The ecological impact of excessive nutrient runoff into waterways includes eutrophication, which is characterized by algal blooms and oxygen depletion. When nutrients such as nitrogen and phosphorus enter water bodies, they stimulate rapid algae growth, leading to decreased light penetration and the death of aquatic plants. This process creates “dead zones” where oxygen levels drop, harming fish and other aquatic organisms. Ultimately, nutrient runoff disrupts aquatic ecosystems and can lead to significant biodiversity loss, highlighting the need for sustainable agricultural practices to manage nutrient inputs effectively.