Blar i NINA Brage på forfatter "Thorstad, Eva Bonsak"
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Recreational anglers in Norway report widespread dislike of invasive pink salmon
Guay, J.D.; Lennox, Robert; Thorstad, Eva Bonsak; Vollset, Knut; Stensland, Stian; Erkinaro, J.; Nguyen, V.M. (Peer reviewed; Journal article, 2023)Pink salmon have returned to Norwegian rivers at high abundance in recent odd-numbered years (2017, 2019, 2021, 2023), presenting potential threats to native biodiversity and ecosystem services, including major sport fishing ... -
Redefining the oceanic distribution of Atlantic salmon
Rikardsen, Audun H.; Righton, David; Strøm, John Fredrik; Thorstad, Eva Bonsak; Gargan, Patrick G.; Sheehan, Timothy F.; Økland, Finn; Chittenden, Cedar; Hedger, Richard David; Næsje, Tor; Renkawitz, Mark; Sturlaugsson, Johannes; Caballero, Pablo; Baktoft, Henrik; Davidsen, Jan Grimsrud; Halttunen, Elina; Wright, Serena; Finstad, Bengt; Aarestrup, Kim (Peer reviewed; Journal article, 2021)Determining the mechanisms driving range-wide reductions in Atlantic salmon marine survival is hindered by an insufcient understanding of their oceanic ecology and distribution. We attached 204 pop-up satellite archival ... -
Repeatable individual variation in migration timing in two anadromous salmonids and ecological consequences
Jensen, Arne Johan; Finstad, Bengt; Fiske, Peder; Diserud, Ola Håvard; Thorstad, Eva Bonsak (Peer reviewed; Journal article, 2020)Consistent individual differences in behavior have been demonstrated for many animals, but there are few studies of consequences of such repeated behavior in the wild. We tested consistency in migration timing to and from ... -
Revealing the full ocean migration of individual Atlantic salmon
Strøm, John Fredrik; Thorstad, Eva Bonsak; Hedger, Richard David; Rikardsen, Audun H. (Journal article; Peer reviewed, 2018)Knowledge of the complete horizontal migration and vertical movements of Atlantic salmon (Salmo salar L.) during the marine phase is important for understanding the link between individual processes and population recruitment. ... -
Rømt oppdrettslaks i Salvassdraget i 2004 og 2005
Fiske, Peder; Lund, Roar Asbjørn; Thorstad, Eva Bonsak; Heggberget, Tor Gravråk; Østborg, Gunnel Marie (NINA Rapport;172, Research report, 2006)Fiske, P., Lund, R.A., Thorstad, E.B., Heggberget, T.G. & Østborg, G. 2006. Rømt opp-drettslaks i Salvassdraget i 2004 og 2005. - NINA Rapport 172. 13 s. Skjellanalyser av henholdsvis 63 og 101 rømte oppdrettslaks fanget ... -
Småblanken i Namsenvassdraget - faglig grunnlag for handlingsplan
Thorstad, Eva Bonsak; Berg, Ole Kristian; Hesthagen, Trygve H.; Hindar, Kjetil; Norum, Ine Cecilie Jordalen; Sandlund, Odd Terje; Saksgård, Laila M. (NINA rapport;660, Research report, 2011)Thorstad, E.B., Berg, O.K., Hesthagen, T., Hindar, K., Norum, I.C.J., Sandlund, O.T. & Saksgård, L. 2011. Småblanken i Namsenvassdraget - faglig grunnlag for handlingsplan. NINA Rapport 660. 33 s. Denne rapporten om ... -
Smoltvandring forbi Laudal kraftverk i Mandalselva
Uglem, Ingebrigt; Økland, Finn; Forseth, Torbjørn; Diserud, Ola Håvard; Fiske, Peder; Thorstad, Eva Bonsak; Hvidsten, Nils Arne; Berger, Hans Mack (NINA Rapport;13, Research report, 2005)Uglem, I., Økland, F., Forseth, T., Diserud, O., Fiske, P., Thorstad, E.B., Hvidsten, N.A. og Berger, H.M. 2005. Smoltutvandring forbi Laudal kraftverk i Mandalselva. NINA Rapport 13 -
Space use patterns and movements of juvenile dusky kob Argyrosomus japonicus in the Great Fish Estuary (South Africa): implications for management
Cowley, Paul D.; Kerwath, Sven; Næsje, Tor; Childs, Amber-Robyn; Gillespie, Lloyd D.; Leggitt, Cordelia; Thorstad, Eva Bonsak; Økland, Finn (NINA Rapport;119, Research report, 2006)Cowley, P.D., Kerwath, S., Næsje, T.F., Childs, A.-R., Gillespie, L.D., Leggitt, C., Thorstad, E.B. and Økland, F. 2006. Space use patterns and movements of juvenile dusky kob Argyrosomus japonicus in the Great Fish Estuary ... -
Spatial behaviour and management of greenhead tilapia (Oreochromis macrochir) in the Zambezi River, Namibia
