Browsing Brage IMR by Author "Bogstad, Bjarte"
Now showing items 21-40 of 135
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Capelin distribution in winter 2004-2017: spatiotemporal correlation between density estimates from different sampling methods
Fall, Johanna Jennifer Elisabeth; Bogstad, Bjarte (Fisken og Havet;2019 - 3, Research report, 2019)The winter distribution of Barents Sea capelin is highly dynamic in space and time, as this is the time of year when mature individuals separate from the immatures and start their spawning migration to the Norwegian and ... -
CEC - a VPA for cod in the Barents Sea with cod - cod cannibalism
Skagen, Dankert W.; Bogstad, Bjarte; Mehl, Sigbjørn (Working paper, 1990) -
Changes in the relationship between sea temperature and recruitment of cod, haddock and herring in the Barents Sea
Bogstad, Bjarte; Dingsør, Gjert Endre; Ingvaldsen, Randi; Gjøsæter, Harald (Journal article; Peer reviewed, 2013-06-14)Cod, haddock and herring in the Barents Sea have strongly variable recruitment. For these three stocks, earlier studies have suggested a high correlation between their recruitment and a positive relationship between high ... -
Climate based multi-year predictions of the Barents Sea cod stock.
Årthun, Marius; Bogstad, Bjarte; Daewel, Ute; Keenlyside, Noel; Sandø, Anne Britt; Schrum, Corinna; Ottersen, Geir (Journal article; Peer reviewed, 2018)Predicting fish stock variations on interannual to decadal time scales is one of the major issues in fisheries science and management. Although the field of marine ecological predictions is still in its infancy, it is ... -
Climatic effects filtered through the food web affect the dynamics of Arcto-Norwegian cod
Hjermann, Dag Ø.; Eikeset, Anne Maria; Bogstad, Bjarte; Ottersen, Geir; Stenseth, Nils Christian (ICES CM documents, Working paper, 2005)The world's largest cod stock, the Arcto-Norwegian cod (a.k.a. North-East Arctic cod), is heavily influenced by temperature in two ways: First, cod recruitment tends to be high when Barents Sea temperature in the spawning ... -
A closed life-cycle model for Northeast Arctic cod
Bogstad, Bjarte; Howell, Daniel; Åsnes, Morten Nygaard (ICES CM documents, Working paper, 2004)For Northeast Arctic cod (Gadus morhua), there is much knowledge available concerning the main population dynamics processes (growth, maturation, fecundity, recruitment, natural mortality, fishing mortality). This knowledge ... -
Cod Consume Capelin
Johannesen, Edda; Johansen, Geir Odd; Bogstad, Bjarte; Mehl, Sigbjørn; Tjelmeland, Sigurd; Dolgov, Andrey V. (Working paper, 2006) -
Consumption of juvenile herring (Clupea harengus) by cod (Gadus morhua) in the Barents Sea: a new approach to estimating consumption in piscivorous fish
Johansen, Geir Odd; Bogstad, Bjarte; Mehl, Sigbjørn; Ulltang, Øyvind (Journal article; Peer reviewed, 2004)Consumption of different age groups of juvenile, Norwegian, spring-spawning herring (Clupea harengus) by northeast Arctic cod (Gadus morhua) in the Barents Sea in 1992–1997 is estimated using cod stomach content data. We ... -
The consumption rate of northeast arctic cod - a comparison of gastric evacuation models
Bogstad, Bjarte; Mehl, Sigbjørn (ICES CM documents, Working paper, 1990)The consumption rares in fish are important but also often weak points in multispecies models. In the Barents Sea multispecies model (MULTSPECI, as in many other models, quantltative stomach content data are combined ... -
Current patterns during pelagic stages determine interannual variability in length-at-age of juvenile Arcto-Norwegian cod
