In context with environment, the Eutrophication refers to the addition of artificial or non-artificial substances, such as nitrates and phosphates, through fertilizers or sewage, to a fresh water system. It can be anthropogenic or natural. It leads increase in the primary productivity of the water body or “bloom” of phytoplankton. The overgrowth causes the loss of oxygen in the water leading to severe reductions in fish and other animal populations.
However, the Nomurai Jellyfish is an exception which shows an increase in population that negatively affects other species in the local ecosystem.