Which type of pollutants are primarily responsible for causing cultural eutrophication?

Cultural eutrophication is primarily driven by the introduction of excess nutrients into aquatic ecosystems, particularly nitrogen and phosphorus. These nutrients can come from agricultural runoff, wastewater discharge, and other human activities that increase nutrient concentrations in water bodies. When nutrient levels become elevated, they stimulate the rapid growth of algae, often leading to algal blooms.

As these algal blooms die and decompose, they consume oxygen in the water, resulting in hypoxic conditions that can harm or kill aquatic life, such as fish and invertebrates. This process disrupts the natural balance of the ecosystem, leading to a decline in biodiversity and the overall health of the water body.

While heavy metals, pathogens, and pharmaceuticals can also impact aquatic environments, they are not the primary contributors to cultural eutrophication. Heavy metals tend to accumulate in organisms and can be toxic, pathogens can cause diseases, and pharmaceuticals can lead to various ecological disruptions, but the key factor in cultural eutrophication is the surplus of nutrients.