Question

A region of a lake is turned into a dead zone. Identify the correct reason.

• A. Eutrophication
• B. Acid rain
• C. Washed off fertilizers in the lake
• D. Washed off fertilizers in the lake,acid rain and Eutrophication (all)

Answer 1

The correct option is D

Washed off fertilizers in the lake,acid rain and Eutrophication (all)

The people in towns and cities, through which the river flows, throw large quantities of garbage, untreated sewage, dead bodies, fertilizers and many other harmful things, directly into the river. Due to excessive nutrient pollution from human activities coupled with other factors, the oxygen required to support most marine life gets depleted. Such regions of a river are considered as "dead", as at many places where the pollution levels are too high to support aquatic life. This phenomenon is called eutrophication.

Dead portion of the lake can be caused by all the mentioned options.

1. Washed off fertilizers in the lake
2. Acid rain
3. Eutrophication