8117

• UCREFRP Catalog Number: 8117
• Author: Modde, T. and G. Smith.
• Title: Flow Recommendations for Endangered Fishes in the Yampa River.
• USFW Year: 1995.
• USFW - Doc Type: Denver, CO.
• Copyright Material: NO

LIST OF FIGURES

Figure 1. Yampa River study area, confluence with the Green River at Echo Park to
Craig, Colorado (river kilometer (0-224), . = locations of USGS river
gauges (from Tyus and Karp 1989) ., . . . . . . . . . . . . . . . . . . . . . . . . . 2

Figure 2. Average annual hydrograph of the Yampa River based on flows at
Oeerlodge Park between 1983 - 1990. . . . . . . . . . . . . . . . . . . . . . . . . .4

Figure 3. Important river reaches for Colorado squawfish, humpback chub, and
razorback sucker in Yampa and Green rivers, Colorado and Utah.
Shading = distribution; dots = spawning areas; Xs = winter concentration,
and lIs = larval drift (from Tyus and Karp 1989). .................7

Figure 4. Relation between discharge, temperature, and initiation of spawning
migration for Colorado squawfish, Yampa River, 1981-83 and 1988. Q =
average daily discharge; T = average daily temperature (USGS records,
Yampa River near Maybell, Colorado). Solid vertical lines = dates first and
last radio-tagged fish exhibited movement to spawning ground; dashed
vertical line = average date radio-tagged fish exhibited migratory
movements; n = number of radio tagged fish (from Tyus and Karp

1989) ............................................... 10

Figure 5. Summary of discharge information coinciding with fish movement in the
Yampa River through Cross Mountain Canyon and the Maybell
diversion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . 12

Figure 6. Relation between discharge and spawning period for humpback chub,
Yampa River, 1987-88. Vertical bars delineate spawning period (from Tyus

and Karp) ........................................,... 13

Figure 7. Relation between discharge and spawning period for razorback sucker,
Yampa River, 1975, 1981, 1988, and 1989 (discharge data incomplete for
_ 1989) (from Tyus and Karp 1989). Vertical bars delineate spawning
period. (One collection of ripe fish in 1988).. . . . . . . . . . . . . . . . . . . 15

Figure 8. Comparison of the relationship of temperature and discharge with the
presence of razorback suck, Xyrauchen texanus, at spawning sites in the
Green and Yampa rivers. Rates represent percent change over a five-day
period preceding the observation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Figure 9. Generalized sequence of spawning migration and spawning of endangered
fishes in the Yampa River. Abbreviations represent RZB = razorback
sucker, CS = Colorado squawfish, HB = Humpback chub, M = Migration,
S = spawning (modified from Tyus and Karp 1989. . . . . . . . . . . . . . . . 17

Figure 10. Percentage of native and nonnative fishes collected in the Yampa

River . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

III