An Investigation of Some Factors Influencing the Performance of a Recreational Trout Fishery

The Tittesworth Reservoir 'put and take' trout fishery was investigated in 1977 following complaints from anglers that the fish were emaciated and difficult to catch. Various fish farms supplied the reservoir with trout until 1976 when the Severn-Trent Water Authority fish farm provided all the trout for stocking. Comparisons were drawn between fish from this source of supply and those from previous sources. Water quality and phytoplankton were monitored and fish marking was undertaken with associated analysis of weight changes and gut contents. In 1978, fish which had been bred at Calverton but cage-reared in an upland reservoir were compared with Calverton-reared fish. It was concluded that repeated drawdown of the reservoir for water supply, including the effects of the 1975/76 drought, may have reduced the numbers and species diversity of food organisms available. Results showed that many fish were not feeding well and had lost weight. Although current supplies of fish are satisfactory for stocking, the trout cage-reared in an upland reservoir appeared to adjust slightly better to conditions in Tittesworth Reservoir.