Blar i Øvrige samlinger på forfatter "Vollset, Knut"
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A test of migratory coupling in the salmon-trout predator-prey complex of a subarctic fjord
Lennox, Robert J.; Espedal, Espen Olsen; Barlaup, Bjørn Torgeir; Mahlum, Shad Kenneth; Vollset, Knut (Peer reviewed; Journal article, 2019)Atlantic salmon (Salmo salar) smolts are vulnerable to predators during their seaward migration. To determine whether sea trout (Salmo trutta) exhibit a coupled migration to exploit the smolt run, we tracked Atlantic salmon ... -
Assessment of the risk to Norwegian biodiversity and aquaculture from pink salmon (Oncorhynchus gorbuscha). Scientific Opinion of the Panel on Alien Organisms and Trade in Endangered Species of the Norwegian Scientific Committee for Food and Environment
Hindar, Kjetil; Hole, Lars Robert; Kausrud, Kyrre Linné; Malmstrøm, Martin; Rimstad, Espen; Robertson, Lucy; Sandlund, Odd Terje; Thorstad, Eva Bonsak; Vollset, Knut; de Boer, Hugo; Eldegard, Katrine; Järnegren, Johanna; Kirkendall, Lawrence Richard; Måren, Inger Elisabeth; Nilsen, Erlend Birkeland; Rueness, Eli Knispel; Nielsen, Anders; Velle, Gaute (Peer reviewed; Journal article, 2020) -
Behaviour of anadromous brown trout (Salmo trutta) in a hydropower regulated freshwater system
Dahlmo, Lotte Svengård; Velle, Gaute; Nilsen, Cecilie Iden; Pulg, Ulrich; Lennox, Robert; Vollset, Knut (Peer reviewed; Journal article, 2023)Many Norwegian rivers and lakes are regulated for hydropower, which afects freshwater ecosystems and anadromous fish species, such as sea trout (Salmo trutta). Lakes are an important feature of many anadromous river systems. ... -
A comparative study of the alternative life history of iteroparous salmonids
Lennox, Robert; Nilsen, Cecilie Iden; Dahlmo, Lotte Svengård; Berhe, Saron; Barlaup, Bjørn Torgeir; Normann, Eirik; Landro, Yngve; Birnie-Gauvin, Kim; Cooke, Steven J.; Vollset, Knut (Peer reviewed; Journal article, 2024)The kelt phase of anadromous iteroparous salmonid life history remains mysterious, particularly aspects of their habitat use and factors influencing survival. Atlantic salmon and sea-run brown trout were captured in the ... -
Development of a risk assessment for sea trout in coastal areas exploited for aquaculture
Finstad, Bengt; Sandvik, Anne Dagrun; Ugedal, Ola; Vollset, Knut; Karlsen, Ørjan; Davidsen, Jan Grimsrud; Sægrov, Harald; Lennox, Robert J. (Peer reviewed; Journal article, 2021)The regulation of aquaculture production in Norway considers the potential impact of salmon lice on wild fish. However, most attention has been focused on impacts on wild Atlantic salmon, despite the fact that anadromous ... -
Digital fisheries data in the Internet age: Emerging tools for research and monitoring using online data in recreational fisheries
Lennox, Robert; Sbragaglia, Valerio; Vollset, Knut; Sortland, Lene K.; McClenachan, Loren; Jarić, Ivan; Guckian, Meaghan L.; Ferter, Keno; Danylchuk, Andy J.; Cooke, Steven J.; Arlinghaus, Robert; Twardek, William M. (Peer reviewed; Journal article, 2022)Recreational fisheries are diverse in scale, scope, and participation worldwide, constituting an important ecosystem service of marine and freshwater ecosystems. Management of these socio-ecological systems is challenged ... -
Drift diving: A quick and accurate method for assessment of anadromous salmonid spawning populations
Skoglund, Helge; Vollset, Knut; Lennox, Robert J.; Skaala, Øystein; Barlaup, Bjørn Torgeir (Peer reviewed; Journal article, 2021)The accuracy of drift diving surveys of Atlantic salmon, Salmo salar L. and sea trout, Salmo trutta L., was evaluated by comparing the abundance and size distribution with catches in a fish trap over 6 years in the River ... -
Ecological regime shift in the Northeast Atlantic Ocean revealed from the unprecedented reduction in marine growth of Atlantic salmon
