Blar i Articles på forfatter "Knutsen, Halvor"
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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 ... -
Highly mixed impacts of near-future climate change on stock productivity proxies in the North East Atlantic
Kjesbu, Olav Sigurd; Sundby, Svein; Sandø, Anne Britt; Alix, Maud; Hjøllo, Solfrid Sætre; Tiedemann, Maik; Skern-Mauritzen, Mette; Junge, Claudia; Fossheim, Maria; Broms, Cecilie; Søvik, Guldborg; Zimmermann, Fabian; Nedreaas, Kjell Harald; Eriksen, Elena; Höffle, Hannes; Hjelset, Ann Merete; Kvamme, Cecilie; Reecht, Yves; Knutsen, Halvor; Aglen, Asgeir; Albert, Ole Thomas; Berg, Erik; Bogstad, Bjarte; Durif, Caroline; Halvorsen, Kim Aleksander Tallaksen; Høines, Åge Sigurd; Hvingel, Carsten; Johannesen, Edda; Johnsen, Espen; Moland, Even; Myksvoll, Mari Skuggedal; Nøttestad, Leif; Olsen, Erik Joel Steinar; Skaret, Georg; Skjæraasen, Jon Egil; Slotte, Aril; Staby, Arved; Stenevik, Erling Kåre; Stiansen, Jan Erik; Stiasny, Martina H.; Sundet, Jan Henry; Vikebø, Frode Bendiksen; Huse, Geir (Peer reviewed; Journal article, 2021)Impacts of climate change on ocean productivity sustaining world fisheries are predominantly negative but vary greatly among regions. We assessed how 39 fisheries resources—ranging from data-poor to data-rich stocks—in the ... -
Inferring genetic connectivity in real populations, exemplified by coastal and oceanic atlantic cod
Spies, Ingrid; Hauser, Lorenz; Jorde, Per Erik; Knutsen, Halvor; Punt, André E.; Rogers, Lauren; Stenseth, Nils Christian (Journal article; Peer reviewed, 2018)Genetic data are commonly used to estimate connectivity between putative populations, but translating them to demographic dispersal rates is complicated. Theoretical equations that infer a migration rate based on the genetic ... -
Inferring genetic connectivity in real populations, exemplified by coastal and oceanic Atlantic cod
Spies, Ingrid; Hauser, Lorenz; Jorde, Per Erik; Knutsen, Halvor; Punt, André E.; Rogers, Lauren; Stenseth, Nils Christian (Journal article; Peer reviewed, 2018)Genetic data are commonly used to estimate connectivity between putative populations, but translating them to demographic dispersal rates is complicated. Theoretical equations that infer a migration rate based on the genetic ... -
"Islands of divergence" in the Atlantic cod genome represent polymorphic chromosomal rearrangements
Sodeland, Marte; Jorde, Per Erik; Lien, Sigbjørn; Jentoft, Sissel; Berg, Paul Ragnar; Grove, Harald; Kent, Matthew Peter; Arnyasi, Mariann; Olsen, Esben Moland; Knutsen, Halvor (Peer reviewed; Journal article, 2016) -
"Islands of divergence" in the Atlantic cod genome represent polymorphic chromosomal rearrangements
Sodeland, Marte; Jorde, Per Erik; Lien, Sigbjørn; Jentoft, Sissel; Berg, Paul Ragnar; Grove, Harald; Kent, Matthew Peter; Arnyasi, Mariann; Olsen, Esben Moland; Knutsen, Halvor (Journal article; Peer reviewed, 2016-03-15)In several species genetic differentiation across environmental gradients or between geographically separate populations has been reported to center at “genomic islands of divergence,” resulting in heterogeneous differentiation ... -
Lobster reserves as a management tool in coastal waters: Two decades of experience in Norway
Knutsen, Jan Atle; Kleiven, Alf Ring; Olsen, Esben Moland; Knutsen, Halvor; Espeland, Sigurd Heiberg; Sørdalen, Tonje Knutsen; Thorbjørnsen, Susanna Huneide; Hutchings, Jeffrey; Chacon, Albert Fernandez; Huserbråten, Mats Brockstedt Olsen; Villegas-Ríos, David; Halvorsen, Kim Aleksander Tallaksen; Kleiven, Portia Joy Nillos; Langeland, Thomas Kiland; Moland, Even (Peer reviewed; Journal article, 2022)The positive effects of reduced fishing pressure in marine protected areas (MPAs) are now well documented globally. Yet, evidence of MPA benefits from long-term replicated before-after control-impact (BACI) studies and ... -
Local cod (Gadus morhua) revealed by egg surveys and population genetic analysis after longstanding depletion on the Swedish Skagerrak coast
Svedang, Hendrik; Barth, Julia Maria Isis; Svenson, Anders; Jonsson, Patrik; Jentoft, Sissel; Knutsen, Halvor; Andre, Carl (Journal article; Peer reviewed, 2018)Dramatic and persistent reductions in Atlantic cod (Gadus morhua) are common in many coastal areas. While offshore cod stocks still were abundant and productive, the Swedish west coast showed signs of diminishing adult cod ... -
Local recruitment of Atlantic cod and putative source spawning areas in a coastal seascape
Synnes, Ann-Elin; Huserbråten, Mats Brockstedt Olsen; Knutsen, Halvor; Jorde, Per Erik; Sodeland, Marte; Moland, Even (Peer reviewed; Journal article, 2021)Increased knowledge on connectivity is crucial to our understanding of the population dynamics, genetic structure, and biogeography of many coastal species. In coastal marine populations, the main factor for structuring ... -
