The fish were then allowed to pass through 

 the gate and commence their ascent of the 

 fishway. When an adequate sample of fish 

 had entered, the entrance gate was closed. 

 Each trial was terminated when all fish 

 entered had passed through the fishway. 



The opening of the entrance gate 

 signaled the start of each trial. Observers 

 stationed at the first weir (54 2^) and the 

 last weir (60 2/) were equipped with push- 

 button switches that activated recording 

 pens in an operations recorder. The moment 

 a fish passed weir 54 or weir 60 the corre- 

 sponding switch was pressed and a recording 



3/ The numbers 54 and 60 refer to the 

 "" elevation of the weir crests in feet 

 above mean sea level. 



pen marked the time of passage (as related 

 to the start) on a continuous paper tape. 



RESULTS AND DISCUSSION 



The results of the four control and 

 four test trials are presented in figure 5 

 (see Appendix 1 for origincil data). The 

 median entry (at weir 54) and median exit 

 (at weir 60) times for the grouped control 

 (n = 103) and grouped test trials (n = 83) 

 correspond to the intersection of the median 

 or 50 percent line sind the respective cumu- 

 lative percent lines. Examination of these 

 median times reveals two main points: (1) 

 the fish were slower in entering the fishway 

 under the dark condition thein under the 

 light condition, as evidenced by the differ- 

 ence in the respective median entry times 

 at weir 54,aand (2) the length of time 



Z 

 U) 



o 



tc 



tu 



Q. 



> 



< 



_J 

 ID 



O 



100 

 90 

 80 

 70 

 60 

 50 



40- 



30- 



20 



10 



Light"entry 



0° "Dark"entry ^j'^ 

 / 



•r.~' ■ 



"Dork" exit-,.. 



.••/ 

 .••/ 



/^■Lighf"exlt 



/ 



._LJ__i. 



/ 



o • I 



I • ' 



o • I 



% •! 



. I 



::/ 

 :/ 



50 



60 



— I 

 65 



— t— 

 5 



— I — 

 10 



15 



20 



1 



25 

 TIME 



— I — 

 30 

 IN 



1 1 — 



35 40 

 MINUTES 



45 



55 



Figure 5. --Cumulative entry and exit (percent) in minutes during light and dark 

 fishway trials. 



4 