Vollset, Knut; Urdal, Kurt; Utne, Kjell Rong; Thorstad, Eva Bonsak; Sægrov, Harald; Raunsgard, Astrid; Skagseth, Øystein; Lennox, Robert; Østborg, Gunnel Marie; Ugedal, Ola; Jensen, Arne Johan; Bolstad, Geir Hysing; Fiske, Peder (Peer reviewed; Journal article, 2022)Ecological regime shifts are abrupt changes in the structure and function of ecosystems that persist over time, but evidence of contemporary regime shifts are rare. Historical scale data from 52,384 individual wild Atlantic ... -
Effects of tag type and surgery on migration of Atlantic salmon (Salmo salar) smolts
Lennox, Robert; Stöger, Elisabeth; Dahlmo, Lotte Svengård; Helle, Turid Myklebust; Wiers, Tore; Hanssen, Erlend Mjelde; Vollset, Knut (Peer reviewed; Journal article, 2022)Tagging salmon smolts to provide information about the timing of outmigration has been a common approach to monitor phenology and model the risk of encountering stressors. However, the validity of tagging has come under ... -
Effekter av vanntemperatur på vekst og rekruttering hos laks og aure i Bjoreio
Skoglund, Helge; Vollset, Knut (LFI - Laboratorium for ferskvannsøkologi og innlandsfiske, Research report, 2020)Tapping av kaldt bunnvann fra Sysenmagasinet for å opprettholde minstevannføringen i Vøringsfossen har ført til lavere temperaturer og dårligere oppvekstsvilkår for laks og sjøaure i Bjoreio. Som et tiltak for å øke ... -
Ekstraordinær overvåking av lakselussituasjonen i Nordhordland våren 2023
Espedal, Espen Olsen; Postler, Christoph; Barlaup, Bjørn Torgeir; Lehmann, Gunnar Bekke; Vollset, Knut (LFI - Laboratorium for ferskvannsøkologi og innlandsfiske, Research report, 2023)I forbindelse med overvåking av utvandrende laksesmolt fra elvene Vosso og Dale ble det tidlig i mai 2023 oppdaget sjøørret med kraftige påslag av lakselus langt inne i fjordsystemet. På oppdrag fra Miljødirektoratet ble ... -
Gytefisktelling av laks og sjøaure på Vestlandet: status og utvikling i perioden 2004-2018
Skoglund, Helge; Vollset, Knut; Barlaup, Bjørn Torgeir; Lennox, Robert (LFI - Laboratorium for ferskvannsøkologi og innlandsfiske, Research report, 2019)I de siste tiårene har situasjonen vært kritisk og uavklart for mange lakse‐ og sjøaurebestander på Vestlandet. Dette gjelder særlig for bestandene i Hardangerfjorden, hvor de fleste viktige laksevassdrag har vært stengt ... -
Habitatkartlegging i Strynselva høsten 2020
Stranzl, Sebastian Franz; Vollset, Knut; Pulg, Ulrich; Postler, Christoph (LFI - Laboratorium for ferskvannsøkologi og innlandsfiske, Research report, 2022)Denne rapporten sammenstiller resultater av habitatkartlegging utført av NORCE LFI i Strynselva i Stryn kommune høsten 2020. Kartleggingen viser at mangel på gytehabitat og skjul er viktige habitatflaskehalser. Det anbefales ... -
How pathogens affect the marine habitat use and migration of sea trout (Salmo trutta) in two Norwegian fjord systems
Lennox, Robert J.; Eldøy, Sindre Håvarstein; Vollset, Knut; Miller, Kristi M.; Li, Shaorong; Kaukinen, Karia H.; Isaksen, Trond Einar; Davidsen, Jan Grimsrud (Peer reviewed; Journal article, 2020)Wild fish are confronting changing pathogen dynamics arising from anthropogenic disturbance and climate change. Pathogens can influence animal behaviour and life histories, yet there are little such data from fish in the ... -
Making the best of lousy circumstances: The impact of salmon louse Lepeophtheirus salmonis on depth preference of sea trout Salmo trutta
Mohn, Agnes Marie; Vollset, Knut; Karlsbakk, Egil (Peer reviewed; Journal article, 2020)ABSTRACT: Sea trout are known for seeking out sources of freshwater to rid themselves of salmon lice. However, the effect of natural haloclines in fjords on parasite dynamics is not well understood. We tagged 48 naturally ... -
Moving cleaner fish from the wild into fish farms: A zero-sum game?
