Blar i Brage IMR på forfatter "Fiksen, Øyvind"
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Body size adaptions under climate change: Zooplankton community more important than temperature or food abundance in model of a zooplanktivorous fish
Ljungström, Anna Jeja Gabriella; Claireaux, Marion; Fiksen, Øyvind; Jørgensen, Christian (Peer reviewed; Journal article, 2020)One of the most well-studied biogeographic patterns is increasing body size with latitude, and recent body size declines in marine and terrestrial organisms have received growing attention. Spatial and temporal variation ... -
Caught in broad daylight: Topographic constraints of zooplankton depth distributions
Aarflot, Johanna Myrseth; Aksnes, Dag Lorents; Opdal, Anders Frugård; Skjoldal, Hein Rune; Fiksen, Øyvind (Journal article; Peer reviewed, 2018)For visual predators, sufficient light is critical for prey detection and capture. Because light decays exponentially with depth in aquatic systems, vertical movement has become a widespread strategy among zooplankton for ... -
Coastal water darkening and implications for mesopelagic regime shifts in Norwegian fjords
Aksnes, Dag Lorents; Dupont, Nicolas; Staby, Arved; Fiksen, Øyvind; Kaartvedt, Stein; Aure, Jan (Journal article; Peer reviewed, 2009-07-28)The light regime of the water column has a strong structuring effect on aquatic food webs and it has been previously hypothesized that coastal water darkening has increased the success of tactile predators relative to ... -
Diel vertical movements determine spatial interactions between cod, pelagic fish and krill on an Arctic shelf bank
Skaret, Georg; Johansen, Geir Odd; Johnsen, Espen; Fall, Johanna Jennifer Elisabeth; Fiksen, Øyvind; Englund, Gøran; Fauchald, Per; Gjøsæter, Harald; Macaulay, Gavin; Johannesen, Edda (Peer reviewed; Journal article, 2020)Predator-prey spatial interactions are essential to understand ecosystem processes like predation rates and trophic interaction strength. In marine systems, such spatial interactions are highly dynamic and difficult to ... -
Do accurate stock estimates increase harvest and reduce variability in fisheries yields?
Myrseth, Johanna; Enberg, Katja; Heino, Mikko; Fiksen, Øyvind (Journal article; Peer reviewed, 2011-03-22)Fisheries managers normally make decisions based on stock abundance estimates subject to process, observation, and model uncertainties. Considerable effort is invested in gathering information about stock size to decrease ... -
Drift, growth, and survival of larval Northeast Arctic cod with simple rules of behaviour
Vikebø, Frode; Jørgensen, Christian; Kristiansen, Trond; Fiksen, Øyvind (Journal article; Peer reviewed, 2007-10-11)Due to vertical variations in ocean circulation, larval Northeast Arctic cod Gadus morhua may influence their own drift routes by migrating vertically. By coupling a larval individual-based model and a general circulation ... -
Effect of food deprivation on distribution of larval and early juvenile cod in experimental vertical temperature and light gradients
Vollset, Knut Wiik; Catalán, I. A.; Fiksen, Øyvind; Folkvord, Arild (Journal article; Peer reviewed, 2013-02-14)How and when food limits the growth and survival of larval fish are essential questions which link oceanography and fisheries science, and theory suggests that food availability may affect survival through behavioural ... -
Evaluation of harvest control rules: simple one-parameter vs. complex multi-parameter strategies
Housholder, Dorothy J.; Heino, Mikko; Fiksen, Øyvind (ICES CM documents, Working paper, 2003)Harvest control rules (HCR) are sets of well-defined rules that can be used for determin-ing annual fish catch quotas. If a management policy can be expressed as a HCR, then the HCR provides means to determine the total ... -
Foraging success in planktivorous fish increases with topographic blockage of prey distributions
Aarflot, Johanna Myrseth; Dalpadado, Padmini; Fiksen, Øyvind (Peer reviewed; Journal article, 2020)Banks and shelves are productive zones of the ocean, and often home to large fish stocks. Can shallower bottom topographies improve foraging opportunities for pelagic fish by blocking zooplankton from hiding in deep, darker ... -
Getting fat in a hurry: food consumption during the feeding migration of NSS herring
