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12 



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10- 



9 



8 



7 



6 



5 



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1 







a a a b 



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Mill 



12 3 4 5 



T I I I I 



12 3 4 5 



I I I II 



12 3 4 5 



3 



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12 3 4 



4 



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■14 

 ■13 

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■ 9 



■ 8 

 7 



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 3 

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Figure 3. Growth in mallard ducklings fed (1) control diet; (2) 0.025% South Louisiana 



crude oil (SLC); (3) 0.250% SLC; (4) 2.5% SLC; and (5) 5.0% SLC. Treatments within a 



given age group that do not have a letter in common were significantly different at P<0.05 



by Scheffe's (1959) procedure for pairwise comparisons (Szaro et al. 1978). 



ACCUMULATION AND LOSS OF OIL 

 BY BIRDS 



After consideration of several invertebrate 

 and waterfowl species, the freshwater crayfish 

 and mallard were selected for food-chain studies. 

 Both can be successfully maintained in sufficient 

 numbers in the laboratory and are available from 

 commercial suppliers. Crayfish are accepted by 

 mallards as a food item. 



Food-chain studies were performed to esti- 

 mate the uptake of aromatic compounds and 

 their distribution in mallard tissue after inges- 

 tion of contaminated crayfish. Crayfish were 

 exposed to the water-soluble fraction of No. 2 

 fuel oil containing known quantities of 

 [ 14 C] naphthalene. (The water-soluble fraction 

 was prepared by gently stirring a mixture of the 

 oil and water for 20 hr and siphoning off the 

 aqueous layer.) After exposure, the live cray- 

 fish were fed to ducks. After an appropriate 

 time interval, the birds were sacrificed and their 



tissues examined for radioactivity. 



Radioactive naphthalene was readily taken 

 up and underwent biomagnification in the cray- 

 fish. Accumulation of radioactivity in ducks fed 

 the crayfish was greatest in the gall bladder, 

 followed by fat, kidney, liver and blood (table 

 7). 



Table 7. Radioactivity in tissues of male and female 

 mallard ducks fed 14 C-naphthalene-No. 2 fuel oil con- 

 taminated crayfish (Tarshis unpubl.). 



Naphthalene (ppm) 



Tissues 



Gall bladder 



Fat 



Kidney 



Liver 



Blood 



Testes 



Egg 

 Oviduct 



