FISHERY BULLETIN: VOL. 74, NO. 3 



"1 r 



24 48 



TIME (hours) 



r 



24 48 



TIME (hours) 



Figure l.-Mean '^C-benzene uptake in tissues (nl/g wet weight) in anchovy (solid lines) and striped bass (dashed lines); sample 

 number: three or four fish. Also shown are mean '^C-benzene concentrations in seawater in anchovy tanks (solid lines) and in striped 

 bass tanks (dashed lines); sample number in Table 2. The concentrations on the Y-axis are calculated from total '^C radioactivity and 

 may include metabolites of benzene. 



similar between species, while in the brain, liver, 

 muscle, and intestine, a maximum level was 

 maintained longer in the anchovy. In both species, 

 the greatest rate of uptake occurred in the first 

 6h. 



Residues were depurated rapidly after cessation 

 of exposure (Table 4). Gallbladder, mesenteric fat, 

 liver, and gill maintained residues the longest. 

 Depuration appeared to occur more rapidly in 

 striped bass than in anchovies in some tissues. In 

 striped bass, depuration is generally described by 

 the logarithmoc form of a power function (In Y = 

 In a + 61n X) after cessation of exposure on day 2 

 until day 4 or 5 (Figure 3). Subsequently, several of 

 the tissues showed a secondary increase and 

 decrease in concentration. In muscle tissue, res- 

 idues were undetectable 24 h after exposure 

 ended. 



DISCUSSION 



Accumulation levels are based solely on 

 radiometric analysis. This analytical technique 

 does not distinguish between >^C-labeled benzene 

 and derived ring metabolites. Complementary 

 analysis by thin-layered chromatography or gas 

 chromatography could have determined some of 

 the actual compounds present, but it was not 

 performed during these experiments. It is 

 hypothesized that fish are capable of excreting and 

 metabolizing benzene. Although there is no direct 

 evidence, the residues reported in selected tissues 

 may be representative of the unchanged parent 

 benzene or associated metabolites and degrada- 

 tion products. Any or all of these may be toxic to 

 fish. 



Benzene and/or metabolites accumulate 



548 



