PCB ACCUMULATION IN LAKE-MICHIGAN COHO AND CHINOOK SALMON - INDIVIDUAL-BASED MODELS USING ALLOMETRIC RELATIONSHIPS

We have developed individual-based models that describe PCB accumulation and variability in Lake Michigan coho and chinook salmon. The models are based on simplified allometric relationships and incorporate a minimum of free parameters. Simulations of high and low growth rates demonstrate that salmon of a given age attain similar PCB concentrations but very different sizes, indicating that age is a better predictor of contaminant level than is size. Model results suggest that a 10-15% reduction in PCB levels for fish of a given size be obtained by for high growth rates. The models also show that prey PCB concentration strongly affects PCB levels in the salmon; however, management options for controlling prey PCBs are fairly limited and expensive.