English
norskBlar i forfatter "Arnekleiv, Jo Vegar"
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Beyond ecological opportunity: prey diversity rather than abundance shapes predator niche variation
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-01)<br> 1. Ecological opportunity (i.e. the diversity of available resources) has a pivotal role in shaping niche variation and trophic specialisation of animals. However, ecological opportunity can be described with regard to both diversity and abundance of resources. The degree to which these two components contribute to niche variation remains unexplored. <br>2. To address this, we used an ... -
DNA Metabarcoding of Preservative Ethanol Reveals Changes in Invertebrate Community Composition Following Rotenone Treatment
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-06-01)The botanical compound rotenone is extensively used to eradicate populations and reduce the negative impacts of freshwater invasive animals. The method is controversial as non-target organisms often are negatively affected, but these effects are highly variable among taxa and may be difficult to monitor on species-level as many invertebrates are challenging or costly to identify using morphology. ... -
Drivers of diet patterns in a globally distributed freshwater fish species
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-09-24)We analysed data of a globally distributed model organism (brown trout) in an attempt to understand relationships among biogeography, prey communities and climate on diet composition at regional spatial scales (Scandinavia), and thereafter explored whether diet patterns remained the same at global scales. At regional scales, we uncovered comprehensive patterns in diet composition among neighbouring ... -
Marine depth use of sea trout Salmo trutta in fjord areas of Central Norway
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-09-15)The vertical behaviour of 44 veteran sea trout <i>Salmo trutta</i> (275–580 mm) in different marine fjord habitats (estuary, pelagic, near shore with and without steep cliffs) was documented during May–February by acoustic telemetry. The swimming depth of <i>S. trutta</i> was influenced by habitat, time of day (day v. night), season, seawater temperature and the body length at the time of tagging. ... -
Marine migration and habitat use of anadromous brown trout Salmo trutta
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-05-22)The biology and ecology of anadromous brown trout Salmo trutta at sea is poorly understood. This study provided information on spatial and temporal distribution of sea trout in the ocean. The behaviour of 115 individuals (veteran migrants, 270-700 mm) was tracked by using acoustic telemetry in a fjord system during April-September in 2012-2013. Overall, fish spent 68% of their marine residence ... -
Marine trophic niche-use and life history diversity among Arctic charr Salvelinus alpinus in southwestern Greenland
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-01-22)Life history strategies and potential marine niche use of Arctic charr <i>Salvelinus alpinus</i> (<i>n</i> = 237, 84–652 mm, total body length, <i>L<sub>T</sub></i>) were determined during the ice‐free season (2012) at three different watercourses in south‐western Greenland. All Arctic charr were collected from freshwater habitats. Based on stable isotopes of δ<sup>34</sup>S, the Arctic charr were ... -
Trophic niche similarity among sea trout Salmo trutta in Central Norway investigated using different time-integrated trophic tracers
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-11-21)From 2011 to 2013, anadromous brown trout Salmo trutta (213−730 mm, total body length, LT) were collected during or shortly after their marine feeding migration at 7 different localities in central Norway. The mean volume of stomach content (%) of marine fish prey eaten by S. trutta captured in marine waters varied from 34 to 89%. There was a high prevalence (67−100%) for parasite groups potentially ...
