6006

• UCREFRP Catalog Number: 6006
• Author: Holden, P. B. and L. W. Crist.
• Title: Documentation of Changes in the Macroinvertebrate and Fish Populations in the Green River Due to Inlet Modification of Flaming Gorge Dam
• USFW Year: 1981.
• USFW - Doc Type: Final Report.
• Copyright Material: NO

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errors which may result with organisms that tend to clump together (EPA
1973).
The invertebrates were identified to genus, or the lowest practical
taxonomic level using a variety of taxonomic references (Merritt and
Cummins 1978; Edmunds 1976; Baumann 1977; Musser 1962; Edmondson 1959;
Wiggins 1977; Usinger 1956; Pennack 1953).
The results of the four benthic samples at each station were pooled
and, from this, the mean, standard deviation and coefficient of variation
were computed. Species diversity for each station was determined, using
the Shannon Weaver species diversity index (EPA 1973).
Fishes
Fishes were collected using an electrofishing unit consisting of a
115 volt A.C. generator and a Coffelt Model II-C VVP, and seines (30' x
6' x ~" and 151 x 41 X 1/8"). Electrofishing runs were timed, and the
area seined was recorded. Fish were identified, enumerated, sufficient
numbers measured to provide length-frequency data and all but a few
reference specimens returned alive. Fish over 200 mm TL were tagged
with coded Floy spaghetti tags. Rare fish were tagged with small
modified Carlin dangler tags. Habitat type, substrate, and a sketch of
the area sampled were recorded for each seine collection. Shocking runs
usua lly covered a vari ety of habitats and substrates, so phys i ca 1 data
recorded for these samples were more generalized.
When rare fish [Colorado squawfish, humpback chub, bony tail chub
(Gil a e 1 egans), and humpback sucker (Xyrauchen texanus)] were captured,