300 



250 



200 



150 



100 



90 



80 



70 



10 20 30 kQ 50 60 



PERCENT SURVIVAL 



70 



80 



90 



100 



FIG 59 COMPARISON OF TOXIC EFFECTS OF COPPER IN EFFLUENT (0) AND IN 

 SEAWATER (X) ON ASCIDIA NIGRA. 



135 



