Applying AQUATOX in determining the ecological risk assessment of polychlorinated biphenyl contamination in Baiyangdian Lake, North China

There is a growing interest in the application of ecological models to improve the ecological risk assessment (ERA) of toxicants. For this study, the AQUATOX model was implemented using 18 pelagic and benthic populations derived from field data obtained at Baiyangdian Lake between April 2009 and March 2010. The model was evaluated to examine its utility in assessing the ecological risk of polychlorinated biphenyl (PCB) contamination in aquatic ecosystems. Model parameters were calibrated to simulate the complex seasonal patterns of Baiyangdian Lake biomass populations. Sensitivity analysis revealed the potential importance of indirect effects and demonstrated the vital role of parameter values in determining the biomass of each trophic level. The model was highly sensitive to parameters related to temperature limitations and respiration rates. Moreover, it was effective in estimating risks associated with the direct toxic PCB effects of each population and the indirect ecological effects distributed through the coupled pelagic-benthic food web. Benchmarks derived from AQUATOX-Baiyangdian were approximately one order of magnitude less than the benchmarks derived from NOEC in a report by the United States of America's Environmental Protection Agency (EPA). Comparison analysis determined the model could provide a good basis in ascertaining ecological protection levels of “chemicals of concern” for aquatic ecosystems. Furthermore, AQUATOX can potentially be used to provide necessary information corresponding to early warning and rapid forecasting of pollutant transport and fate in the management of chemicals that put aquatic ecosystems at risk.