Analysis of water samples collected at 54 sites in the Great Lakes Watershed confirmed the ubiquitous presence of Contaminants of Emerging Concern (CECs). Cluster analyses of CECs suggest that the co-occurrence of CECs is linked to dichotomous urban or agricultural land use. Urban mixtures contained steroidal estrogens, BPA, alkyphenols, pharmaceuticals and personal care products. Agricultural samples contained herbicides, pesticides, BPA, and alkylphenols. Resident and caged sunfish were collected from 27 sampling sites and analyzed for indicators of stress associated with CEC exposure. At high aqueous CEC concentrations, glucose concentrations spiked in sunfish plasma and liver cells exhibited toxic stress response. Canonical correspondence analyses revealed that concurrent with indicators of toxic stress, biomarkers of reproductive potential declined. To further examine the population level consequences, fathead minnows were exposed in the laboratory for three generations to the empirically derived CEC mixtures at environmentally relevant concentrations and found to alter fecundity. This integrated series of studies indicates that CECs in Great Lakes tributaries may impact fish population health and sustainability.Ope
