Browsing Bergen Open Research Archive by Author "Jensen, Knut Helge"
Now showing items 1-17 of 17
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Correlative evidence for competition between fucus serratus and the introduced chlorophyte codium fragile subsp. fragile on the southwest coast of Norway
Armitage, Caroline Susanne; Sjøtun, Kjersti; Jensen, Knut Helge (Peer reviewed; Journal article, 2014)The distribution of Codium fragile subsp. fragile and the native canopy-forming alga Fucusserratus was recorded at 51 sites in a 20 km long, sheltered region on the southwest coast of Norway. The purpose of the study was ... -
Duration of the parasitic phase determines subsequent performance in juvenile freshwater pearl mussels (Margaritifera margaritifera)
Marwaha, Janhavi; Jensen, Knut Helge; Jakobsen, Per Johan; Geist, Jürgen (Peer reviewed; Journal article, 2017-03)Host–parasite systems have been useful in understanding coevolutionary patterns in sympatric species. Based on the exceptional interaction of the long‐lived and highly host‐specific freshwater pearl mussel (FPM; Margaritifera ... -
Effects of habitat enrichment and food availability on the foraging behaviour of juvenile Atlantic Cod (Gadus morhua L)
Moberg, Olav; Braithwaite, Victoria A.; Jensen, Knut Helge; Salvanes, Anne Gro Vea (Peer reviewed; Journal article, 2011-04-13)The environment can play an important role in shaping how an animal behaves, and how well the animal performs in a particular environment can be influenced by early experiences. The tradition of releasing captive-reared ... -
Empirical Support for Optimal Virulence in a Castrating Parasite
Jensen, Knut Helge; Little, Tom; Skorping, Arne; Ebert, Dieter (Peer reviewed; Journal article, 2006-05-30)The trade-off hypothesis for the evolution of virulence predicts that parasite transmission stage production and host exploitation are balanced such that lifetime transmission success (LTS) is maximised. However, the ... -
An enriched environment promotes shelter-seeking behaviour and survival of hatchery-produced juvenile European lobster (Homarus gammarus)
Aspaas, Stian; Grefsrud, Ellen Sofie; Fernø, Anders; Jensen, Knut Helge; Trengereid, Henrik; Agnalt, Ann-Lisbeth (Peer reviewed; Journal article, 2016-08-25)The high loss of newly released hatchery-reared European lobster (Homarus gammarus) juveniles for stock enhancement is believed to be the result of maladaptive anti-predator behaviour connected to deprived stimuli in the ... -
Enrichment promotes learning in fish
Strand, David A.; Utne-Palm, Anne Christine; Jakobsen, Per Johan; Braithwaite, Victoria A.; Jensen, Knut Helge; Salvanes, Anne Gro Vea (Peer reviewed; Journal article, 2010-08-18)Captive birds and mammals reared in enriched rearing environments have been shown to behave more flexibly compared to animals reared in impoverished or plain environments. Recent evidence has shown that this is also true ... -
Feeding Hotspots and Distribution of Fin and Humpback Whales in the Norwegian Sea From 2013 to 2018
Løviknes, Sunniva; Jensen, Knut Helge; Krafft, Bjørn Arne; Anthonypillai, Valentine; Nøttestad, Leif (Journal article; Peer reviewed, 2021)Fin whales (Balaenoptera physalus) and humpback whales (Megaptera novaeangliae) are commonly found in the Norwegian Sea during the summer months. Records from around 1995 to 2004 show that their distribution patterns were ... -
Improving Salmonid Monitoring by Nocturnal Counting in Rivers
Kambestad, Marius; Hellen, Bjart Are; Jensen, Knut Helge; Sægrov, Harald (Journal article; Peer reviewed, 2022)Accurate abundance estimates are crucial for evidence-based fisheries management. In rivers, drift dive counting and electrofishing are commonly used for quantifying fish abundance. However, the likelihood that fish are ... -
Ontogenetic Change in Behavioral Responses to Structural Enrichment From Fry to Parr in Juvenile Atlantic Salmon (Salmo salar L.)
