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. oxides of nitrogen

Answer 1

The correct option is C

death of fish due to lack of oxygen

When sewage enters a lake or stream, microorganisms begin to decompose the organic materials. Oxygen is consumed as micro-organisms use it in their metabolism. This results in the death of fishes due to lack of oxygen.