9432 ‎(2)‎

• UCREFRP Catalog Number: 9432
• Author: Modde, T. and M. Fuller.
• Title: Feasibility of Channel Catfish Reduction in the Lower Yampa River.
• USFW Year: 2002.
• USFW - Doc Type: Vernal.
• Copyright Material: NO

construction of the passageway at Redlands, other movement chronologies have been
documented. First, some non-radio-tagged fish that have moved through the
passageway have remained upstream following release; others have moved downstream
over the dam. Second, some fish that have moved through the passageway and
released upstream of the diversion dam, have subsequently moved downstream over
the diversion dam and reascended the same passageway.
Non-listed fishes
The Gunnison River was sampled with electrofishing in early-September and
early-October 1996 from Hartland Diversion Dam to Redlands Dam. Recapture of
three species of native fish that had previously been collected in the fish trap
and marked revealed that they had dispersed upstream from the Redlands
passageway. Some of the marked flannelmouth sucker and bluehead sucker dispersed
upstream 57 miles to the base of Hartland Diversion Dam by October and were both
distributed similarly in number (Figure 9). The farthest marked roundtail chub
was found upstream about 15 river miles. A total of 55 flannelmouth sucker, 46
bluehead sucker, and 3 roundtail chub previously marked were recaptured. This
accounted for 1.9%, 1.2%, and 0.7% of the total number of each species marked,
respectively, at the fish trap (Appendix; Table F.1.).
Radiotelemetry
1996-Tagged Fish
Capture and Release. Eleven adult Colorado pikeminnow were captured and
implanted with 29-gram LOTEV radio transmitters between 13 May and 12 June (mean
TL=733 mm; range=627-863 mm). Four of these fish were initially captured from
the large backwater area at WWWA (RM 163.3) in the 18-mile reach, five from
Hotspot and Gardner ponds (RM 174.4) in the 15-mile reach of the Upper Colorado
River, and two from the 2.3-mile reach of the Lower Gunnison River (Appendix;
Table J.1.). All fish were released in the Lower Gunnison River immediately
downstream of the Redlands Diversion Dam plunge pool (RM 2.9).
Movement and Dispersal. Contact was established and maintained with nine
of the eleven pi kemi nnow from 1 June to 13 November in 1996 and until August 1997
with four of these eleven pikeminnow. Two fish were never contacted following
release. Contact duration ranged from 20-451 days. Six of these eleven fish
were contacted over 300 days, well beyond the 260-day tag-life expectancy
guaranteed by the manufacturer (Appendix; Table K.1.). The maximum displacement
was predominantly downstream (mean of 19.9 miles for 11 fish); the maximum
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