Does the Exposure to Agrichemicals on Larval Fathead Minnows Affect the Sensitivity to Atrazine as Adults?

Agrichemicals, such as pesticides and herbicides, applied to row crops make their way into local water sheds due to agricultural runoff. The object of my project was to determine if Fathead minnows, Pimephales promelas, exposed to agrichemicals as larvae had an altered sensitivity to agrichemical exposures as adults. Many of these agrichemicals, e.g. the herbicide atrazine, are known endocrine disruptors that interfere with the hormone system of vertebrates, such as Fathead minnows, however, it has not been studied whether exposure to agrichemicals during the crucial stages of development could induce long term endocrine effects as adults. Fathead minnow larvae were exposed at 0 and 5 days post hatch, which is an important time for development and differentiation of these species, to Elkhorn River water at the Elkhorn River Research Station for a week. The exposure coincided with the pulse, which is when the concentrations of agrichemicals peak in the Elkhorn River. After the exposure the larvae were raised for 4 months in laboratory aquaria before being exposed to atrazine as adults to test for altered endocrine responses through hepatic gene expression. This study was beneficial to understand the importance of timing of an environmental exposure as well as a proof of concept for the utility of larval Fathead minnows as environmental sentinels