The process of Eutrophication can be defined as the presence of inordinate levels of certain nutrients in the waters of estuaries, streams and lakes. These nutrients play a major role in facilitating the growth of plants in these water bodies. The plants that mainly grow due to the presence of these nutrients include periphtyon attached to algae and weeds. This growth is termed as an 'algal bloom'. It causes the levels of dissolved oxygen in water to fall thereby making the survival of other water organisms difficult. Their existence is threatened by this hypoxic water. These harmful nutrients are drained into the waters from various farms and fields, gardens and lawns as well as golf courses and by the residual wastes of sewage treatment units. The burning of fossil fuels and the consequent creation of atmospheric nitrogen and the use of fertilizers rich in these two components also lead to Eutrophication.
Cause of Eutrophication
Eutrophication is caused by the dissolution of Phosphorus and Nitrogen into water bodies. These two elements are present in minimal quantities in probably all natural water bodies. Their levels strike a fine balance and help in the growth of plants biomass. These components are naturally released by the metabolic processes of the aquatic animals and microbes that are present in the water. However, the levels record a rise when the discharge from the various plants affects the normal concentration of phosphorus and nitrogen.
The attention of the environmentalists was directed towards this phenomenon during the 1960s and 70s when several water bodies were found to be filled with excessive plant growth. It forced them to make an intensive study of the reasons behind the cause of such growth. It led them to prohibit the dissolution of detergents high in phosphate content in the lakes and estuaries. The system of disposal of wastes in sewage treatment plants also needed to be overhauled. The increase in human activities has taken a toll on the aquatic ecosystems and proved to be major threat to the marine life forms. It leads to a vicious chemical and biological chain reaction which limits their growth and affects the quality of the ecosystem. Some areas where Eutrophication has cast a damaging effect include the Danish estuaries and the Chesapeake Bay. Careful examination of various coastal areas exhibit a trend which indicates that the areas to be affected most in the coming future are the southern and eastern parts of Asia.
Consequences of Eutrophication
The consequences of Eutrophication also include the discharge of large volume of mucilage by the algae blooms which when come into contact with the coastal winds are brought to the shore and render it unfit for tourists. Some species of planktons also generate harmful chemicals that can affect the digestive, respiratory and nervous systems of the aquatic animals.
Eutrophication can be done away with by discarding these activities or by ensuring better disposal techniques. Some of the steps that can be taken to eradicate this include the use of fertilizers with minimum levels of phosphorus and nitrogen, effective treatment of sewage disposal, restoration of water bodies and reduction in the levels of these components emitted from vehicles. The initiatives undertaken to curb this global problem include the introduction of the program for the National Coastal Nutrient Management Strategy and the issuance of the European Union's Water Framework Directive.