7418

• UCREFRP Catalog Number: 7418
• Author: Tyus, H. M. and C. A. Karp.
• Title: Stream Flow Needs of Rare and Endangered Fishes, Yampa River, Colorado.
• USFW Year: 1988.
• USFW - Doc Type: Vernal, Utah.
• Copyright Material: NO

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Table 2. Optimum Colorado squawfish spawning period, Yampa River 1981-1987.
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Year Type Wa~er Discharge2 Optimum Spawning -------------------------
Water Temperature (C)4
Year Period
1981 Low Mean = 893 6/23-7/13 Range: 18-25.5
Max. = 1,327 Mean max. = 24.8
Min. = 437 Mean min. = 19.3
1982 Ave. Mean = 3,825 7/8-8/1 Range:. 16.5-27.5
Max. = 6,230 Mean max. = 23.3
Min. = 2,430 Mean min. = 19.5
1953 High Mean = 3,044 7/15-8/10 Range: 18-27
Max. = 4,990 Mean max. = 24.3
Min. = 1,470 Mean min. = 21
1984 High Mean = 2,535 7/16-8/15 Range: 20-24
Max. = 4,550 Mean max. = 23.8
Min. = 1,040 Mean min. = 20.3
1985 High Mean = 2,261 6/25-7/17 Range: 14.5-25.5
Max. = 4,800 Mean max. = 22.8
Min. = 1,010 Mean min. = 17.8
1986 High Mean = 2,383 7/2-8/2 Range: 18.5-23
Max. = 4,600 Mean max. = 22.5
Min. = 933 Mean min. = 19.5
1987 Low Mean = 2,110 6/9-7/3 Range: 16.5-24.5
Max. = 4,530 Mean max. = 22.9
Min. = 847 Mean min. = 17.4
1 Designation of low, aver age, and high water years a fter Butler (1988)
(i.e., low:<1514cfs, ave rage:I514-2760cfs, high:>27 60cfs).
2 USGS Records (1981 sum o f Maybell and Little Snake Gauges; 1982-1987
Deerlodge Gauge). Daily discharge data for optimum spawning period were
used.
3 Derived from contact wit h radiotagged adults and co llection of ripe fish
on spawning ground, and back calculation of larval age.
4 USGS Records (1981-Maybe ll Gauge, 1982-Deerlodge Ga uge) and Hand-Held
Thermometers (1983-1987, data collected on spawning ground). Mean minimum
and maximum values were calculated from early morni ng and afternoon
temperatures respectivel y, for optimum spawning per iod.
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