10 MIN.- I SjOOO C.P.S. 



63 



10 MIN. CONTROL 



64 



gy 



78 



53 



42 



64 



10 MIN. -18,000 C.P.S. 



65 



66 



16 



25 



10 MIN.- CONTROL 



Figure 19.-Distribution of fish in pens, experiments 63-66. All experiments started with 1,000 fish m pen 

 No. 1 (far left). In controls, gates between pens lifted for indicated period, then lowered. Tests same, except 

 sou'nds of indicated durations and frequencies (cycles per second) appUed at indicated location while gates 

 up. Numbers and dark bars show distribution of fish after gates lowered. 



19 



