Question

A lake with an inflow of domestic sewage rich in organic waste may result in

• A. Drying of the lake very soon due to algal bloom
• B. An increased production of fish due to lot of nutrients
• C. Death of fish due to lack of oxygen
• D. Increased population of aquatic food web organisms

Answer 1

Answer: (C)

Death of fish due to lack of oxygen

Domestic sewage contains biodegradable organic matter, which readily gets decomposed by bacteria. Microorganisms involved in biodegradation of organic matter in the receiving water body consume a lot of oxygen, and as a result, there is a sharp decline in dissolved oxygen. This causes mortality of fish and other aquatic creatures

So, the correct answer is 'Death of fish due to lack of oxygen'