7610

• UCREFRP Catalog Number: 7610
• Author: Wick, E. J. and J. A. Hawkins.
• Title: Colorado Squawfish Winter Habitat Study, Yampa River, Colorado, 1986-1987
• USFW Year: 1987.
• USFW - Doc Type: Final Report Year 1.
• Copyright Material: NO

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This report summarizes the first year's progress on a two year research
agreement between Colorado State University (CSU) and the Upper Yampa Water
Conservancy District (UYWCD) entitled "Winter Habitat Requirements of Colorado
Squawfish in the Upper Yampa River".
INTRODUCTION
Background
This study of Colorado squawfish (Ptychocheilus lucius) winter habitat
requirements resulted from consultation prescribed by Section 7 of the
Endangered Species Act (1973) between the Bureau of Reclamation (BOR), the
United States Fish and Wildlife Service (USFWS), and the UYWCD in regards to
r the proposed construction of Stagecoach Reservoir on the upper Yampa River
near Steamboat Springs, Colorado. Impacts on endangered species (primarily
Colorado squawfish) from the proposed project could possibly occur during the
winter months. Although adequate data had been previously collected on
migration, spawning requirements, habitat preferences, and flow needs of
Colorado squawfish during spring, summer, and early fall, no data had been
collected on habitat requirements and behavior during the winter. Information
on the winter habitat needs of Colorado squawfish would give the USFWS the
ability to make flow recommendations on a year round basis.
This study was designed to determine the winter habitat use and behavior
of Colorado squawfish using radiotelemetry.
0 The objectives of this investigation were to:
1. Determine if adult Colorado squawfish remain in specific river
segments from Fall to early Spring in the upper Yampa River.
2. Determine microhabitat (depth, velocity, substrate, temperature, and
cover) used by Colorado squawfish during winter months (December
through March).
3. Develop winter habitat utilization curves based on microhabitat data
collected during the study (Bovee 1986).
4. Evaluate Physical Habitat Simulation (PHABSIM) data output derived
from utilization curves relative to actual Colorado squawfish habitat
use patterns observed during the study in areas evaluated by the
1-PrS ( Bovee 1986).
Study area
This study was conducted on the Yampa River from Lily Park, river mile
(RMI , to GZvprnment Rr;rige RMI 99.4 (Figure 1). River segments selected
for radiotagging squawfish were based on existing '-n ;:-,'re?---:?"-
'Y?'"sites established by the USFWS. These sites were located at
Lil P rk RMI 53-2, Maybell RMI _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 96.4-97.2) and Maybell (RMI
79.2-81.71)