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2512004 
Journal Article 
Eutrophication: Threat to Aquatic Ecosystems 
Ansari, AA; Gill, SS; Khan, FA 
2011 
143-170 
WOS:000283620400007 
Eutrophication was recognized as a pollution problem in
European and North American lakes and reservoirs in the mid-twentieth century. Since then, it has
become more widespread. Surveys showed that most of the lakes in Asia, Europe, North America,
South America, and Africa are found in eutrophic state. Eutrophication leads to significant
changes in water quality. It lowers the value of surface waters for the industrial and
recreational uses. The overpopulation of algae makes water unfit for swimming. The algae growing
in long strands often twine around boat propellers and make boating difficult. Eutrophic waters
tend to be scummy, cloudy, or even soupy green. The rapidly growing aquatic plants may wash onto
the shores in storms or high winds, where these plants die, decay, and produce a bad smell all
around such water bodies. The eutrophication in an aquatic ecosystem also causes significant
changes in biodiversity. The eutrophication causes an increase in plant and animal biomass,
frequency of algal blooms, growth of rooted plants, and decreases the species diversity. Due to
eutrophication, an increase in turbidity and anoxic conditions occurs. Because of the high
density of aquatic organisms in a eutrophic system, there is often a lot of competition for
resources. This high degree of competition and high chemical or physical stress make the struggle
for the survival in eutrophic systems higher. As a result the diversity of organisms is lower in
eutrophic than in oligotrophic systems. 
Eutrophication; Aquatic ecosystem; Biodiversity; Nutrients