Q.How can we control eutrophication ?

Eutrophication is controlled by cutting off the excess nutrient (nitrogen and phosphorus) supply to water bodies and by physically restoring oxygen levels/removing algal overgrowth.

Eutrophication occurs when excessive nutrients, mainly nitrates and phosphates from fertiliser runoff, sewage, and detergents, enter a water body and trigger explosive algal/plant growth (algal blooms); when this biomass dies and decomposes, dissolved oxygen is depleted, killing fish and other aquatic life. Control measures therefore focus on limiting the nutrient supply at its source: treating domestic sewage and industrial effluents in wastewater treatment plants before releasing them into rivers/lakes, promoting the use of phosphate-free detergents, applying agricultural fertilisers judiciously and using vegetative buffer strips/riparian zones along field edges to filter nutrient runoff before it reaches water bodies, and strictly preventing the direct dumping of untreated waste or animal manure into water. In already-affected water bodies, remedial steps include mechanical/biolog …