Blar i Brage IMR på forfatter "Vøllestad, Leif Asbjørn"
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Age of European silver eels during a period of declining abundance in Norway
Durif, Caroline; Diserud, Ola Håvard; Sandlund, Odd Terje; Thorstad, Eva Bonsak; Poole, Russell; Bergesen, Knut Aanestad; Escobar, Rosa; Shema, Steven; Vøllestad, Leif Asbjørn (Peer reviewed; Journal article, 2020)The European eel (Anguilla anguilla) is critically endangered throughout its range. Knowledge about age distribution of future spawners (silver eels) is essential to monitor the status and contribute to the recovery of ... -
Age of European silver eels during a period of declining abundance in Norway
Durif, Caroline; Diserud, Ola Håvard; Sandlund, Odd Terje; Thorstad, Eva Bonsak; Poole, Russell; Bergesen, Knut; Bergesen, Knut Aanestad; Escobar-Lux, Rosa H; Shema, Steven; Vøllestad, Leif Asbjørn (Peer reviewed; Journal article, 2020)The European eel (Anguilla anguilla) is critically endangered throughout its range. Knowledge about age distribution of future spawners (silver eels) is essential to monitor the status and contribute to the recovery of ... -
Analysis of European eel (Anguilla anguilla) time series in Norway
Durif, Caroline M.F.; Knutsen, Jan Atle; Johannessen, Tore; Vøllestad, Leif Asbjørn (Fisken og havet, Research report, 2008)The European eel Anguilla anguilla is found all over Europe and in extremely diverse habitats both in freshwater and saltwater systems. Its life strategy also varies, from catadromous to a strictly marine life cycle. Eels ... -
Contemporary ocean warming and freshwater conditions are related to later sea age at maturity in Atlantic salmon spawning in Norwegian rivers
Villar, Jaime Otero; Jensen, Arne Johan; L'abee-Lund, Jan Henning; Stenseth, Nils Christian; Storvik, Geir Olve; Vøllestad, Leif Asbjørn (Peer reviewed; Journal article, 2012) -
Contemporary ocean warming and freshwater conditions are related to later sea age at maturity in Atlantic salmon spawning in Norwegian rivers
Villar, Jaime Otero; Jensen, Arne Johan; L'abee-Lund, Jan Henning; Stenseth, Nils Christian; Storvik, Geir Olve; Vøllestad, Leif Asbjørn (Peer reviewed; Journal article, 2012) -
Contemporary ocean warming and freshwater conditions contribute to delay the completion of maturation in Atlantic salmon
Otero, Jaime; Jensen, Arne J.; L’Abée-Lund, Jan Henning; Stenseth, Nils Christian; Storvik, Geir; Vøllestad, Leif Asbjørn (ICES CM documents;2010/S:13, Working paper, 2010)The completion of maturation in Atlantic salmon (Salmo salar) depends on environmental conditions that affect both feeding opportunities and growth, which would provide sufficient lipid stores for reproduction. However, ... -
Environmental effects on ocean entry of Atlantic salmon (Salmo salar) smolt across its range of distribution
Otero, Jaime; Antonsson, T.; Armstrong, J.; Arnason, F.; Arnekleiv, J.V.; Baglinière, J.-L.; Caballero, P.; Castro-Santos, T.; Dempson, J. Brian; Erkinaro, Jaakko; Gudjonsson, S.; Horton, G.; Hvidsten, N.A.; Jensen, Arne J.; Jokikokko, E.; Jonsson, I.R.; Kocik, J.F.; L’Abée-Lund, Jan Henning; Lamberg, A.; Letcher, B.H.; Niemelä, Eero; Romakkaniemi, A.; Russell, I.; Stenseth, Nils Christian; Storvik, Geir; Veselov, A.J.; Vøllestad, Leif Asbjørn (ICES CM documents;2010/S:26, Working paper, 2010) -
Factors affecting year-to-year and within river variability of one-sea-winter Atlantic salmon in Norwegian rivers
Otero, Jaime; Jensen, Arne J.; L’Abée-Lund, Jan Henning; Stenseth, Nils Christian; Storvik, Geir; Vøllestad, Leif Asbjørn (ICES CM documents;2009/E:14, Working paper, 2009)Many Atlantic salmon, Salmo salar, populations are decreasing throughout its distributional range due to several factors acting in concert. A number of studies have documented the influence of freshwater and ocean ... -
Genetic population structure of the monogenean parasite Gyrodactylus thymalli and its host European grayling (Thymallus thymallus) in a large Norwegian lake
Pettersen, Ruben Alexander; Junge, Claudia; Østbye, Kjartan; Mo, Tor Atle; Vøllestad, Leif Asbjørn (Peer reviewed; Journal article, 2020)Understanding how populations are structured in space and time is a central question in evolutionary biology. Parasites and their hosts are assumed to evolve together, however, detailed understanding of mechanisms leading ... -
Habitat use and growth of yellow-stage European eel in coastal and freshwater ecosystems in Norway
