Blar i forfatter "Sandlund, Odd Terje"

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    • Contrasting Population and Life History Responses of a Young Morph-Pair of European Whitefish to the Invasion of a Specialised Coregonid Competitor, Vendace 

      Sandlund, Odd Terje; Gjelland, Karl Øystein; Bøhn, Thomas; Knudsen, Rune; Amundsen, Per-Arne (Journal article; Tidsskriftartikkel; Peer reviewed, 2013)
      Invasions of non-native species represent a global problem of great scientific interest. Here we study in detail the response in population and life history characteristics of closely related native species, with divergent habitat preferences, that are impacted by an invading species over a sufficient time period to allow a new stable state to become established. A time series of 20 years starting ...

    • Effects of water level regulation in alpine hydropower reservoirs: an ecosystem perspective with a special emphasis on fish 

      Hirsch, Philipp E.; Eloranta, Antti; Amundsen, Per-Arne; Brabrand, Åge; Charmasson, Julie; Helland, Ingeborg Palm; Power, Michael John; Sanchez-Hernandez, Javier; Sandlund, Odd Terje; Sauterleute, Julian Friedrich; Skoglund, Sigrid Østrem; Ugedal, Ola; Yang, Hong (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-02-04)
      Sustainable development of hydropower demands a holistic view of potential impacts of water level regulation (WLR) on reservoir ecosystems. Most environmental studies of hydropower have focused on rivers, whereas environmental effects of hydropower operations on reservoirs are less well understood. Here, we synthesize knowledge on how WLR from hydropower affects alpine lake ecosystems and highlight ...

    • Forsøk med trål og ekkolodd i Mjøsa, 2012 

      Gjelland, Karl Øystein; Rustadbakken, Atle; Haugen, Thrond O; Sandlund, Odd Terje (Research report; Forskningsrapport, 2013)
      Trål har i liten grad vore brukt ved undersøkingar av fiskesamfunn i norske innsjøar. Gjennom innføringa av Vanndirektivet har Norge forplikta seg til meir regulær oppfølging av den økologiske tilstanden i større vassførekomstar. Tettleik, rekruttering, artsfordeling og vekst hjå fisk er alle parametrar der ein kan forvente relativt rask respons på miljøendringar. Det er derfor viktig å ha ...

    • Growth of invasive pink salmon (Oncorhynchus gorbuscha) at sea assessed by scale analysis 

      Paulsen, Tora; Sandlund, Odd Terje; Østborg, Gunnel Marie; Thorstad, Eva Bonsak; Fiske, Peder; Muladal, Rune; Tronstad, Stig (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-11-01)
      Invasive pink salmon (Oncorhynchus gorbuscha) has been present in variable, but low, numbers in Norwegian waters since c. 1960, but beginning in 2017 their numbers have exploded in rivers in northern Norway, with considerable numbers also recorded in rivers in southern Norway and other countries bordering the North Atlantic. Analysis of pink salmon scales from two rivers draining to the western ...

    • Introduction of Mysis relicta (Mysida) reduces niche segregation between deep-water Arctic charr morphs 

      Knudsen, Rune; Eloranta, Antti; Siwertsson, Anna; Paterson, Rachel A.; Power, Michael; Sandlund, Odd Terje (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-04-26)
      Niche diversification of polymorphic Arctic charr can be altered by multiple anthropogenic stressors. The opossum-shrimp (<i>Mysis relicta</i>) was introduced to compensate for reduced food resources for fish following hydropower operations in Lake Limingen, central Norway. Based on habitat use, stomach contents, stable isotopes (δ<sup>13</sup>C, δ<sup>15</sup>N) and trophically transmitted parasites, ...

    • Invader population speeds up life history during colonization 

      Amundsen, Per-Arne; Salonen, Erno; Niva, Teuvo; Gjelland, Karl Øystein; Præbel, Kim; Sandlund, Odd Terje; Knudsen, Rune; Bøhn, Thomas (Journal article; Tidsskriftartikkel; Peer reviewed, 2012)
      We explore the long-term developments in population biology and life history during the invasion and establishment of the fish species vendace Coregonus albula in a subarctic watercourse by comparing life-history traits and molecular genetic estimates between the source and the colonist population. The two populations exhibited highly contrasting life-history strategies. Relative to the source ...

    • On the numerous concepts in invasion biology 

      Falk-Petersen, Jannike; Bøhn, Thomas; Sandlund, Odd Terje (Journal article; Tidsskriftartikkel; Peer reviewed, 2006-01-20)
      The study of biological invasions has triggered the production of a diversity of concepts. The terminology has, however, often been applied inconsistently and inaccurately. This article lists and assesses the most commonly used terms and concepts in invasion ecology. In each case the most coherent definition and use is suggested.

    • Rapidly changing life history during invasion 

      Bøhn, Thomas; Sandlund, Odd Terje; Amundsen, Per-Arne; Primicerio, Raul (Journal article; Tidsskriftartikkel; Peer reviewed, 2004-05-17)
      The fish species vendace (<i>Coregonus albula</i>) invaded the sub‐arctic Pasvik watercourse during the second half of the 1980s, and became the dominant pelagic species in the upstream part of the watercourse within a few years. Life history traits of the pioneer population of vendace in Pasvik were recorded from 1991–2000. A rapid increase in population density in the upstream part of the watercourse ...

    • Status for småblankbestanden i Namsen 

      Thorstad, Eva Bonsak; Hindar, Kjetil; Berg, Ole Kristian; Saksgård, Laila M.; Norum, Ine Cecilie Jordalen; Sandlund, Odd Terje; Hesthagen, Trygve H.; Lehn, Lars Ove (Research report; Forskningsrapport, 2009-01)
      Småblanken, som finnes kun i Namsenvassdraget, er den eneste bestanden av ferskvannsstasjonær laks i Europa som lever hele livet i elva og ikke har vandringer til innsjøer. Her utredes status for bestanden basert på 1) oppsummering kjent kunnskap, 2) materiale samlet inn ved overvåking i 2007-2008 (el-fiske på 17 stasjoner og garnfiske på 13 stasjoner), 3) noe tilleggs-materiale samlet inn i ...

    • Ørekyt i Namsenvassdraget. Utbredelse, spredningsrisiko og tiltak 

      Thorstad, Eva Bonsak; Sandlund, Odd Terje; Heggberget, Tor Gravråk; Finstad, Anders Gravbrøt; Museth, Jon; Berger, Hans Mack; Hesthagen, Trygve H.; Berg, Ole Kristian (Research report; Forskningsrapport, 2006-04)
      Undersøkelser i Namsenvassdraget i 2005 viste at ørekyt forekommer i tette bestander i innsjøer og flyer øverst i vassdraget. I Otersjøen øverst i Sanddøla har ørekyt forekommet i solide bestander siden 1960-tallet. I Tunnsjøen og i Namsvatnet ble arten først registrert på 1990-tallet. Kartleggingen i 2005 viste at ørekyt hadde spredt seg fra Tunnsjøen til Tunnsjøflyan, men ikke videre ned ...