Figure lU. Distribution of fish in pens, experiments 37-U2. Experiments 37, 

 38, U2 started with 1,000 fish in pen No. 1 (far left); 39, UO with 500 fish 

 each in pens 5 and 6 (from left) and hi with 1,000 in pen No. 10 (far right). 

 In controls, gates between pens lifted for indicated period, then lowered. 

 Procedure same in tests, except sounds of indicated duration and frequency 

 (cycles per second) applied at indicated location while gates up. Numbers and 

 dark bars indicate distribution of fish after gates lowered. 



16 



