7331

• UCREFRP Catalog Number: 7331
• Author: Kinnear, B. S. and R. E. Vincent.
• Title: Fishes and Fish Habitats in Black Canyon of the Gunnison National Monument.
• USFW Year: 1967.
• USFW - Doc Type: Fort Collins, Colorado.
• Copyright Material: NO

CHAPTER I
INTRODUCTION
Water, and its efficient use, is of major importance in the arid
and semi-arid west. This significance is manifest in large and numerous
water storage projects throughout western America. Economic studies of
the impact of these projects indicate that many benefits have accrued
to the region. Ecological impact of these projects on the native flora
and fauna are less well known.
BACKGROUND TO THE STUDY
In 1956, the 86th Congress authorized the Curecanti river-storage
unit of the Gunnison River as one of four initial units of the larger
Colorado River storage project (House Document No. 201, 1960). The
Curecanti storage unit will consist of three dams in Black Canyon of the
Gunnison River. Their purposes will be to provide hydro-electric power,
water storage for irrigation, flood control, and recreation. The first
of these dams, Blue Mesa, began storage of water in October, 1965.
As a result of the water control provided by these structures,
changes are expected in water quality, habitats, and in fish populations
that now exist downstream from the reservoirs. Neel (1963) presented
an excellent discussion of similar changes below reservoirs and Jenkins
0
(1965) compiled an extensive bibliography of articles concerning reser-
voirs and tailwaters.
Pfitzer (1954) discussed major ecological changes in rivers below
large dams in the Tennessee Valley. He indicated that reduction of tem-
. o
perature extremes; lower average temperature; and erratic, seasonal dis-
solved oxygen patterns resulted in these rivers. Furthermore, many of
the minnow species disappeared and only a few of those remaining were