7163 ‎(2)‎

• UCREFRP Catalog Number: 7163
• Author: Haynes, C. M. and J. R. Bennett.
• Title: Relationship between the Preservation of Wilderness Values and Endangered Species
• USFW Year: 1985.
• USFW - Doc Type: A Case-Study from the Upper Colorado River Basin, U.S.A.
• Copyright Material: NO

C
METHODS
Fish populations in the White River were sampled at eight
river sites (Figure 2) between the Green and White River
confluence and Taylor Draw Dam between 30 September and 22
October 1992, and 7 April and 22 September 1993. These sample
sites were selected because they were accessible, represented
typical habitat types, and corresponded to previous study sample
sites.
A seine (10 m X 1.5 m X 10 mm stretch mesh) was used to
sample fish in slow moving current and backwater areas. A
trammel net (2 m X 30 m X 100 mm stretch mesh) was either set or
drifted in deep pool and run areas. A Coffelt electrofishing
boat unit (90-120 Hz frequency, 800-1,100 variable DC) was used
to capture fish in deep run, pool, riffle, and backwater habitat
areas. Sampling efforts emphasized obtaining a representative
sample of all fish species in all habitat types throughout the
White River.
The annual abundance, composition, movements, and home range
of adult Colorado squawfish up- and downstream of Taylor Draw Dam
was determined using both radio telemetry and mark and recapture
methods. All captured squawfish were measured (mm, Total Length
(TL)) and weighed (g). Each fish received a PIT (Passive
Integrated Transponder) tag. Mark and recapture techniques
(Everhart and Youngs 1992) and Jolly-Seber (Ricker 1975, Begon
1979) and Maximum Likelihood (Hilburn arid-Walters 1992) methods
were used to estimate population size of squawfish in the first
2.4-rkm below Taylor Draw Dam.
Twelve wild adult Colorado squawfish captured in the first
0.5-rkm below Taylor Draw Dam were surgically implanted with
radio transmitter modules in September and October 1992 and April
1993. Surgical procedures followed those of Hart and Summerfelt
(1975), Tyus (1984), Martinez (1986), and Valdez et al. (1992).
The radio transmitter used was a Custom Telemetry brand
equipped with an internal loop antenna, powered by 24-month
lithium battery, and emitted a unique signal (frequency and pulse
rate) in the 40.660-40.700 MHz frequency range. The transmitters
measured 52 mm by 18 mm diameter and weighed 16 g (dry weight).
Implanted fish weighed at least 1,000 g to assure that
r transmitter weight was no more than 2t of its body weight
(Bidgood 198-0, Marty and Summerfelt 1990).
Ground and aerial radio tracking was conducted using an ATS
digital radio search-receiver with an omni-directional whip and
bi-directional loop antenna (Tyus 1982, 1988; Winter 1983; Miller
et al. 1983). A Christian Huskey airplane, air speed 55-130
knots, was equipped with two omni-directional whip antennas with
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