Plastics and Parasites: Monitoring Parasites and Microplastics in Freshwater Fish in Raccoon Creek and Pumpkinvine Creek, Georgia, USA

The release of microplastics into freshwater and marine environments is an emerging issue impacting ecosystems worldwide. Microplastics are commonly introduced into ecosystems through various sources, including personal care products, synthetic textiles, and the deterioration of large plastics such as water bottles and tires. Previous studies have found that microplastics can have multiple negative impacts on fish populations, including altered gene expression, physiology, immunity, reproduction, feeding, and survival. However, the effects of microplastics on host-parasite interactions in fish are less understood. In the current study, we surveyed 254 fluid-preserved fish specimens collected from Raccoon Creek and Pumpkinvine Creek in Georgia, USA, between 2000 and 2015. Initially, we screened the external body of the fish for ectoparasites, then removed the stomach and intestines, examining them for ingested microplastics. Next, we examined all internal organs, including the stomach and intestines, for macroparasites. We analyzed the parasite load and microplastic presence and abundance data to search for potential correlations. Although microplastics were found in both creeks, no relationship was found between microplastic load and parasite abundance in the freshwater fish surveyed. Museum specimens provide a valuable method for assessing temporal changes and should be considered in future microplastic studies. As microplastic pollution intensifies and poses increased threats to marine and aquatic ecosystems, monitoring its influence is paramount to achieving effective management and remediation of the issue.