7150

• UCREFRP Catalog Number: 7150
• Author: Holden, P. B. and L. W. Crist.
• Title: Documentation of Modification of Endemic Fish Species and Macroinvertebrates in the Green River below Flaming Gorge Dam.
• USFW Year: 1978.
• USFW - Doc Type: Logan, Utah.
• Copyright Material: NO

~ ..

INTRODUCTION

This biannual report is the first for the outlet modification of
Flaming Gorge Dam study, and includes the Yampa River stations funded
by Dinosaur National Monument. It reports on the sampling conducted
between March 1, 1978 and June 30, 1978. Field samples were made on
March 10-16 and June 9-15 on the Green River, and on June 16 and 17 on
the Yampa River. Testing of the outlet modifications occurred in late
June, after these samples had been taken. An additional sample in early
July, 1978, will be taken on the Green River stations. It is anticipated
that this will also be a "before" sample since it is doubtful that warm
water releases starting in late June will measurably affect the bio-
logical communities for several weeks. This report does not analyze
or report in depth on the study to date, but rather shows what has been
found and outlines future work.

METHODS

Macroinvertebrates have been collected with a modified Hess sampler,
usually in water 12-18 inches deep over a gravel-cobble substrate.
Stations for invertebrate samples are Little Hole, Taylor Flats Bridge,
Lodore, and Jensen (U.S.G.S.) on the Green River, and Lily Park and
Boxelder Park (Lower Yampa) on the Yampa River (Figure 1). The Yampa
River stations were not sampled in March. These stations are as
suggested in BID/WEST's proposal, except that the Lodore station was
moved downstream approximately 3 miles to the nearest area of cobble

J '