WWRC 97-05kk
Use of Radiometry to Define Winter Habitat Use by Small Rainbow Trout in
the Big Horn River, Wyoming
Introduction
Coldwater rivers downstream from reservoirs in
Wyoming provide sport fisheries of state-wide and
national significance (Braaten and Annear 1994).
These regulated rivers, often referred to as tailwaters,
support year-around trout fisheries. Recently, it has
become apparent that the overwinter survival of small
(20- to 25-cm TL) rainbow trout (Oncorhynchus
mykiss) in these tailwaters has declined. Such is the
case with the Big Horn River, downstream from
Boysen Dam (Yekel 1990; 1994). However,
research on the overwinter survival, movement, and
habitat use of rainbow trout in tailwaters is limited.
Only two studies on the winter habitat of rainbow
trout in tailwaters have been published, both were on
the Henrys Fork of the Snake River below Palasides
Dam in Idaho (i.e. Griffith and Smith 1995; Smith
and Griffith 1994).
The goal of this study was to identify winter habitat
features that may limit the overwinter survival of
naturally spawned (wild) and recently stocked
(hatchery) rainbow trout (20- to 25-cm TL) in the Big
Horn River downstream from Boysen Dam. Our
objectives were to: (1) describe physical habitat,
including the magnitude and variation in flow, air and
water temperature, and ice formation during the
1995-96 winter (November through March); (2)
describe the distribution and movements of small
rainbow trout relative to changing physical habitat
characteristics during the winter; and (3) assess the
influence of ice formation on the habitat use and
movements of small rainbow trout.
Water Resources Publications List
Water Resources Data System Library |
Water Resources Data System Homepage
