8215

• UCREFRP Catalog Number: 8215
• Author: U.S. Fish and Wildlife Service.
• Title: Final Environmental Assessment
• USFW Year: 1997.
• USFW - Doc Type: Management and Control of Noonative Fish Species in Floodplain Ponds of the Upper Colorado and Gunnison Rivers.
• Copyright Material: NO

opportunities in the Upper Colorado River Basin that would be compatible
with recovery of the endangered fishes.
Recovery Program participants identified an urgent need_to control or manage
nonnative fish species in the Upper Colorado River Basin if recovery of the
endangered fishes was to be achieved. They participated in the development
of a strategic plan to remove or reduce existing populations of nonnative
fish species from habitat used by the endangered Colorado River fishes (Tyus
and Saunders 1996). One of the highest priorities in the Recovery Program's
strategic plan for control of nonnative fishes is prevention of chronic
escapement of nonnative fish species from off-channel ponds along the Upper
Colorado and Gunnison rivers that could further exacerbate existing
interactions of nonnative fishes (i.e., predation and competition) on the
endangered fishes. Most of the floodplain ponds are located in bottomlands
that were inventoried by Irving and Burdick (1995).
Recovery Program participants believe it is unlikely that the endangered
fishes will be recovered (i.e., establish viable, self-sustaining
populations through natural reproduction) until problems associated with
nonnative fishes are addressed.
D. Background Information. The fish fauna in most reaches of the Colorado
River Basin bears little resemblance to the historic fish community.The
geologic isolation of the Colorado River and its tributaries from other
watersheds gave rise to a fish fauna in which. 64% of the native species are
found nowhere but in the Basin (Miller 1959). In addition to being unique,
the fish fauna of the Colorado River Basin is depauperate when compared with
other North American river basins with only 36 species of native fishes.
The native fishes of the Colorado River Basin were adapted to the natural
aquatic conditions (e.g., extremely variable streamflows and high sediment
loads). These fishes evolved together and, more than likely, formed a
stable fish community-where competition and predation were balanced. The
main fish predator on the native fishes in the Upper Colorado River Basin
was the Colorado squawfish. The other native species occupied various
niches that reduced competition for limited resources, particularly food and
habitat. _.
1. Recovery Program. The Recovery Implementation Program for Endangered
Fishes in the -Upper Colorado River Basin (Recovery Program) was
implemented as a cooperative effort among the States of Colorado, Utah,
and Wyoming; U.S. Bureau of Reclamation; U.S. Fish and Wildlife Service,
Western Area Power Administration, water development interests, and
environmental organizations with a goal of allowing water development
to proceed to meet the needs of society in the Upper Colorado River
Basin while seeking solutions for recovery of the endangered fishes
(U.S. Fish and Wildlife Service 1987a). The Recovery Program was
intended to serve as a reasonable and prudent alternative to avoid
jeopardy to the continued existence of the endangered Colorado River
fishes and their critical habitat from historic and new water
development projects in the Upper Colorado River Basin in consultations
related to Section 7 of the Endangered Species Act.
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