Write critical notes on the following.

A) Eutrophication

B) Biological magnification

C) Ground water depletion and ways for its replenishment

A) Eutrophication:
Natural ageing of water bodies due to enrichment of nutrients is eutrophication. Nutrients like nitrates and phosphates are carried into the water bodies promote the growth of algae and plants. As a result, animal life burgeons, and organic matter is deposited on the bottom of water body.

B) Biological magnification:
Increase in the concentration of the pollutant or toxicant at successive trophic levels in an aquatic food chain is called biomagnifications. Increased concentration of DDT at successive trophic levels in aquatic food chain leads to thinning of eggshell and premature breaking of eggs. This in turn, leads to decline in bird population.

C) Ground water Depletion and Ways for its Replenishment:

Causes: 

• No seasonal rains.
• Prolonged summer.
• Excessive usage of water by pump sets.

Replenishment Methods:

• Rainwater harvesting wells should be constructed.
• Growing trees helps in water logging.