Eutrophication is the artificial enrichment of a water body or aquatic system with phosphorus and nitrogen nutrients, usually with excessive amounts of nutrients. This process causes excessive growth of plants and algae and, due to the biomass load, can result in reduced oxygen in the water body. For example, as a response to increased nutrient levels, there is a large increase in phytoplankton in the water body, called an algal bloom. Nutrients can come from animal waste, fertilizers often used in agriculture, and sewage that is washed by rain or irrigation into water bodies through surface runoff. This will increase nutrient levels and contribute to eutrophication. Eutrophication can be divided into cultural eutrophication, which is caused by human activity, and natural eutrophication, which is a natural process. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essay Cultural eutrophication is the process that accelerates natural eutrophication due to human activity. Due to land clearing and the construction of towns and cities, land runoff is accelerated and more nutrients such as phosphates and nitrates are supplied to lakes and rivers, and thus to estuaries and coastal bays. In many countries, additional nutrients are also provided by treatment plants, golf courses, fertilizers, farms and untreated sewage. Natural eutrophication is a natural process. Eutrophication occurs in many lakes in temperate grasslands. Paleolimnologists now recognize that climate change, geology and other external influences are critical in regulating the natural productivity of lakes. Some lakes also demonstrate the reverse process, becoming less nutrient-rich over time. The main difference between natural and anthropogenic eutrophication is that the natural process is very slow and occurs on geological time scales. Eutrophication is mainly caused by human action due to its dependence on the use of fertilizers. Agricultural practices and the use of fertilizers on lawns, golf courses and other fields contribute to the accumulation of phosphate and nitrate nutrients. When the concentration of nutrients increases to the point where the soil can no longer assimilate them, the nutrients are transported by rainfall into rivers and aquifers that flow into lakes or seas. Plankton, algae and other aquatic plants are therefore well nourished and their photosynthesis activity increases. They grow and reproduce more rapidly, resulting in dense growth of algal blooms and plant life. This will disrupt the normal functioning of the ecosystem and cause many problems. (Referappendix-1) On the other hand, eutrophication can be caused by the input of untreated sewage as well as discharge from wastewater treatment plants. We can see that wastewater is directly discharged into water bodies such as rivers, lakes and oceans in various parts of the world, especially in developing nations. The result of this is the release of a high amount of chemical nutrients that stimulate the disproportionate growth of algae and other aquatic plants which in many ways threaten the survival of aquatic life. Some countries may also treat wastewater, but after treatment they still discharge it into water bodies. Even if the water is treated, it can still cause excess nutrients to build up and lead to eutrophication. (See appendix-1) Apart from this, it is also caused by aquaculture. Aquaculture is a technique of growing shellfish, fish and even aquatic plants in containing waterdissolved nutrients. Therefore, uneaten food particles along with fish excrement can significantly increase nitrogen and phosphorus levels in water if aquaculture is not managed properly. This will result in the dense growth of microscopic floating plants. Finally, eutrophication can be caused by natural events such as flooding and the natural flow of rivers and streams. Excess nutrients will be washed out of the soil and into water systems causing excessive growth of algal blooms. Additionally, as lakes age, they naturally accumulate sediment such as phosphorus and nitrogen nutrients that contribute to explosive phytoplankton growth and cyanobacterial blooms. How does this happen? First, excess nutrients are applied to the soil. Then they are drained into ponds, lakes or rivers. This encourages the rapid growth of photosynthesizing organisms, especially algae. This results in a population explosion known as an algal bloom. The algal bloom prevents sunlight from reaching the bottom of the body of water. As a result, aquatic plants under the algal bloom die because they cannot receive sunlight for photosynthesis and this further decreases the oxygen supply in the water. Eventually, the algal bloom dies and sinks to the bottom of the lake, the decaying microorganisms, especially aerobic bacteria, grow rapidly and consume oxygen for respiration at a high rate. Aerobic bacteria consume oxygen faster than it can be replenished. This causes biochemical oxygen demand (BOD) to increase resulting in depletion of oxygen in the water. Due to the low level of oxygen concentration, larger life forms, such as fish, suffocate and are unable to survive. In extreme cases, if the oxygen level continues to drop until the water becomes completely deoxygenated, aerobic bacteria will grow and release toxic substances. gases harmful to aquatic life. This body of water can no longer support life and this process is called eutrophication. (Referappendix-2) Aquatic plants need two essential nutrients to grow such as nitrogen (N) and phosphorus (P). In a healthy lake, biochemical oxygen demand (BOD) must be low, indicating better water quality, and nutrients must be present in small quantities for the survival of aquatic plants. Conversely, if nutrients are present in large quantities a serious water pollution problem will occur. Too many nutrients will stimulate the rapid growth of plants and algae, clogging waterways and sometimes creating a serious algal bloom. If this were to happen, the survival of fish and other aquatic life will be threatened. Algal blooms caused by excess nutrients in the water body will limit the amount of dissolved oxygen required for aquatic life forms to respire. When algae and aquatic plants die and decompose, the growth of debris is encouraged and oxygen is depleted. When dissolved oxygen reaches hypoxic levels, underwater plant and animal species such as shrimp, fish and other aquatic organisms will suffocate to death. In extreme cases, anaerobic conditions favor the growth of bacteria that produce toxins that are deadly to marine mammals and birds. The growth of phytoplankton also causes a reduction in light penetration into the water. This can cause dead aquatic areas, loss of aquatic life and even a decrease in biodiversity. (See Appendices-3). It also leads to deterioration of water quality and limited access to safe drinking water. This.