Which nutrient pollutant is known to contribute to eutrophication in aquatic ecosystems?

Phosphate is a key nutrient pollutant that significantly contributes to the process of eutrophication in aquatic ecosystems. Eutrophication occurs when water bodies receive excess nutrients, primarily phosphorus and nitrogen, leading to excessive growth of algae. Phosphates, often originating from agricultural runoff, detergents, and wastewater, are particularly effective at stimulating algal blooms.

When phosphates enter a water body, they promote the rapid growth of algae, which can lead to dense algal mats that block sunlight from reaching submerged plants. The eventual decay of algae, coupled with the subsequent depletion of dissolved oxygen in the water, can create hypoxic conditions that are harmful or even fatal to fish and other aquatic organisms. This process not only disrupts the local ecosystem but can also lead to negative impacts on water quality and recreational activities.

Other nutrients like nitrogen can also contribute to eutrophication, but phosphates are often the limiting factor in freshwater systems, making them a primary driver of this ecological phenomenon. Potassium and carbon, while essential for plant and animal life, do not directly cause eutrophication in the way that phosphates do.