What is one significant effect of excess nutrients in wastewater?

Excess nutrients in wastewater, particularly nitrogen and phosphorus, can lead to the phenomenon known as algal blooms in water bodies. When these nutrients are released into aquatic environments, they promote rapid growth of algae, which can lead to blooms. This uncontrolled growth can have detrimental effects on aquatic ecosystems, as the overabundance of algae can block sunlight from reaching underwater plants, disrupting the food chain and harming aquatic life. Furthermore, when these algae die and decompose, it can deplete oxygen levels in the water, leading to hypoxic conditions that are harmful to fish and other organisms.

The other options do not accurately reflect the typical impact of excess nutrients. For instance, reduced turbidity and enhanced water clarity are not outcomes of nutrient overload; instead, turbidity often increases due to algal blooms and sediment suspension. Increased oxygen levels are also counterintuitive, as the decomposition process associated with algal die-off consumes oxygen, further stressing aquatic life.