Which nutrient is of highest concern regarding eutrophication?

Phosphorus is of the highest concern regarding eutrophication because it is often the limiting nutrient in freshwater ecosystems. Eutrophication occurs when excessive nutrients, particularly phosphorus, enter water bodies, leading to increased growth of algae and aquatic plants. This overgrowth can diminish oxygen levels in the water, harm aquatic life, and disrupt the balance of the ecosystem. Phosphorus is typically found in fertilizers, detergents, and industrial discharges, making it particularly relevant in agricultural and urban runoff situations. Although nitrogen can also contribute to eutrophication, phosphorus is usually the key factor that triggers these processes in freshwater environments.

While potassium and sulfur are essential nutrients for plant growth, they do not play a significant role in eutrophication compared to phosphorus. As such, phosphorus stands out as the nutrient that most directly influences the eutrophication process and its consequences in aquatic systems.