Bull. Environ. Contam. Toxicol. (1989) 43:548-549 �9 1989 Springer-Verlag New York Inc.

E n v i r o n m e n t a l ~ C o n t a m i n a t i o n ~and Toxicology

Relationships Between Organochlorine Concentrations in Liver and Muscle of Otters

C. F. Mason

Department of Biology, University of Essex, Colchester C04 3SQ, United Kingdom

The European o t t e r ( ~ . ~ ~.9~A) i s now t h r e a t e n e d or e n d a n g e r e d o v e r much of i t s European r a n g e (Mason and Macdonald 1986}. The d e c l i n e , w h i c h has t a k e n p l a c e m a i n l y d u r i n g t h e p a s t t h r e e d e c a d e s , has been a t t r i b u t e d t o t h e t o x i c e f f e c t s o f o r g a n o c h l o r i n e r e s i d u e s , w i t h e m p h a s i s b e i n g p l a c e d on d i e l d r i n ( C h a n i n and J e f f r i e s 1978) o r PCBs (O l s son e_t a ] . , 1981}. Few o t t e r s were a n a l y z e d f o r o r g a n o c h l o r i n e s d u r i n g t h e main p e r i o d o f d e c l i n e but t h e r e i s now c o n s i d e r a b l e i n t e r e s t in t h e s p e c i e s . M a t e r i a l f o r a n a l y s i s d e r i v e s m a i n l y from a c c i d e n t a l m o r t a l i t y such as t r a f f i c a c c i d e n t s o r d rown ing i n f i s h i n g g e a r and comes m o s t l y from t h o s e a r e a s where o t t e r s a r e s t i l l t h r i v i n g .

E x p e r i m e n t s w i t h r a n c h mink ( H . ~ ~ 9 ~ ) h a v e shown t h a t r e p r o d u c t i v e f a i l u r e s when PCB c o n c e n t r a t i o n s i n t h i g h musc l e a p p r o a c h 50 mg kg - l i p i d ( J e u s e n e t all. 1977) . Because o t t e r s a r e c l o s e l y r e l a t e d and have s i m i l a r h a b i t s t h i s v a l u e i s becoming w i d e l y used to i n t e r p r e t t h e p o t e n t i a l s i g n i f i c a n c e o f PCB c o n c e n t r a t i o n s d e t e r m i n e d i n o t t e r s ( O l s s o n e t a l . , 1981, Mason e t a l . , 1986. B r o e k h u i z e n and De R u i t e r - O i j k m a n 1988) . F u r t h e r m o r e , a l t h o u g h t h e mink d a t a r e f e r t o c o n c e n t r a t i o n s i n m u s c l e , i n t e r p r e t a t i o n s o f c o n c e n t r a t i o n s in o t t e r s have f r e q u e n t l y been based on a n a l y s e s o f l i v e r s ( e . g . B r o e k h u i z e n and De R u i t e r - D i j k m a n 1988) . Because o f t he d i v e r s e s o u r c e s o f m a t e r i a l in Europe , o n l y l i m i t e d t i s s u e s may be made a v a i l a b l e f o r a n a l y s i s , w h i l e c o s t s may a l s o p r o h i b i t t h e a n a l y s i s o f s e v e r a l t i s s u e s f r o m a s i n g l e c a r c a s e . The r e l a t i o n s h i p b e t w e e n c o n c e n t r a t i o n s o f o r g a n o c h l o r i n e s in musc l e and l i v e r t i s s u e s in o t t e r s has no t been d e t e r m i n e d . T h i s i s t h e p u r p o s e o f t h e p r e s e n t c o m m u n i c a t i o n .

MATERIALS AND METHODS

Of 40 o t t e r s from t h e B r i t i s h o t t e r s a n a l y z e d f o r o r g a n o c h l o r J n e r e s i d u e s (Mason e t a l . , 1986 , Mason 1988 and u n p u b l i s h e d ) , d e t e r m i n a t i o n s on b o t h l i v e r and t h i g h m u s c l e t i s s u e were made f o r 16 i n d i v i d u a l s . A n a l y t i c a l methods a r e g i v e n i n Mason e t a l . , (1986} and Mason (1988}. The r e l a t i o n s h i p be tween o r g a n o c h l o r i n e s i n l i v e r and m u s c l e were examined by l i n e a r r e g r e s s i o n .

