Eutrophication

Eutrophication is a general term describing a process in which nutrients accumulate in a body of water, resulting in an increased growth of organisms that may deplete the oxygen in the water; ie. the process of too many plants growing on the surface of a river, lake, etc., often because chemicals that are used to help crops grow have been carried there by rain.^[1][2] Eutrophication may occur naturally or as a result of human actions. Manmade, or cultural, eutrophication occurs when sewage, industrial wastewater, fertilizer runoff, and other nutrient sources are released into the environment.^[3] Such nutrient pollution usually causes algal blooms and bacterial growth, resulting in the depletion of dissolved oxygen in water and causing substantial environmental degradation.^[4] Many policies have been introduced to combat eutrophication, including the United Nations Development Program (UNDP)'s sustainability development goals.^[5]

Approaches for prevention and reversal of eutrophication include minimizing point source pollution from sewage and agriculture as well as other nonpoint pollution sources.^[1] Additionally, the introduction of bacteria and algae-inhibiting organisms such as shellfish and seaweed can also help reduce nitrogen pollution, which in turn controls the growth of cyanobacteria, the main source of harmful algae blooms.^[6]