What are the environmental impacts of excessive phosphorus application?

The environmental impact of excessive phosphorus application predominantly leads to eutrophication of water bodies, which is the correct focus here. When phosphorus levels increase due to agricultural runoff, it can trigger a rapid growth of algae in lakes and rivers, resulting in algal blooms. These blooms can significantly deplete oxygen levels in the water as the algae die and decompose, leading to hypoxic conditions that can harm aquatic life, including fish and other organisms.

Eutrophication is a serious environmental issue because it disrupts the aquatic ecosystem, leading to a loss of biodiversity and, in severe cases, the creation of dead zones where life cannot be sustained. This chain reaction not only affects the water quality but can also impact recreational activities and local economies that depend on healthy water bodies.

While other choices might reflect valid concerns in different contexts, they do not directly illustrate the primary and most significant environmental consequence associated with excessive phosphorus application like eutrophication does.