7066

• UCREFRP Catalog Number: 7066
• Author: Behnke, R. J. and D. E. Benson.
• Title: Endangered and Threatened Fishes of the Upper Colorado River Basin.
• USFW Year: 1980.
• USFW - Doc Type: Bulletin 503A,
• Copyright Material: NO

unusual fishes of the Colorado River that are found
nowhere else in the world. The continued existence
of these rare fishes will require the cooperation of
diverse interest groups, as well as improved communi-
cation between persons of diverse fields of knowledge
and expertise.
All future development will not grind to a halt
because of such unusual fishes as the squawfish and
the humpback chub, as claimed by some alarmists.
Some delay, compromises, and modifications in future
projects may be necessary, however, to maintain cer-
tain environmental conditions and avoid the extinction
of the rare fishes.
Concerned citizens are urged to assist in gather-
ing information on the fishes discussed in this bul-
letin. The areas involved cover vast expanses of
habitat. Scientific collecting gear has not been
highly effective in capturing fishes such as squaw-
fish, razorback suckers, and bonytail and humpback
chubs. Fishermen catching any of these endangered
or threatened species must, according to the law,
release them unharmed; however, a report of the catch,
giving size of fish and location and date of capture
should be made to a local District Wildlife Manager
or to a regional office of the State Division of Wild-
life. Squawfish and humpback chubs are being tagged
as part of current research projects. If a tagged
fish is caught, the tag number should be included in
the report of the catch. Such information may pro-
vide new distribution records for a species or may
lead to the discovery of a species such as the bony-
tail chub -- now believed extinct in Colorado.
The native fishes of the Colorado River basin
received little attention until recent times. The
area involved is large and the physical, chemical,
and biological interactions affecting the well-being
of the native fishes are complex. Thus, detailed
data and documentation on cause and effect relation-
ships to explain the decline of rare fishes are largely
lacking. The assessments we make here on the basis
of available information, must be considered in the
realm of speculation.
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