Pollution has a significant impact on freshwater biodiversity, threatening aquatic ecosystems and the species that inhabit them. Contaminants such as chemicals, heavy metals, and plastics disrupt the natural balance, leading to habitat degradation and species declines. Polluted waterways can adversely affect fish populations, amphibians, and other aquatic organisms. High nutrient loads can also cause eutrophication, leading to algal blooms that deplete oxygen levels in the water. Protecting freshwater ecosystems from pollution is essential for preserving biodiversity and maintaining ecosystem health.