Question

Runoff of excess fertiliser from farm fields into nearby waterways can result in

• A. Ozone depletion
• B. Air pollution
• C. Biomagnification
• D. Acidification
• E. Eutrophication

Answer 1

The correct option is E Eutrophication

A. Ozone depletion is the reduction in the amount of ozone in the stratosphere due to various ozone-depleting substances such as chlorofluorocarbon (CFC).

B. Air pollution is the undesirable change in the natural characteristics of the air due to the contamination of the indoor and outdoor environment by any chemical, biological and physical agent.

C. When a toxic substance gets incorporated into the food chain and its concentration gets increased or magnified at each successive trophic level, the phenomenon is known as biomagnification.

D. Acidification is the decrease in pH that occurs in water bodies due to absorption of carbon dioxide.

E. Eutrophication is the phenomenon of nutrient enrichment (nitrogen, phosphorus) of a water body that initially supports a dense growth of plants and animal. This causes decomposition of nutrients through the bacteria and by the process of anaerobic respiration.

Hence runoff of excess fertiliser from farm fields into nearby waterways can result in nutrient enrichment of phosphorus and nitrogen and this will lead to Eutrophication.

So, the correct answer is 'Eutrophication'.