Predicted THg concentrations in grebe blood increased by 824% from 0.26 μg/g ww to 2.37 μg/g ww over the observed range of THg concentrations in prey fish among lakes (0.03 ± 0.01 μg/g dw at Eagle Lake to 0.70 ± 0.18 μg/g dw at Bridgeport Reservoir; Figure 1a).