May, 1945 



Bennett: Overfishing^ Onized Lake 



395 



Table 22. — Average growth of bluegills in Illinois, based on growth in five large bodies of 

 water representing northern, central and southern locations, and three types of lakes. 



Average Total Length in Inches at End of Growing Season 



Sixth Seventh Eighth 



8.0 8.2 8.0 



u 



r 

 u 



z 



Fig. 7. — Average rate of growth of bluegills in Onized Lake (final 1941 collection] 

 Lake (1938 brood) and in five large natural lakes in Illinois (1930-1938). 



in 



Fork 



Schloemer. Bluegill growth in Onized 

 Lake was considerably faster than that in 

 the five lakes, but much slower than the 

 growth in Fork Lake, where the popula- 

 ) tion was not crowded because the lake had 

 been newl}- stocked the preceding year 

 and there was little competition for food. 



Warmouth Bass 



C/iaenobryttus gulosus (Cuvier) 



Warmouth bass were of little value to 

 the fishermen of Onized Lake. Although 

 1,638 of these fish were collected in the 

 final census ( 1941 ) , their total weight was 

 only 28.6 pounds, and only 13 were large 

 ; enough to interest fishermen, tables 7 and 

 8. In the yield taken by fishermen (1938- 



1941), 105 warmouth bass weighing 33.4 

 pounds were recorded, table 5. 



Table 23 gives the length and age 

 distribution of the warmouth bass collect- 

 ed in the 1941 final census of Onized 

 Lake. None of the 1941 spawn were seen 

 or collected, but it is probable that because 

 of their small size they were not observed 

 when the treatment was first applied. 



Calculated lengths based on scale studies 

 were determined for 101 warmouth bass, 

 which included most of the larger individ- 

 uals, table 24. 



In fig. 8, the growth curve of warmouth 

 bass from Onized Lake is compared with 

 a growth curve constructed from Schof¥- 

 man's data (1940) on the warmouth bass 

 in Reelfoot Lake. In Onized Lake the 



