Polychlorinated biphenyls (PCBs) are highly persistent global contaminants with a broad range of long-term environmental and health effects (Fishbein 1974). Body burdens of many chlorinated aryl compounds in aquatic organisms accumulate by combinations of passive absorption directly from water or by partitioning into lipids of foods. Both routes have been shown to contribute significantly to levels found in fish (Stalling and Mayer 1972; Hansen et al. 1976).