Browsing NTNU Open by Author "Forseth, Torbjørn"

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    • AlternaFuture - Final Report 

      Vereide, Kaspar; Mo, Birger; Forseth, Torbjørn; Lia, Leif; Nysveen, Arne; Dahlhaug, Ole Gunnar; Schäffer, Linn Emelie; Bustos, Ana Adeva; Sundt-Hansen, Line; Øvregård, Eirik; Glimen, Pål; Hesthagen, Trygve; Skår, Margrete; Nielsen, Torbjørn Kristian (HydroCen Report;18, Research report, 2020)
      AlternaFuture has been a multidisciplinary research project in Hydrocen to investigate the potential of extreme upgrading of existing hydropower system with a positive effect on the environmental conditions. The project ...

    • Biologiske undersøkelser i Altaelva 1981-2006. Oppsummering av kraftreguleringens konsekvenser for laksebestanden 

      Ugedal, Ola; Thorstad, Eva B.; Finstad, Anders G.; Fiske, Peder; Forseth, Torbjørn; Hvidsten, Nils Arne; Jensen, Arne J.; Koksvik, Jan Ivar; Reinertsen, Helge; Saksgård, Laila; Næsje, Tor F. (NINA rapport;, Research report, 2007)
      Nøkkelord : kraftregulering, Altaelva, Finnmark, laks, laksefangster, ungfisktetthet, vinterdødelighet, smoltproduksjon, bunnfauna, begroing

    • 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 ...

    • Classification of hydropeaking impacts on Atlantic salmon populations in regulated rivers 

      Bakken, Tor Haakon; Harby, Atle; Forseth, Torbjørn; Ugedal, Ola; Sauterleute, Julian Friedrich; Halleraker, Jo Halvard; Alfredsen, Knut (Peer reviewed; Journal article, 2021)
      This article proposes and demonstrates a new classification system of fish population level effects of hydropeaking operations in rivers. The classification of impacts is developed along two axes; first, the hydromorphological ...

    • Combining green LiDAR bathymetry, aerial images and telemetry data to derive mesoscale habitat characteristics for European grayling and brown trout in a Norwegian river 

      Sundt, Håkon; Alfredsen, Knut; Museth, Jon; Forseth, Torbjørn (Peer reviewed; Journal article, 2021)
      While many studies provide microscale relationships between fish and habitat characteristics, studies covering longer river reaches are scarce. Modern remote sensing techniques may enable new and effective ways of mapping ...

    • Density independent use of shallow riverine areas in juvenile Atlantic salmon 

      Puffer, Michael; Berg, Ole Kristian; Hamnes, Frøydis Bolme; Bentsen, Vidar; Koch, Wouter; Ugedal, Ola; Forseth, Torbjørn; Arnekleiv, Jo Vegar; Einum, Sigurd (Journal article; Peer reviewed, 2018)
      Habitat use of aquatic organisms is essential to evaluate effects of many environmental challenges like effects of hydro-power regulation, where stranding may occur under hydropeaking (rapid dewatering of shallow river ...

    • El-fiskemetodikk - Gamle problemer og nye utfordringer 

      Forseth, Torbjørn; Forsgren, Elisabet (NINA Rapport;488, Research report, 2009)
      El-fiske er et viktig verktøy i studier av elvelevende fisk. Metoden har bred anvendelse fra ren innsamling av fisk til tetthets- og bestandsestimater. I dag brukes tetthetsestimater rutinemessig i bestandsovervåkning ...

    • Energetic Consequences of Stranding of Juvenile Atlantic Salmon (Salmo salar L.) 

      Puffer, Michael; Berg, Ole Kristian; Einum, Sigurd; Saltveit, Svein Jakob; Forseth, Torbjørn (Journal article, 2017)
      An effect of hydropower and hydropeaking regulation in rivers is stranding of fish. Those fishes that survive stranding may experience stranding as a stressful situation. In four experimental stranding experiments (each ...

    • Experimental hydraulics on fish-friendly trash-racks: an ecological approach 

      Szabo-Meszaros, Marcell; Navaratnam, Christy Ushanth; Aberle, Jochen; Silva, Ana T.; Forseth, Torbjørn; Calles, Olle; Fjeldstad, Hans-Petter; Alfredsen, Knut (Journal article; Peer reviewed, 2018)
      The obstruction of fish migratory routes by hydroelectric facilities is worldwide one of the major threats to freshwater fishes. During downstream migration, fish may be injured or killed on the trash-racks or in the ...

    • Gytebestandsmål for laksebestander i Norge 

      Hindar, Ketil; Diserud, Ola; Fiske, Peder; Forseth, Torbjørn; Jensen, Arne J.; Uggedal, Ola; Jonsson, Nina; Sloreid, Svein Erik; Arnekleiv, Jo V.; Saltveit, Svein Jakob; Sægrov, , Harald; Sættem, Leif Magnus (NINA rapport;226, Research report, 2007)
      Denne rapporten gir forslag til gytebestandsmål for laks (Salmo salar) i 80 viktige laksevassdrag i Norge. Vassdragene er valgt ut på bakgrunn av at de er definert som – eller vurdert som – nasjonale laksevassdrag. Vi har ...

