1108

• UCREFRP Catalog Number: 1108
• Author: Valdez, R. A.
• Title: Fisheries Biology And Rafting Annual Summary Report - 1987
• USFW Year: 1988.
• USFW - Doc Type: ‎(Contract no. 6-CS-40-03980)‎.
• Copyright Material: NO

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REXD9JEN[V\TI(R;

The following recommendations are made relative to the objectives of the study
as a result of the 1987 investigations in Cataract Canyon:

General Recommendations:

1. Additional studies within Cataract Canyon and the vicinity are recommended
for at least 1988.

2. As in 1987, six "canyon trips" are recommended through Cataract Canyon from
late June through early October, 1988.

3. Larval and YOY sample efforts on the Green and Colorado rivers should
continue to be closely coordinated with those of the FWS and the Utah
Division of wildlife Resources (rMR) to minimize the mortality on young
squawfish from seining efforts.

4. Sampling for YOY and juvenile Colorado squawfish should be conducted on the
Colorado River from Potash to the confluence in a similar manner to that
presently being done on the Green River from Mineral Bottom to the con-
fluence.

5. An intensive 5 to 7-day survey is proposed in late March, 1988, to assess
over-winter survival of YOY Colorado squawfish. Seining should be conducted
according to the Standardized Monitoring Program on the Green River from
Mineral Bottom to the confluence and on the Colorado River from Potash to
the confluence. This effort should be coordinated with UDWR and FWS.

6. Larval drift netting should be continued during the first three or four
canyon trips in 1988, even though this sample gear has not yield many fish.
The value in continuing this sample method is in gaining a better
understanding of drift patterns in the area.

Objective 1: Determine spawning locations of endangered fishes in Cataract.

1. Continue intensive electrofishing and gill/trammel netting are recommended
during canyon trips 1 and 2. The effort should be concentrated in each of
two specific locations for 3 to 4 days. The recommended locations are
Cataract Lake (RM 206.8-205.5) and upper Ten Cent (RM 201.1-201.4). This
sampling scheme is recommended because (a) these are areas that have yielded
Colorado squawfish, humpback chub, and suspected bonytail, (b) these areas
are accessible to our rafts and sample gear during the high flows of early
July, and (c) these are areas that contain possible spawning habitat
Colorado squawfish and humpback chub.

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