6004

• UCREFRP Catalog Number: 6004
• Author: Wick, E. J., J. A. Hawkins and C. A. Carlson.
• Title: Colorado Squawfish Population and Habitat Monitoring.
• USFW Year: 1986.
• USFW - Doc Type: SE3-8,
• Copyright Material: NO

a
INTRODUCTION
This report discusses data collection for the Colorado squawfish
(Ptychocheilus lucius) population and habitat monitoring program for 1985.
Appendices list all endangered fish tagged from 1979 to 1985 and include a
preliminary Habitat Suitability Index (HSI) model for the squawfish in the
•
upper Yampa River. A habitat census was originally planned for 1984 but
record high flows that year delayed the census until 1985. This was also our
final year of testing a scaled-down standardized fish monitoring program on
S
the Yampa River that would require few man-hours, but provide adequate data
to access the status of squawfish.
The report is organized as follows. First, fish collections for 1985 are
•
reported, including threatened and endangered (T&E) fish. Habitat parameters
for all squawfish captures on the Yampa River from 1979 to 1985 are then
summarized. Results of the habitat census conducted in 1985 are presented,
these data were the basis for developing the HSI model for squawfish in
Colorado. Finally, we evaluate the monitoring program and make
recommendations for future monitoring and research.
Our objectives in 1985 were as follows.
1) Monitor the adult Colorado squawfish population on the Yampa River
to determine:
a
a. relative abundance,
b. age composition,
c. recruitment,
•
d. distribution, and
e. habitat preference.

2) Determine distribution and amount of preferred habitat available to
squawfish at runoff, spawning, and base flows.
3) Develop a habitat evaluation procedure for use on other Colorado
rivers based on the Yampa River model.
•