7406

• UCREFRP Catalog Number: 7406
• Author: Bestgen, K. R.
• Title: Status Review of the Razorback Sucker,
• USFW Year: 1990.
• Copyright Material: NO

and occasionally in the Colorado River near Grand Junction,
Colorado. The razorback sucker is rare or incidental throughout
remaining warmwater reaches of the mainstream Green and Colorado
rivers. Small concentrations are also present in the Dirty
Devil, San Juan, and Colorado river arms of Lake Powe 1, Utah
(Persons and Bulkley 1982, Meyer and Moretti 1988, pers. comm.,
R. D. Williams, U.S. Bureau of Reclamation). These
concentrations are composed almost exclusively of large, and
presumably, old adults (McAda and Wydoski 1980, Tyus 1987,
Lanigan and Tyus 1989).
To facilitate recovery of rare fishes in the Upper Colorado
River Basin, the Recovery Implementation Program (RIP) for
Endangered Fish Species in the Upper Colorado River Basin (U.S.
Fish and Wildlife Service 1987) was developed. This group is
composed of many state and federal agencies, and private
organizations that have a mutual interest in how UCRB water
resource development activities affect the well-being of rare
fish species (U.S. Fish and Wildlife Service 1987). One of the
goals of this recovery program is to recover and delist three
endangered fish species (bonytail, humpback chub, Colorado
squawfish) and manage a fourth species, the razorback sucker, so
that it does not need the protection of the Endangered Species
Act (U.S. Fish and Wildlife Service 1987). The razorback sucker
has been proposed as an endangered species (U.S. Fish and
Wildlife Service, Federal Register Vol. 15, No. 156, 15 August
1989). Research and management projects such as this one are
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