Microplastic Contamination in Aquatic Environments Exploring Ecological Impacts Bioaccumulation Mechanisms and Sustainable Mitigation Strategies

Microplastic pollution of rivers, lakes, estuaries, and coastal waters has become one of the most pervasive forms of pollution, as a result of the ongoing trend of increased plastic production, inadequate waste management practices, and the eventual breakdown of larger plastic waste. The objective of the present study was to explore the distribution of microplastics in interconnected aquatic systems, the potential for ecological impacts on aquatic biota, the potential for bioaccumulation and biomagnification along the food chain, and sustainable solutions for reducing contamination. Twenty-four stations on river, lake, estuarine and coastal systems were visited, and in each location surface water, bottom sediment and representative aquatic organisms were sampled, processed and analyzed for abundance of particles, particle shape and polymer type. In general, microplastics were found at all stations, and the highest concentrations were found in estuaries; the concentrations in sediments far exceeded those of overlying water, making sediments long-term sinks for microplastics. The most prevalent polymer types were polyethylene and polypropylene, while the most prevalent particle shape was fiber. Reduced feeding, growth, and reproductive output of test organisms were associated with exposure, and effects were higher with increasing exposure. Bivalves and shrimp that filter feed had the highest body burdens, and particles were detected in the edible parts of fish, suggesting direct transfer to humans. Advanced wastewater treatment, constructed wetlands, and stormwater filtering were the most effective mitigation options evaluated to reduce the amount of microplastic released. The study concludes microplastic contamination is a long-term, systemic issue that requires a multi-faceted approach at the source, on transport routes, and in receiving waters.