308 . HARRISON AND RICE 



TABLE 2 



AVERAGE COPPER CONCENTRATIONS* IN WATER 

 AND OYSTERS FROM EXPERIMENT 4 



♦Fractional standard deviation (SD/mean) generally ranged from 

 0.2 to 0.4 for the concentrations expressed in micrograms per gram 

 and from 0.4 to 0.6 for the total amounts. 



increases were not linear with concentrations in the water, however; 

 the highest levels were found in the oysters in water containing 

 230 [Jig Cu/liter. The quantities of copper contained in oysters held in 

 seawater with copper concentrations greater than 230 jUg/liter did 

 not differ significantly from each other. 



The quantities of ^"^Cu (decay corrected) in the total soft tissues 

 at the end of the 24-hr exposure were different from oysters in each 

 of the three copper concentrations. The highest concentrations of 

 ^^Cu were detected in animals held in water with the lowest copper 

 concentrations (Table 3). Some regulation of copper accumulation is 

 suggested; the '''^Cu concentrations would have been similar in the 

 animals from the three test systems if the amount of copper 

 accumulated per unit time was directly proportional to the copper 

 concentration in the water (no homeostasis). 



The ^"^Cu in the tissues of oysters placed in each of the three 

 copper concentrations increased with time, except in the digestive 



