• Alien plants, animals, fungi and algae in Norway: an inventory of neobiota 

      Sandvik, Hanno; Dolmen, Dag; Elven, Reidar; Falkenhaug, Tone; Forsgren, Elisabet; Hansen, Haakon; Hassel, Kristian; Husa, Vivian; Kjærstad, Gaute; Ødegaard, Frode; Pedersen, Hans Christian; Solheim, Halvor; Stokke, Bård Gunnar; Åsen, Per Arvid; Åström, Sandra Charlotte Helene; Brandrud, Tor Erik; Elven, Hallvard; Endrestøl, Anders; Finstad, Anders Gravbrøt; Fredriksen, Stein; Gammelmo, Øivind; Gjershaug, Jan Ove; Gulliksen, Bjørn; Hamnes, Inger Sofie; Hatteland, Bjørn Arild; Hegre, Hanne; Hesthagen, Trygve H.; Jelmert, Anders; Jensen, Thomas Correll; Johnsen, Stein Ivar; Karlsbakk, Egil; Magnusson, Christer; Nedreaas, Kjell Harald; Nordén, Björn; Oug, Eivind; Pedersen, Oddvar; Pedersen, Per Anker; Sjøtun, Kjersti; Skei, Jon Kristian; Solstad, Heidi; Sundheim, Leif; Swenson, Jon; Syvertsen, Per Ole; Talgø, Venche; Vandvik, Vigdis; Westergaard, Kristine Bakke; Wienerroither, Rupert; Ytrehus, Bjørnar; Hilmo, Olga; Henriksen, Snorre; Gederaas, Lisbeth (Journal article; Peer reviewed, 2019)
      We present the results of an inventory and status assessment of alien species in Norway. The inventory covered all known multicellular neobiota, 2496 in total, 1039 of which were classified as naturalised. The latter ...
    • Alien species and the Water Framework Directive: Recommendations for assessing ecological status in fresh waters in Norway 

      Sandvik, Hanno; Taugbøl, Annette; Bærum, Kim Magnus; Hesthagen, Trygve H.; Jensen, Thomas Correll; Johnsen, Stein Ivar; Sandlund, Odd Terje; Schartau, Ann Kristin (Peer reviewed; Journal article, 2022)
      1. Invasive alien species are recognized as a significant anthropogenic threat to freshwater ecosystems, because they may bring about the local extinction of native species and the collapse of habitat types of special ...
    • Alien species in Norway: results from quantitative ecological impact assessments 

      Sandvik, Hanno; Hilmo, Olga; Henriksen, Snorre; Elven, Reidar; Åsen, Per Arvid; Hegre, Hanne; Pedersen, Oddvar; Pedersen, Per Anker; Solstad, Heidi; Vandvik, Vigdis; Westergaard, Kristine Bakke; Ødegaard, Frode; Åström, Sandra Charlotte Helene; Elven, Hallvard; Endrestøl, Anders; Gammelmo, Øivind; Hatteland, Bjørn Arild; Solheim, Halvor; Nordén, Björn; Sundheim, Leif; Talgø, Venche; Falkenhaug, Tone; Gulliksen, Bjørn; Jelmert, Anders; Oug, Eivind; Sundet, Jan Henry; Forsgren, Elisabet; Finstad, Anders Gravbrøt; Hesthagen, Trygve H.; Nedreaas, Kjell Harald; Wienerroither, Rupert; Husa, Vivian; Fredriksen, Stein; Sjøtun, Kjersti; Steen, Henning; Hansen, Haakon; Hamnes, Inger Sofie; Karlsbakk, Egil; Magnusson, Christer; Ytrehus, Bjørnar; Pedersen, Hans Christian; Swenson, Jon; Syvertsen, Per Ole; Stokke, Bård Gunnar; Gjershaug, Jan Ove; Dolmen, Dag; Kjærstad, Gaute; Johnsen, Stein Ivar; Jensen, Thomas Correll; Hassel, Kristian; Gederaas, Lisbeth (Journal article, 2020)
      1. Due to globalisation, trade and transport, the spread of alien species is increasing dramatically. Some alien species become ecologically harmful by threatening native biota. This can lead to irreversible changes in ...
    • Biocide Treatment of Invasive Signal Crayfish: Successes, Failures and Lessons Learned 

