Blar i Bergen Open Research Archive på forfatter "Fiksen, Øyvind"
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Atlantic bluefin tuna spawn early to avoid metabolic meltdown in larvae
Fiksen, Øyvind; Reglero, Patricia (Journal article; Peer reviewed, 2022)To predict shifts in phenology and distribution of organisms we need to understand how survival through early life stages depends on environmental conditions. Here, we present a mechanistic model of development, feeding ... -
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 (Journal article; Peer reviewed, 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 (Peer reviewed; Journal article, 2019-05)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 ... -
Dying from the lesser of three evils: facilitation and non-consumptive effects emerge in a model with multiple predators
Fouzai, Nadia; Opdal, Anders Frugård; Jørgensen, Christian; Fiksen, Øyvind (Peer reviewed; Journal article, 2019)Prey modify their behaviour to avoid predation, but dilemmas arise when predators vary in hunting style. Behaviours that successfully evade one predator sometimes facilitate exposure to another predator, forcing the prey ... -
Effects of copepod size on fish growth: A model based on data for North Sea sandeel
Van Deurs, Mikael; Jørgensen, Christian; Fiksen, Øyvind (Peer reviewed; Journal article, 2015-02-03)In productive marine off-shore ecosystems, the flow of energy from zooplankton to large predators is channeled through a few species of short-lived, highly abundant schooling planktivorous fish. There are indications that ... -
Effects of temperature and food availability on larval cod survival: A model for behaviour in vertical gradients
Fouzai, Nadia; Opdal, Anders Frugård; Jørgensen, Christian; Fiksen, Øyvind (Peer reviewed; Journal article, 2015-06-08)Recruitment success in living marine resources is variable due to high survival variability of early life stages. Improving our understanding of how environmental and ecological factors mechanistically interact and influence ... -
The emotion system promotes diversity and evolvability
Giske, Jarl; Eliassen, Sigrunn; Fiksen, Øyvind; Jakobsen, Per Johan; Aksnes, Dag Lorents; Mangel, Marc; Jørgensen, Christian (Peer reviewed; Journal article, 2014-08-06)Studies on the relationship between the optimal phenotype and its environment have had limited focus on genotype-to-phenotype pathways and their evolutionary consequences. Here, we study how multi-layered trait architecture ... -
Evolution of a portfolio-based design in ecology: a three-year design cycle
Esterhazy, Rachelle; Fiksen, Øyvind (Peer reviewed; Journal article, 2019)Portfolio-based designs are among the most popular student-centered approaches in higher education. While the pedagogical literature typically provides generic advice on ideal portfolio-based designs, there is little ... -
Foraging success in planktivorous fish increases with topographic blockage of prey distributions
Aarflot, Johanna Myrseth; Dalpadado, Padmini; Fiksen, Øyvind (Journal article; Peer reviewed, 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 ... -
Land use change and coastal water darkening drive synchronous dynamics in phytoplankton and fish phenology on centennial timescales
Opdal, Anders Martin Frugård; Lindemann, Christian; Andersen, Tom; Hessen, Dag Olav; Fiksen, Øyvind; Aksnes, Dag Lorents (Journal article; Peer reviewed, 2024)At high latitudes, the suitable window for timing reproductive events is particularly narrow, promoting tight synchrony between trophic levels. Climate change may disrupt this synchrony due to diverging responses to ... -
Light comfort zone in a mesopelagic fish emerges from adaptive behaviour along a latitudinal gradient
Langbehn, Tom; Aksnes, Dag Lorents; Kaartvedt, Stein; Fiksen, Øyvind; Jørgensen, Christian (Peer reviewed; Journal article, 2019)Throughout the oceans, small fish and other micronekton migrate between daytime depths of several hundred meters and near-surface waters at night. These diel vertical migrations of mesopelagic organisms structure pelagic ... -
Model of mesopelagic fish predation on eggs and larvae shows benefits of tuna spawning under full moon
Ottmann, Daniel; Langbehn, Tom; Reglero, Patricia; Alvarez-Berastegui, Diego; Fiksen, Øyvind (Journal article; Peer reviewed, 2023)Most mesopelagic fish are small planktivores that migrate up at nightfall to feed in the safety of darkness and descend to depth at dawn to escape visual predators. However, the trophic roles can reverse since mesopelagic ... -
No room for dessert: A mechanistic model of prey selection in gut-limited predatory fish
Fall, Johanna; Fiksen, Øyvind (Peer reviewed; Journal article, 2020)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 ... -
Optimal reproductive phenology under size-dependent cannibalism
Takashina, Nao; Fiksen, Øyvind (Journal article; Peer reviewed, 2020)Intra-cohort cannibalism is an example of a size-mediated priority effect. If early life stages cannibalize slightly smaller individuals, then parents face a trade-off between breeding at the best time for larval growth ... -
Poleward distribution of mesopelagic fishes is constrained by seasonality in light
Langbehn, Tom; Aksnes, Dag Lorents; Kaartvedt, Stein; Fiksen, Øyvind; Ljungström, Anna Jeja Gabriella; Jørgensen, Christian (Journal article; Peer reviewed, 2022)Aim: Mesopelagic fishes have a near-global distribution in the upper 1,000 m from tropical to sub-Arctic oceans across temperature regimes. Yet, their abundance decreases poleward and viable populations seem excluded from ... -
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 (Journal article; Peer reviewed, 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 ... -
Relationships between spawning ground identity, Latitude and early life thermal exposure in Northeast Arctic Cod
Opdal, Anders Frugård; Vikebø, Frode B.; Fiksen, Øyvind (Peer reviewed; Journal article, 2008)from its feeding grounds in the Barents Sea to various spawning banks along the Norwegian coast. Prior to the 1990s these banks were located on a wide latitudinal range from Finnmark (~71º N) to Møre (~63º N), or even to ... -
Scaling laws in phytoplankton nutrient uptake affinity
Lindemann, Christian; Fiksen, Øyvind; Andersen, Ken Haste; Aksnes, Dag Lorents (Peer reviewed; Journal article, 2016-03-11)Nutrient uptake affinity affects the competitive ability of microbial organisms at low nutrient concentrations. From the theory of diffusion limitation it follows that uptake affinity scales linearly with the cell radius. ... -
Spawning site distribution of a bluefin tuna reduces jellyfish predation on early life stages
Ottmann, Daniel; Fiksen, Øyvind; Martín, Melissa; Alemany, Francisco; Prieto, Laura; Álvarez-Berastegui, Diego; Reglero, Patricia (Journal article; Peer reviewed, 2021)Bluefin tunas across the world migrate long distances to spawn in particularly warm and oligotrophic areas constrained by oceanographic fronts. The low abundance of predators in these areas increases survival chances of ... -
Vertical salmon lice behaviour as a response to environmental conditions and its influence on regional dispersion in a fjord system
Johnsen, Ingrid Askeland; Fiksen, Øyvind; Sandvik, Anne Dagrun; Asplin, Lars (Peer reviewed; Journal article, 2014)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 ...