9311

• UCREFRP Catalog Number: 9311
• Author: Utah Division of Wildlife, Ute Indian Tribe and U.S. Fish and Wildlife Service.
• Title: Duchesne River Fisheries Study Progress Report
• USFW Year: 1999.
• USFW - Doc Type: 1998.
• Copyright Material: NO

RM 12.0-12.9.
Results
Adult Sampling
Twenty species were captured during adult sampling, seven native and 13 nonnative. The
most abundant species was the common carp, followed by the flannelmouth sucker, white sucker,
and channel catfish. The native fish captured were the flannehnouth sucker, bluehead sucker,
razorback sucker, Colorado pikeminnow, roundtail chub, speckled dace, and mountain whitefish.
Seventeen Colorado pikeminnow and three razorback suckers have been captured. The catch
data for each sampling trip is summarized in Tables 2-8.
Larval Sampling
Results of larval and post-larval sampling are given in Tables 9-17 for 1997 and Tables
18-21 for 1998.
Li t tra s. In 1997, larval native species collected included 96 speckled dace, 17
flannehnouth sucker, and 1 chub (Tables 10 and 12). The 17 flannehnouth sucker and 1 chub
larvae were all collected within 1 '/z miles of the confluence with Green River from 10 June to 1
July. A1196 speckled dace larvae were collected upriver from RM 6.4 from 9 July to 30 July.
Nonnative species collected in light traps included: 47% red shiner, 2% fathead minnow,
3.5% sand shiner, .06% carp, .04% smallmouth bass, .02% brook stickleback, and .02% white
sucker. Also included in these collections was a nonnative cyprinid category (NNC) consisting
of additional red shiner, fathead minnows, and/or sand shiners too small or damaged to identify
individual species. This category accounted for approximately 44% of the collection (Table 10,
12, 13).
The entire 1997 collection was composed of 97% minnows, < 1 % suckers, < 1 % non-
cypriniform species, and approximately 3% were unidentified due to small size or damage.
In 1998, flows peaked at 58$0 cfs on 18 June, more than three weeks later than the peak
of the Green River and two weeks later than the peak of 4120 cfs on 3 June of 1997. River flows
during this sampling period ranged from 436 cfs on 21 July to the peak of 5880 cfs on 18 June
with a mean of 2579 cfs. These flows made it difficult to maintain sampling equipment in
effective sampling locations. This was particularly the case with light traps.
Flows experienced during the eighteen sampling days ranged from 449 - 5240 cfs with a
mean of 2309 cfs. Temperatures in sample locations ranged from 12 - 24 °C. Analysis of these
samples, indicate a larval razorback sucker was captured in a light trap from a backwater at river-
mile 1.6 on 271VIay (based on pigmentation characteristics and developmental state; personal
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