Seasonal habitat selection by lake trout (Salvelinus namaycush) in a small canadian shield lake: constraints imposed by winter conditions

Autor: Blanchfield, P.J., Tate, L.S., Plumb, J.M., Acolas, Marie-Laure, Beaty, K.G.
Přispěvatelé: Irstea Publications, Migration, COLUMBIA RIVER RESEARCH LABORATORY COOK USA, Partenaires IRSTEA, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Ecosystèmes estuariens et poissons migrateurs amphihalins (UR EPBX), Centre national du machinisme agricole, du génie rural, des eaux et forêts (CEMAGREF)
Jazyk: angličtina
Rok vydání: 2009
Předmět:
Zdroj: Aquatic Ecology
Aquatic Ecology, Springer Verlag, 2009, 43, pp.777-787
ISSN: 1386-2588
1573-5125
Popis: The need for cold, well-oxygenated waters significantly reduces the habitat available for lake trout (Salvelinus namaycush) during stratification of small temperate lakes. We examined the spatial and pelagic distribution of lake trout over two consecutive summers and winters and tested whether winter increased habitat availability and access to littoral regions in a boreal shield lake in which pelagic prey fish are absent. In winter, lake trout had a narrowly defined pelagic distribution that was skewed to the upper 3 m of the water column and spatially situated in the central region of the lake. Individual core areas of use (50% Kernel utilization distributions) in winter were much reduced (75%) and spatially non-overlapping compared to summer areas, but activity levels were similar between seasons. Winter habitat selection is in contrast to observations from the stratified season, when lake trout were consistently located in much deeper waters ([6 m) and widely distributed throughout the lake. Winter distribution of lake trout appeared to be strongly influenced by ambient light levels; snow depth and day length accounted for up to 69% of the variation in daily median fish depth. More restricted habitat use during winter than summer was in contrast to our original prediction and illustrates that a different suite of factors influence lake trout distribution between these seasons.
Databáze: OpenAIRE
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