Date Awarded


Document Type


Degree Name

Doctor of Philosophy (Ph.D.)


Virginia Institute of Marine Science


Long-term bioaccumulation studies were conducted using ('14)C-Kepone and unlabeled Kepone to determine the significance of dietary accumulation to final Kepone body burdens in spot (Leiostomus xanthurus) and grass shrimp (Palaemonetes pugio). Both food (grass shrimp) and consumer organisms were exposed to aqueous Kepone concentrations of 0.04 (mu)g/l at 23�C for 16-19 days, followed by a 21-28 day clearance phase. Dietary and aqueous sources of Kepone were shown to be additive for both species. Dietary contributions of Kepone represented 9, 18 and 38% of the total Kepone body burden in spot fed contaminated food rations of 4, 8 and 20% mean body weight, respectively. at rations of 4 and 8%, dietary Kepone contributions to final shrimp body burdens were 24 and 33%, respectively. There were no significant differences in organism size or lipid content among treatments for either species. Ration size had no effect in either organism on the uptake and clearance rate constants estimated for dietary accumulation and bioconcentration by a first-order pharmacokinetic model. Shrimp had a slower clearance rate of Kepone than spot and, hence, a greater bioaccumulation potential. Kepone derived from aqueous exposures to both species appeared to be cleared more slowly than residues derived from dietary exposure. Kepone assimilation efficiencies for spot and shrimp were 15% and 21%, respectively, for the finely ground food source used in this study. These values are low compared to literature data for other lipophilic chlorinated hydrocarbons. This indicates that grinding of the food reduced Kepone availability to the consumer organisms. Event at these low assimilation efficiencies, Kepone from the diet contributed significantly to final Kepone body burdens in spot and shrimp. An accelerated test methodology was adequate to describe spot bioaccumulation kinetics, especially at the larger food ration size tested. Uptake of Kepone from contaminated artificial food was similar to uptake from contaminated natural food.



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