species composition changes rapidly to shortbill 

 spearfish. 



Turning again to Figure 10 it is apparent that sail- 

 fish are encountered all along the coastal waters of 

 the Americas between about lat. 30°N and lat. 30°S. 

 They are extremely abundant along the coast of 



central and southern Mexico and Central America, 

 reaching their greatest abundance throughout the 

 winter months between lat. 20°N and the equator. 

 There appears to be a movement of fish northward 

 with the displacement of warm waters to the north 

 during the summer and fall. During the southern 



Figure 1 1. — Average number of swordfish caught per 1,000 hooks by Japanese 

 longline vessels in the eastern Pacific by quarters, 1956-1970, by 5-degree areas, a. 

 First quarter, b. Second quarter, c. Third quarter, d. Fourth quarter. 



320 



