-49- 



of 3.5 acres o 



Abundances of the various species in the rotenone returns from Heyburn and 

 Upper Spavinaw are shown in Table 13. In summary^ the outstanding differences 

 were these. 



1, In clear Upper Spavinaw^ the gizzard shad represented 73.7 percent of 



the total weight of fishes^ followed in order by bluegills (6.1 percent), 

 largemouth bass (5.7 percent )„ carp (3.8 percent )„ with the channel and 

 flathead catfishes of no significance (both representing less than 0.01 

 percent of the total weight of fishes). 

 2o In muddy Heyburn, shad ranked only fourth in 1955 (eighth in 1954) „ 

 with carp first (23=7 percent )j channel catfish second (15.8 percent), 

 river carpsucker third (16.0 percent )„ flathead catfish fifth, bass 

 sixth, and bluegills eleventh, 



3. The ratio of the forage fishes (shad, minnows and the small sunfishes) 

 to the predaceous bass and crappie was approximately 1 to 1 at Heyburn 

 and approximately 13 to 1 at Upper Spavinaw, While the 13 to 1 ratio 

 is somewhat higher than is generally believed desirable, it is of the 

 order necessary to maintain a satisfactory sport fishery such as Upper 

 Spavinaw now supports „ 



4. In Heyburn the combined weight of the rough fishes (carp, river carp- 

 suckers, and the two species of bullheads) represented 42.4 percent 

 of the population by weight, as compared with a total of 7.0 percent 

 for the carp, bullheads, and the 5 spjecies of suckers present at Upper 

 Spavinaw. 



On the basis of supplementary sampli-ng data, the proportfons xsf various 

 species in Heyburn rotenone samples are believed to reflect accurately the true 



