Question

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

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

Answer 1

The correct option is A

Death of fish due to lack of oxygen

The correct answer is option (a) – Death of fish due to lack of oxygen.

• The dissolved oxygen will be reduced when the sewage is released into the rivers.
• Algal bloom happens when the fertility in lakes will increase.
• Algal bloom will reduce the quality of water.
• Natural ageing of lakes by nutrient enrichment of water is eutrophication.
• Aquatic organisms will grow when nutrients are introduced into the lake.