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• UCREFRP Catalog Number: 7400
• Author: Valdez, R. A.
• Title: The Endangered Fish of Cataract Canyon
• USFW Year: 1990.
• USFW - Doc Type: Final Report.
• Copyright Material: NO

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CATARACT CANYON STUDIES I

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Four Years

1985

Four Basic Gear Types

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Eight Habitat Types

Figure 9. Basic study elements of the Cataract Canyon studies, 1985-1988.

Sample efforts were generally concentrated within Cataract Canyon, and included logistic support from
Tag-A-Long Tours, a commercial river company in Moab. Confluence trips were usually 5 days afield,
with sampling conducted only above the confluence of the Green and Colorado Rivers. Flatbottom
boats and sportboats were launched and taken out at either Potash or Mineral Bottom, and all logistics
were handled by BIO/WEST. The number of canyon trips (six) each year was const.ant for all 4 years
of the st.udy. Except for one spring confluence trip each in 1987 and 1988, and one spring canyon trip
in 1988, all sample trips were conducted during the post-runoff period, from late June to mid-October
(Figure 8). Trips were conducted for one of five primary purposes identified in Table 1.

Launch sites were alternated in late summer to syst.ematically sample larval and YOY Colorado
squawfish in the lower Green River. The lower Colorado River was not sampled in the same manner
because work on YOY was being performed by the FWS/Grand Junction Field Station. Trips 3 and 5,
each in 1985, 1986, and 1987, were launched from Mineral Bottom to sample the lower Green River.
In 1988, trips 1, 3, 5, 7 and 8 were launched from Mineral Bottom. All other trips were launched from
Potash on the Colorado River. Thus, in the 4 years of study, 29 trips were conducted, including 11
launches from Mineral Bottom and 18 from Potash. Of these 29 trips, 25 were canyon trips and 4 were
confluence trips.

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