9705

• UCREFRP Catalog Number: 9705
• Author: Green River Study Plan ad hoc Committee.
• Title: Study plan for the implementation and evaluation of flow and temperature recommendations for endangered fishes in the Green River downstream of Flaming Gorge Dam.
• USFW Year: 2007.
• USFW - Doc Type: Upper Colorado River Endangered Fish Recovery Program
• Copyright Material: NO

GREEN RIVER STUDY PLAN

33

February 2, 2007

· Habitat conditions at beginning of base flow period in Reach 2 (information need).

Implementation

· Ongoing Project 138.-Annual age-O Colorado pikeminnow monitoring is ongoing, and a
fmal report on monitoring results is due in August 2008. This report will use past and
current data to evaluate the relationship of age-O Colorado pikeminnow size and relative
numbers to backwater characteristics, flow, and temperature.

· Ongoing Project 22f -Annual monitoring of Colorado pikeminnow is ongoing, and used
to determine timing and duration of spawning by Colorado pikeminnow and presence and
abundance of larvae in the system as measured by capture of larvae downstream of
spawning areas in the lower Yampa River. Monitoring would continue indefinitely. The
need for modifications of monitoring protocols and the need for continued monitoring
would be evaluated periodically.

· Ongoing Project 144. This study evaluates response of native fish to nonnative predator
removal with a synthesis report due in 2007.

· New Start.-This study should integrate data collected under Projects 138, 144, and
Western's backwater topography studies to further evaluate the effects of flow variability
on Colorado pikeminnow abundance and condition and nonnative fish communities.
This integration report should be started in FY 2008 and completed in FY 2009.

3.3.3 Nonnative Fish Mana~ement in Reach 1 and UDDer Reach 2

.
Nonnative fish are considered a major impediment to recovery of the endangered fish
species throughout the Colorado River Basin. The Recovery Program has implemented
numerous programs to manage and control the more problematic species, including northern
pike, smallmouth bass, and channel catfish. Many of these programs are ongoing and are not
directly related to the flow and temperature recommendations for the Green River.

Flow and temperature options may be available for managing nonnative fish populations
and reducing their threat to endangered fish species. Aspects of the life history of nonnative fish
that may be affected by flow and temperature conditions should be investigated.

The fish community in Reach 1 is most directly affected by Flaming Gorge Dam releases.
Research and monitoring should continue in this portion of the river (e.g., Study #115) to
evaluate the effects of flow and temperature recommendations. Information from this study
coupled with experimental releases in the future may lead to flow and temperature
recommendations to control nonnative fish populations. Relationships established in Reach 1
between flow and temperature and various aspects of nonnative species life history could assist
Recovery Program efforts throughout the Upper Basin. .

Entrainment of nonnative fish in the spillway at Flaming Gorge Dam should be evaluated
and escapement through the dam needs to be determined to understand the risk of spills. In
Reach 2, fish populations should continue to be monitored in Whirlpool and Split Mountain