RESULTS 



The numbers of fish recovered in the 

 narrow channel for each treatment have been 

 summed and are listed with the total numbers 

 of fish recovered downstream for each treat- 

 ment : 



Positive Upstreajn: 



700 guided 1,607 total downstream 



Positive Downstream: 



735 guided 1,512 total downstream 



Alternate Polarity: 



681 guided 1,616 total downstream 



The mean data, grouped by electrical 

 treatments and release lots (table 2), give 

 a comparison of the effects of the electri- 

 cal treatments and the three release lots. 

 These data were analyzed for differences 

 between treatments, days, and sample sizes. 

 Results show that fish group size and days 

 experiments were conducted had no effect on 

 guiding efficiency, but a significeuit dif- 

 ference was found in guiding efficiency by 

 type of treatment (table 3). 



DISCUSSION AND CONCLUSION 



Szunple Size 



Control: 



237 guided 1,502 total downstream 



This relative guiding effectiveness is 

 portrayed in figure 5. 



\///A Tolol Oownstreom 

 I I Narrow Channel 



Positive Alternote 



Downstream Polarity 



Control 



Figure 5. - Relative fish-guiding effectiveness of three 

 methods of energizing an electrode array. The ef- 

 fectiveness is indicated by the ratio of the number 

 of fish in the narrow channel to the total number 

 recovered downstream. Totals for all release lots 

 are combined. 



The daily behavior of the fish is 

 rather variable. This variability was 

 treated as variance (analyses in appendix) 

 with the figures grouped according to the 

 treatment by samples size (number of fish 

 downstream). In each case the variance 

 decreased from the 15-fish release to the 

 100-fish release, a relation portrayed in 

 figure 6. 



^ i. 



10 20 30 40 50 60 70 80 



AVERAGE NUMBER DOWN 



Figure 6. --Relation of standard deviation of percent 

 effectiveness to average number of fish down- 

 stream (sample size). 



In previous experiments and explora- 

 tory trials, release lots of 50 fish each 

 were generally used. Following the explora- 

 tions described in the beginning of this 

 report, a complete experiment was carried 

 out using releases of 50 fish. Eight repli- 

 cations of four conditions were tested in 

 a period of 4 days. No differences were 

 found between three electrical conditions. 



