Test of a Model for Predicting the Body Burden of Trace Contaminants in Aquatic Consumers

A model for predicting the accumulation and retention of trace contaminants obtained through food ingestion in aquatic consumers was tested for short-term exposure conditions. Model parameters were determined in a single-feeding experiment using bluegill (Lepomis macrochirus) and food labeled with 137Cs. Independent of this single-feeding experiment, bluegill were allowed to ingest 137Cs contaminated food over a 16-day period and the predicted and measured body burden of the radionuclide were compared. The model realistically simulated the absorption of 137Cs from the gastrointestinal tract and its accumulation over the 16-day period. Average body burden of 137Cs in bluegill was within 25% of the predicted body burden when the experiment was terminated. Apparent equilibrium of 137Cs in bluegill by day 16 suggests that this two-compartment linear model does not apply to the long-term accumulation of cesium in fish. The model appears most applicable for predicting body burdens of trace contaminants under ac...