Nutrient runoff significantly impacts freshwater ecosystems, primarily through the introduction of excess nutrients such as nitrogen and phosphorus. This nutrient enrichment often leads to eutrophication, a process that causes algal blooms, which can deplete oxygen levels in the water. As algae die and decompose, it results in hypoxic conditions, adversely affecting aquatic life and disrupting food webs. Additionally, toxins from certain algal blooms can harm fish and other organisms, creating further ecological imbalances. Effective management strategies are essential to minimize nutrient runoff and protect freshwater biodiversity.