Natural aging and nutrient enrichment of a water body is termed as eutrophication. Due to the human activities of adding sewage and industrial waste, water bodies like lake have been heavily eutrophised. Contaminants like nitrates and phosphates overstimulate algal growth as a consequence deplete the oxygen level in water body. Also, other pollutants poison the population of aquatic life leading to their death and increasing the rate of decomposition by bacteria which further depletes the oxygen level.