Now showing items 31-36 of 36
The association between parasite infection and growth rates in Arctic charr: do fast growing fish have more parasites?
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-01-01)
Trophically transmitted parasites are known to impair fish growth in experimental studies, but this is not well documented in natural populations. For Arctic charr [<i>Salvelinus alpinus</i> (L.)], individual growth is positively correlated with food consumption. However, increased food consumption will increase the exposure to trophically transmitted parasites. Using a correlative approach, we ...
Contrasting patterns in trophic niche evolution of polymorphic Arctic charr populations in two subarctic Norwegian lakes
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-05-15)
Parallelism in trophic niches of polymorphic populations of Arctic charr was investigated in two similar subarctic lakes, Tårnvatn and Skøvatn, in northern Norway. Analysis of eleven microsatellite loci confirmed, respectively, the existence of three and two genetically differentiated morphs. Three methods were used to describe their trophic niches: habitat choice and stomach contents for the recent ...
From clear lakes to murky waters – tracing the functional response of high-latitude lake communities to concurrent ‘greening’ and ‘browning’
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-02-21)
Climate change and the intensification of land use practices are causing widespread eutrophication of subarctic lakes. The implications of this rapid change for lake ecosystem function remain poorly understood. To assess how freshwater communities respond to such profound changes in their habitat and resource availability, we conducted a space‐for‐time analysis of food‐web structure in 30 lakes ...
Exploring trophic niches and parasite communities of sympatric Arctic charr and brown trout populations of southern Norway
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-05-09)
Catchment-scale variation between lake habitats has the potential to simultaneously influence the trophic niche and parasite community of fish hosts. In this study, we investigated the trophic niche and parasite community of sympatric Arctic charr and brown trout populations from two inter-connected southern Norwegian lakes at different altitudes. Arctic charr and brown trout occupied profundal and ...
Introduction of Mysis relicta (Mysida) reduces niche segregation between deep-water Arctic charr morphs
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-04-26)
Niche diversification of polymorphic Arctic charr can be altered by multiple anthropogenic stressors. The opossum-shrimp (<i>Mysis relicta</i>) was introduced to compensate for reduced food resources for fish following hydropower operations in Lake Limingen, central Norway. Based on habitat use, stomach contents, stable isotopes (δ<sup>13</sup>C, δ<sup>15</sup>N) and trophically transmitted parasites, ...
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 ...