Eutrophication is characterized by excessive plant and algal growth due to the increased availability of one or more limiting growth factors needed for photosynthesis, such as sunlight, carbon dioxide, and nutrient fertilizers. Eutrophication occurs naturally over centuries as lakes age and is filled in with sediments. However, human activities have accelerated the rate and extent of eutrophication through both point-source discharges and nonpoint loadings of limiting nutrients, such as nitrogen and phosphorus, into aquatic ecosystems (i.e., cultural eutrophication), with dramatic consequences for drinking water sources, fisheries, and recreational water bodies. Eutrophication is one of the causes of the deterioration of water quality. Nutrients can have a natural or anthropogenic origin and come from:
a) Domestic wastewater
b) Industrial waste
c) Agriculture (fertilizer use)Atmospheric deposition of nitrogen (livestock and gases)