What causes excessive aquatic plant growth in water bodies?

• A. Nutrient enrichment from nitrogen and phosphorus enhances aquatic plant growth.
• B. High salinity levels.
• C. Increasing water transparency.
• D. Cooler water temperatures.

Answer: (A)

Excess nutrients in water act like fertilizer for aquatic life. When nitrogen and phosphorus enter lakes, rivers, and wetlands from sources like agricultural runoff, wastewater, and detergents, they fuel rapid growth of algae and aquatic plants. This nutrient enrichment pushes the ecosystem toward a state called eutrophication, where plant and algal blooms become extensive, reducing water quality, blocking light, and depleting oxygen as plants and algae die and decompose. That’s why nutrient enrichment from nitrogen and phosphorus is the primary cause of excessive aquatic plant growth.

Other factors don’t drive this kind of overgrowth in the same way. High salinity isn’t typically a promoter of lush growth in freshwater systems and can inhibit many freshwater plants. Increasing water transparency can help plants grow by allowing more light, but without the nutrients to support growth, light alone won’t cause excessive proliferation. Cooler water temperatures generally slow plant growth rather than accelerate it.