Eutrophication (Greek: eutrophia — healthy, adequate nutrition, development; German: Eutrophie) or more precisely hypertrophication, is the movement of a body of water′s trophic status in the direction of increasing biomass, by the addition of artificial or natural substances, such as nitrates and phosphates, through fertilizers or sewage, to an aquatic system. In other terms, it is the "bloom" or great increase of phytoplankton in a water body. Negative environmental effects include hypoxia, the depletion of oxygen in the water, which induces reductions in specific fish and other animal populations. Other species (such as Nomura's jellyfish in Japanese waters) may experience an increase in population that negatively affects other species. Wikipedia, Eutrophication