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Increased catches of rainbow trout in 1972 and 1981 are attributable, in part, to increased lake elevations in 1971 and 1980. Greater water area amounts to increased production and greater survival of trout. Historically, fishing pressure was highest in 1967 and generally declined through 1971 (Figure 6). From 1972 through 1976, U.S. Forest Service use esti- mates were used to calculate fishing pressure. During those years, estimated fishing pressure increased dramatically, even though investigators and creel clerks felt that the indicated increase was, in fact, not occurring. When use of Forest Service data was discontinued and the aerial count survey was ini- tiated in 1978, the resulting estimate was similar to the 1971 estimate. Consequently, fishing pressure in the intervening years was taken to be a straight line between 1971 and 1978. The interpolated pressure estimates seem more in line with expected fishing pressure, given the general declining fishing success, gas shortages during 1973 and 1974 and the general observations made by biologists and long-term residents of the area (Schmidt et al. 1980b). Annual harvest has declined drastically since second peak in 1974, which approached the historic questionable pressure estimates and is, therefore, based on interpolated pressure estimates from 1972 general declining trend. Estimates of the harvest lowest yield of the fishery. 1965 and 1966 (Figure 5). The high was based upon suspect. Harvest estimates through 1977 followed the in 1980 represented the Rainbow trout have always constituted the largest proportion of the harvest from Flaming Gorge (Table 19), with brown trout and lake trout contributing most of the rest of the harvest. Total numbers of rainbow trout declined steadily from 1973 to 1980. The increase in harvest of rainbow trout during 1981 and 1982 from levels seen in 1979 and 1980 may be related to increases in produc- tivity and survival of stocked rainbow trout due to increasing reservoir eleva- tions. It is doubtful that the numbers of rainbow trout in the harvest or their percentage return to the creel will ever approach the number harvested prior to 1975. Competition between rainbow trout, Utah chub, white sucker, and kokanee salmon for available plankton, predation by lake trout and brown trout and intense fishing pressure affect survival rates of stocked rainbow trout. Average lengths and weights of rainbow trout (Table 26) have varied little bet- ween 1978 and 1982. Most of the rainbow trout harvested are.l year old (Schmidt et al. 1980b), and very few beyond 3 years of age are ever seen in the creel. Poor returns and survival of rainbow trout in view of the conditions which they face in Flaming Gorge, are problems which will not be overcome easily. Unless a strain of rainbow trout can be found which does not depend on plankton and will use a forage fish, the future of the rainbow fishery in Flaming Gorge does not look bright. Stocking of strains of rainbow trout which become predacious and live longer would likely mean that the reservoir would have to be managed as a trophy fishery rather than a family-oriented, fast catch rate type fishery. Plans have already been made to test McConaughy, Eagle Lake, and Gerrard (Kamloops) strains of rainbow trout starting in 1986. Equal numbers of each strain will not be available until that year. The basic guideline for the strain evaluation will be that rainbow must return to the creel at least one pound of fish for each pound of trout stocked. Should any strains of rainbow fail to provide an acceptable fishery or fit into a suitable management plan in any area of the reservoir, then attempts should be abandoned to revive the fishery for that strain of rainbow in those areas. Clearly, returns of rainbow -46- r r r 1 1 s