Lennox, Robert; Barrett, Luke T.; Nilsen, Cecilie Iden; Berhe, Saron; Barlaup, Bjørn Torgeir; Vollset, Knut (Journal article; Peer reviewed, 2022)Fish that engage in mutualistic cleaning behaviour (‘cleaner fishes’) have recently been popularized as a nature-based method of controlling ectoparasite outbreaks in fish farms. Outbreaks impact animal welfare and threaten ... -
Negative impacts of the sea lice prophylactic emamectin benzoate on the survival of hatchery released salmon smolts in rivers
Lennox, Robert J.; Salvanes, Anne Gro Vea; Barlaup, Bjørn Torgeir; Stöger, Elisabeth; Madhun, Abdullah; Helle, Turid Myklebust; Vollset, Knut (Peer reviewed; Journal article, 2020)Emamectin benzoate (EB) is a prophylactic pharmaceutical used to protect Atlantic salmon (Salmo salar) smolts migrating out of rivers and into the ocean against sea lice parasites. Randomized control trials comparing the ... -
Predation by Eurasian otters on adult Atlantic salmon
Sortland, Lene; Lennox, Robert; Vollset, Knut; Velle, Gaute (Master thesis, 2022)The return of the Eurasian otter to western Norway has sparked human-predator conflicts as otters prey on vulnerable Atlantic salmon populations. Although predation may not be the direct cause of salmon population declines, ... -
Predicting the nationwide outmigration timing of Atlantic salmon (Salmo salar) smolts along 12 degrees of latitude in Norway
Vollset, Knut; Lennox, Robert J.; Lamberg, Anders; Skaala, Øystein; Sandvik, Anne Dagrun; Sægrov, Harald; Kvingedal, Eli; Kristensen, Torstein; Jensen, Arne Johan; Haraldstad, Tormod; Barlaup, Bjørn Torgeir; Ugedal, Ola (Journal article; Peer reviewed, 2021)Aim Accurate predictions about transition timing of salmon smolts between freshwater and marine environments are key to effective management. We aimed to use available data on Atlantic salmon smolt migration to predict ... -
The quest for successful Atlantic salmon restoration: perspectives, priorities, and maxims
Lennox, Robert; Alexandre, Carlos M; Almeida, Pedro R; Bailey, Kevin M.; Barlaup, Bjørn Torgeir; Bøe, Kristin; breukelaar, Andre; Erkinaro, Jaakko; Forseth, Torbjørn; Gabrielsen, Sven-Erik; Halfyard, Edmund; Hanssen, Erlend Mjelde; Karlsson, Sten; Koch, Stephanie; Koed, Anders; Langåker, Roy, M; Lo, Håvard; Lucas, Martyn C.; Mahlum, Shad Kenneth; Perrier, Charles; Pulg, Ulrich; Sheehan, Timothy F.; Skoglund, Helge; Svenning, Martin; Thorstad, Eva Bonsak; Velle, Gaute; Whoriskey, Frederick G.; Vollset, Knut (Peer reviewed; Journal article, 2021)Atlantic salmon is often a focal species of restoration efforts throughout the north Atlantic and it is therefore an excellent case study for how best to design programmes to address and mitigate threats and correct ...