what is eutrophication ?

Eutrophication refers to the nutrient enrichment in the water bodies leading to lack of oxygen and deadening of life supporting environment. Usually rapid increases in the nutrient status of a body of water happen, by both natural and occurring as a byproduct of human activity. It may be caused by run – off of artificial fertilizers from agricultural land, or by input of sewage or animal waste. This increased nutrient content of the water body causes excess growth of algae. This algal bloom covers the water surface, secrete toxins and reduce oxygen content of water. Oxygen deficiency may cause the death of aquatic animals.