8185

• UCREFRP Catalog Number: 8185
• Author: Valdez, R. A. and B. R. Cowdell.
• Title: Annual Summary Report-1992\
• USFW Year: 1993.
• Copyright Material: NO

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river flows that desiccated or inundated backwater. However, fish displaced from backwaters are expected to
move a short distance before finding another suitable backwater.

Distribution data from this study indicate that extensive downstream movement during the winter period was
minimal. Figure 3 shows average catch rates from fall and spring sampling for all 5-mile sections sampled
since 1987 on Green River Reach 3. Figure 4 is the cumulative CPE from the beginning of the reach (Green
River, RM 120) to the confluence (RM 0), cumulative CPE for fall mirrors that for spring sampling. These
data suggest a 5 - 10 mile downstream movement from fall to spring in some 5 mile sections, but there is no
consistent evidence of substantial movement of fish into or out of Reach 3 during the 6 month winter period.

Fall to spring decreases in catch rates for Green River Reach 3 were probably not significantly influenced by
movement of fish during the winter period. Downstream movement appeared to be minimal-- 5 - 10 miles
at the most. This short-range movement likely accounted for some of the yearly fall to spring differences
observed within the 5-mile sampling sections.

I ~ FALL SAMPLING. SPRING SAMPLING I

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Five-Mile River Sections

Figure 3. Geometric mean CPE for all five-mile river sections sampled in Green River Reach 3 during fall
and spring sampling (1987 through 1992 combined).

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