22 



24 



5 MIN.- 120 C.RS. 



MIN.- 140 C.RS. 



14 



22 



14 



5 MIN.- 140 C.R S. (INTERMITTENT) ONE SEC. INTERVALS 

 ■99J 21 I 



5 MIN. CONTROL (WITH FISH AS END OF TEST NO. 21) 



(INTERMITTENT- ONE SEC. INTERVALS) 

 5 MIN.- 140 C.RS. (WITH FISH AS END OF TEST NO. 22) 



5 MIN. CONTROL 



J 



Figure 11. Distribution of fish In pens, experiments 19-2U. Experiments 19, 

 20 and 2li started with 1,000 fish in pen No. 1 (far left); 20 started with 

 1,0$0 fish in pen No. 1, others as Indicated. In ccntrols, gates between pens 

 were raised for indicated period, then lonered. Procedure same in tests, 

 except sounds of indicated frequency (cycles per second) and duration applied 

 at Indicated location while gates up. Numbers and dark bars show distribution 

 of fish after gates lowered. 



13 



