Eutrophication

Eutrophication is a process whereby water bodies such as lakes, rivers, and coastal areas receive an excess of nutrients, primarily nitrogen and phosphorus. The increased nutrient levels lead to a proliferation of algae and other aquatic plants, which can severely disrupt the aquatic ecosystem.

Causes can include agricultural runoff, sewage discharge, industrial effluents and atmospheric deposition, where nitrogen compounds can enter water bodies through precipitation, contributing to nutrient overload.

Eutrophication poses several significant threats to aquatic environments and human health. Excessive nutrient levels promote the rapid growth of algae, leading to algal blooms that cover the surface of the water. These blooms can block sunlight, hindering the growth of other aquatic plants and disrupting the habitat.

When algae die and decompose, it consumes oxygen in the water, leading to hypoxia or oxygen depletion. This condition can cause massive fish kills and affect other aquatic organisms that depend on oxygen.

The altered environment harbours species that can adapt to low-oxygen conditions, often leading to a decline in biodiversity as more sensitive species are unable to survive.

Excess nutrients can lead to health risks for humans and can be an economic problem, affecting sectors such as fish, aquaculture and tourism.