104B Base Grants – Effects of Microplastic Exposure

Microplastics (MPs) are globally ubiquitous in aquatic environments and have become a critical environmental issue in recent years due to their adverse impacts on the physiology, reproduction, and survival of aquatic biota. However, exposure to MPs also has potential to induce sub-lethal behavioral changes that can affect individual fitness. For example, many plastics additives introduced during the manufacture of MPs are known endocrine-disrupting chemicals (EDCs) that mimic the action of natural hormones and alter sexual and competitive behavior and impair mating success in fish. Emerging evidence also suggests that such chemicals could be leached into the bodies of aquatic organisms after ingestion. More importantly, EDCs and other aquatic contaminants may also adhere to MPs in the environment, which can then serve as transport vectors for these compounds. To date, no prior research has investigated the independent or facilitatory effects of microplastics and associated contaminants on the reproductive behavior of fish. The goal of this research is to evaluate the significance of MPs in the environment for fish populations and aquatic communities. The central hypothesis of the project is that exposure to MPs in urban- impacted freshwater systems alters intraspecific reproductive interactions and reduces the mating success of fish. To test this hypothesis, this project will evaluate the biological effects of virgin MP particles, and those exposed in an urban-impacted river system, on dominance, territorial acquisition, courtship, and mating success in a freshwater fish, Pimephales promelas. The results will fill critical gaps in knowledge regarding the direct and indirect (vector-borne) effects of MPs on the behavior of aquatic vertebrates and provide new information on the effects of MPs in freshwater systems. In addition, this research will provide training for graduate and undergraduate students in research, data analysis, and peer-reviewed written and oral dissemination of scientific information.