Integration of a dynamic organism model into the DynA Model: Development and application to the case of DDT in Lake Maggiore, Italy

- An integrated single organism-water-sediment dynamic model was developed.
- The model was applied to investigate p,p′-DDT bioaccumulation in whitefish.
- Comparisons with measured data revealed good model performance.
- Results highlighted the importance of ecological parameter dynamics.

The Single Organism (SO) model was developed to investigate the influence of temporal dynamics of aquatic organism properties on their exposure to organic chemicals in water. SO was then integrated with an existing dynamic surface-water model (DynA), to form the coupled water-bioaccumulation model EcoDynA. In order to evaluate the model performance, the results produced by EcoDynA were compared to the p,p′-DDT concentrations measured in specimens of whitefish of different age and sex caught in Lake Maggiore after the discovery of a DDT spill. The comparison showed a good agreement. Other satisfying results were obtained comparing model results with p,p′-DDT concentration values measured in another species of whitefish which were available in the literature. A preliminary sensitivity analysis confirmed that accounting for dynamics of parameters such as organism lipid fraction and feeding rate is necessary to obtain accurate exposure predictions.