-48- 



that any of the scaled fishes could ever be important in the Heyburn fishery, 

 future management would do well to concentrate on catfish production. 



Total Population Estimates 



On the basis of rotenone samples, the standing crop of fish per acre at 

 Heyburn was considerably less than that at Upper Spavinaw, and far below that 

 for other Oklahoma reservoirs. Six coves, totalling 12.8 acres, were rotenoned 

 at Heyburn in 1954, and an additional 3 coves, totalling 3.7 acres, were treated 

 in 1955. One large cove of 10.0 acres was treated at Upper Spavinaw in 1955. 

 All coves were closed off with nets to minimize movement by fish in or out of 

 the sample areas. The data for 1955 for both reservoirs (Table 13 > were based 

 on complete recoveries of all but the smallest fishes. These small fishes were 

 relatively scarce at Heyburn, but the fry of sunfishes, brook silversides, and 

 fingerling bass, were extremely abtmdant at Upper Spavinaw, and their weights 

 were estimated. For 1954, however, the Heyburn data are less complete since 

 recoveries from three of the areas treated included only those fish which 

 surfaced the first day. Should the total average recovery of 55.5 pounds per 

 acre be doubled, the adjusted figure of 111.0 F»otmds is believed to represent 

 .the maximum possible poundage from these areas. Both this yield, and the yield 

 of 117 pounds per acre from Heyburn in 1955 are well below the yield of 177 

 pounds per acre from Upper Spavinaw, and much below the averages recorded from 

 similar experiments in other Oklahoma reservoirs. Thompson (1950) treated 

 8 areas, totaling 15.75 acres of clear Grand Lake (46,300 acres), and re- 

 covered an average of 623 pounds per acre. Jackson (1955) treated 8 acres of 

 the clear Lower Spavinaw Reservoir (1,637 acres) and recovered an average of 

 540.6 pounds per acre. From the turbid Claremore City Lake (470 acres), 

 Jenkins (1949) recovered an average of 236.4 pounds per acre from a treatment 