Ottersen, Geir; Helle, Kristin; Bogstad, Bjarte (ICES CM documents, Working paper, 2001) -
Daily rations of cod from the Barents Sea
Dolgov, Andrey V.; Yaragina, Natalia A.; Ajiad, Adnan Mosa; Mehl, Sigbjørn; Bogstad, Bjarte (PINRO-IMR Symposium, Conference object, 1992)Diurnal feeding rhythms and daily diets of the North-East Arctic cod were investigated based on data obtained at several stations made in the summer of 1988-1989. A well-pronounced feeding rhythmicity was recorded under ... -
Description of the Norwegian/Russian stomach data set
Bogstad, Bjarte; Mehl, Sigbjørn (Working paper, 1992) -
The diet of North-East Arctic cod 1984-1994
Bogstad, Bjarte; Mehl, Sigbjørn (Working paper, 1995) -
Diets of the Barents Sea cod (Gadus morhua) from the 1930s to 2018
Townhill, Bryony; Holt, Rebecca Emma; Bogstad, Bjarte; Durant, Joël; Pinnegar, John K.; Dolgov, Andrey V.; Yaragina, Natalia A.; Johannesen, Edda; Ottersen, Geir (Peer reviewed; Journal article, 2021)A new dataset on the diet of Atlantic cod in the Barents Sea from the 1930s to the present day has been compiled to produce one of the largest fish diet datasets available globally. Atlantic cod is one of the most ecologically ... -
Diets of the Barents Sea cod (Gadus morhua) from the 1930s to 2018
Townhill, Bryony; Holt, Rebecca Emma; Bogstad, Bjarte; Durant, Jo l M.; Pinnegar, John K.; Dolgov, Andrey V.; Yaragina, Natalia A.; Johannesen, Edda; Ottersen, Geir (Peer reviewed; Journal article, 2021)A new dataset on the diet of Atlantic cod in the Barents Sea from the 1930s to the present day has been compiled to produce one of the largest fish diet datasets available globally. Atlantic cod is one of the most ecologically ... -
Distribution of rorquals and Atlantic cod in relation to their prey in the Norwegian high Arctic
Solvang, Hiroko K.; Haug, Tore; Knutsen, Tor; Gjøsæter, Harald; Bogstad, Bjarte; Hartvedt, Siri; Øien, Nils; Lindstrøm, Ulf (Peer reviewed; Journal article, 2021)Recent warming in the Barents Sea has led to changes in the spatial distribution of both zooplankton and fish, with boreal communities expanding northwards. A similar northward expansion has been observed in several rorqual ... -
Do abiotic mechanisms determine interannual variability in length-at-age of juvenile Arcto-Norwegian cod?
Ottersen, Geir; Helle, Kristin; Bogstad, Bjarte (Journal article; Peer reviewed, 2002)For the large Arcto-Norwegian stock of cod (Gadus morhua L.) in the Barents Sea, year-to-year variability in growth is well documented. Here three hypotheses for the observed inverse relation between abundance and the mean ... -
Estimation of predation mortalities on capelin using a cod - capelin model for the Barents Sea
Bogstad, Bjarte; Tjelmeland, Sigurd (ICES CM Documents;1990/H:16, Working paper, 1990)The Barents Sea capelin stock collapsed during the period 1983-1986. One of the main factors causing the collapse was a rapid increase in consumption of capelin by cod. Based on measurements of stomach evacuation rates ... -
Evaluation of candidate management plans, with reference to North-East Arctic Cod
Skagen, Dankert W.; Bogstad, Bjarte; Sandberg, Per; Røttingen, Ingolf (ICES CM documents, Working paper, 2003)We here discuss the scope, nature and quality standards of simulation models that may be used in order to evaluate proposed or candidate management plans, including their parameters (reference points). A recently proposed ... -
Evaluation of maximum long-term yield for northeast Arctic cod
Kovalev, Yuri; Bogstad, Bjarte (IMR/PINRO Joint Report Series, Conference object, 2005)