7166

• UCREFRP Catalog Number: 7166
• Author: Miller, W. H., et al.
• Title: Yampa River Fishes Study
• USFW Year: 1982.
• USFW - Doc Type: Final Report.
• Copyright Material: NO

the Yampa River only during special radiotracking collections; one
individual was taken from the Green River during standardized sampling.
Of the 24 total species collected during the study, nine were native
(six endemic to the Colorado River Basin) and 15 were exotic (introduced)
species. In addition, the following suspected hybrids were collected:
flannelmouth x bluehead sucker; flannelmouth x white sucker; bluehead x
white sucker; and flannelmouth x razorback sucker.
Relative abundance and distribution of species are presented in
Table 6 and Figure 7. Catch per hour electrofishing is given in Tables
7 and 8, catches per 10m seining in Tables 9 and 10, and catches per
hour from trammel nets are depicted in Tables 11 and 12. Catch data
should be used with caution in interpreting a species general occurrence
in different habitats, and prevalence over a period of time. For example,
40 adult Colorado squawfish were captured in Stratum 1 on the Yampa
River, which could lead to the conclusion that the species was common.
One must note that the Colorado squawfish is highly migratory, and 35 of
these individuals were collected during a period of only 9 days from a
very restricted (1.5 mi) area. Thus, considering the overall study,
Colorado squawfish were rare in Stratum 1.
Total number of fishes generally increased upstream with the
exception of Cross Mountain Canyon (Stratum 5) and Juniper Canyon
(Stratum 7) on the Yampa (Figure 7). Except for Strata 4 and 5 on the
Yampa River, juveniles were collected in much lower numbers than young
or adults (Figure 7). Total effort by strata for 3 gear types (Table
13) indicate that the general upstream increase in total fish numbers
did not result from differences in sampling effort.
Occurrence of fishes found in the present study was generally in
agreement with that reported by Holden and Stalnaker (1975a, 1975b),
Seethaler et al. (1978), and Tyus et al. (1981). Holden and Stalnaker
(1975b), however, did not find sand shiner and red shiner in the Yampa
River in 1968-71 and reported redside shiner abundant in Yampa Canyon
in DNM.
In 1981 red shiner was not found in Stratum 7 on the Yampa River
but was otherwise common or abundant in all strata except in Strata 2,
5, and 8 in the Yampa where it was rare. Sand shiner was common, but
never abundant in most strata, except in Yampa Strata 1, 2, and 3 where
it was rare. Joseph et al. (1977) reported redside shiner to be a
dominant species in the Yampa River in 1975-76 and implied that lack of
documented Colorado squawfish reproduction since 1969 was correlated
with redside shiner increasing to a dominant species status. This is
questionable, since all collections reported (Joseph et al. 1977) during
1975-77 were made above RM 52 (km 83.2), and Colorado squawfish repro-
duction has never been reported or implied in the Yampa except in the
lower few miles of the river (near the Greem/Yampa confluence). Holden
and Stalnaker (1975b) reported redside shiner abundant in DNM in 1968-
71. In contrast, the results of our study showed the redside shiner to
be rare to uncommon in Yampa Canyon. The species was common upstream of
Deerlodge Park (RM 46; km 73.6) in the Yampa, and relatively common in
the Green River below the Yampa/Green confluence.
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