Question

Explain in detail ‘Eutrophication’.

Answer 1

Eutrophication is an ecological process where a body of water becomes too enriched in chemical nutrients such as nitrates and phosphates, resulting in severe ecosystem degradation. This enrichment is often caused by agricultural runoff carrying chemical fertilisers or municipal sewage discharged into lakes and rivers. These nutrients serve as a rich food source for surface algae and phytoplankton, resulting in an explosive and uncontrolled development known as an algal bloom. The resulting dense green mat prevents necessary sunlight from reaching deeper waters, preventing submerged aquatic plants from photosynthesis and causing them to die. As these plants and algae perish, aerobic bacteria multiply rapidly to digest the immense volume of dead organic matter, consuming large amounts of dissolved oxygen in the process. This rapid oxygen depletion significantly raises Biochemical Oxygen Demand (BOD), resulting in hypoxic "dead zones" where fish and other aquatic species swiftly suffocate and perish.