Respiration of aquatic insect larvae (Ephemeroptera, Plecoptera) in acid mine water.

E c o t o x i c o l o g y ( T R U H A U T 1975) is the s tudy of the h a r m fu l e f f ec t s of n a t u r a l s u b s t a n c e s and a r t i f i c i a l po l lu t an t s ex p e r i e n c e d by o r g a n i s m s in the e n v i r o n m e n t . The d e g r e e of r e s p o n s e exh ib i t ed by an o r g a n i s m t o w a r d the p r e s e n c e of nox ious s u b s t a n c e s can of ten be d e t e r m i n e d by m o n i t o r i n g a p h y s i o l o g i c a l p a r a m e t e r . One s u c h p a r a m e t e r is r e s p i r a t i o n (CHENG & R O D R I C K 1974; K A W A T S K I et a l . 1974). The m a j o r i t y of s t ud i e s dea l i ng wi th the b i o l o g i c a l i m p a c t of a c i d m i n e d r a i n a g e h a v e been e c o l o g i c a l s u r v e y s . No s t ud i e s have been r e p o r t e d w h i c h d e a l wi th the p h y s i o l o g i c a l r e s p o n s e of an o r g a n i s m to a c i d m i n e w a t e r o t h e r than a c u t e t o x i c i t i e s of the v a r i o u s c o m p o n e n t s ex p e c t e d in an e f f luen t S t r e a m ( B E L L & N E B E K E R 1 9 6 9 ; K I M M E L & H A L E S 1973; W A R N I C K & B E L L 1969). T h e s e s t ud i e s did not c o n s i d e r p o s s i b l e s y n e r g i s t i c e f f ec t s b e t w e e n ind iv idua l c o m p o n ents of a c i d m i n e w a t e r o r the m o d e of a c t i o n of po l l u t an t s in vo lved . The w o r k we r e p o r t was u n d e r t a k e n to d e t e r m i n e w h e t h e r the tox ic m o d e of a c t i o n of an a c i d w a t e r e f f luen t i nvo lves a ny a s p e c t of the r e s p i r a t o r y p r o c e s s e s in t h r e e s p e c i e s of a q u a t i c i n s e c t l a r v a e . A l t h o u g h r e s p i r o m e t r y can be v a l u a b l e in d e t e c t i n g s igns of m e t a b o l i c i n v o l v e m e n t , one m u s t be a w a r e tha t it is not a t e c h n i q u e f o r the i d e n t i f i c a t i o n of s p e c i f i c tox ic m e c h a n i s m s (CHENG & R O D R I C K 1974).