Thorstad, Eva Bonsak; Hay, Clinton J.; Økland, Finn; Nickanor, Nande; Næsje, Tor (NINA Rapport;287, Research report, 2007)Thorstad, E.B., Hay, C.J., Økland, F., Nickanor, N. & Næsje, T.F. 2007. Spatial behaviour and management of greenhead tilapia (Oreochromis macrochir) in the Zambezi River, Namibia. - NINA Report 287. 26 pp. The large ... -
Status for ål i Siravassdraget
Thorstad, Eva Bonsak; Kroglund, Frode; Saksgård, Randi J.; Midtbø, Rolf (NINA rapport;974, Research report, 2014)Bakgrunnen for denne undersøkelsen var at de siste kjente observasjoner av ål i Sira-vassdraget var fra tidlig på 1990-tallet, og det ble stilt spørsmål om ålen som art hadde forsvunnet fra vassdraget. Formålene med ... -
Status for småblankbestanden i Namsen
Thorstad, Eva Bonsak; Hindar, Kjetil; Berg, Ole Kristian; Saksgård, Laila M.; Norum, Ine Cecilie Jordalen; Sandlund, Odd Terje; Hesthagen, Trygve H.; Lehn, Lars Ove (NINA Rapport;403, Research report, 2009)Thorstad, E.B., Hindar, K., Berg, O.K., Saksgård, L., Norum, I.C.J., Sandlund, O.T., Hesthagen, T. & Lehn, L.O. 2009. Status for småblankbestanden i Namsen. - NINA Rapport 403. 95 s. Småblanken, som finnes kun i Namsenvassdraget, ... -
Systematic review and meta-analysis of PIT tagging effects on mortality and growth of juvenile salmonids
Vollset, Knut; Lennox, Robert J.; Thorstad, Eva Bonsak; Auer, Samuel; Bär, Kerstin; Larsen, Martin H.; Mahlum, Shad Kenneth; Näslund, Joacim; Stryhn, Henrik; Dohoo, Ian (Peer reviewed; Journal article, 2020)A systematic review and meta-analysis was conducted to evaluate the appropriate tag:fish size ratio when tagging juvenile salmonids (genera Oncorhynchus, Salmo, and Salvelinus). The review yielded 18 publications with 211 ... -
Tåler sjøørret fra Vefsna håndtering i forbindelse med bevaringstiltak? Undersøkelse av vandringer og overlevelse ved bruk av radiotelemetri
Thorstad, Eva Bonsak; Foldvik, Anders; Bjørnå, Thomas; Lo, Håvard; Stensli, John Haakon (NINA Rapport;550, Research report, 2010)Thorstad, E.B., Foldvik, A., Bjørnå, T., Lo, H. & Stensli, J.H. 2010. Tåler sjøørret fra Vefsna håndtering i forbindelse med bevaringstiltak? Undersøkelse av vandringer og overlevelse ved bruk av radiotelemetri. - NINA ... -
Temporal shifts in the marine feeding of individual Atlantic salmon inferred from scale isotope ratios
Power, Michael; Thorstad, Eva Bonsak; Forseth, Torbjørn; Fiske, Peder (Peer reviewed; Journal article, 2023)Given the limited information on prey use during the marine residency period for Atlantic salmon, scales were collected from salmon at return to the River Namsen (Norway) for spawning after 1 year at sea, and scale material ... -
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 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, ... -
Timing and pattern of annual silver eel migration in two European watersheds are determined by similar cues
Sandlund, Odd Terje; Diserud, Ola Håvard; Poole, Russell; Bergesen, Knut Aanestad; Dillane, Mary; Rogan, Gerard; Durif, Caroline; Thorstad, Eva Bonsak; Vøllestad, Leif Asbjørn (Journal article; Peer reviewed, 2017)Many animals perform long-distance migrations in order to maximize lifetime reproductive success. The European eel migrates several thousand kilometers between their feeding habitats in continental waters (fresh-,brackish, ... -
Tracking animals in freshwater with electronic tags: past, present and future
Cooke, Steven J.; Midwood, Jonathan D.; Thiem, Jason D.; Klimley, Peter; Lucas, Martyn C.; Thorstad, Eva Bonsak; Eiler, John H.; Holbrook, Chris; Ebner, Brendan C (Peer reviewed; Journal article, 2013)Considerable technical developments over the past half century have enabled widespread application of electronic tags to the study of animals in the wild, including in freshwater environments. We review the constraints ... -
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. ... -
Using scale-derived estimates of body size in analyses of Atlantic salmon life-history variation: a cautionary note
Burton, Tim; Ugedal, Ola; Karlsson, Sten; Thorstad, Eva Bonsak; Bolstad, Geir Hysing (Peer reviewed; Journal article, 2024)Measurements of individual body length at different life stages are critical in understanding fish ecology and evolution. Such data can be obtained via back-calculation from measurements of fish scales or by using the size ...