Assessing the relationship between ambient toxicity and instream biological response

Abstract

Abstract Robust canonical correlation and classification methods were used to evaluate relationships between ambient toxicity and instream biological response. Ten studies of freshwater aquatic systems were used in the analysis. These studies included eight site studies conducted by the U.S. Environmental Protection Agency's Complex Effluent Toxicity Testing Program, one study by the University of Kentucky and one study by the University of North Texas. Results from ambient toxicity tests, including Ceriodaphnia neonate production and Pimephales promelas dry weight and survival, were used to predict impact at sampling stations. Instream biological response variables, including fish and benthic richness, were used to classify whether or not a station was impacted. The strength of the relationship between ambient toxicity and instream impact was determined by statistically evaluating agreement between the predicted and observed impacts. Results of the analysis showed that statistically significant relationships between ambient toxicity and instream impact were found in each of the studies.