      Peay, Stephanie; Johnsen, Stein Ivar; Bean, Colin W.; Dunn, Alison M.; Sandodden, Roar; Edsman, Lennart (Journal article; Peer reviewed, 2019)
      Signal crayfish, as an invasive alien species in Europe, have caused impacts on aquatic communities and losses of native crayfish. Eradication of recently established populations may be possible in small ponds (<2.5 ha) ...
    • Effect of mesh size on baited trap catch composition for noble crayfish (Astacus Astacus) 

      Johnsen, Stein Ivar; Skurdal, Jostein; Taugbøl, Trond; Garnås, Erik (Peer reviewed; Journal article, 2014)
      Minimum size is a common management regulation in noble crayfish (Astacus astacus) fisheries. The most used catching method baited traps, catch crayfish down to 50 mm total length (TL). In Norway the minimum size is 95 mm ...
    • Environmental DNA (eDNA) Monitoring of Noble Crayfish Astacus astacus in Lentic Environments Offers Reliable Presence-Absence Surveillance – But Fails to Predict Population Density 

      Johnsen, Stein Ivar; Strand, David; Rusch, Johannes; Vrålstad, Trude (Peer reviewed; Journal article, 2020)
      Noble crayfish is the most widespread native freshwater crayfish species in Europe. It is threatened in its entire distribution range and listed on the International Union for Concervation Nature- and national red lists. ...
    • Holder fisketrappene mål i forhold til Vannforskriften? 

      Kraabøl, Morten; Museth, Jon; Skurdal, Jostein; Johnsen, Stein Ivar (Journal article; Peer reviewed, 2012)
    • Hva om Hunderørret var laks 

      Kraabøl, Morten; Johnsen, Stein Ivar; Forseth, Torbjørn; Museth, Jon; Skurdal, Jostein (Peer reviewed; Journal article, 2012)
      Storørret defineres som en selvreproduserende stamme med regulær forekomst av store fiskespisende individer, ofte med et nisjeskift og markert vekstomslag ved overgangen til fiskediett. Den mest kjente storørretstammen her ...
    • Introduced European smelt (Osmerus eperlanus) affects food web and fish community in a large Norwegian lake 

      Eloranta, Antti; Johnsen, Stein Ivar; Power, Michael; Bærum, Kim Magnus; Sandlund, Odd Terje; Finstad, Anders Gravbrøt; Rognerud, Sigurd; Museth, Jon (Journal article; Peer reviewed, 2018)
      Invasive and introduced fishes can affect recipient ecosystems and native species via altered competitive and predatory interactions, potentially leading to top-down and bottom-up cascading impacts. Here, we describe a ...
    • Movement patterns of juvenile and adult noble crayfish (Astacus astacus) in a small stream, determined by radiotelemetry 

      Daněk, Tomáš; Musil, Jiří; Vlašánek, Petr; Svobodová, Jitka; Barteková, Tereza; Štrunc, David; Barankiewicz, Miroslav; Bouše, Eduard; Svobodová, Eva; Johnsen, Stein Ivar; Andersen, Oddgeir (Peer reviewed; Journal article, 2019)
      This article reports on the results of the first radiotelemetric field study comparing the movement patterns of juvenile and adult noble crayfish (Astacus astacus) over the 24-h cycle. During our study (in summer, outside ...
    • Overvåking av fiskesamfunn i store vassdrag etter vannforskriften 

      Museth, Jon; Johnsen, Stein Ivar; Kraabøl, Morten; Dokk, John Gunnar; Skurdal, Jostein (Journal article; Peer reviewed, 2013)
      Vannforskriften skal sikre en mer helhetlig og økosystembasert vannforvaltning i Norge, og om nødvendig iverksette forebyggende eller forbedrende miljøtiltak for å sikre miljøtilstanden i ferskvann, grunnvann og kystvann. ...