8025

• UCREFRP Catalog Number: 8025
• Author: Valdez, R., et al.
• Title: Colorado River Fishery Project, Tributary Report ‎(Gunnison and Dolores River)‎ Final Report.
• USFW Year: 1982.
• USFW - Doc Type: Grand Junction, CO.
• Copyright Material: NO

INTRODUCTION

General Setting

The Colorado River drainage contains fish species found nowhere else
in the world. Four endemic species have declined in numbers and are
threatened with extinction. The Colorado River Fisheries Project (CRFP)
was originally established to assess habitat requirements of the
endangered Colorado squawfish (Ptychochei1us 1ucius) and humpback chub
(Gila cypha). TIle bony tail chub (Gila elegans) was added to this list of
target species after being listed ~ndanger~d by the U.S. Fish and
Wildlife Service (~~lS) in May 1980. Razorback sucker (Xyranchen texanus)
were also considered by CRFP because of their unknown status.

CRFP was established through a lfemorandum of Understanding (MOU)
with the Bureau of Reclamation (BR) on 14 April 1979 (Contract No.
9-07-40-L-1016). The Bureau of Land Management (BLM) supplied funding
for fishery research in the State of Colorado through a MOU (Contract No.
CO-910-IA9-933).

The MOU established biological criteria needed to assess the habitat
requirements of the four target species, including: a) spawning
requirements, b) habitat requirements of young-of-the-year, juveniles
and adults, c) migration and movements d) effects of salinity,
temperature and selected chemicals, e) feasibility of propagation and
rearing of endangered fish, and f) fish pathogens and parasites.

CRFP consisted of three field stations; Vernal, Utah, Grand
Junction, Colorado and Flagstaff, Arizona. The Grand Junction Field
Station (GJFS) was assigned to conduct fishery research on the upper
Colorado River and lower Dolores and Gunnison Rivers.

Objectives

This report deals with the status of endangered fishes in the
Dolores and Gunnison rivers (two major tributaries of the upper Colorado
River). Objectives of this research include determining use and
abundance, migration and movement, habitat requirements and interspecific
competition of the four target species in these tributaries. A CRFP
report on the fishes of the main stem upper Colorado River is under a
separate cover.

METHODOLOGY

Study Area

Gunnison River

Tne Gunnison River is one of the major tributaries of the upper
Colorado River, contributing approximately 2x106 acre-feet of water or
about 14% of the total average annual runoff of the Colorado River