How can agricultural practices negatively affect wetlands?

Agricultural practices can negatively affect wetlands primarily through nutrient overload caused by runoff. When fertilizers and pesticides are applied to fields, excess nutrients, particularly nitrogen and phosphorus, can wash into nearby waterways during rainfall or irrigation. This runoff can lead to eutrophication, a process where nutrient-rich waters stimulate excessive growth of algae and aquatic plants.

In wetlands, this algal bloom can block sunlight and disrupt the ecosystem's balance, harming aquatic organisms, including fish and other wildlife that depend on clear, healthy water. The decomposition of this excessive plant material can further deplete oxygen levels in the water, leading to dead zones where few organisms can survive. The alteration of natural nutrient cycles not only diminishes biodiversity in wetland habitats but can also disrupt the water quality and overall health of the surrounding environment.

This underscores the impact of agricultural runoff as a critical factor in the degradation of wetlands, highlighting the need for sustainable farming practices that manage nutrient application and reduce runoff.