.35 - 



PHOSPHATE 



i 1 1 r 



"i r 



1 r 



ZS 4 



SILICATE 



JUL. ' AUG. ' SEP. ' OCT. I NOV. I DEC. I JAN. I FEB.' MAR. I APR. I MAY I JUN. I JUL. I AUG. I SEP. ' OCT. ' NOV. I DEC 

 1967 1968 



Figure 8. — Average phosphate (a) and silicate (b) in the lower Columbia River, July 1967 through December 1968. 



20 



18 1- 



16 - 



- 14 - 

 2 



J 12 



2 10 I- 



3 81- 

 4 

 u 6 



-| r 



i 6 



5 



2 4 



to 



z 2 



i o 



10 



8 



1 6 

 a: 



2 4 



a 2 

 o 



t 1 1 1 1 1 1 r 



t 1 r 



MAGNESIUM 



i r 



i r 



i r 



n 1 1 1 1 r 



SODIUM 



JUL. ' AUG. 'SEP. I OCT. I NOV. ' DEC. ' JAN ' FEB. 1 MAR I APR. 1 MAY ' JUN. I JUL. ' AUG. ' SEP. ' OCT. ' NOV. ' OEC. 

 1967 1968 



Figure 9. — Average calcium (a), magnesium (b), and sodium (c) in the lower Columbia River, July 1967 



through December 1968. 



