Eutrophication: A Bionomical Vision

Introduction

Eutrophication is a process that occurs when water bodies become overly enriched with nutrients, particularly nitrogen and phosphorus. These nutrients promote the growth of algae and other aquatic plants, leading to an excessive proliferation known as an algal bloom. The excessive growth of these organisms can have detrimental effects on the ecosystem and the water quality of the affected area. Due to ever increasing human interventions of natural as well as managed ecosystems, eutrophication has become an urgent environmental issue worldwide. The Organization for Economic Cooperation and Development (OECD) (2016) defined eutrophication as ‘the enrichment of water with nutrient salts that causes structural changes to the ecosystem, namely, the increase in production of microalgae and aquatic plants, depletion of fish species, general deterioration of water quality and other effects that reduce and preclude use’. The potential sources triggering eutrophication in lakes are complicated and involve various types of factors, which can be classified into natural-driven factors and human intervention factors. Hence, eutrophication can be broadly divided into natural eutrophication and cultural eutrophication (Lin et al. 2020). The main difference is that natural eutrophication is a natural process taking place in geological time scale while cultural eutrophication is the process that speeds up natural eutrophication due to human activities. It is a rapid process taking only decades. There can be point and non-point sources of eutrophication. In point, sources nutrient waste travels directly from the source to water. They are relatively easy to regulate. However, in non-point sources, they come from diffused sources and are difficult to regulate. The contribution of non-point sources to eutrophication is much more than point sources (Carpenter et al. 1998).

Eutrophication typically occurs as a result of human activities, such as agricultural runoff, sewage discharge, and the use of fertilizers. When these nutrients enter water bodies, they stimulate the rapid growth of algae and other plants. As the algae bloom, they block sunlight from reaching the deeper parts of the water, hindering the growth of underwater plants and disrupting the balance of the ecosystem. Once the algae die and decompose, bacteria consume the organic matter, consuming oxygen in the process. This leads to a depletion of oxygen levels in the water, creating hypoxic or anoxic conditions, which are harmful to many aquatic organisms. The reduced oxygen levels can result in fish kills and the decline of other marine life. Additionally, eutrophication can lead to the formation of harmful algal blooms (HABs), which produce toxins that can be harmful to humans and other animals, imposing a threat to public health (Rathore et al. 2016). To combat eutrophication, it is important to reduce nutrient inputs into water bodies. This can be achieved through improved agricultural practices, such as minimizing the use of fertilizers and implementing buffer zones to trap runoff. Wastewater treatment plants can also play a significant role in removing nutrients from sewage before it is discharged into water bodies. Overall, addressing eutrophication requires a combination of measures aimed at reducing nutrient pollution, promoting sustainable land use practices, and raising awareness about the importance of protecting water quality.Top of Form So this chapter will focus on eutrophicaton, its global status, causes, impact and the various management options to combat it.