Eutrophication of water bodies is caused by the:

The correct answer is High amounts of nitrogenous nutrients and orthophosphate.

Key Points

• The enrichment of waters by inorganic plant nutrients is called eutrophication.
• This phenomenon can be caused by various sources, both artificial and natural.
• Eutrophication has relevant effects on water bodies: the main is algal blooming, excessive aquatic macrophyte growth, and oxygen depletion.
• When algal blooms are dense, they form visible green or yellowish-brown coverings that appear to float on the water surface. This blocks sunlight that is needed by organisms in the water and further depletes oxygen.

Additional Information

• Some algal blooms are the result of an excess of nutrients (particularly phosphorus and nitrogen) into waters and higher concentrations of these nutrients in water cause increased growth of algae and green plants.
  • As more algae and plants grow, other organisms die.
• After such organisms die, bacterial degradation of their biomass results in oxygen consumption, thereby creating the state of hypoxia.