35° 



N 



130' 

 20' 



AVERAGE 

 PLANKTON VOLUMES 



I960 COMPARED TO 1951-56 AND 1958-59 



., 110° 



/ 



I960 



125° 



.Ji^ 



Figure 3.— Average plankton volumes In 1960 compared with average volumes 1951-56, and average volumes in 1958-59, 



by month and area. 



