Plastic is constantly finding its way into aquatic environments due to its use in everyday consumer goods, many of which are single-use. Plastic waste can break down into smaller pieces (<5 mm), leading to increasing ecotoxicological concerns in the aquatic environment. Despite microplastic (MP) pollution affecting air, water, and soil widely, these ecosystems are often viewed distinctly while being interlinked. Because it is ubiquitously present in the aquatic environment, MP pollution has become a significant global issue. Thus, this chapter focuses on the gaps limited to the understanding of the occurrence and characterization of MPs, their distribution in various segments of aquatic ecosystems, their transfer and fate at different trophic levels, and the implementation of policies for the mitigation of MPs in freshwater. Last, the chapter highlights future scope, focusing on long-term fate and transport studies, as well as interconnectivity and toxicity studies, followed by early detection technologies for MPs in aquatic ecosystems.