OCR Text |
Show The extreme annual fluctuations of Upper Stillwater Reservoir and Hayes Reservoir would curtail the prod activity of trout by creating undesirable changes in food production and water temperature. Currant Creek, Lower Stillwater, Bottle Hollow, and Jordanelle Reservoirs would have small or long- term drawdowns and trout prodjctivity would be better. Investigations have shown that fish production, in new reservoirs tends to increase rapidly for several years depending upon the densities of resident and introduced fish populations and the productivity of the basin. After a period of high tcout productivity and good angling the reservoir ecosystem reaches an equilibrium and introduced trout must compete for food and cover with native species of fish ( usually " tcash" fish), which are more adapted to the reservoir environment. Since the native species are prolific reproducers, they gradually out compete the trout. At this tLme trout production and fishing success decline. Heavy fish plantings alone usually cannot alter the above situation, although large plantings of " catchable" size trout can sustain a trout fishery. Such plantiags, however, are very costly. Tne usual manner of solving this fishery management problem is to eliminate or substantially reduce the " tcash" fish population by chemical treatment. In large reservoirs such a process is costly and very difficult. The most practical approach is to chemically treat reservoir sites prior to storage of water. This will be done on the Strawberry River between Soldier Creek Dam and the existing Strawberry reservoir Dam. The quality of trout fishing in Deer Creek and Starvation Reservoirs is presently adversely affected by the presence of excessive numbers of " trash" fish-- particularly the Utah chub. This problem does not occur in Strawberry Reservoir because the population of competitive " tcash" fish is low, ^° the reservoir having been chemically treated in 1961. lei |