7153

• UCREFRP Catalog Number: 7153
• Author: Holden, P. B.
• Title: Study of the Habitat Use and Movement of the Rare Fishes in the Green River, Utah.
• USFW Year: 1978.
• USFW - Doc Type: Logan, Utah.
• Copyright Material: NO

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larger squawfish in the Green River may change habitat preference
with. season. During high water (spring and early summer) back-
waters appear to be preferred; whereas, during low water (fall)
eddies and runs are predominantly used. Kidd (1977) indicated
that squawfish used backwaters almost exclusively in the Colorado
River near Grand Junction, although times of capture were not noted.
Small humpback chubs have s~mi1ar habitat preferences to small
squawfish but use more of a variety of areas, especially eddies.
No previous study has reported on preferred habitats of small
humpback chubs.
Habitat preferences of adult humpback chubs have generally
included eddies near fast current (Holden and Stalnaker, 1975)
and/or depths of 20+ feet (Kidd, 1977). The data collected during
the present study show no distinct preference for either depth or
velocity, although some humpbacks were caught in very fast cur-
rents (2.5 fps) and in very deep areas (20 ft.).
Rare Fish Movements
The three young-of-the-year squawfish recaptured in the sam-
ple backwater provide little data on movement. The fact that a
relatively large number of fish were marked and that successive
samples ~found re1ati vely large numbers of unmarked fi sh, indi cates
several possibilities. First, a fairly large population is indi-
cated. Secondly, failure to recapture marked fish suggests either
low sampling efficiency or absence of marked fish. The mouth of

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