Question

Why does water covered with excessive algal growth become polluted?

Answer 1

Contamination of water bodies with a high amount of phosphate from the inflow of agricultural wastewater polluted with fertilizers and pesticides and the disposing of the industrial wastewater can contaminate the water with phosphates which lead to the rapid growth of algae.

Such profuse growth of algae covers the water surface and reduces the concentration of oxygen in water. This leads to anaerobic conditions, commonly with accumulation of abnoxious decay and animal death.