Nanomaterials, due to their unique properties and widespread use, are increasingly finding their way into aquatic environments. This can raise concerns about their sources, distribution, and impacts on these ecosystems. The different sources of nanomaterials in aquatic environments include industrial discharges, consumer products, agricultural runoff, wastewater treatment plants, and atmospheric deposition. In aquatic environments, these particles are distributed either in the water column, sediments, or biota and may undergo physical, chemical, and biological transformations, affecting their stability and mobility. Nanomaterials can be toxic to aquatic organisms, affecting reproduction, growth, and behavior. Persistent nanomaterials can accumulate in organisms, leading to higher trophic level exposure and disrupting microbial communities, affecting nutrient cycling and ecosystem functioning. Sometimes, nanomaterials can interact with other pollutants, potentially increasing their toxicity or altering their behavior. Regulatory frameworks are evolving to address these emerging contaminants, with a focus on developing guidelines for the safe production, use, and disposal of nanomaterials to mitigate their environmental impact.