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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flows made comparisons unrealistic and caused statistical testing to
show non-significant differences. Stations on the Yampa River and at
Jensen on the Green River did not show significant differences in
total densities between years.
Species Occurrence and Distribution
Spatial Trends. Occurrence of individual taxa for each station
from 1978 through 1980 is listed in Table 7. Individual taxa den-
sities for each sample period from 1978 to 1980 are presented in Table
27 of Appendix II. Baetis spp., Simulium sp., Chironomidae, and
Gammarus lacustris all exhibited highest densities near the dam at
Little Hole (7 MBD) and Taylor Flats (16.5 MBD) (Figure 2) and were
the domi nant taxa present at these stat ions. Wade and Curt is (49 MBD)
supported many of the same taxa as Little Hole and Taylor Flats (Table
7). However, greater numbers of organi sms whi ch occurred sporadi ca lly
at the upper two stat ions such as Ephemere 11 a i nermi s, Brachycentrus
sp., Hydropsyche sp., and Hydroptila sp. were often observed at this
station. Dominant taxa at Wade and Curtis included Baetis spp.,
Chironomidae and Brachycentrus sp. Stations on the Yampa River and
the lower Green River (Jensen) supported many additional taxa, pri-
marily Ephemeroptera and Trichoptera, not found in the Green River
immediately below Flaming Gorge. Dominant taxa at these stations
varied seasonally, dependent on the life histories of the organisms
involved. Baetis spp. and Chironomidae tended to dominate spring and
early summer samples while seasonally abundant species such as
Traverella albertana, Tricorythodes spp., Hydropsyche sp., and