What is one impact of excess nutrients in water bodies?

Excess nutrients, particularly nitrogen and phosphorus, in water bodies can lead to a significant ecological phenomenon known as eutrophication. When nutrient levels are elevated, they promote the rapid growth of algae, resulting in algal blooms. These blooms can cover the surface of the water, blocking sunlight from reaching aquatic plants, which can disrupt the entire ecosystem. As the algae die and decompose, the decomposition process consumes a large amount of dissolved oxygen, often leading to hypoxic or anoxic conditions that can be harmful or lethal to fish and other aquatic organisms. Therefore, the presence of excessive nutrients is closely linked to this increased algal growth, demonstrating why the impact of excess nutrients is characterized by algal blooms and the subsequent process of eutrophication.