Blar i Scientific publications på forfatter "Havn, Torgeir Børresen"

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    • Behaviour and survival of wild Atlantic salmon Salmo salar captured and released while surveillance angling for escaped farmed salmon 

      Lennox, Robert J.; Havn, Torgeir Børresen; Thorstad, Eva Bonsak; Liberg, Egil; Cooke, Steven J.; Uglem, Ingebrigt (Journal article; Peer reviewed, 2017)
      In many Norwegian rivers, spawning stocks are surveyed for escaped farmed salmon with surveillance fishing by rod and reel after the recreational angling season. However, the benefits of surveillance fishing depend on the ...

    • Bioenergetic consequences of warming rivers to adult Atlantic salmon Salmo salar during their spawning migration 

      Lennox, Robert J.; Eliason, Erika J.; Havn, Torgeir Børresen; Johansen, Martin Rognli; Thorstad, Eva Bonsak; Cooke, Steven J.; Diserud, Ola Håvard; Whoriskey, Frederick G.; Farrell, Anthony P.; Uglem, Ingebrigt (Journal article; Peer reviewed, 2018)
      1. Climate change poses a challenge to wild fishes, yet little is known about the behavioural use and metabolic consequences of thermally heterogeneous water encountered by wild salmon during their energetically demanding ...

    • Does Catch-and-Release Angling Alter the Behavior and Fate of Adult Atlantic Salmon During Upriver Migration? 

      Lennox, Robert J.; Uglem, Ingebrigt; Cooke, Steven J.; Næsje, Tor; Whoriskey, Frederick G.; Havn, Torgeir Børresen; Ulvan, Eva Marita; Solem, Øyvind; Thorstad, Eva Bonsak (Journal article; Peer reviewed, 2015)
      To reproduce, Atlantic Salmon Salmo salar return to freshwater rivers and migrate upriver to spawning areas. This migration is the basis for recreational fisheries, which for conservation reasons are increasingly characterized ...

    • Impacts of a weir and power station on downstream migrating Atlantic salmon smolts in a German river 

      Havn, Torgeir Børresen; Thorstad, Eva Bonsak; Borcherding, Jost; Heermann, Lisa; Teichert, Maxim A. K.; Ingendahl, Detlev; Tambets, Meelis; Sæther, Stein Are; Økland, Finn (Peer reviewed; Journal article, 2020)
      Weirs are barriers built across rivers for a wide range of other purposes than hydropower production. Like hydropower installations, weirs can negatively impact fish migrations. Downstream migration and mortality of Atlantic ...

    • Influence of gear switching on recapture of Atlantic salmon (Salmo salar) in catch-and- release fisheries 

      Lennox, Robert J.; Diserud, Ola Håvard; Cooke, Steven J.; Thorstad, Eva Bonsak; Whoriskey, Frederick G.; Solem, Øyvind; Havn, Torgeir Børresen; Uglem, Ingebrigt (Journal article; Peer reviewed, 2016)
      Anglers that release Atlantic salmon (Salmo salar) in recreational fisheries do so with the intention that the fish will survive and contribute to succeeding generations. In some instances, salmon that are released may be ...

    • Mortality of Atlantic salmon after catch and release angling: assessment of a recreational Atlantic salmon fishery in a changing climate 

      Van Leeuwen, Travis E.; Dempson, J. Brian; Burke, Chantelle M.; Kelly, Nicholas I.; Robertson, Martha J.; Lennox, Robert J.; Havn, Torgeir Børresen; Svenning, Martin; Hinks, Ross; Guzzo, Matthew M.; Thorstad, Eva Bonsak; Purchase, Craig F.; Bates, Amanda E. (Peer reviewed; Journal article, 2020)
      Human activities have the potential to accelerate population-level decline by contributing to climate warming and decreasing the capacity of species to survive warming temperatures. Here we build a predictive model to test ...

    • Movements of dead fish in rivers 

      Havn, Torgeir Børresen; Økland, Finn; Teichert, Maxim A.K.; Heermann, L.; Borcherding, J; Sæther, Stein Are; Tambets, M.; Diserud, Ola Håvard; Thorstad, Eva Bonsak (Journal article; Peer reviewed, 2017)
      Background: The aim of telemetry studies is often to determine the fate and mortality rates of ish. A moving ish is usually regarded as alive and a long-term stationary ish as dead—and the site where it became stationary ...

    • The effect of catch-and-release angling at high water temperatures on behaviour and survival of Atlantic salmon Salmo salar during spawning migration 

      Havn, Torgeir Børresen; Uglem, Ingebrigt; Solem, Øyvind; Cooke, Steven J.; Whoriskey, Frederick G.; Thorstad, Eva Bonsak (Journal article; Peer reviewed, 2015)
      In this study, behaviour and survival following catch-and-release (C&R) angling was investigated in wild Atlantic salmon Salmo salar (n = 75) angled on sport fishing gear in the River Otra in southern Norway at water ...

    • The risk of individual fish being captured multiple times in a catch and release fishery 

      Thorstad, Eva B.; Diserud, Ola Håvard; Solem, Øyvind; Havn, Torgeir Børresen; Bjørum, Lars Rasmus Oftedal; Kristensen, Torstein; Urke, Henning Andre; Johansen, Martin Rognli; Lennox, Robert J.; Fiske, Peder; Uglem, Ingebrigt (Peer reviewed; Journal article, 2019)
      The proportion of angled Atlantic salmon Salmo salar L. being caught and released has increased. If individuals are repeatedly captured, this may have fish welfare consequences. Of 995 Atlantic salmon tagged during catch ...

    • The use of external electronic tags on fish: an evaluation of tag retention and tagging effects 

      Jepsen, Niels; Thorstad, Eva Bonsak; Havn, Torgeir Børresen; Lucas, Martyn C. (Peer reviewed; Journal article, 2015)
      External tagging of fish with electronic tags has been used for decades for a wide range of marine and freshwater species. In the early years of fish telemetry research, it was the most commonly used attachment method, ...

    • Use of simulation approaches to evaluate the consequences of catch-and-release angling on the migration behaviour of adult Atlantic salmon (Salmo salar) 

      Lennox, Robert J.; Cooke, Steven J.; Diserud, Ola Håvard; Havn, Torgeir Børresen; Johansen, Martin R.; Thorstad, Eva Bonsak; Whoriskey, Frederick G.; Uglem, Ingebrigt (Journal article; Peer reviewed, 2016)
      Given most Atlantic salmon (Salmo salar) released by anglers survive (proportion = 0.97 in this study), eco-nomically and culturally important recreational Atlantic salmon fisheries are increasingly incorporatingcatch-and-release. ...