Q. 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
Explanation
Due to addition of domestic wastes (sewage, phosphates, nitrates, etc) water body become rich in nutrients. With the addition of nutrients, there is stimulated luxuriant growth of algae in water leads to algal blooms. The algal blooms complete with other aquatic plants for light and photosynthesis. Thus, oxygen level is depleted. Moreover, these blooms also release some toxic chemicals, which kill fish and other animals.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.