Diurnal shifts in use of summer habitat by age-0 brown trout in a regulated mountain stream

Abstract

Diurnal shifts in habitat use by age-0 (< 50 mm total length) brown trout (Salmo trutta) were observed from June to July 1989 and 1990 in low-gradient (< 1% channel slope) reaches of Douglas Creek, Medicine Bow National Forest, Wyoming. Fish were visually located during day and night, and water depth, water velocity, distance from the stream edge, substrate, habitat type, and cover were determined at each location. The fish were found predominantly in locations with slow water velocities in streammargin and backwater-pool habitats. They were observed in slower water, closer to the stream edge at night than during the day.

Use of three types of stream-margin habitat by age-0 brown trout late in the growing season

“…If age-0 brown trout behave similar to other salmonid species, they would be expected to use deeper and faster water as they grew. Consequently, they would use deeper and faster water in August and September than was reported during July and August by Harris et al (1992) and Hubert et al (1994) .…”

“…The use of stream-margin habitat by age-0 brown trout has been studied (Harris et al, 1992 ;Hubert et al, 1994) . Reseachers observed diurnal variation in habitat use ; age-0 brown trout (Salmo trutta) were found at greater depths and in faster water velocities during the day than at night, and as they grew during the early summer, they shifted to deeper and faster water .…”

“…We hypothesized that differences in habitat features used by age-0 brown trout would differ among the three habitat types and over sampling periods (August-September) . We also hypothesized that the habitat features used late in the growing season would differ from those described in the same stream for smaller fish in June and July by Harris et al (1992) and Hubert et al (1994) .…”

Habitat De La Truite Commune (Salmo Trutta L.) Pendant La Période Juvénile en Ruisseau : Préférences, Mouvements, Variations Journalières Et Saisonnières.

“…En milieu naturel, les alevins de plusieurs espèces de salmonidés fréquentent ces habitats de bordure : Salmo clarki (MOORE et GREGORY, 1988), Salvelinus fontinalis (WALSH et al, 1988), Thymallus thymallus (BARDONNET et al, 1991), Oncorhynchus mykiss (KOCIK et TAYLOR, 1996). Chez Salmo trutta, HUBERT et al (1994) remarquent que le nombre d'alevins de taille comprise entre 23 à 48 mm (Longueur Fourche) baisse sensiblement pendant la journée dans les habitats de bordure, indiquant que les déplacements entre berge et chenal se prolongent plusieurs semaines après l'émergence.…”

Daytime habitat selection for juvenile parr brown trout (Salmo trutta) in small lowland streams

“…There is little knowledge on physical habitat requirements in small lowland streams that can be used to evaluate the effects of different water management actions such as water abstraction or stream restoration activities aimed at increasing stream flow and improving physical habitat conditions Conallin et al, 2010a;Nislow and Armstrong, 2012). Four habitat variables are known to affect the habitat selection of salmonids and carrying capacity in streams (Vezza et al, 2012); water depth (Kennedy and Strange, 1982;Heggenes, 1988aHeggenes, , 2002, water velocity (Heggenes and Traaen, 1988;Heggenes et al, 1999;Heggenes and Dokk, 2001), bed substrate (Heggenes, 1988b;Knapp and Preisler, 1999;Kondolf, 2000), and cover (Hubert et al, 1994;Bovee et al, 1998). However, differences in stream characteristics can influence the importance of these variables on brown trout habitat selection, i.e.…”