Updated: Jul 9
Eutrophication happens when pollution caused by the surplus concentration of nutrients such as nitrogen and phosphorus enters a water ecosystem, such as lakes and rivers (“Eutrophication”).
Usually, when a lake experiences eutrophication, it eventually turns into a marsh or land due to the increasing amount of sediments and decomposers brought by itsrivers, but that is a slow process.
Human activities would accelerate it in the ways of depriving oxygen in aquatic ecosystems and impacting biodiversity. Human discharges would pollute industrial and nutritive water from agricultural runoffs into lakes; algae will absorb the elements inside it, and they will grow drastically. Algaes will grow all over the water’s surface and block oxygen and sunlight, causing aquatic animals and plants to die. After that, cyanobacteria generated due to lack of oxygen will create toxins (Johnson and Carpenter 2010).
The enrichment of nutrients will also cause human health concerns, leading to gastrointestinal and dermatological diseases (Zhidkova 2020).
Due to the increase in living conditions and population, it is predicted that this situation will be further intensified.
Several sources concerned a large number of eutrophic lakes all over the world; for example, in China, the country with the largest population and rapid economic growth, 44% of lakes in China are eutrophic, while only 6% of lakes are oligotrophic (Jin 2003). The data indicate that phytoplanktons such as algae and diatoms had grown up, and the creatures living underwater would die due to lack of oxygen. As a result, water industries such as fishing will be heavily impacted, eventually causing unemployment and poverty (Walter et al. 2021). Moreover, the eutrophication process is gradually intensifying. Due to insufficient solutions to the problem, the concentration of nitrogen and phosphorous are observed to be considerable in three large lakes (Gao and Zhang 2010; Qin et al. 2007).
Not only in China, eutrophication is also a global water quality concern. An investigation held by UNEP stated that around 40% of the world’s water systems are eutrophic. In significant areas such as the U.S., 77.8% of the water system is eutrophic (“Report of the Online Groups on Eutrophication, Contaminants and Marine Litter”). These data explains the extent of eutrophication in the world nowadays, and societies are heavily impacted by it.
Not only the economic impacts, eutrophication will also cause to loss of biodiversity. Losing biodiversity obstructs ecosystems from functioning efficiently and eventually causes nature’s inability to support a wholesome environment (Roe 2021).
Additionally, eutrophication leads to human health concerns such as gastrointestinal and dermatological (skin) diseases due to allergies brought by cyanobacteria (Johnson and Carpenter 2010). This considerable concern reveals an urgent precaution to prevent further eutrophication and other impacts caused by it.
To prevent further eutrophication processes, it is essentialfor governments to issue harsher regulations that ensures an efficient treatment of industrial, especially in chemical or mineral-related companies, domestic sewage, and artificial fertilizers, as these are three main sources that give rise to the amount of nutrients in the water.
Figure 1 revealed the extent caused by insufficient treatment for these three elements by the U.K. government: after the increase in population and sewage discharge and the need for fertilizer increased, lake Cumbria turned from oligotrophic to eutrophic. With that explained, the importance of managing sewage and fertilizers submerged. Industrial sewage discharge, especially in mineral or chemical-related industries, can be tough to manage: although being banned by governments, some factories have secretly discharged sewage into aquatic systems.
This issue is, again, significant in China. Due to its population and rapid economic growth, industry is crucial for China, and that causes China to experience a predicament dealing with contaminated water. Scientific research is concerned that China’s total freshwater resource is 2.8·1012 m3, while the available resource is only 1.1·1012 m3 (Wang et al., 2021). The rest of 1.7·1012 m was contaminated by eutrophication and other effects brought by water pollution. Several conservational groups have repeatedly emphasized that it is paramount for the government to decree stricter regulations and protocols against water pollution, which would coerce enterprises to use more environmentally-friendly production methods.
Additionally, it is vital to prevent control of domestic and sanitary sewage discharge, increasing the concentration of nutrients. Domestic and sanitary sewage includes a shower, water basin, and water consumed by the toilet and laundry. This water, being contaminated by other chemical elements, will discharge into water bodies in the vicinity of human habitats. Regulating domestic and sanitary sewage, for instance, reducing the discharge of sewage into the water and establishing sewage plants, can also limit the eutrophication process, as less nitrogen and phosphorous will be discharged. Moreover, it is also essential to control artificial fertilizers such as Ammonium Nitrate and Ammonium Phosphate. The fertilizers will sediment due to rain and runoffs and be washed into water bodies by underground water. Fertilizers are also crucial for eutrophication: in 2019, the world consumed 108 million metric tons of fertilizer, and it has also been studied that around 20% of the fertilizers are leached into underground water( Statistia 2022; Maciolek 2005). Limiting regulating protocols of the use of fertilizers can reduce the further increase of eutrophication considerably. By controlling these extensive resources of eutrophication, the process would be managed, and the other eutrophic process would be prevented.
While managing the current sewage discharge and preventing further eutrophic processes, organizations and governments must control the discharges. However, certain limitations hinder the precaution. For industrial sewage, it is difficult to find another way that reduces sewage can be sent to; it is unrealistic to build a water plant near every factory. Also, if the method of sewage treatment is not efficient, factories can store a considerable amount of sewage, and it will emit toxins that can cause diseases. For sanitary and domestic sewage, it is hard only to send water into water plants, and it will consume a profusion of electricity. More fossil fuels would burn to generate electricity. If eutrophication is reduced, it is ineffectual to the environment, but the greenhouse effect intensifies. Also fertilizers, no fertilizer is environmental-friendly. However, fertilizers are still essential for crops to grow. As a result, the limitation of using fertilizers can cause crop deprivation, potentially leading to hunger. All the limitations must be carefully handled with moderation; if the regulation gets extreme drastically, then it will still cause certain negativity in environments.
In conclusion, eutrophication is a worldwide pollution concern that has great impact on economy and environment.
It has three main contributors: industrial sewage, sanitary and domestic sewage, and artificial fertilizers such as Ammonium Nitrate.
It is important for a government to further regulate more draconian punishment against industrial, domestic, and sanitary water discharge, and develop a careful precaution to use artificial fertilizers or encourage people to use more eco-friendly fertilizers.
However, the improvements are heavily limited:
For controlling water discharge, it requires to build water plants, and that will use a lot of electricity, which means a lot of fossil fuels would be burnt; also, construction itself will also cause CO2 discharge into the atmosphere.
For fertilizers, there is no absolute eco-friendly fertilizer to use, and if the protocol is too strict, food shortage might occur.
For improvements, there is one thing in common: it should be stricter than current existing regulations but not too harsh.
It is indeed important for governments to regulate the contributors in a moderate manner in order not to cause other environmental impacts.
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