Question

The eutrophication of water body results in:

• A. loss of Biodiversity.
• B. breakdown of organic matter.
• C. increase in biodiversity.
• D. decrease in BOD.

Answer 1

The Correct Option is A

Eutrophication is a process that occurs in aquatic environments when nutrients, mainly phosphorus and nitrogen, accumulate in a water body, often due to runoff from the land. This leads to an increase in plant and algae growth, disrupting the ecological balance and can result in several detrimental effects on the water body.

1. Loss of Biodiversity: As eutrophication progresses, the dense algae and plant growth can lead to a loss of biodiversity. When algal blooms occur, they block sunlight from reaching other aquatic plants, thus reducing their ability to photosynthesize and grow. Without sunlight, these plants die off, causing a decline in plant diversity. Moreover, as the algal blooms die and decompose, the process depletes oxygen levels in the water, leading to hypoxic conditions. Many aquatic organisms cannot survive in low-oxygen environments, resulting in their death and thus reducing biodiversity.
2. Breakdown of Organic Matter: While the breakdown of organic matter does occur in eutrophication, it is not the direct answer to the outcome of eutrophication but rather a process that contributes to loss of biodiversity. The decomposition process consumes oxygen, exacerbating oxygen depletion.
3. Increase in Biodiversity: This option is incorrect as eutrophication typically results in a lowering of biodiversity. The harsh conditions created—such as hypoxia and poor light availability—are detrimental to most aquatic organisms.
4. Decrease in BOD (Biological Oxygen Demand): This is incorrect. Eutrophication generally causes an increase in BOD, as the large amount of organic matter (from dying algae) requires more oxygen to decompose, thus increasing the demand for oxygen in the water.

From the above analysis, the correct result of eutrophication is the loss of biodiversity due to the reduction in oxygen levels and the unfavorable conditions for aquatic life.