9314 ‎(2)‎

• UCREFRP Catalog Number: 9314
• Author: Wick, E. J. and J. A. Hawkins.
• Title: Colorado Squawfish Winter Habitat Study.
• USFW Year: 1989.
• USFW - Doc Type: Fort Collins.
• Copyright Material: NO

STUDY AREA
Site selection
This study was conducted on the Yampa River from Lily Park, river mile
(R-11) 51, to Morgan Gulch, RMI 105 (Figure 1). River segments selected for
radiotagging squawfish were based on existing Instream Flow Incremental
Methodology (IFIM) sites established by USFWS. These sites were located at
Lily Park RMI 53.2, Maybell RU 72, and Government Bridge RMI 97.2. Because
initial radiotag implantation efforts at Lily Park were unsuccessful, fish
were implanted only at Government Bridge (RMI 105-95) and Maybell (RMI 82-70)
in the first year of the study. Lily Park (F44I 54-51) was successfully added
to the study areas during Winter 2.
Description of study areas
Government ad!j Le (MI 105-951
A predominant habitat type of this river reach during the base flaw
period is eddy, mostly associated with man-made rock jetties. Because of
heavy agricultural activity in this reach involving irrigation, rock
stabilization of banks and irrigation structures are common. A unique habitat
resulting from this activity was a large, 50x100 meter (m) backwater located
at RNII 95.7 (Figure 2). Backwaters of this size and structure are not ccumon
habitat features on the Yampa River during the base-flaw period. This
backwater is relatively new, resulting from 1984 flood waters which eroded the
river bank around car bodies and boulders placed along the river bank. Abet
100 m of dirt bank and alfalfa field were eroded away, resulting in extensive
gravel bar deposition and a wide, braided channel. Another predominant
habitat type of this reach is long, slowmoving run habitat. It is difficult
to accurately identify this habitat because at first appearance the long, law
velocity habitats appear to be pools. But they lack sufficient depth and
reduction in velocity relative to the main current to warrant the classic pool
definition (Appendix A). At extremely low winter flows, these shallow (2-5
foot deep) runs contain a large volume of law velocity habitat and could be
called shallow pools. However, because of the ice cover, it was difficult to
make these determinations and we tended to define run habitat based'on channel
characteristics during open water. combed to other study areas, this river
reach was most impacted by man. Deep pool habitat was not cannon, although a
large, deep naturally occurring eddy and pool combination is located just
below a high gradient reach at RMI 99. This river reach contains several
backwaters which form as a result of high flaws during spring runoff. These
high-flaw backwaters (dammed side channels, flooded tributary streams, and
irrigation returns) are used frequently by squawfish (Wick et al. 1986).
3