8134

• UCREFRP Catalog Number: 8134
• Author: Valdez, R. A.
• Title: Significance of the Palisade to Grand Junction Reach of the Colorado River to the Endangered Fishes ERI ‎(C035-06)‎.
• USFW Year: 1985.
• USFW - Doc Type: \
• Copyright Material: NO

3-3

3.2 Historic Fisheries Information

Colorado squawfish. and razorback sucker are caught almost annually
from the IS-mile reach of river between the Grand Valley Canal and the mouth
of the Gunnison River. Both species were caught by Kidd (1977. 1979. 1982)
in 1974. 1975. 1976. 1979. and 1980; and by Wick et al. (1981) in 1980.
Subsequent studies by the FWS (Valdez et al. 1982; Archer et al. 1984) al so
reveal ed the presence of squawfi sh and razorbacks within the reach in 1980.
1981. and 1982. Kidd (Northwest Fisheries Research. personal communication
with Richard Valdez. U.S. FWS. June 1979. Grand Junction. Colorado) also
reported one humpback chub near the upper part of the reach in 1977. The
varyi ng catches probably refl ect the different sampl i ng i ntens it ies and not
necessarily the relative fish densities.

3.2.1 Colorado Squawfish

At least 50 adult Colorado squawfish have been captured in the IS-mile
reach between 1974 and 1984 (Table 3-1). Forty-three of the reported 50
fish were caught in inundated gravel pits. including Palisade labor Camp.
Clifton Ponds. and Island Pond (Figure 2-1). The remainder were caught in
natural backwaters or in the main channel. The high incidence of the
species in gravel pits reflects a higher catchability in this habitat and
not necessarily a preference over other habitats.

Perhaps the observation that has prompted FWS to examine more closely
this reach of river occurred in 1982 during radiotelemetry studies in the
Colorado and Gunnison Rivers (Miller et al. 1983). On July 13. 1982, three
radiotagged squawfish were tracked to a small pool in a side channel at RM
178.3 near Clifton. Colorado (Figure 2-1). A total of nine adult squawfish.
including five ripe males were simultaneously captured. suggesting .a
spawning-related aggregation of fish like those previously observed in the
Yampa and Green Rivers (Archer and Tyus 1984; Tyus 1985). This aggregation
included one fish that had been radiotagged in upper lake Powell on April 8.
1982; the fish had traveled upstream for 199 miles in 101 days (Miller et
a 1. 1984).

In the 2 weeks following July 13. 1982. five radiotagged squawfish were
tracked to a 1 arge eddy at RM 176. A ri pe male and a suspected maturi ng
female were collected at this location. but no spawning activity was noted.
It was not reported if some or a 11 of these fi sh were the same as those
observed or captured at RM 178.3.

Miller et al. (1983) noted that "Although an aggregation of ripe males
is a significant observation. it does not necessarily indicate that spawning
occurred in the immediate viCinity." It' was also pointed out that ripe
males were seen to move 10 to 15 miles between captures during the time they
were ripe. indicating that ripe males are not necessarily found exclusively
on spawning grounds.

Although spawning by Colorado squawfish was not documented at either RM
176.0 or 178.3. collection of larval squawfish between RM 170.0 and 180.0
during August 1982 indicates that spawning did occur womewhere in the Grand
Junction area (Miller et ale 1983); recently-hatched squawfish often drift
downstream and their capture location may not reflect the spawning site.
The exact numbers of fish captured are not available, but l,arvae and YOY