XI 



a. 

 a. 



600 

 550 

 500 

 '450 



400 

 350 



300 

 250 



200 



1^0 



20 30 kO 50 60 



PERCENT SURVIVAL 



70 



80 



90 



100 



FIG. 57 COMPARISON OF TOXIC EFFECTS OF COPPER IN EFFLUENT (0) AND IN 

 SEAWATER (X) ON MbNIPPE MERCENARIA. 



133 



