When a water body gets enriched with nutrients, the process is called

Nutrient enrichment of a water body is called eutrophication, spurring excessive algal growth.

Oligotrophication describes nutrient-poor waters, the opposite condition.

Mesotrophication refers to an intermediate, moderately nutrient-rich state.

Dystrophication describes acidic, humus-rich waters low in nutrients.

Eutrophication is often driven by nitrogen and phosphorus from fertilisers and sewage.

Algal blooms then deplete oxygen and can kill aquatic life.