WSP02208

• File Number: 8240.200.10.B
• Description: UCRBRIP Program Summaries/Status Reports
• Basin: Colorado Mainstem
• Date: 8/1/1995
• Author: UCRBRIP
• Title: Status Report
• Water Supply Pro - Doc Type: Publication

Non-native fish management in the Green River

Studies conducted during 1993 and 1994 demonstrated that small mouth bass, small channel cat-
fish and green sunfish can prey heavily on young-of-the-year Colorado squawfish. To help reduce
this problem, smallmouth bass will be removed from two one-kilometer sections of the Green
River in 1995. Biologists will collect the fish by electro-fishing.

Action:

Annual report due on efforts to remove smallmouth bass from selected reach-
es of the Green River.
Dec. 15, 1995.

Date:

Action
Date:

Final report due on effectiveness of electro-fishing as a removal method.
Dec. ] 5, 1996.

Questions?

Please call Dick Wydoski at [phone], ext. 228.

Experimental removal of northern pike from the Yampa River

Northern pike have expanded their range from the Yampa River to upper sections of the Green
River - areas that are critical nursery habitat for young Colorado squawfish. In a Utah State
University study on the Green River, researchers documented that young squawfish constituted 5
percent of the diet of north em pike, even though squawfish made up a much smaller portion of the
available food base in the river. The researchers estimated that a single northern pike could con-
sume 100 or more squawfish per year. Also, northern pike are known to prey on native roundtail
chub and may also feed on humpback chubs in the Yampa River. The Yampa River is one of the
last truly "wild" rivers in the West and provides some of the best remaining native fish habitat in
the entire Colorado River basin. Ensuring continued availability of this habitat is crucial.

The purpose of the removal effort would be to detennine whether pike densities can be reduced
in critical habitat of endangered fish over the long term and whether endangered fish will benefit.
Northern pike would be captured alive and transferred to public waters open to sport fishing. In
June 1995, the Management Committee decided to postpone any work on this project to allow for
public involvement and completion of a strategic plan for controlling non-native fish throughout
the upper Colorado River basin. This plan is to be available in January 1996.

Date:

Strategic plan to be completed for controlling non-native fish in the upper
Colorado River basin.
Jan. 15, 1996.

Action:

Questions?

Please call Dick Wydoski at [phone], ext. 228.

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