Spatially explicit bioaccumulation modeling in aquatic environments: Results from 2 demonstration sites

Area of Science:

• Environmental chemistry and toxicology
• Ecological risk assessment
• Contaminated sediment site management

Background:

• Bioaccumulation models are crucial for assessing chemical exposure in aquatic organisms at contaminated sites.
• Current models often lack predictive accuracy due to limitations in exposure concentration data.
• Concerns exist regarding the mathematical complexity versus deterministic inputs in bioaccumulation modeling.

Purpose of the Study:

• To evaluate the predictive performance of a spatially explicit exposure model (FishRand).
• To compare FishRand's bioaccumulation estimates against conventional nonspatial techniques and monitoring data.
• To assess the model's utility in heterogeneous exposure environments considering food web dynamics and foraging behavior.

Main Methods:

• Application of the spatially explicit FishRand model at two contaminated field sites.
• Comparison of model predictions with results from nonspatial bioaccumulation models.
• Evaluation using various model performance metrics and monitoring data.

Main Results:

• The spatially explicit model (FishRand) demonstrated superior predictive performance over conventional nonspatial techniques.
• Differences in predicted fish tissue concentrations were observed, though sites were only mildly contaminated.
• FishRand showed improved accuracy across multiple performance metrics.

Conclusions:

• Spatially explicit modeling significantly enhances the predictive power of bioaccumulation assessments.
• The FishRand model offers greater flexibility for evaluating complex food web interactions and foraging behaviors.
• This approach improves risk assessment and decision-making for contaminated sediment sites.