ulrike E.; Shohami, David; Signer, Johannes; Toledo, Sivan; Vilk, Ohad; Westrelin, Samuel; Whiteside, Mark A.; Jarić, Ivan (Peer reviewed; Journal article, 2022)
      Understanding animal movement is essential to elucidate how animals interact, survive, and thrive in a changing world. Recent technological advances in data collection and management have transformed our understanding of ...
    • 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 ...
    • 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 ...
    • Effects of salmon lice infection on the behaviour of sea trout in the marine phase 

      Gjelland, Karl Øystein; Serra-Llinares, Rosa Maria; Hedger, Richard David; Arechavala-Lopez, Pablo; Nilsen, Rune; Finstad, Bengt; Uglem, Ingebrigt; Skilbrei, Ove Tommy; Bjørn, Pål Arne (Peer reviewed, 2014)
      Salmon lice Lepeophtheirus salmonis Krøyer may affect survival and growth of anadromous salmonids through physiological stress and/or behavioural changes. Using acoustic telemetry tracking, we investigated the behaviour ...
    • Fiskesamfunnet i Aursunden, Røros kommune 

      Johnsen, Stein Ivar; Sandlund, Odd Terje; Dokk, John Gunnar; Museth, Jon; Rognerud, Sigurd; Gjelland, Karl Øystein; Helland, Ingeborg Palm; Westberg, Tron Steffen (NINA Rapport;864, Research report, 2012)
      Det er imidlertid ikke gjort noen større fiskeundersøkelse de siste 10 årene. Det var derfor ønskelig med en ny oppdatert status av fiskesamfunnet i Aursunden, med et særlig fokus på sik-, ørret- og røyebestandene. De ...
    • Fiskesamfunnet i Mjøsa; de lange linjer 

      Sandlund, Odd Terje; Gjelland, Karl Øystein; Museth, Jon; Bækkelie, Knut Andreas Eikland; Lie, Erik Friele (Peer reviewed; Journal article, 2021)
      Fiskebestanden i Mjøsa ble undersøkt i 2018 som en del av overvåkingen av store innsjøer under vannforskriften. Det ble fisket med nordiske oversiktsgarn i strandsona og dypere bunnområder og med el-fiskebåt på grunt vann. ...
    • Fiskesamfunnet i Osensjøen, Trysil og Åmot kommuner Hedmark. Status i 2013 og endringer siden 1970-åra 

      Sandlund, Odd Terje; Linløkken, Arne; Gjelland, Karl Øystein; Johnsen, Stein Ivar; Rognerud, Sigurd; Museth, Jon; Dokk, John Gunnar; Garmo, Øyvind Aaberg; Walseng, Bjørn (NINA rapport;1046, Research report, 2014)
      Målsetningen for undersøkelsene i Osensjøen i 2013 var å fastslå status for fiskebestandene mer enn 30 år etter åpningen av Osa kraftverk i 1981. Mer spesifikt skulle vi også vurdere mulige effekter av planlagte endringer ...
    • Forsøk med trål og ekkolodd i Mjøsa, 2012 

      Gjelland, Karl Øystein; Rustadbakken, Atle; Haugen, Thrond O; Sandlund, Odd Terje (NINA Rapport;927, Research report, 2013)
      Trål har i liten grad vore brukt ved undersøkingar av fiskesamfunn i norske innsjøar. Gjennom innføringa av Vanndirektivet har Norge forplikta seg til meir regulær oppfølging av den økologiske tilstanden i større ...
    • Migration of Atlantic salmon post-smolts in a fjord with high infestation pressure of salmon lice 

      Halttunen, Elina; Gjelland, Karl Øystein; Glover, Kevin; Johnsen, Ingrid Askeland; Serra-Llinares, Rosa-Maria; Skaala, Øystein; Nilsen, Rune; Bjørn, Pål Arne; Karlsen, Ørjan; Finstad, Bengt; Skilbrei, Ove Tommy (Journal article; Peer reviewed, 2018)
      Understanding Atlantic salmon Salmo salar post-smolt coastal migration behaviour is crucial for predicting their exposure to ecological challenges such as the parasite salmon louse Lepeophtheirus salmonis. We compared the ...
    • Positioning aquatic animals with acoustic transmitters 

