Question

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

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

Answer 1

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

A river with an inflow of domestic sewage rich in organic waste will reduce the dissolved oxygen (DO). The organic waste will increase biological oxygen demand of the river thus depleting the O2 content and may result in the death of fish due to lack of oxygen.

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