1106

• UCREFRP Catalog Number: 1106
• Author: Gosse, J.
• Title: Microhabitat of Rainbow and Cutthroat Trout in the Green River Below Flaming Gorge Dam.
• USFW Year: 1982.
• USFW - Doc Type: Logan, UT.
• Copyright Material: NO

23

For the same life stage and activity, rainbow trout tended
to have higher fish velocities than did cutthroat trout. For all
flows combined, juvenile rainbow trout occupied significantly
(P -< 0.05) higher velocities than juvenile cutthroat trout for
both seasons. 4Adult rainbow trout occupied significantly
(P < 0.05) higher velocities than adult cutthroat trout during
the winter, but there was no significant (p > 0.05) difference
during the summer. Fish velocities tended to be higher (for the
same flow) during the summer than in winter with the exception of
juvenile cutthroat trout.
~ndom swimming. For the activity of random swimming, fish
velocity did not change consistently with increasing flows (Table
3). Flow changes generally produced little change in fish velo-
city during random swimming, and increased flows did not neces-
sarily produce increases in fish velocity. For the activity of
random swinming, juvenile rainbow trout exhibited the most dra-
matic increases in fish velocity with flow increases during the

wi nter.

Howeve.., the number of observations was small (Tabl e 3)

and this may be an aberration.
There was a slight tendency for fish to use lower velocities
in summer than in winter. Juvenile cutthroat trout chose lower
velocities during summer than during winter for all flows. This
was agaln probably a result of their small size and recent stock-
ing.

For all flows combined, adult rainbow trout were found in
significantly (P < 0.05) higher velocities than adult cutthroat

trout during both seasons.

Juvenile rainbow trout were also

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