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75 and 100 ppm for all three species, with 100 ppm as the approximate level 

 above which spawning success was severely restricted, or non-existent. The 

 critical limit for bass appeared to be somewhat below that for the sunfishes. 

 Successful reproduction was achieved in the newer, hard-bottomed ponds at 

 somewhat higher turbidities than in older ponds, but reproduction was generally 

 of low proportions when turbidities exceeded 100 ppm. As mentioned pre- 

 viously, a small number of young bass and redear were recovered from one 

 pond having an average turbidity of 239 ppm. This was somewhat surprising 

 since no young were recovered from several ponds having much lower turbidities. 

 It is believed possible that these young fish were stocked by one of the many 

 persons having an interest in the pond since it was located in a comparatively 

 urban area, and both young bass and redears were available from adjacent ponds. 



Table 5 shows that Pond No. 19 was the most turbid (average turbidity: 76 

 ppm) from which a reasonably large weight of yoiing bass was recovered. This 

 yield was at the rate of 24.2 pounds per acre of young of the year bass, which 

 represented an est mated 1300 individuals per acre averaging 3.0 inches in 

 length. The next most turbid pond (94ppm) yielded only 4.8 pounds, or 650 

 individuals per acre with a smaller average length of 2.6 inches. The next 

 record is for a pond having an average turbidity of 122 ppm, from which the 

 yield was 4.6 pounds per acre, representing 87 individuals with an average 

 length of 4.6 inches. A very limited number of young bass were seined from 

 one other pond having an average turbidity of 148 ppm, and no reproduction was 

 found in any pond having a higher turbidity with the exception of the single 

 pond mentioned above. 



Pond No. 19 with an average turbidity of 76 ppm also yielded fairly large 

 numbers of young redears (Table 5), but production dropped notably in more 



