Blar i forfatter "Johansen, Torild"

Viser treff 1-6 av 6

    • Distinct genetic clustering in the weakly differentiated polar cod, Boreogadus saida Lepechin, 1774 from East Siberian Sea to Svalbard 

      Sanchez, Maria Quintela; Bhat, Shripathi; Præbel, Kim; Gordeeva, Natalia; Seljestad, Gaute Wilhelmsen; Hanebrekke, Tanja Lexau; Mateos-Rivera, Alejandro; Vikebø, Frode Bendiksen; Zelenia, Daria; Cheng, Chi-Hing Christina; Johansen, Torild (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-07-03)
      The cold-adapted polar cod Boreogadus saida, a key species in Arctic ecosystems, is vulnerable to global warming and ice retreat. In this study, 1257 individuals sampled in 17 locations within the latitudinal range of 75–81°N from Svalbard to East Siberian Sea were genotyped with a dedicated suite of 116 single-nucleotide polymorphic loci (SNP). The overall pattern of isolation by distance (IBD) ...

    • Genetic differentiation between inshore and offshore populations of northern shrimp (Pandalus borealis) 

      Hansen, Agneta; Westgaard, Jon-Ivar; Søvik, Guldborg; Hanebrekke, Tanja Lexau; Nilssen, Einar Magnus; Jorde, Per Erik; Albretsen, Jon; Johansen, Torild (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-09-20)
      Many marine organisms have a permanent presence both inshore and offshore and spawn in multiple areas, yet their status as separate populations or stocks remain unclear. This is the situation for the northern shrimp (Pandalus borealis) around the Arctic Ocean, which in northern Norway represents an important income for a small-scale coastal fishery and a large-vessel offshore fleet. In Norwegian ...

    • Hierarchical genetic structure in an evolving species complex: Insights from genome wide ddRAD data in Sebastes mentella 

      Saha, Atal; Kent, Matthew Peter; Hauser, Lorenz; Drinan, Daniel P.; Nielsen, Einar E.; Westgaard, Jon-Ivar; Lien, Sigbjørn; Johansen, Torild (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-05-27)
      The diverse biology and ecology of marine organisms may lead to complex patterns of intraspecific diversity for both neutral and adaptive genetic variation. Sebastes mentella displays a particular life-history as livebearers, for which existence of multiple ecotypes has been suspected to complicate the genetic population structure of the species. Double digest restriction-site associated DNA was ...

    • Maximizing sampling efficiency to detect differences in fish community composition using environmental DNA metabarcoding in subarctic fjords 

      Guri, Gledis; Westgaard, Jon-Ivar; Yoccoz, Nigel; Wangensteen, Owen S.; Præbel, Kim; Ray, Jessica Louise; Kelly, Ryan P.; Shelton, Andrew Olaf; Hanebrekke, Tanja Lexau; Johansen, Torild (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-04-14)
      Environmental DNA (eDNA) has gained popularity as a tool for ecosystem biomonitoring and biodiversity assessment. Although much progress has been made regarding laboratory and fieldwork protocols, the issue of sampling efficiency requires further investigation, particularly in three-dimensional marine systems. This study focuses on fish community composition in marine ecosystems and aims to analyze ...

    • Migration patterns of Greenland halibut in the North Atlantic revealed by a compiled mark-recapture dataset 

      Vihtakari, Mikko; Elvarsson, Bjarki Pór; Treble, Margaret; Nogueira, Adriana; Hedges, Kevin; Hussey, Nigel E.; Wheeland, Laura; Roy, Denis; Ofstad, Lise Helen; Hallfredsson, Elvar Halldor; Barkley, Amanda; Estevez-Barcia, Daniel; Nygaard, Rasmus; Healey, Brian; Steingrund, Petur; Johansen, Torild; Albert, Ole Thomas; Boje, Jesper (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-07-18)
      Marine fisheries are often allocated to stocks that reflect pragmatic considerations and may not represent the species’ spatial population structure, increasing the risk of mismanagement and unsustainable harvesting. Here we compile mark–recapture data collected across the North Atlantic to gain insight into the spatial population structure of Greenland halibut (Reinhardtius hippoglossoides), an ...

    • Movement diversity and partial sympatry of coastal and Northeast Arctic cod ecotypes at high latitudes 

      Strøm, John Fredrik; Bøhn, Thomas; Skjæraasen, Jon Egil; Gjelland, Karl Øystein; Karlsen, Ørjan; Johansen, Torild; Hanebrekke, Tanja Lexau; Bjørn, Pål Arne; Olsen, Esben Moland (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-07-24)
      Movement diversity within species represent an important but often neglected, component of biodiversity that affects ecological and genetic interactions, as well as the productivity of exploited systems. By combining individual tracking data from acoustic telemetry with novel genetic analyses, we describe the movement diversity of two Atlantic cod Gadus morhua ecotypes in two high-latitude fjord ...