Question

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

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

Answer 1

The correct option is B Death of fish due to lack of oxygen

A river with an inflow of domestic sewage rich in organic waste may result in death of fish due to lack of oxygen.
Eutrophication is the natural aging of lake by nutrient enrichment of its water. As the fertility of lake increases, alagal bloom occurs which causes degradation of water quality and fish mortality.
So, the correct answer is option 'b'.