Question

A lake with an inflow of domestic sewage rich in organic waste may result in ______.

Options

• Drying of the lake very soon due to algal bloom

• An increased production of fish due to lot of nutrients

• Death of fish due to lack of oxygen

• Increased population of aquatic food web organisms

Answer 1

A lake with an inflow of domestic sewage rich in organic waste may result in death of fish due to lack of oxygen.

Explanation:

Decomposers use dissolved oxygen while breaking down organic sewage, reducing the oxygen available to fish. Nutrient enrichment may cause algal growth, but it does not ensure a lasting increase in fish or aquatic organisms.