What is eutrophication?

• A. Eutrophication is the nutrient enrichment leading to algal blooms and oxygen depletion.
• B. Eutrophication is the process of desalination of seawater.
• C. Eutrophication refers to the removal of nutrients from water.
• D. Eutrophication is the process of increasing salinity.

Answer: (A)

Eutrophication happens when a body of water receives extra nutrients, especially nitrogen and phosphorus, which fuel rapid growth of algae and aquatic plants. This sudden bloom can block sunlight from reaching other organisms, and when the excess plant material dies, bacteria decompose it and use up dissolved oxygen in the water. The reduction in oxygen creates stressful or lethal conditions for fish and other aquatic life.

Common sources of these nutrients include fertilizer runoff from farms and gardens, waste from sewage, and detergents. This description matches the idea that nutrient enrichment leads to algal blooms and subsequent oxygen depletion.

Desalination is the removal of salts from water, which is a different process. Removing nutrients would lessen eutrophication, not cause it. Increasing salinity changes salt levels, not nutrient-driven overgrowth.