Varpe, Øystein; Fiksen, Øyvind; Slotte, Aril (ICES CM Documents;2004/K:64, Working paper, 2004)The Norwegian spring-spawning (NSS) herring Clupea harengus inhabits a seasonal environment where food is abundant only during a short period of the year. During that period NSS herring store energy for metabolic ... -
Linking behavioural ecology and oceanography: larval behaviour determines growth, mortality and dispersal
Fiksen, Øyvind; Jørgensen, Christian; Kristiansen, Trond; Vikebø, Frode; Huse, Geir (Journal article; Peer reviewed, 2007-10-11)Highly resolved general circulation models (GCMs) now generate realistic flow fields, and have revealed how sensitive larval drift routes are to vertical positioning in the water column. Sensible representation of behavioural ... -
Modelling rule-based behaviour: habitat selection and the growth–survival trade-off in larval cod
Kristiansen, Trond; Jørgensen, Christian; Lough, R. G.; Vikebø, Frode; Fiksen, Øyvind (ICES CM documents;2009/T:03, Working paper, 2009) -
No room for dessert: A mechanistic model of prey selection in gut-limited predatory fish
Fall, Johanna Jennifer Elisabeth; Fiksen, Øyvind (Journal article; Peer reviewed, 2019)Predatory fish structure communities through prey pursuit and consumption and, in many marine systems, the gadoids are particularly important. These predators have flexible feeding behaviours and often feed on large prey ... -
Parental migration, climate and thermal exposure of larvae: spawning in southern regions gives Northeast Arctic cod a warm start
Opdal, Anders Frugård; Vikebø, Frode; Fiksen, Øyvind (Journal article; Peer reviewed, 2011-10-20)Temporal variability in environmental conditions met by early life stages is considered a key driver of fluctuations in recruitment and abundance of fish stocks. Variability in spawning grounds selected by the parental ... -
Piscivorous fish patrol krill swarms
Kaartvedt, Stein; Røstad, Anders; Fiksen, Øyvind; Melle, Webjørn; Torgersen, Thomas; Breien, M. T.; Klevjer, Thor A. (Journal article; Peer reviewed, 2005-09-01)Dense swarms of the krill Meganyctiphanes norvegica in the Norwegian Sea were patrolled by large, piscivorous fish, which apparently use the krill swarms as feeding grounds in their hunt for planktivores. For the krill, ... -
Predator–prey overlap in three dimensions: cod benefit from capelin coming near the seafloor
Fall, Johanna Jennifer Elisabeth; Johannesen, Edda; Englund, Göran; Johansen, Geir Odd; Fiksen, Øyvind (Peer reviewed; Journal article, 2021)Spatial overlap between predator and prey is a prerequisite for predation, but the degree of overlap is not necessarily proportional to prey consumption. This is because many of the behavioural processes that precede ... -
Recruitment variability in Norwegian spring-spawning herring (Clupea harengus L.): the effect of temperature in larval drift trajectories
Fiksen, Øyvind; Slotte, Aril (ICES CM documents, Working paper, 2000)During late winter, the Norwegian spring-pawning (NSS) herring migrate southward along the Norwegian coast to spawn in March-April. The larvae drift northwards in the Norwegian coastal current during their first months and ... -
Stock–environment recruitment models for Norwegian spring spawning herring (Clupea harengus)
Fiksen, Øyvind; Slotte, Aril (Journal article; Peer reviewed, 2002)Different stock–environment recruitment models for Norwegian spring spawning herring (Clupea harengus) are fitted to a time series of spawning stock, recruitment, and temperature data extending back to 1907. In addition ... -
Survey report from the CODFUN 2016114 Barents Sea survey 5.-11. oktober 2016
Skaret, Georg; Johannesen, Edda; Fall, Johanna Jennifer Elisabeth; Fiksen, Øyvind (Rapport fra havforskningen;Nr. 41 - 2016, Research report, 2016)The survey is part of the project “The cod – capelin interaction in the Barents Sea: spatial dynamics in predator prey overlap and functional response (CODFUN)” funded by the Norwegian Research Council (NRC project number ... -
Vertical salmon lice behaviour as a response to environmental conditions and its influence on regional dispersion in a fjord system
Johnsen, Ingrid A.; Fiksen, Øyvind; Sandvik, Anne Dagrun; Asplin, Lars (Journal article; Peer reviewed, 2014-06-04)The salmon louse Lepeophtheirus salmonis is a major parasite of salmon, and is able to travel between farms during its pelagic phases. We investigated the spatial dispersion of L. salmonis planktonic stages in the ...