7728

• UCREFRP Catalog Number: 7728
• Author: Stone, R. C. and F. Eiserman.
• Title: Background of Flaming Gorge Reservoir Fisheries Investigations.
• USFW Year: 1979.
• USFW - Doc Type: Publication # 78-9,
• Copyright Material: YES

86 trout per ha (56 to 213 per ac). Rainbow trout that were stocked, including
both spring and fall spawn, ranged in size from 44 to 573 per kg (20 to 260 per Ib).
From these plants the yield to the fisherman in pounds varied from a low
153,800 kg (339,000 Ibs) to a high ofapproximately 367,400 kg (810,000 Ibs). As
has been noted, catch rates varied from almost 1.3 fish per hour to a low of 0.5
fish per hour.

As a result ofthe development of nongame fish species, in particular the Utah
chub, plus changing physical conditions in the reservoir which precluded a
single species management concept, additional game fish species were
introduced. To provide a game fish that would take advantage of the abundant
chub population, especially in the inflow area, brown trout (Salmo trutta) were
introduced, Food habit studies have since indicated that this species has
capi talized on this abundant food base and provides trophy-size fish to the catch.
Kokanee (Oncorhynchus nerka) a more efficient plankton feeder than the chub
was also introduced. In addition to the plants of salmonids and to take
advantage of the chub forage base available in the littoral zone during summer,
smallmouth and largemouth bass introduction programs are currently
underway. At the time of this writing, the success of these latter stockings has
not been evaluated; however, there is information verifying limited populations
of smallmouth bass. In addition to the stocked salmonids, lake trout and
cutthroat trout occupy the reservoir through immigration, Findings over the
first nine years of work noted that as the reservoir aged, an imbalance in the
biological pyramid developed with a substantial bulk of the fishery population
being made up of nondesirable components. To increase the magnitude of
desirable components and decrease the size of undesirable components, the
following recommendations were made and essentially implemented.

1, Increase the average size of rainbow trout planted to five inches.

2. Introduce a littoral area predator that would capitalize upon nongame fish
species found in these areas during the summer months and would provide a
summer fishery.

3. Introduce a forage species that would compete with Utah chub by more
effectively utilizing plankton resources, Ideally, it should also serve as
forage for the salmonid species, especially during the summer.

It is interesting to note that at the time of this writing, the lake trout, not
introduced, has developed as a trophy species. Although this species does not
now contribute in significant numbers to the catch, it is considered a valuable
additon to the sport fishery,

White sucker populations have developed to the point that they could become a
significant problem in the future, This species was not collected in
preimpoundment studies, It has become established in some tributary lakes of
the middle Green River drainage in Wyoming, probably from fisherman
introductions via the Platte River system, and thus into Flaming Gorge
Reservoir, At the time of this writing, the Utah chub appears to be the most
significant deterrent to a productive salmonid fishery and has dictated
management programs in reaction to its abundance.

Redside shiners have maintained their position of abundance in the spectrum of
fish populations both in pre- and post-impoundment estimates. However, this
species does not appear to be a significant interspecific competitor, nor does it

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