Date of this Version
Schoup, A. (2022). Evaluating American Bullfrog (Lithobates Catesbeianus) Tadpole Exposure to Neonicotinoid and Fungicide Agrochemicals in the Landscape Surrounding AltEn Ethanol. Undergraduate Honors Thesis. University of Nebraska-Lincoln.
Agrochemicals are used globally in agricultural landscapes to protect crops from weeds, pests, and disease. Widespread use of these chemicals has raised concerns surrounding their impact on the health of the environment and non-target organisms in agriculture-intensive areas. AltEn Ethanol was the largest processor of seed-treated corn in the United States and operated in Mead, Nebraska between 2015 and 2021. The plant was responsible for multiple major agrochemical contamination events which prompted a One Health investigation into the impacts of agrochemical contamination. My thesis research served as a pilot study to evaluate concentrations of neonicotinoids and fungicides in American bullfrog (Lithobates catesbeianus) tadpoles as a sentinel species to understand the levels of agrochemical contamination in the ecosystem surrounding AltEn Ethanol. Tissues from tadpoles collected from five surface water sites within 15 km of AltEn Ethanol were analyzed for 166 pesticides and degradates using gas and liquid chromatography-tandem mass spectrometry. Ten neonicotinoid and fungicide pesticides and degradates were detected in tadpole tissue. Samples collected from tadpoles at a site approximately 10 km downstream from AltEn Ethanol had the highest frequency of agrochemical detection in tadpole tissues. For agrochemicals detected in samples from both upstream and downstream sites, the agrochemical concentration was significantly higher in samples from downstream sites. Our results provide evidence that AltEn Ethanol contamination is reaching wildlife living in downstream environments, potentially impacting wildlife and broader human, animal, and ecosystem health. These findings support the need for continued investigation into the short- and long-term effects of AltEn Ethanol contamination.