9314 ‎(2)‎

• UCREFRP Catalog Number: 9314
• Author: Wick, E. J. and J. A. Hawkins.
• Title: Colorado Squawfish Winter Habitat Study.
• USFW Year: 1989.
• USFW - Doc Type: Fort Collins.
• Copyright Material: NO

1
r Squawf ish could have been attracted to the warmer waters of the Little Snake
River and to better feeding opportunities.
Average movement of radiotagged fish related to spawning was 65 miles
r (range 34.5 - 84.5 miles) for both years. This was the one-way distance from
the point of last contact above Yampa Canyon to the lowest river mile location
in Yampa Canyon. In the summer 1987, three fish (A08, All, and B11) were
located within the spawning area of Yampa Canyon (personal communication H.M.
r Tyus, USFWS, Vernal, Utah). All three fish were located back at their over-
wintering areas in the fall, 1987. Four fish (A91, B85, C87, and C89) were
known to migrate to the Yampa Canyon spawning area in the summer, 1988,
r (personal communication, H.M. Tyus, USFWS, Vernal, Utah). Fish C87 was
located during a radiotelemetry spot check of 'the area by the authors. Fish
B85 was collected by CROW during the Fall 1988, at RMI 80.8 (Table 3). These
r fish exhibited a high degree of homing ability and fidelity by locating and
using the same habitats previously used after spawning migration. Three of the
implanted fish (BB7,' C87, and C95) had capture histories that also indicated
fidelity to a specific river reach over one or more years. For example, fish
r radlotracked over an entire winter, and relocated during
C87 was recaptured
,
the fall of the next year only 0.1 mile from where it had been originally
caught and Carlin tagged 7 years earlier (Table 3).
r Although fish remained in specific areas during the winter, they were
also quite active within each habitat. Fish in embayments and backwaters
would move between several favored spots within the habitat, staying in a spot
r for several minutes to several hours before moving. Fish would often repeat
this pattern of movement. These spots were often used by more than one
squawfish at the same time. Movement did not appear to be influenced by the
presence of other Colorado squawfish. This would often result in small
r congregations of two to three Colorado squawfish within a one meter diameter
spot. Fish using run and shoreline habitats appeared to be more active,

r moving within and between habitats more frequently. Fish found in larger
pools and eddys behaved similar to those in backwater and embayment habitats.
Those using smaller pools and eddys behaved similar to fish in run and
shoreline habitats.
r H
bit
t U
a
a
se
There was a distinct difference in winter habitat use between years.
r During Winter 1, fish most often used habitats off the main channel (off-
channel habitats). In winter 2, fish used main-channel habitats (Figures 6
and 7). Predominant habitats used Winter 1 were backwater, embayment, and
r run. Run and pool habitat were used more Winter 2. Flows during Winter 1
ri
hi
t
s
o
c
were higher, whereas flaws during Winter 2 were lower than mean
winter flows (Figure 8 and Appendix C). High use of pool habitat in Winter 2
was due to the addition of the Lily Park study area, which is characterized by
r pool and eddy habitat and absence of backwater and embayment habitat.
Habitat use by Colorado squawfish varied between study areas as did
habitat availability. When a variety of habitats was available within a river
r reach, fish often selected off-channel habitats over main-channel types.
Backwater use in Winter 1 was exclusively at the EM 95.7 backwater. This
backwater was drastically altered during ice-off and spring runoff the first
year; this may be a reason for limited use in winter 2. During winter 1, this
r backwater habitat apparently satisfied the needs of fish sufficiently that

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