      Lennox, Robert; Aarestrup, Kim; Alós, Josep; Arlinghaus, Robert; Aspillaga, Eneko; Bertram, Michael G.; Birnie-Gauvin, Kim; Brodin, Tomas; Cooke, Steven J.; Dahlmo, Lotte Svengård; Dhellemmes, Félicie; Gjelland, Karl Øystein; Hellström, Gustav; Hershey, Henry; Holbrook, Christopher; Klefoth, Thomas; Lowerre-Barbieri, Susan; Monk, Christopher T.; Nilsen, Cecilie Iden; Pauwels, Ine; Pickholtz, Renanel; Prchalová, Marie; Reubens, Jan; Říha, Milan; Villegas-Ríos, David; Vollset, Knut; Westrelin, Samuel; Baktoft, Henrik (Peer reviewed; Journal article, 2023)
      1. Geolocating aquatic animals with acoustic tags has been ongoing for decades, relying on the detection of acoustic signals at multiple receivers with known positions to calculate a 2D or 3D position, and ultimately ...
    • Positioning of aquatic animals based on time-of-arrival and random walk models using YAPS (Yet Another Positioning Solver) 

      Baktoft, Henrik; Gjelland, Karl Øystein; Økland, Finn; Thygesen, Uffe Høgsbro (Journal article; Peer reviewed, 2017)
      Aquatic positional telemetry offers vast opportunities to study in vivo behaviour of wild animals, but there is room for improvement in the data quality provided by current procedures for estimating positions. Here we ...
    • A role for lakes in revealing the nature of animal movement using high dimensional telemetry systems 

      Lennox, Robert; Westrelin, Samuel; Souza, Allan T.; Šmejkal, Marek; Říha, Milan; Prchalová, Marie; Nathan, Ran; Koeck, Barbara; Killen, Shaun S.; Jarić, Ivan; Gjelland, Karl Øystein; Hollins, Jack; Hellstrom, Gustav; Hansen, Henry Arne; Cooke, Steven J.; Boukal, David; Brooks, Jill L.; Brodin, Tomas; Baktoft, Henrik; Adam, Timo; Arlinghaus, Robert (Peer reviewed; Journal article, 2021)
      Movement ecology is increasingly relying on experimental approaches and hypothesis testing to reveal how, when, where, why, and which animals move. Movement of megafauna is inherently interesting but many of the fundamental ...
    • Seasonal habitat use of three predatory fishes in a freshwater ecosystem 

      Říha, Milan; Rabaneda-Bueno, Ruben; Jarić, Ivan; Souza, Allan T.; Vejřík, Lukáš; Draštík, Vladislav; Blabolil, Petr; Holubová, Michaela; Jůza, Tomas; Gjelland, Karl Øystein; Rychtecký, Pavel; Sajdlová, Zuzana; Kočvara, Luboš; Tušer, Michal; Prchalová, Marie; Seďa, Jaromír; Peterka, Jiří (Peer reviewed; Journal article, 2022)
      To understand the spatiotemporal overlap in the habitat use of sympatric predators, we studied longitudinal activity and reservoir section and depth use of pike (Esox lucius), pikeperch (Sander lucioerca) and catfsh (Silurus ...
    • The effects of hydrodynamics on the three-dimensional downstream migratory movement of Atlantic salmon 

      Silva, Ana T.; Bærum, Kim Magnus; Hedger, Richard David; Baktoft, Henrik; Fjeldstad, Hans-Petter; Gjelland, Karl Øystein; Økland, Finn; Forseth, Torbjørn (Journal article; Peer reviewed, 2019)
      Anthropogenic structures in rivers are major threats for fish migration and effective mitigation is imperative given the worldwide expansion of such structures. Fish behaviour is strongly influenced by hydrodynamics, but ...
    • Transmission dynamics of the monogenean Gyrodactylus salaris under seminatural conditions 

      Hendrichsen, Ditte Katrine; Kristoffersen, Roar; Gjelland, Karl Øystein; Knudsen, Rune; Kusterle, Stefan; Rikardsen, Audun H.; Henriksen, Eirik Haugstvedt; Smalås, Aslak; Olstad, Kjetil (Journal article; Peer reviewed, 2015)