Rohtla, Mehis; Daverat, Françoise; Arts, Michael T.; Browman, Howard; Parzanini, Camilla; Skiftesvik, Anne Berit; Thorstad, Eva Bonsak; van der Meeren, Terje; Vøllestad, Leif Asbjørn; Durif, Caroline (Peer reviewed; Journal article, 2022)Many anguillid eel species display facultative catadromy. Some eel spend their entire life cycle in marine coastal areas, but the geographical extent of this, especially at the extremes of their distributional ranges, is ... -
Habitat use and growth of yellow-stage European eel in coastal and freshwater ecosystems in Norway
Rohtla, Mehis; Daverat, Françoise; Arts, Michael T.; Browman, Howard; Parzanini, Camilla; Skiftesvik, Anne Berit; Thorstad, Eva Bonsak; van der Meeren, Terje; Vøllestad, Leif Asbjørn; Durif, Caroline (Peer reviewed; Journal article, 2022)Many anguillid eel species display facultative catadromy. Some eel spend their entire life cycle in marine coastal areas, but the geographical extent of this, especially at the extremes of their distributional ranges, is ... -
Harvesting changes mating behaviour in European lobster
Sørdalen, Tonje Knutsen; Halvorsen, Kim Aleksander Tallaksen; Harrison, Hugo B.; Ellis, Charlie D.; Vøllestad, Leif Asbjørn; Knutsen, Halvor; Moland, Even; Olsen, Esben Moland (Journal article; Peer reviewed, 2018)Removing individuals from a wild population can affect the availability of prospective mates and the outcome of competitive interactions, with subsequent effects on mating patterns and sexual selection. Consequently, the ... -
Influence of oceanic factors on Anguilla anguilla (L.) over the twentieth century in coastal habitats of the Skagerrak, southern Norway
Durif, Caroline M.F.; Gjøsæter, Jakob; Vøllestad, Leif Asbjørn (Journal article; Peer reviewed, 2010-08-26)The European eel (Anguilla anguilla L.) is distributed all over Europe, but reproduction takes place in the Atlantic Ocean, in the Sargasso Sea. The population has been undergoing a steady decline since the 1980s. The eel ... -
Life history and demographic determinants of effective/census size ratios as exemplified by brown trout (Salmo trutta)
Serbezov, Dimitar; Jorde, Per Erik; Bernatchez, L; Olsen, Esben Moland; Vøllestad, Leif Asbjørn (Journal article; Peer reviewed, 2012)A number of demographic factors, many of which related to human-driven encroachments, are predicted to decrease the effective population size (Ne) relative to the census population size (N), but these have been little ... -
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 ... -
Magnetic Compass Orientation in the European Eel
Durif, Caroline M.F.; Browman, Howard I.; Phillips, John B.; Skiftesvik, Anne Berit; Vøllestad, Leif Asbjørn; Stockhausen, Hans Hagen (Journal article; Peer reviewed, 2013-03-15)European eel migrate from freshwater or coastal habitats throughout Europe to their spawning grounds in the Sargasso Sea. However, their route (~ 6000 km) and orientation mechanisms are unknown. Several attempts have been ... -
Magnetic Compass Orientation in the European Eel
Durif, Caroline; Browman, Howard; Phillips, John B.; Skiftesvik, Anne Berit; Vøllestad, Leif Asbjørn; Stockhausen, Hagen (Peer reviewed; Journal article, 2013) -
Marine protected areas rescue a sexually selected trait in European lobster
Sørdalen, Tonje Knutsen; Halvorsen, Kim Aleksander Tallaksen; Vøllestad, Leif Asbjørn; Moland, Even; Olsen, Esben Moland (Peer reviewed; Journal article, 2020)Marine protected areas (MPAs) are increasingly implemented worldwide to maintain and restore depleted populations. However, despite our knowledge on the myriad of positive responses to protection, there are few empirical ... -
Marine protected areas rescue a sexually selected trait in European lobster
Sørdalen, Tonje Knutsen; Halvorsen, Kim Aleksander Tallaksen; Vøllestad, Leif Asbjørn; Moland, Even; Olsen, Esben Moland (Peer reviewed; Journal article, 2020)Marine protected areas (MPAs) are increasingly implemented worldwide to maintain and restore depleted populations. However, despite our knowledge on the myriad of positive responses to protection, there are few empirical ... -
Movement patterns of temperate wrasses (Labridae) within a small marine protected area
Halvorsen, Kim Aleksander Tallaksen; Larsen, Torkel; Browman, Howard; Durif, Caroline; Aasen, Nicolai; Vøllestad, Leif Asbjørn; Cresci, Alessandro; Sørdalen, Tonje Knutsen; Bjelland, Reidun Marie; Skiftesvik, Anne Berit (Peer reviewed; Journal article, 2021)The movement patterns of three commercially important wrasse (Labridae) species inside a small marine protected area (~ 0.15 km2) on the west coast of Norway were analysed over a period of 21 months. The mean distance ...