Blar i Articles på forfatter "Aanes, Sondre"

Viser treff 1-15 av 15

    • Age-dependent patterns of spatial autocorrelation in fish populations 

      Marquez, Jonatan; Sæther, Bernt-Erik; Aanes, Sondre; Engen, Steinar; Salthaug, Are; Lee, Aline Magdalena (Peer reviewed; Journal article, 2021)
      The degree of spatial autocorrelation in population fluctuations increases with dispersal and geographical covariation in the environment, and decreases with strength of density dependence. Because the effects of these ...

    • Catchability and the spatial distribution of fishing vessels 

      Salthaug, Are; Aanes, Sondre (Journal article; Peer reviewed, 2003)
      A central problem when using commercial catch per unit effort (CPUE) as an index of fish stock abundance is that fishing vessels search for concentrations of fish. For a given stock abundance, CPUE may become high if ...

    • Caveats with estimating natural mortality rates in stock assessment models using age aggregated catch data and abundance indices 

      Aldrin, Magne Tommy; Aanes, Fredrik L; Tvete, Ingunn Fride; Aanes, Sondre; Subbey, Samuel (Peer reviewed; Journal article, 2021)
      We consider the challenge in estimating the natural mortality, M, in a standard statistical fish stock assessment model based on time series of catch- and abundance-at-age data. Though anecdotal evidence and empirical ...

    • Cod, haddock, saithe, herring, and capelin in the Barents Sea and adjacent waters: a review of the biological value of the area 

      Olsen, Erik; Aanes, Sondre; Mehl, Sigbjørn; Holst, Jens Christian; Aglen, Asgeir; Gjøsæter, Harald (Journal article; Peer reviewed, 2009-10-09)
      Cod, haddock, saithe, herring, and capelin are the most important fish species in the Barents Sea and adjacent waters. Ecosystem-based management requires species-specific knowledge of the biological value and vulnerability ...

    • Effects of local density dependence and temperature on the spatial synchrony of marine fish populations 

      Marquez, Jonatan; Herfindal, Ivar; Sæther, Bernt-Erik; Aanes, Sondre; Salthaug, Are; Lee, Aline Magdalena (Peer reviewed; Journal article, 2023)
      Disentangling empirically the many processes affecting spatial population synchrony is a challenge in population ecology. Two processes that could have major effects on the spatial synchrony of wild population dynamics are ...

    • Estimating catch-at-age by combining data from different sources 

      Hirst, David; Storvik, Geir; Aldrin, Magne; Aanes, Sondre; Huseby, Ragnar Bang (Journal article; Peer reviewed, 2005)
      Estimating the catch-at-age of commercial fish species is an important part of the quota-setting process for many different species and almost all countries with a fishing fleet. Current procedures are usually very ...

    • Estimation of the parameters of fish stock dynamics from catch-at-age data and indices of abundance: can natural and fishing mortality be separated? 

      Aanes, Sondre; Engen, Steinar; Sæther, Bernt-Erik; Aanes, Ronny (Journal article; Peer reviewed, 2007)
      Models for fluctuations in size of fish stocks must include parameters that describe expected dynamics, as well as stochastic influences. In addition, reliable population projections also require assessments about the ...

    • Evaluation of sampling strategies for age determination of cod (Gadus morhua) sampled at the North Sea International Bottom Trawl Survey 

      Jourdain, Natoya; Breivik, Olav Nikolai; Fuglebakk, Edvin; Aanes, Sondre; Vølstad, Jon Helge (Peer reviewed; Journal article, 2020)
      The North Sea cod stock assessment is based on indices of abundance-at-age from fishery-independent bottom trawl surveys. The age structure of the catch is estimated by sampling fish for otoliths collection in a length-stratified ...

    • Improving management decisions by predicting fish bycatch in the Barents Sea shrimp fishery 

      Aldrin, Magne; Mortensen, Bjørnar; Storvik, Geir; Nedreaas, Kjell Harald; Aglen, Asgeir; Aanes, Sondre (Journal article; Peer reviewed, 2011-11-20)
      When the bycatch of juvenile fish within the Barents Sea shrimp fishery is too large, the area is closed to fishing for a certain period. Bycatch is estimated from sampled trawl hauls, for which the shrimp yield is recorded, ...

    • Predicting density-dependent somatic growth in Norwegian spring-spawning herring 

      Stenevik, Erling Kåre; Hølleland, Sondre Nedreås; Enberg, Katja; Høines, Åge Sigurd; Salthaug, Are; Slotte, Aril; Vatnehol, Sindre; Aanes, Sondre (Peer reviewed; Journal article, 2022)
      Density-dependent growth, which might influence the effects of fisheries on a population, is often ignored when management strategies are evaluated, mainly due to a lack of appropriate models readily available to be ...

    • Predicting density-dependent somatic growth in Norwegian spring-spawning herring 

      Stenevik, Erling Kåre; Hølleland, Sondre Nedreås; Enberg, Katja; Høines, Åge Sigurd; Slotte, Aril; Salthaug, Are; Vatnehol, Sindre; Aanes, Sondre (Peer reviewed; Journal article, 2022)
      Density-dependent growth, which might influence the effects of fisheries on a population, is often ignored when management strategies are evaluated, mainly due to a lack of appropriate models readily available to be ...

    • Spatial scaling of population synchrony in marine fish depends on their life history 

      Fredricson Marquez, Jonatan; Lee, Aline Magdalena; Aanes, Sondre; Engen, Steinar; Herfindal, Ivar; Salthaug, Are; Sæther, Bernt-Erik (Peer reviewed; Journal article, 2019)
      The synchrony of population dynamics in space has important implications for ecological processes, for example affecting the spread of diseases, spatial distributions and risk of extinction. Here, we studied the relationship ...

    • Spatiotemporal variation in climatic conditions across ecosystems 

      Herfindal, Ivar; Aanes, Sondre; Benestad, Rasmus; Finstad, Anders Gravbrøt; Salthaug, Are; Stenseth, Nils Christian; Sæther, Bernt-Erik (Peer reviewed; Journal article, 2021)
      Environmental variation in time and space affects biological processes such as extinction risk and speed of adaptation to environmental change. The spatial structure of environmental variation may vary among ecosystems, ...

    • Spatiotemporal variation in climatic conditions across ecosystems 

      Herfindal, Ivar; Aanes, Sondre; Benestad, Rasmus; Finstad, Anders Gravbrøt; Salthaug, Are; Stenseth, Nils Christian; Sæther, Bernt-Erik (Peer reviewed; Journal article, 2021)
      Environmental variation in time and space affects biological processes such as extinction risk and speed of adaptation to environmental change. The spatial structure of environmental variation may vary among ecosystems, ...

    • The specification of the data model part in the SAM model matters 

      Aldrin, Magne Tommy; Tvete, Ingunn Fride; Aanes, Sondre; Subbey, Samuel (Peer reviewed; Journal article, 2020)
      This paper considers a general state-space stock assessment modeling framework that integrates a population model for a fish stock and a data model. This way observed data are linked to unobserved quantities in the population ...