POWER OFF 



195 205 215 225 235 245 255 265 275 285 295 305 315 325 335 

 TOTAL FISH LENGTH (MM) 



195 205 215 225 235 245 255 265 275 285 295 305 315 325 335 



TOTAL FISH LENGTH (MM) 



Figure 8. — Chub length-frequency distribution with elec- 

 trode array 2. Solid line, power on (N= 226; mean 

 = 250.7) ; dashed line, power off (N = 92; mean 

 = 243.2). Z test for the difference between the two 

 sample means at 0.05 level of probability: calculated 

 Z = 3.15, tabular Z = 1.96; significant. 



Figure 10. — Chub length-frequency distribution with 

 electrode arrays 1, 2, and 3 combined. Solid line, 

 power on (N = 387; mean = 250.7) ; dashed line, 

 power off (N = 208; mean = 245.7). Z test for 

 the difference between the two sample means at 0.05 

 level of probability: calculated Z = 4.58, tabular Z 

 — 1.96; significant. 



205 215 225 235 245 255 265 275 265 295 305 315 325 

 TOTAL FISH LENGTH (MM) 



Figure 9. — Chub length-frequency distribution with elec- 

 trode array 3. Solid line, power on (N = 62 ; mean 

 = 258.4); dashed line, power off (N = 81; mean 

 = 253.7). Z test for the difference between the two 

 sample means at 0.05 level of probability: calculated 

 Z = 1.69, tabular Z = 1.96; not significant. 



POWER OFF 



165 175 185 195 205 215 225 235 245 255 265 275 



TOTAL FISH LENGTH (MM) 



Figure ll.-Yellow perch length-frequency distribution 

 with electrode array 2. Solid line, power on (N = 55 ; 

 mean = 195.9); dashed line, power off (N = 20; 

 mean =: 191.0). Z test for the difference between 

 the two sample means at 0.05 level of probability: 

 calculated Z = 0.75, tabular Z = 1.96; not signifi- 

 cant. 



