Introduction to Eutrophication

Eutrophication is a process in which different nutrients accumulate in the water body which increases the growth of plants and other microorganisms. The indicator of this process is the excessive growth (bloom) of Algae and other plankton. It is considered one of the most important environmental degradation concerns because it pollutes the water and depletes the dissolved oxygen in the water body. When the process of eutrophication runs for a long the water body finally becomes a dead zone and is unable to support life further.

Causes of Eutriophication

Nutrients such as nitrogen and phosphorus increase the growth of plants. When this nutrient such as nitrogen and phosphorus are enriched in the water body it increases the normal growth of Algae and Plants and becomes the cause of eutrophication.

Way through which the water body becomes nutrient-enriched

Phosphorus is the main nutrient that increases the growth of plants in water bodies. It enters the water body through soil erosion. The other main sources of nutrient enrichment are

• The fertilizers used in agriculture are the main source of nutrient enrichment. When we use fertilizers such as nitrate and phosphate some of them are consumed by the crops while the rest run in the water and ultimately reach the water body and lead to nutrient enrichment.
• Some detergents available in the market contain large amounts of phosphate. When we use it reaches the water body and causes enrichment.
• Untreated sewage from different sources contains phosphate and nitrate which increase the amount of nutrients in the water body.
  (The industrial discharge is another source of nutrient enrichment.

What happens when a large concentration of Algae in Eutrophic water?

When a high concentration of Algae is produced in the water body. The Algae become dead after completing their life cycle and sink to the bottom of the water body. The microorganisms in the water body start the decomposition of this dead Algae. In this process, the microorganism utilizes the dissolved oxygen of the water body. Excessive use of oxygen by microorganisms leads to the depletion of oxygen in water bodies. The lack of oxygen leads to suffocation and eventual death in other organisms like fish.

The picture given in this post is captured from a Pond near Timergara, Pakistan. You can see the Algal bloom which fully covers the water body.