Mapping Biological Resources in the Coastal Zone: An Evaluation of Methods in a Pioneering Study from Norway
Knutsen, Jan Atle; Knutsen, Halvor; Rinde, Eli; Christie, Hartvig; Bodvin, Torjan (Journal article; Peer reviewed, 2010)For many years, the planning and management 8 of terrestrial areas has been supported by a detailed 9 knowledge of the distribution of habitats and their associ- 10 ated species. However, the detailed mapping of biological ... -
Mixed origin of juvenile Atlantic cod (Gadus morhua) along the Swedish west coast
Henriksson, Simon; Pereyra, Ricardo; Sodeland, Marte; Ortega-Martinez, Olga; Knutsen, Halvor; Wennhage, Håkan; Andre, Carl (Peer reviewed; Journal article, 2022)Cryptic population structure in exploited fishes poses a major challenge for fisheries management. In Atlantic cod, sympatric ecotypes are well-known, for instance off the coast of northern Norway. Recently, two sympatric ... -
New perspectives on fish movement: kernel and GAM smoothers applied to a century of tagging data on coastal Atlantic cod
Espeland, Sigurd Heiberg; Olsen, Esben Moland; Knutsen, Halvor; Gjøsæter, Jakob; Danielssen, Didrik S.; Stenseth, Nils Christian (Journal article; Peer reviewed, 2008-12-09)Tagging–recovery studies have been used successfully on many occasions, and the data analysed in a variety of ways with respect to fish movement. Here we provide a synoptic account of useful statistical techniques for ... -
Northern refugia and recent expansion in the North Sea: the case of the wrasse Symphodus melops (Linnaeus, 1758)
Robalo, Joana I.; Castilho, Rita; Francisco, Sara M.; Almada, Frederico; Knutsen, Halvor; Jorde, Per Erik; Pereira, Ana M.; Almada, Vitor C. (Peer reviewed; Journal article, 2012) -
Not that clean: Aquaculture-mediated translocation of cleaner fish has led to hybridization on the northern edge of the species' range
Faust, Ellika; Jansson, Eeva; André, Carl; Halvorsen, Kim Aleksander Tallaksen; Dahle, Geir; Knutsen, Halvor; Sanchez, Maria Quintela; Glover, Kevin Alan (Peer reviewed; Journal article, 2021)Translocation and introduction of non-native organisms can have major impacts on local populations and ecosystems. Nevertheless, translocations are common practices in agri- and aquaculture. Each year, millions of wild-caught ... -
Population genetic structure in a deepwater fish Coryphaenoides rupestris: patterns and processes
Knutsen, Halvor; Jorde, Per Erik; Bergstad, Odd Aksel; Skogen, Morten D. (Journal article; Peer reviewed, 2012-07-24)We observed significant genetic structure in a widely distributed North Atlantic demersal deepwater fish, the roundnose grenadier Coryphaenoides rupestris (Pisces: Macro - uridae). The overall estimate of genetic ... -
Population structure and connectivity in the genus Molva in the Northeast Atlantic
McGill, L.; McDevitt, A.D.; Hellemans, B.; Neat, F.; Knutsen, Halvor; Mariani, S.; Christiansen, Henrik; Johansen, Torild; Volckaert, F.A.M.; Coscia, I. (Peer reviewed; Journal article, 2023)In fisheries, operational management units and biological data often do not coincide. In many cases, this is not even known due to the lack of information about a species’ population structure or behaviour. This study ... -
Population structure in Atlantic cod in the eastern North Sea-Skagerrak-Kattegat: early life stage dispersal and adult migration
André, Carl; Svedang, Hendrik; Knutsen, Halvor; Dahle, Geir; Jonsson, Patrik; Ring, Anna-Karin; Sköld, Mattias; Jorde, Per Erik (Journal article; Peer reviewed, 2016-02-03) -
Possible adverse impact of contaminants on Atlantic cod population dynamics in coastal ecosystems
Ono, Kotaro; Knutsen, Halvor; Olsen, Esben Moland; Ruus, Anders; Hjermann, Dag Øystein; Stenseth, Nils Christian (Journal article; Peer reviewed, 2019)While many in-laboratory ecotoxicological studies have shown the adverse impact of pollutants to the fitness of an individual, direct evidence from the field on the population dynamics of wildlife animals has been lacking. ... -
Potential of a no‐take marine reserve to protect home ranges of anadromous brown trout (Salmo trutta)
Thorbjørnsen, Susanna Huneide; Moland, Even; Simpfendorfer, Colin A.; Heupel, Michelle R.; Knutsen, Halvor; Olsen, Esben Moland (Journal article; Peer reviewed, 2018)The extent to which no‐take marine reserves can benefit anadromous species requires examination. Here, we used acoustic telemetry to investigate the spatial behavior of anadromous brown trout (sea trout, Salmo trutta) in ... -
Rapid polymerase chain reaction–restriction fragment length polymorphism method for discrimination of the two Atlantic cryptic deep-sea species of scabbardfish
Stefanni, Sergio; Bettencourt, Raul; Knutsen, Halvor; Menezes, Gui (Journal article; Peer reviewed, 2009-03)The present investigation provides an efficient diagnostic method based on polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) analysis to discriminate between two cryptic species of scabbardfish, ...