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basic food production, and fishing success., 



Turbidities were measured by the Jackson Turbidimeter which makes no 

 determinations low^r than 25 ppm. For the purpose of computing average 

 turbidities for those ponds which ranged above and below the 25 ppm level, 

 an arbitrary value of 15 ppm was substituted in the calculations for all 

 readings of "less than 25 ppm." 



Plankton referred to are net plankton collected with a Wisconsin 

 type net made up with No. 25 mesh silk bolting cloth. Plankton counts 

 were made by use of the Sedgwick-Rafter counting cells Volumetric measure- 

 ments were made by centrifuging the plankton concentrates from 30 liter 

 samples at 3000 RPM for two minutes. 



All fish lengths were recorded in inches and tenths and all weights 

 in pounds and hundredths of pounds. All lengths used herein refer to total 

 lengths. 



Final population estimates in the farm ponds were computed from the 

 percentage of marked fish recovered following treatment by rotenone. Fish 

 were ordinarily marked one or two days previous to the rotenone treatment. 

 The marking technique used was to remove a small section of the upper lobe 

 of the caudal fin» Bass of all sizes were marked, but it was found im- 

 practical to mark sunfishes less than 3 inches in length. The smallest 

 bass were mostly longer than 3 inches, but on one occasion bass as small 

 as l.,9 inches were successfully marked and recovered. Numbers and weights 

 of small, unmarked bluegill and redear were estimated by collecting all 

 fish for as many days as they continued to appear (7 days in some instances) 

 and multiplying the totals by three. The multiple of three was chosen on 

 the basis of returns from a marking experiment made in one small pond and 



