7870

• UCREFRP Catalog Number: 7870
• Author: Lentsch, L. D., et al.
• Title: Options For Selective Control Of Nonnative Fishes In The Upper Colorado River Basin - Final Report.
• USFW Year: 1996.
• USFW - Doc Type: \
• Copyright Material: NO

independent of D.O. at concentrations as low as 2.0 ppm
(critical oxygen concentration for upper temperature
tolerance between 1.2 and 2.0 ppm) [Rutledge and Beitinger
1989].
¦ For fish from the Brazos River, Texas, collected
above and below a reservoir, selected median water
temperature ranged 23.0-30.9 and 21.2-28.5°C for the
two populations, respectively, and final temperature
preferenda were 30.0 and 23.3°C, respectively [Calhoun et
al. 1982].
¦ For fish from the Virgin River, Utah-Nevada-Arizona,
preferred mean water temperatures were 12, 22, and 27°C
and calculated CTMs were 30.10, 33.07, and 38.80°C at
respective acclimation temperatures of 10, 15, and
25°C; CTMs provide insight into distributional patterns
(thermally labile species) [Deacon et al. 1987].
¦ Classified as having high thermal tolerance,
nonselectivity in thermal gradients, and adaptive Type
1 traits (i.e., adapted to harsh environments and
relatively nonselective within physicochemical
gradients) [Matthews 1987].
Flow and Temperature.-
¦ For fish in the Yampa River, 1980-1984, earlier
initiation of spawning, longer spawning season, and
higher catch-per-unit-effort (CPUE) of age-0
individuals were associated with low peak discharge,
low to moderate daily mean and total discharges, and
moderate to high numbers of cumulative degree-days.
Conversely, later initiation of spawning, shorter
spawning season, and lower CPUE were associated with
high peak discharge, moderate to high daily mean and
total discharges, and low to moderate numbers of
cumulative degree-days [Muth and Nesler 1993).
¦ For fish in the Colorado (Colorado and Utah) and
Gunnison rivers, moderate to significant inverse
relationships were noted between magnitude of discharge
and abundance of red shiner [McAda and Kaeding 1989a;
Osmundson and Kaeding 1989, 1991; Valdez 1990].
¦ In Green River, Utah, 1979-1988, most abundant in
backwaters > 15 cm deep and having cooler water
temperatures (< 22.5°C). CPUE decreased with
increasing summer flows [Haines and Tyus 19903.
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