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RESULTS AND DISCUSSION

The r e l a t i o n s h i p s b e t w e e n c o n c e n t r a t i o n s o f o r g a n o c h l o r i n e r e s i d u e s (my kg - l i p i d } i n m u s c l e (y ) a n d l i v e r (x ) w e r e a s f o l l o w s : -

PCBs y = 1 . 0 9 x - 2 . 7 5 r = 0 . 9 4 P < 0 . 0 0 1 D i e l d r i n y = 0 . 5 4 x ~ 7 . 2 0 r = 0 . 9 4 P < 0 . 0 0 1 T o t a l DDTs y = 0 . 6 0 x + 0 . 2 1 r = 0 . 8 7 P < 0 . 0 0 1 I, i n d a n e y = 1 . 3 4 x -. 0 . 3 3 r = 0 . 7 4 P < 0 . 0 0 1

--I I n t e r p o l a ~ A n g a v a l u e o f 50 mg kg l i p i d i n l i v e r i n t o t h e a b o v e e q u a t i o n s w o u l d p r e d i c t t h e f o l l o w i n g c o n c e n t r a t i o n s i n m u s c l e : -

PCBs, 5 ] . 8 ; d i e l d r i n , 3 4 . 2 ; t o t a l DDTs, 3 0 . 2 ; ] i n d a n e , 6 6 . 7 .

Thus c o n c e n t r a t i o n s o f PCBs i n l i v e r and m u s c l e a r e v e r y s i m i l a r a n d l e v e l s i n e i t h e r t i s s u e l c a n be u s e d t o c o m p a r e w i t h t h e c r i t i c a l v a l u e o f 50 mg k g l i p i d i n m u s c l e w h i c h i n h i b i t s r e p r o d u c t i o n i n m i n k . C o n c e n t r a t i o n s o f d i e l d r i n a n d DDT r e s i d u e s a r e l o w e r i n m u s c l e t h a n l i v e r , w h i l e c o n c e n t r a t i o n s o f l i n d a n e a r e h i g h e r i n m u s c l e t h a n l i v e r .

REFERENCES

B r o e k h u i z e n S, De R u i t e r - D i j k m a n E M ( 1 9 8 8 } . O t t e r s L u t r a l u t r a met P C B ' s : de z e e h o n d j e s v a n h e r z o e t e w a t e r ? L u t r a 3 1 : 6 8 - 7 8 .

C h a n i n PRF, J e f f e r i e s D J {1978} . The d e c l i n e o f t h e o t t e r L u t r a l u t r a L. i n B r i t a i n : a n a n a l y s i s o f h u n t i n g r e c o r d s a n d d i s c u s s i o n o f c a u s e s . B i o l J L i n n Soc 1 0 : 3 0 5 - - 3 2 8 .

J e n s e n S, K i h l s t r o m J E, O i s s o n M, L u n d b e r g C, O r b e r g J ( 1 9 7 7 ) E f f e c t s o f PCB a n d DI)T on m i n k ( M u s t e l a v i s o n ) d u r i n g t h e r e p r o d u c t i v e s e a s o n , h m b i o 6 : 2 3 9 .

Mason C F (1988} C o n c e n t r a t i o n s o f o r g a n o c h ] o r i n c r e s i d u e s and m e t a l s i n t i s s u e s o f o t t e r s LutA:a " ls f r o m t h e B r i t i s h I s l e s , 1 9 8 5 - 1 9 8 6 . L u t r a 3] : 6 2 - 6 7 .

Mason C F, F o r d T C, L a s t N I ( 1986 ) O r g a n o c h t o r i n e r e s i d u e s i n B r i t i s h o t t e r s . B u l l E n v i r o n Contam T o x i c o l 3 6 : 6 5 6 - 6 6 1 .

Mason C F, M a c d o n a l d S M (1986) O t t e r s : e c o l o g y a n d c o n s e r v a t i o n . C a m b r i d g e U n i v e r s i t y P r e s s .

O l s s o n M, R e u t e r g a r d h L, S a n d e g r e n F { 1 9 8 1 ) V a t a r u t t e r n ? S v e r i g e s N a t u r 6 / 8 : 2 3 4 - 2 4 0 .

R e c e i v e d O c t o b e r 1, 1988; a c c e p t e d A p r i l 6, 1989 .

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