Effects–Based Monitoring Under the Great Lakes Restoration Initiative: Evaluation of Spatial and Temporal Patterns in the Milwaukee Estuary
Citation:
Maloney, E., G. Ankley, B. Blackwell, J. Cavallin, D. Feifarek, K. Jensen, M. Kahl, S. Poole, E. Randolph, AND Dan Villeneuve. Effects–Based Monitoring Under the Great Lakes Restoration Initiative: Evaluation of Spatial and Temporal Patterns in the Milwaukee Estuary. SETAC North America, Fort Worth, TX, November 15 - 19, 2020. https://doi.org/10.23645/epacomptox.13122380
Impact/Purpose:
The Great Lakes Restoration Initiative, Action Plan II outlined a commitment to identify emerging contaminants and assess impacts on Great Lakes fish and wildlife. As part of this commitment, efforts at US EPA Great Lakes Toxicology and Ecology Division (GLTED) have focused on the development of tools and approaches to identify potential effects from exposure to environmental mixtures. These approaches have been piloted across the Great Lakes and provide a valuable, complementary approach to determining the impact of CECs in the environment and prioritizing associated monitoring and management actions.
Description:
A commitment under the “Toxic Substances and Areas of Concern” Focus Area of the Great Lakes Restoration Initiative (GLRI) was to identify emerging contaminants and evaluate their potential impacts on Great Lakes fish and wildlife. Here we present data and results from GLRI supported studies conducted in 2017 and 2018 that employed biological effects-based approaches to help identify potential hazards and priority contaminants in the Milwaukee River Estuary area of concern (AOC) located near Milwaukee, WI. In 2017, adult fathead minnows (Pimephales promelas) were caged at eight sites within the AOC. The same sites were evaluated in 2018, along with three additional sites. The aim was to characterize spatial and temporal variability of biological effects and contaminants associated with a range of surrounding land uses and sources (e.g., agriculture vs urban land use; wastewater discharges). Following 4 d of exposure, fish tissues were sampled and used for both targeted (i.e., sex steroid concentrations, gene expression) and untargeted (i.e., microarray and metabolomics) effects analyses. Additionally, 4 d composite water samples were concurrently collected at each caged fish site and analyzed for 178 wastewater indicators and pharmaceuticals as well as evaluated for estrogenic activity using the T47-Kbluc assay. Detected chemicals varied across sampling sites and years, ranging from 46 to 77 at one or more sites in 2017 and 2018, respectively, with higher numbers generally found downstream and/or nearby WWTPs. In addition, estrogenic activity was observed in cell-based bioassays at multiple sites during both 2017 and 2018. Induction of several hepatic and intestinal genes associated with xenobiotic metabolism was observed at several sites suggesting the presence of chemicals that activate the aryl hydrocarbon receptor and often correlated with higher numbers of pharmaceutical and PAH detections. Exposure-activity ratios (EARs), based on the concentration of detected chemicals per site, were calculated from high-throughput screening results obtained from the USEPA ToxCast program. EAR analysis identified multiple sites, chemicals and biological pathways that warrant future prioritization for assessment. Overall, this study demonstrates that better environmental assessment of complex mixtures can be achieved through integration of chemical and biological measurements.
URLs/Downloads:
DOI: Effects–Based Monitoring Under the Great Lakes Restoration Initiative: Evaluation of Spatial and Temporal Patterns in the Milwaukee Estuary