9555

• UCREFRP Catalog Number: 9555
• Author: Bestgen, K. R., C. D. Walford, A. A. Hill and J. A. Hawkins.
• Title: Native Fish Response to Removal of Non-native Predator Fish in the Yampa River, Colorado.
• USFW Year: 2007.
• USFW - Doc Type: 140,
• Copyright Material: NO

INTRODUCTION
Introduction and establishment ofnon-native fish in western rivers of ~
threat to conservation of native fish assemblages (Minckley and Deacon 1
USA is a major
Stanford and
Ward 1986, Moyle et al. 1986, Carlson and Muth 1989, Minckley and Deaco 1991, Olden et al.
2006). In the upper Colorado River Basin, non-native fish invasions began o er 100 years ago,
with introduction of channel catfish Ictalurus punctatus, common carp Cypri us carpio, and
salmonids for sport fishery purposes. In the 1960's, small-bodied species suc as red shiner were
relatively rare in the Green River sub-basin of the Upper Colorado River Bas n (Vanicek et al.
1970), but by the 1970's were expanding rapidly (Holden and Stalnaker 1975 and 197Sb). By
the 1980's, red shiner was a dominant species in low-velocity habitat used by early life stages of
native fishes, and potential negative effects of that species and other small-b died fishes have
been documented (Haines and Tyus 1990; Dunsmoor 1993; Ruppert et al. 19 3; Muth and
Snyder 1995; Bestgen et al. 1997; 2006a). More recently, piscivores such as smallmouth bass
Micropterus dolomieu and northern pike Esox Lucius have established and ar common in the
lower Yampa River and the upper and middle Green River basins (Anderson 2002, 2005;
Bestgen et al. 2006b; Finney 2006).
The predatory threat of these large-bodied taxa is substantial and pro~rams for their
control via mechanical removal have been implemented in different rivers of the upper Colorado
River Basin. However, effects of removal on restoration of native fishes is u known.
Estimating the response of the native fish community to predator removal is eeded to
understand if removal programs are having the desired effect. Therefore, the goal of this project
is to document fish community changes in response to predaceous fish
Yampa River, Colorado.
Specific objectives necessary to achieve the goal for Yampa River
evaluation studies are a follows:
1. Select treatment and reference areas for study.
1
]s in a reach of the
removal