Which nutrient is primarily responsible for causing accelerated eutrophication in water bodies?

Phosphorus is primarily responsible for causing accelerated eutrophication in water bodies due to its role as a key nutrient that supports the growth of algae. When phosphorus is introduced into aquatic systems, often through runoff from agricultural land, wastewater discharge, or urban sources, it can lead to excessive algae blooms.

These blooms can block sunlight from reaching underwater plants and deplete oxygen levels in the water as the algae die and decompose. This oxygen depletion can harm aquatic life, resulting in dead zones where fish and other organisms cannot survive. The cycle of algae growth and die-off can significantly disrupt the balance of ecosystems, making phosphorus a critical factor in the management of water quality and the health of aquatic environments.

In contrast, nitrogen is also a contributor to eutrophication, but phosphorus is typically the limiting nutrient in freshwater systems, meaning that its availability is the primary factor driving algae growth. The other nutrients mentioned—potassium and magnesium—are not directly linked to the process of eutrophication in the same way, as they do not generally promote excessive biomass growth to the extent that phosphorus does.