7300

• UCREFRP Catalog Number: 7300
• Author: Tyus, H. M. and C. A. Karp.
• Title: Habitat Use and Streamflow Needs of Rare and Endangered Fishes, Yampa River, Colorado.
• USFW Year: 1989.
• USFW - Doc Type: Biological Report 89‎(14)‎,
• Copyright Material: NO

Colorado squawfish persists in the Yampa and Green
rivers, the upper Colorado River mainstream, and the
lower San Juan River (Archer et al. 1985; Tyus et al.
1987; Meyer and Moretti 1988; Tyus 1989). The
humpback chub is presently self-sustaining in the
Yampa River and upper Colorado River (Archer et al.
1985; Karp and Tyus 1989). The razorback sucker
persists in the lower Yampa and Green rivers, the
mainstream Colorado River, and the lower San Juan
River, but there is little indication of recruitment in
these remnant populations (Tyus et a1.1986; Meyer and
Moretti 1988; Lanigan and Tyus 1989; Tyus 1989). The
bonylail chub is extremely rare in the upper Colorado
River basin (Valdez and Clemmer 1982; U.S. Fish and
Wildlife Service 1987). All four fishes have been
extirpated in the Green River between Flaming Gorge
Dam and the Yampa River confluence, due to loss of
usable habitat following closure of the dam (Vanicek et
al. 1970). However, the Yampa River supports all its
native fish fauna (including self-sustaining populations
of some of the rare species), contains much rare fish
habitat, and contributes to the maintenance and
availability of usable rare fish habitat in the downstream
Green River.
Our objective is to evaluate habitat use and
streamflow needs of Colorado squawfish, bonytail chub,
humpback chub, and razorback sucker in the Yampa
River. Habitat requirements and factors limiting the
distribution and abundance of each species are
discussed by life history stage. Flow events considered
essential to the survival of these four fishes in the Green
River basin are identified for further quantification. Our
intent is to describe flow needs of Colorado squawtish,
bonytail and humpback chubs, and razorback sucker as
indicated by their habitat use. We do not provide a
quantification of these needs.
Distribution, Abundance, and
Habitat Use
The distribution and abundance of fishes indigenous
to the Yampa River have been studied since the early
1900's (Ellis 1914; Beckman 1952; Banks 1964; Vanicek
et al. 1970; Holden and Stalnaker 1975). Early field
studies provided much baseline information, although
they were generally restricted in scope to seasonal fish
surveys. More intensive, long-term sampling programs
in the 1970's and 1980's (Prewitt et al. 1977; Seethaler
1978; Wicket a1.1979, 1982, 1985; McAda and Wydoski
1980; Miller et a1.1982; Tyus et a1.1982a,1987; Haynes
et a1.1984) have provided more quantitative approaches
to the evaluation offish habitat use and needs. In 1979,
U.S. Fish and Wildlife Service (Service) developed
standardized methods for studying the Colorado River
fishes (Archer et al. 1980) and, in cooperation with the
State of Colorado and the National Park Service,
initiated fish studies in the Yampa River in fall 1980.
The lower 198.4 km (Echo Park to near Williams Fork)
was divided into eight relatively homogeneous river
sections, using topographic and geologic maps, aerial
surveys, and field reconnaissance, in an effort to
evaluate habitat use of the rare fishes (Miller et a1.1982).
The initial study area was extended to RK 224 because
of angler-captured tag returns of Colorado squawfish
from Craig, Colorado (see map opposite page 1). Data
gaps identified in the initial studies (Miller et al. 1982)
were evaluated in subsequent investigations using the
same river stratification and fish sampling techniques.
Habitat use data were compiled for all fish species
captured by U.S. Fish and Wildlife Service and
Colorado Division of Wildlife biologists (e.g., major
habitat type, depth, velocity, and substrate information)
using radiotelemetry, electrofishing, trammel netting,
angling, and seining. Reproductive behavior of
Colorado squawGsh in the Yampa River was studied
from 1981 to 1988 (Wick et al. 1983; Archer and Tyus
1984; Tyus et al. 1987; present study). Studies of winter
habitat use by Colorado squawfish and general habitat
use by humpback chub were initiated in the Yampa
River in 1986 (Karp and Tyus 1989; Wick and Hawkins
1989). Razorback sucker spawning and winter habitat
use have also been investigated (Miller et al. 1982;
Valdez and Masslich 1989; U.S. Fish and Wildlife
Service, unpublished data). The present report includes
data from published sources and unpublished data from
Service files in Vernal, Utah.
In 1984, the Biology Subcommittee of the Upper
Colorado River Basin Coordinating Committee and the
U.S. Fish and Wildlife Service identified river reaches
considered important to the survival and recovery of the
rare Colorado River fishes (Upper Colorado River
Basin Coordinating Committee 1984; Archer et al.
1986). This information was more recently updated in
the Recovery Implementation Program (U.S. Fish and
Wildlife Service 1987). We provide additional
information for further delineation of critical river
reaches in the Yampa River. This information is
summarized in Fig. 4 and discussed in the following
sections.
Colorado Squawfish
Adult
Adult Colorado squawfish are distributed in the
mainstream Yampa River from its mouth upstream to
Craig, Colorado (Fig. 4). The upper Yampa River (RK
81.6-198.4) is considered a concentration area for
overwintering adults (Archer et al. 1986; Fig. 4), as
evidenced by migration patterns of radio-tagged fish
(Tyus et a1.1987) and abundance data (Miller et a1.1982;
4