7144

• UCREFRP Catalog Number: 7144
• Author: Inslee, T. D.
• Title: Spawning and Hatching of the Razorback Sucker
• USFW Year: 1982
• USFW - Doc Type: Western Association of Fish & Game Agencies
• Copyright Material: NO

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13

River contains the most viable remaining population of the Colorado
squawfish and that any further development of the Grp.en River basin
could severely affect the continued reproductive success of squawfish.
He judged that the major threats to the squawfish are loss of habitat
through dewatering, altered streamflow patterns, and competition with
exotic fish species.
Joseph et al. (1977) noted that on the basis of the available
data, the Green River from its confluence with the Yampa to its ter-
minus at the Colorado River is important habitat for all four rare and
endangered species in the Colorado System, i.e., the Colorado squawfish,
razorback sucker, humpback chub, and bony tail chub.
BIO/WEST, Inc., has been sampling a station at Jensen for the
past two years as part of a study to determine the effects of Flaming
Gorge Dam penstock modifications upon fishes in the Green River. Young
and adult squawfish and adult razorback suckers have been captured
there with some frequency (Holden and Crist 1978) (Table 1).
Benthic Macroinvertebrates - Information on the benthic inverte-
brates of the Moon Lake study reach of the Green River is found in only
two reports. Pearson (1967) studied the distribution of macroinverte-
brates in the river. While most of his emphasis was on the reach im-
mediately below Flaming Gorge Dam, he did establish supplementary sites
at Split Mountain and at Ouray. At Split Mountain, mayflies (Ephemeroptera)
and chironomids comprised a major portion of the invertebrate fauna in
1964 and 1965. Pearson stated that the Split Mountain data was generally
similar to data he collected in Island Park 12 miles upriver. The Ouray