Eutrophication, or moreprecisely hypertrophication,is the enrichment of a water body with nutrients ( normally nitrogen andphosphorus compounds ), usually with an overabundance measure of nutrients. Asyndrome of ecosystem responses to human activities that fertilize water bodieswith nitrogen and phosphorus, frequently prompting changes in creature andplant populations and degradation of water and habitat quality. Eutrophicationcan be a natural process in lakes and streams, happening as they age throughgeological time. Human activities can increase the rate at which nutrientsenter ecosystems and causes eutrophication.
1.1.1 Process of EutrophicationPlants need a supply of nitrates for making theirproteins, and a source of phosphates for many chemical reactions in theircells. The rate at which plants grow is often limited by how much nitrate andphosphate they can obtain. In recent years, the amount of nitrate and phosphatein our rivers and lakes has been greatly increased.
This leads to anaccelerated process of eutrophication ( Refer to Appendix A.1 ).Eutrophication is the enrichment of natural waterswith nutrients which allow the water to support an increasing amount of plantlife. This process takes place naturally in many inland waters but usually veryslowly. The excessive enrichment which results from human activities leads toan overgrowth of microscopic algae ( Refer Appendix A.2 ).
These aquatic algae are at the bottom of the foodchain. Fertilisers are often used in farming, sometimes these fertilisersrun-off into nearby water causing an increase in nutrient levels. This causesphytoplankton to grow and enable them to increase so rapidly that they cannotbe kept in check by microscopic animals which normally eat them. So, they dieand fall to broken down by bacteria. The bacteria need oxygen to carry out thisbreakdown and the oxygen is taken from the water.
So much oxygen is taken thatthe water becomes deoxygenated and can no longer support animal life. Fish andother organisms die from suffocation ( Refer to Appendix A.3 ).