8204

• UCREFRP Catalog Number: 8204
• Author: Tyus, H. M.
• Title: Razorback Sucker ‎(Xyrauchen texanus)‎ Recovery Plan.
• USFW Year: 1998.
• USFW - Doc Type: Boulder, Colorado.
• Copyright Material: NO

in the past. A recent MOU between the Fish and Wildlife Service, Bureau of
Reclamation, and Gunnison River water users will guarantee a minimum flow of
at least 300 cfs below the Redland diversion at all times. Completion of fish
passage around the Redlands diversion dam in 1996 allows fish movement
between this reach and the Colorado River..
RZ7: Colorado River from Rifle, Colorado to Westwater Canyon.
The Colorado River near Grand Junction contains adult razorback suckers and
there is some evidence of spawning. Physical habitat is suitable for razorback
suckers, but the Government Highline Dam at the lower end of DeBeque Canyon
and the Price-Stubb Dam downstream completely block upstream movements.
Fish passage structures have been completed for the downstream Grand Valley
Diversion, and are being discussed for these other sites. Flows below these
structures are greatly altered from the natural hydrograph and the river channel
is constrained by dikes and riprap. Management actions have been taken to
provide water to the reach and to restore parts of the floodplain. Selenium levels
are high in some areas. Although predaceous game fish occur in this reach the
State of Colorado- has removed bag and possession limits.
RZ8: Colorado River from Westwater to the Dirty Devil River.
Razorback suckers are present in this reach and were historically abundant in
this portion of the Colorado River. Although the reach contains bottomland and
other habitats, inadequate water quantity and nonnative fish species threaten to
the small population of razorback sucker in this reach.
RZ9: San Juan River from Hogback Diversion to Neskahai Canyon.
Anecdotal information from long-time area residents indicated that razorback
sucker once occurred as far upstream as the Animas River (L. Ahlm, NM Dept.
of Game and Fish, pers. comm.). Habitat has been fragmented by construction
of diversion structures and degraded by associated water depletions. The flow
regime is now regulated by Navajo Dam, and channel geometry has been
altered by establishment of nonnative tamarisk and Russian olive. Water quality
has been degraded by discharges from domestic, agricultural, and industrial
sources. Nonnative fish species have become established throughout the
reach, and they compete with and prey on the native fish fauna. Despite the
alterations, some suitable habitat remains for the razorback suckers (Bliesner
and Lamarra 1995, 1996; Ryden and Pfeifer 1995).
RZ10: Colorado River from Paria River to Hoover Dam.
This segment of the Colorado River contains riverine and lacustrine habitat. The
riverine portion below Glen Canyon Dam consists of cold, high-velocity water,
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