Alnes, Ingeborg Bjerkvik; Jensen, Knut Helge; Skorping, Arne; Salvanes, Anne Gro Vea (Journal article; Peer reviewed, 2021)Enrichment is widely used as a tool for studying how changes in environment affect animal behavior. Here, we report an experimental study investigating if behaviors shaped by stimuli from environmental enrichment depending ... -
Oral health and quality of life among people with severe or long-term mental illness: A call for interprofessional collaboration
Bjørkvik, Jofrid; Quintero, Diana Patricia; Jensen, Knut Helge; Virtanen, Jorma (Journal article; Peer reviewed, 2023)People with severe or long-term mental illness (SMI) have poorer oral health than the general population has, but little is known about how, to what extent, and in what ways oral health problems affect daily functioning, ... -
Rapid life‑history evolution in a wild Daphnia pulex population in response to novel size‑dependent predation
Wathne, Ingrid; Enberg, Katja; Jensen, Knut Helge; Heino, Mikko Petteri (Journal article; Peer reviewed, 2020)The effect of size-selective predation on prey communities and their traits is well documented, but the relative roles of genetic adaptation and phenotypic plasticity continue to be debated. We looked for evidence of genetic ... -
Safety assessment of the functional feed additive phenylcapsaicin in a commercial broiler diet
Paulsen, Torbjørn Rage; Jensen, Knut Helge; Jan van, Harn; Teun, Veldkamp (Journal article; Peer reviewed, 2023)Introduction: Intestinal colonisation of Salmonella is a major concern in the poultry industry, and a low dose of the high-purity synthetic capsaicin analogue phenylcapsaicin (PheCap) has the potential to be a phytobiotic ... -
Size Dependent Male Reproductive Tactic in the Two-Spotted Goby (Gobiusculus flavescens)
Utne-Palm, Anne Christine; Eduard, Kjartan; Jensen, Knut Helge; Mayer, Ian; Jakobsen, Per Johan (Peer reviewed; Journal article, 2015-12-07)Male investment in testes and sperm duct gland in the polygamous nest breeding two-spotted goby Gobiusculus flavescens (Fabricius) was investigated in relation to time in reproductive season and individual physical parameters. ... -
State-dependent spatial and intra-school dynamics in pre-spawning herring (Clupea harengus L.) in a semi-enclosed ecosystem
Langård, Lise; Fatnes, Ole Andreas; Johannessen, Arne; Skaret, Georg; Axelsen, Bjørn Erik; Nøttestad, Leif; Slotte, Aril; Jensen, Knut Helge; Fernø, Anders (Peer reviewed; Journal article, 2013)Distribution and aggregation patterns of pelagic fish in marine ecosystems are hard to predict and understand, particularly since focused studies are typically limited to single field efforts. Our study targets coastal ... -
Summer distribution and demography of Antarctic krill Euphausia superba Dana, 1852 (Euphausiacea) at the South Orkney Islands, 2011–2015
Krafft, Bjørn Arne; Knutson, T; Krag, Ludvig Ahm; Jensen, Knut Helge; Skaret, Georg; Krakstad, Jens-Otto; Larsen, Stuart; Melle, Webjørn Raunsgård; Iversen, Svein Arnholt; Godø, Olav Rune (Peer reviewed; Journal article, 2018-11-22)We carried out a survey of Antarctic krill (Euphausia superbaDana, 1850) from 2011 to 2015 to establish a long-term, time-series dataset of distribution, abundance, and demography for this species in the South Orkney Islands ... -
Uncertainty and ignored information in the analysis of bat ultrasound: Bayesian approximation to the rescue
Michaelsen, Tore Christian; Rydell, Jens; Bååth, Rasmus; Jensen, Knut Helge (Journal article; Peer reviewed, 2022)Bat ultrasound analysis has been around for several decades and it is one of the most important tools in studies of bat ecology. Discrimination between species is based on intra-specific features of echolocation calls. ... -
When to reproduce? A new answer to an old question
Skorping, Arne; Jensen, Knut Helge; Mennerat, Adele; Högstedt, Göran (Peer reviewed; Journal article, 2016-04)We present a life-history model based on the assumptions that juvenile survival follows a negative exponential function and that fecundity gain increases linearly with time to maturity. This model predicts that the optimal ...