7324

• UCREFRP Catalog Number: 7324
• Author: Schmidt, B., et al.
• Title: Flaming Gorge Reservoir and Green River Post-Impoundment Investigations Annual Performance Report 1977.
• USFW Year: 1978.
• USFW - Doc Type: Publication No. 78-4,
• Copyright Material: NO

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Growth of catchable trout differed between those planted in 1977
and 1976. Those stocked in 1977 showed a large increase in average
length between stocking and the first period of capture, while the
older fish stocked in 1976 had their largest increment of growth in
1977 late in the fishing season. The most likely explanation of the
apparently large growth early in the season and slower growth later
for the 1977 plants is that anglers were selecting for the larger of
the catchables early in the season and returning the smaller ones to
the water.. Later in the season, when some growth had actually occurred,
the anglers probably were less selective. Therefore, the estimates of
growth based on angler caught fish are most likely unreliable.
Growth of fingerling rainbow trout was determined from electro-
shocked fish, since they were too small to enter the creel. Rainbow
trout fingerling stocked in late summer, 1976, exhibited poor growth
when captured in October, 1977. These fish were planted as 127-mm
(5-in) fingerlings,but after more than a full year in the river, they
were only 203 mm (8 in) in the vicinity of the tailrace. Growth was
better farther downstream, presumably due to warmer summer water
temperatures. After a year, these same fish reached 269 mm (10.6 in)
at Little Hole and 312 mm (12.3 in) at Brown's Park. Although growth
was greater in Brown's Park, the harvest of these fish was small--far
below the catch at Little Hole or at the tailrace.
Species composition in the Green River in October as determined
from electro-shocking differed from creel caught fish. The largest
single component of the population was fingerling rainbow trout planted
in 1976 (Table 20). Fish stocked as catchables, the largest component