Blar i NTNU Open på forfatter "Thorstad, Eva Bonsak"
-
A comparison of life history and biological characters between Atlantic salmon first-time and repeat spawners in two Norwegian rivers
Jacobsen, Marit Melby (Master thesis, 2023)Iteroparitet er en avveiningsstrategi mellom nåværende og fremtidig reproduksjon. Risikoen for svikt i reproduksjonen er spredt over tid dersom fisken kan overleve sin første gyting og gyte igjen på et senere tidspunkt. ... -
Assessment of the risk of negative impact on biodiversity from import and release of eggs or live fish from landlocked Atlantic salmon from Klarälven in Sweden to Trysilelva in Norway. Scientific Opinion of the Panel on Alien Organisms and Trade in Endangered Species of the Norwegian Scientific Committee for Food and Environment
Thorstad, Eva Bonsak; Garseth, Åse Helen; Gjøen, Tor; Gulla, Snorre; Lo, Håvard; Malmstrøm, Martin; Mo, Tor Atle; Velle, Gaute; de Boer, Hugo; Eldegard, Katrine; Hindar, Kjetil; Hole, Lars Robert; Järnegren, Johanna; Kausrud, Kyrre; Kirkendall, Lawrence R.; Måren, Inger Elisabeth; Nilsen, Erlend Birkeland; Olsen, Rolf Erik; Rimstad, Espen; Rueness, Eli Knispel; Øverli, Øyvind; Nielsen, Andreas (VKM Report;, Research report, 2021) -
Assessment of the risk of negative impact on biodiversity from import and release of eggs or live fish from landlocked Atlantic salmon from Klarälven in Sweden to Trysilelva in Norway. Scientific Opinion of the Panel on Alien Organisms and Trade in Endangered Species of the Norwegian Scientific Committee for Food and Environment
Thorstad, Eva Bonsak; Garseth, Åse Helen; Gjøen, Tor; Gulla, Snorre; Lo, Håvard; Malmstrøm, Martin; Mo, Tor Atle; Velle, Gaute; de Boer, Hugo; Eldegard, Katrine; Hindar, Kjetil; Hole, Lars Robert; Järnegren, Johanna; Kausrud, Kyrre; Kirkendall, Lawrence R.; Måren, Inger Elisabeth; Nilsen, Erlend Birkeland; Olsen, Rolf Erik; Rimstad, Espen; Rueness, Eli Knispel; Øverli, Øyvind; Nielsen, Anders (Peer reviewed; Journal article, 2021)Introduction Atlantic salmon in the River Klarälven in Sweden live the entire life in freshwater, undertaking feeding migrations to Lake Vänern. The upper part of the watershed is in Norway and comprises the River Trysilelva ... -
Assessment of the risk to Norwegian biodiversity from import and keeping of American bison, European bison, domesticated water buffalo and domesticated yak. Scientific Opinion of the panel on Alien Organisms and Trade in Endangered Species (CITES) of the Norwegian Scientific Committee for Food and Environment
Nilsen, Erlend Birkeland; Austrheim, Gunnar; Gjøen, Tor; Kvie, Kjersti Sternang; Malmstrøm, Martin; Ytrehus, Bjørnar; Eldegard, Katrine; Hindar, Kjetil; Järnegren, Johanna; Nielsen, Anders; Kausrud, Kyrre; Kirkendall, Lawrence R.; Rueness, Eli Knispel; Thorstad, Eva Bonsak; Velle, Gaute (Peer reviewed; Journal article, 2021) -
Brown trout (Salmo trutta L. 1758) and Arctic charr (Salvelinus alpinus (L. 1758)) display different marine behaviour and feeding strategies in sympatry
Davidsen, Jan Grimsrud; Halvorsen, Andrine Emilie; Eldøy, Sindre Håvarstein; Thorstad, Eva Bonsak; Vøllestad, Leif Asbjørn (Peer reviewed; Journal article, 2023)Brown trout (Salmo trutta L. 1758) and Arctic charr (Salvelinus alpinus (L. 1758)) tagged with acoustic transmitters migrated from freshwater to the sea mainly in May and June, but with large individual variation in migration ... -
Changes in growth and migration patterns of sea trout before and after the introduction of Atlantic salmon farming
Eldøy, Sindre Håvarstein; Ryan, Diarmuid; Roche, William; Thorstad, Eva Bonsak; Næsje, Tor; Sjursen, Aslak Darre; Gargan, Paddy; Davidsen, Jan Grimsrud (Peer reviewed; Journal article, 2020)Marine growth has strong implications for reproductive potential and ultimate fitness of sea trout. Hence, the effects of anthropogenic factors on marine growth are important when evaluating population responses and ... -
Comparing the early marine migration behaviour of Atlantic salmon post-spawners and brown trout veteran migrants entering the same fjord system
Nilsen, Håvard Vedeler (Master thesis, 2021)Til tross for å være forskjellige arter med forskjellige livshistorier, er anadrom Atlanterhavslaks (Salmo salar L.) og brunørret (Salmo trutta L.) som regel underlagt den samme forvaltningsstrategien. Implementering av ... -
Early marine migration of European silver eel (Anguilla anguilla) in Northern Norway
Davidsen, Jan Grimsrud; Finstad, Bengt; Økland, Finn; Thorstad, Eva Bonsak; Mo, Tor Atle; Rikardsen, Audun H. (Journal article; Peer reviewed, 2011) -
Early-season brown trout (Salmo trutta) migrants grow and survive better at sea
Jensen, Arne Johan; Diserud, Ola Håvard; Finstad, Bengt; Fiske, Peder; Thorstad, Eva Bonsak (Peer reviewed; Journal article, 2022)The timing of seaward migration is a key life-history trait for many anadromous fish species, with growth and survival at sea depending on a match/mismatch scenario between the timing of the sea entry and optimal conditions. ... -
