Modeling bioaccumulation of organic chemicals in complex aquatic food webs which include birds and mammals feeding from the aquatic environment

A linked aquatic-terrestrial food web model has been developed which quantifies bioaccumulation in both aquatic organisms and air-breathing organisms which feed from the aquatic environment. The model was applied to the Southern California Bight and to Lake Erie, in order to quantify the uptake and loss of DDT compounds and PCBs, respectively. A preliminary uncertainty analysis was applied to the Campfens and Mackay model and both ecosystems presented here in order to identify those parameters contributing to the variance in the chemical concentration in each organism. A modeling framework was also developed which can be used to calculate the metabolic half-lives of contaminants in organisms, based on the physiology and feeding habits of the organism and the physio-chemical properties of the substance and observed bioaccumulation factors. Thus, it was determined that it is feasible to quantify contaminant fate in complex aquatic-terrestrial food webs provided sufficient data are available on the chemical, the organisms and their dietary preferences.