Figure 18.--Distribution of fish in pens, experiments 57-62. All experiments started with 1,000 fish in pen 

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

 sounds of indicated durations and frequencies (cycles per second) applied at indicated location while gates 

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