Effects of sound exposure from a seismic airgun on heart rate, acceleration and depth use in free-swimming Atlantic cod and saithe
Davidsen, Jan Grimsrud; Dong, Hefeng; Linne, Markus; Andersson, Mathias H.; Piper, Adam; Prystay, Tanya S.; Hvam, Eivind B.; Thorstad, Eva Bonsak; Whoriskey, Frederick G.; Cooke, Steven J.; Sjursen, Aslak Darre; Rønning, Lars; Netland, Tim Cato; Hawkins, Anthony D. (Journal article; Peer reviewed, 2019)Recent vegetation changes in arctic-alpine tundra ecosystems may affect several ecosystem processes that regulate microbe and soil functions. Such changes can alter ecosystem carbon (C) cycling with positive feedback to ... -
Habitat use of sea trout (Salmo trutta) veterans in two Norwegian estuaries
Harbak, Signe Brekke (Master thesis, 2022)Elvemunningar er eit viktig habitat for sjøaure (Salmot trutta) til alle årstider, og kan brukast gjennom vinterhalvåret som ein alternativ strategi til den meir vanlege overvintringa i ferskvatn. I denne studien blei ... -
Home ranges and habitat utilisation of the river-resident Atlantic salmon, Salmo salar, småblank
Eikaas, Linda (Master thesis, 2016)Home ranges and habitat utilisation of the river resident Atlantic salmon, småblank, Salmo salar, in Nord Trøndelag, Norway, were studied by the use of radio telemetry during the period August 2014 to January 2016. The aim ... -
Homing behaviour of Atlantic salmon (Salmo salar) during final phase of marine migration and river entry
Davidsen, Jan Grimsrud; Rikardsen, Audun H.; Thorstad, Eva Bonsak; Halttunen, Elina; Mitamura, Hiromichi; Præbel, Kim; Skardhamar, Jofrid; Næsje, Tor (Journal article; Peer reviewed, 2013-03-11)Little is known about Atlantic salmon behaviour during the last phase of the marine homing migration and subsequent river entry. In this study, 56 adult Atlantic salmon in the Alta Fjord in northern Norway were equipped ... -
The influence of physiology, life history and environmental conditions on the marine migration patterns of sea trout
Eldøy, Sindre Håvarstein (Doctoral theses at NTNU;2020:204, Doctoral thesis, 2020)The marine migration of sea trout (anadromous brown trout, Salmo trutta) is an evolutionary adaption to exploit richer feeding opportunities at sea compared to the freshwater habitat. Over the last decades, there has been ... -
Long-term variation in numbers and biomass of silver eels being produced in two European river systems
Poole, W. Russell; Diserud, Ola Håvard; Thorstad, Eva Bonsak; Durif, Caroline; Dolan, Conor; Sandlund, Odd Terje; Bergesen, Knut Aanestad; Rogan, Gerard; Kelly, Sean D.; Vøllestad, Leif Asbjørn (Journal article; Peer reviewed, 2018)The European eel (Anguilla anguilla) population has been in decline at least since the 1960s and reliable regional information, particularly on the spawner production and escapement (i.e. the silver eel life stage), is a ... -
Marine depth use of sea trout Salmo trutta in fjord areas of Central Norway
Eldøy, Sindre Håvarstein; Davidsen, Jan Grimsrud; Thorstad, Eva Bonsak; Whoriskey, Frederick G.; Aarestrup, Kim; Næsje, Tor; Rønning, Lars; Sjursen, Aslak Darre; Rikardsen, Audun H.; Arnekleiv, Jo Vegar (Journal article; Peer reviewed, 2017)The vertical behaviour of 44 veteran sea trout Salmo trutta (275–580 mm) in different marine fjord habitats (estuary, pelagic, near shore with and without steep cliffs) was documented during May–February by acoustic ... -
Marine migration and habitat use of anadromous brown trout Salmo trutta
Eldøy, Sindre Håvarstein; Davidsen, Jan Grimsrud; Thorstad, Eva Bonsak; Whoriskey, F.; Aarestrup, K.; Næsje, Tor; Rønning, Lars; Sjursen, Aslak Darre; Rikardsen, Audun H.; Arnekleiv, Jo Vegar (Journal article, 2015)The biology and ecology of anadromous brown trout (Salmo trutta) at sea is poorly understood. This study provided information on spatial and temporal distribution of sea trout in the ocean. The behaviour of 115 individuals ... -
Migration and habitat use of sea trout Salmo trutta in relation to a marine protected area A study conducted in Beiarfjorden national salmon fjord
Steinkjer, Enghild Kristine (Master thesis, 2021)Kystområder er viktige leveområder for anadrom brun ørret (sjøørret, Salmo trutta), men også sårbare for menneskeskapte påvirkninger, slik som oppdrettsanlegg, på grunn av den frie bevegelsen av patogener mellom oppdrettsmær ... -
Migration and habitat use of the landlocked riverine Atlantic salmon Salmo salar småblank
Davidsen, Jan Grimsrud; Eikås, Linda; Hedger, Richard David; Thorstad, Eva Bonsak; Rønning, Lars; Sjursen, Aslak Darre; Berg, Ole Kristian; Bremset, Gunnbjørn; Karlsson, Sten; Sundt-Hansen, Line Elisabeth Breivik (Peer reviewed; Journal article, 2020)“Småblank” is the only population of Atlantic salmon in Europe living its entire life in the river habitat without performing migrations to the sea or lakes. Home range size and habitat use were compared between an unregulated ... -
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 ...