Eutrophication is the continuous increase of phosphorus, nitrogen, and other plant nutrients in an aged aquatic habitat, such as a lake. As the amount of organic material that can be broken down into nutrients grows, so does the productivity or fertility of such an ecosystem. This material enters the environment mostly from runoff from land, which brings detritus and byproducts of terrestrial organism reproduction and death. Water blooms, or high concentrations of algae and tiny creatures, frequently form on the surface, blocking light penetration and oxygen absorption, both of which are required for undersea life. Eutrophic waters are frequently murky, and they may sustain fewer big creatures like fish and birds than non-eutrophic waterways.

What is Eutrophication?

The process through which a body of water gets too enriched in nutrients is known as eutrophication. You might remember this concept by recalling that the word “eutrophic” originates from Greek and means “well-nourished.” As a result, a ‘well-nourished’ lake is one that has experienced eutrophication.

While it may appear that adding additional nutrients to water is a desirable thing, eutrophication usually has a negative impact. An excess of nutrients promotes the fast development of algae and aquatic plant life. This excessive development depletes the water’s dissolved oxygen levels to the point that other creatures, such as fish, cannot live.

Eutrophication develops, a body of water can see explosive development of algae at or near the water’s surface, known as algal blooms. When algal blooms are dense enough, they produce visible green or yellowish-brown coatings that float on the water’s surface. This obstructs sunlight, which is required by aquatic creatures, and depletes oxygen even further.

Eutrophication Mechanism

Eutrophication is often caused by an excess of nutrients, most commonly nitrogen or phosphorus, which causes overgrowth of plants and algae in aquatic habitats. After such creatures die, bacterial breakdown of their biomass causes oxygen consumption, resulting in hypoxia.

Phosphate is the key limiting element in eutrophication. Phosphorus is typically beneficial to excessive plant growth and decay. It also favours simple algae and plankton and has a negative impact on water quality. Phosphorus may be an essential ingredient for plants to measure, as well as a limiting component for plant development in many freshwater habitats.

• Cultural eutrophication: Cultural eutrophication is a mechanism that accelerates natural eutrophication. Because of land clearance and the construction of towns and cities, land runoff is expedited, and additional nutrients, such as phosphates and nitrates, are given to lakes and rivers, then to coastal estuaries and bays.
• Natural Eutrophication: Eutrophication occurs naturally in many lakes in temperate grasslands. Paleo Limnologists currently believe that global climatic change, geological changes, and other external variables are crucial in controlling lake natural production. Natural activity is incredibly slow, taking place over geologic time spans.
• Lakes and rivers: Algae decomposes as it dies. As a result, microbes transform the nutrients in it into inorganic form. This breakdown process consumes a large amount of oxygen, lowering the quantity of dissolved oxygen. Depleted oxygen levels may result in fish deaths and a range of other impacts that reduce biodiversity.
• Coastal waters: Eutrophication is a common occurrence in coastal waters. Unlike in freshwater systems, where phosphorus is typically the limiting nutrient, nitrogen is more generally the limiting component in marine environments.

Eutrophication Causes

1. Compound fertilisers (nitrates and phosphates)

Human activity is the primary source of eutrophication. Nutrient buildup is aided by agricultural practices and the use of fertilisers on lawns, golf courses, and other areas.

2. Intensive animal feeding operations

Concentrated animal feeding operations (CAFOs) are also a major source of phosphorus and nitrogen nutrients, which contribute to eutrophication.

3. Direct dumping of sewage and industrial waste into bodies of water

In certain parts of the globe, particularly in underdeveloped countries, sewage water is dumped straight into bodies of water such as rivers, lakes, and seas. As a result, it introduces large amounts of chemical fertilisers, supporting the dense growth of algal blooms and other aquatic plants, endangering aquatic life in a variety of ways.

4. Natural occurrences

Natural phenomena such as floods and the natural flow of rivers and streams can also carry extra nutrients from the land into water systems, causing algal blooms to flourish excessively.

Eutrophication’s Effects

• Eutrophication causes physical, chemical, and biological changes in water, lowering its quality.
• The presence of high levels of nitrogen and phosphorus in water bodies promotes the rapid development of aquatic plants such as algae, resulting in an algal bloom that prevents light from penetrating deeper layers.
• The decomposition of an algal bloom depletes the oxygen content while increasing the CO level in the water. Aquatic species begin to die as a result of the low oxygen supply, transforming clean water into a stinky sewer.
• The loss of dissolved oxygen causes anaerobic decomposition of organic matter, which creates H2S, CH4, and NH3, resulting in a foul odour and putrefied taste of the water.
• Algae, diatoms, and rooted weeds demonstrate dominance by interfering with hydroelectric power, clogging water filters during the water treatment process, slowing water flow, and damaging water quality and water works.

Eutrophication Control Measures

• Waste water, such as sewage, must be adequately treated before being discharged into bodies of water.
• Algal blooms should be removed from water after death before further decomposition, since they would otherwise provide plant nutrients during decomposition.
• To reduce eutrophication, use phosphate-free detergents.
• Algae growth in water may also be inhibited by using algaecides such as CuSO4.
• Precipitation, nitrification, denitrification, electro-dialysis, reverse osmosis, and ion-exchange technologies can all be used to remove nitrate and phosphate from wastewater before discharge into rivers.
• Prevent water from agricultural soil containing fertilisers from overflowing the water system.

Conclusion

Eutrophication is the continuous increase of phosphorus, nitrogen, and other plant nutrients in an aged aquatic habitat, such as a lake. The process through which a body of water gets too enriched in nutrients is known as eutrophication. An excess of nutrients promotes the fast development of algae and aquatic plant life. Eutrophication develops, a body of water can see explosive development of algae at or near the water’s surface, known as algal blooms. Eutrophication is often caused by an excess of nutrients, most commonly nitrogen or phosphorus, which causes overgrowth of plants and algae in aquatic habitats. Because of land clearance and the construction of towns and cities, land runoff is expedited, and additional nutrients, such as phosphates and nitrates, are given to lakes and rivers, then to coastal estuaries and bays.