9433

• UCREFRP Catalog Number: 9433
• Author: Anderson, R.
• Title: Riverine Fish Flow Investigations.
• USFW Year: 2002.
• USFW - Doc Type: Federal Aid Project F-288-R5,
• Copyright Material: NO

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The three stations used during this flow study turned out to be excellent for observing the
progress of smaUmouth bass in establishing dominance at Duffy in the Yampa River. The
habitat at Duffy is optimal for small mouth bass and recruitment was strong during all 4 years. At
Sevens there does not appear to be much suitable habitat for spawning or YOY bass in normal
runoff years, but local production increased in 2001. Lily Park is the most productive of the
three sites and even though bass comprised only 5% in 2001, the number of bass over 15 cm
collected there were higher than at Duffy. 2001 was the last year of sampling fish on the Yampa
for this project. It would be extremely interesting to monitor these sites for a few more years to
follow the fishery during its transition. I suggest the nonnative management section consider this
as a priority issue.

COLORADO RIVER

Species Composition - Fish longer than 15 cm

Flannelmouth sucker was the most common species found at both sites (Corn Lake and
Clifton) in 2001 comprising 40% and 42% of the fish over 15 cm, respectively (Table 6). For the
three year period 1999, 2000 and 2001 flannel mouth sucker composition at Corn Lake was 38%,
31 % and 40%, and at Clifton it was 33%,33% and 42%, respectively (Table A4). Bluehead
sucker was a very close second place in 2001 comprising 37% offish >15 cm at Corn Lake and
27% at Clifton (Table 6). In 1999,2000 and 2001 bluehead sucker composition at Corn Lake
was 35%,36% and 37%, and at Clifton it was 23%,41% and 27%, respectively (Table A4).
These two species combined made up about 70% of the larger fish group during the study period
and these native suckers combined had consistently higher composition, although only slightly,
at Corn Lake compared to Clifton.

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