7980

• UCREFRP Catalog Number: 7980
• Author: Archer, D. L., H. M. Tyus and R. Valdez.
• Title: Field Methodologies of the Fish and Wildlife Service's Colorado River Fisheries Project.
• USFW Year: 1980.
• USFW - Doc Type: Denver, Colorado.
• Copyright Material: NO

It rCher; Vo.lde:Cd-- TyuS
tcrtsD /

13

FIELD METHODOLOGIES OF THE
FISH AND WILDLIFE SERVICE'S
COLORADO RIVER FISHERIES PROJECT

By

Donald L. Archer, Harold Tyus and Richard Valdez
U.S. Fish and Wildlife Service, Colorado Fisheries Project

Introduction

In April, 1979, the U.S. Fish and Wildlife Service and Bureau of
Reclamation signed an agreement which established the Colorado River
Fisheries Project. Since then, other co-operators have joined this
program by providing financial support and field assistance. This
project has developed programs to study the ecology and physiological
characteristics of the Colorado squawfish (Ptychocheilus lucius) and
the humpback chub (Gila cypha) .

Most research presentations begin by r~counting what was done in
order to accumulate data about some population of animals or their
habitat. We believe that it is more important to begin by telling
"why we did what we did" and relate the development of our methods to
research needs. We are presenting methods being used by the Colorado
River Fishery Team to study the rare fishes in the mainstream of the
Upper Colorado and Green Rivers.

The Colorado, as other rivers, is a unique ecosystem because of:
(1) current, (2) transport of water over long distances, (3) extensive
water/land interface, and (4) extreme flow fluctuations. A river's
far-flung nature, variability over distance and time, swift currents,
turbidities, and great depths provide a very difficult environment for
obtaining reliable research results.

Our field investigations took two differing approaches to acqu~r~ng
data. The first was a systematic assessment of the fish population
and associated habitats in the entire river system; the second was a
very indepth investigation of the habitat/life history requirements of
the humpback chub and Colorado squawfish.

The broader investigations are intended to look at fish populations
and associated habitats throughout the river system. The very intensive
studies are to examine such biological factors as spawning requirements,
food habits, movement, interspecific relationships and other facets of
these fishes' life histories.

Research Design

Sarno linp,

The Upper Colorado system is made up of a wide variety of habitats
from sluggish backwaters and shallow sandy runs to series of waterfalls

(j 7q g 0
----

..-.'Oc'~<