    • Interactions between local population density and limited habitat resources determine movements of juvenile Atlantic salmon 

      Teichert, Maxim; Foldvik, Anders; Einum, Sigurd; Finstad, Anders Gravbrøt; Forseth, Torbjørn; Ugedal, Ola (Journal article; Peer reviewed, 2017)
      Competition for limited resources and the resulting density-dependent processes are key factors in driving stream salmonid population dynamics. Here we test for the combined effects of density and shelter availability on ...

    • Kartlegging og digitalisering av elver med fjernmåling 

      Sundt, Håkon; Alfredsen, Knut; Forseth, Torbjørn; Harby, Atle (HydroCen brief;Nr. 9, Report, 2023)

    • Methods to safeguard downstream migration of salmonids past hydropower structures 

      Szabo-Meszaros, Marcell (Doctoral theses at NTNU;2019:104, Doctoral thesis, 2019)
      Sustainable development of hydropower production must include measures to reduce the negative consequences of river fragmentations. Migratory Atlantic salmon (Salmo salar, L) is one of the species that can be severely ...

    • Modelling climate change effects on Atlantic salmon: Implications for mitigation in regulated rivers 

      Sundt-Hansen, Line Elisabeth Breivik; Hedger, Richard David; Ugedal, Ola; Diserud, Ola Håvard; Finstad, Anders Gravbrøt; Sauterleute, Julian Friedrich; Tøfte, Lena S; Alfredsen, Knut; Forseth, Torbjørn (Journal article; Peer reviewed, 2018)
      Climate change is expected to alter future temperature and discharge regimes of rivers. These regimes have a strong influence on the life history of most aquatic river species, and are key variables controlling the growth ...

    • Modelling mitigation measures for smolt migration at dammed river sections 

      Szabo-Meszaros, Marcell; Forseth, Torbjørn; Baktoft, Henrik; Fjeldstad, Hans-Petter; Silva, Ana T.; Gjelland, Karl Øystein; Økland, Finn; Uglem, Ingebrigt; Alfredsen, Knut (Journal article; Peer reviewed, 2019)
      There is no generic solution to establish safe passage of downstream migrating fish passed hydropower facilities and mitigation measures are species‐ and site‐specific. Development of solutions is thus often based on “trial ...

    • Multi-criteria decision analysis in Bayesian networks - diagnosing ecosystem service trade-offs in a hydropower regulated river 

      Barton, David Nicholas; Sundt, Håkon; Adeva Bustos, Ana; Fjeldstad, Hans-Petter; Hedger, Richard David; Forseth, Torbjørn; Köhler, Berit; Aas, Øystein; Alfredsen, Knut; Madsen, Anders L. (Journal article; Peer reviewed, 2019)
      The paper demonstrates the use of Bayesian networks in multicriteria decision analysis (MCDA) of environmental design alternatives for environmental flows (eflows) and physical habitat remediation measures in the Mandalselva ...

    • Novel large-scale mapping highlights poor state of sea trout populations 

      Fiske, Peder; Forseth, Torbjørn; Thorstad, Eva Bonsak; Bakkestuen, Vegar; Einum, Sigurd; Falkegård, Morten; Garmo, Øyvind A.; Garseth, Åse Helen; Skoglund, Helge; Solberg, Monica Favnebøe; Utne, Kjell Rong; Vollset, Knut; Vøllestad, Leif Asbjørn; Wennevik, Vidar (Peer reviewed; Journal article, 2024)
      1. The state of sea trout in 1251 Norwegian watercourses was assessed based on a scoring system for human pressures, abundance data, and local knowledge. 2. Over 16,000 km of rivers and lakes were available to sea trout ...

    • Ontogenetic timing of density dependence: location-specific patterns reflect distribution of a limiting resource 

      Teichert, Maxim; Einum, Sigurd; Finstad, Anders Gravbrøt; Ugedal, Ola; Forseth, Torbjørn (Journal article; Peer reviewed, 2013)
      Theoretical considerations suggest that the relative abundance of age-specific limiting resources determines the ontogenetic timing of density dependence. Structural shelters may represent one such resource which can become ...

    • Predation of Atlantic salmon across ontogenetic stages and impacts on populations 

      Falkegård, Morten; Lennox, Robert; Thorstad, Eva Bonsak; Einum, Sigurd; Fiske, Peder; Garmo, Øyvind Aaberg; Garseth, Åse Helen; Skoglund, Helge; Solberg, Monica Favnebøe; Utne, Kjell Rong; Vollset, Knut; Vøllestad, Leif Asbjørn; Wennevik, Vidar; Forseth, Torbjørn (Peer reviewed; Journal article, 2023)
      Managers and stakeholders increasingly ask whether predation is a driving force behind the poor status of many species, and whether predator control is likely to be a successful management action to intervene. We review ...

    • Remotely sensed data for bathymetric mapping and ecohydraulics modelling in rivers 

      Sundt, Håkon (Doctoral theses at NTNU;2022:135, Doctoral thesis, 2022)
      River management decisions must be based on the best knowledge available. But acquiring information on river conditions and translating it into sufficient mitigation measures can be both time- and resource demanding. Remote ...