Question

State the effects of discharging organic wastes rich in nutrients in a water body.

Answer 1

Discharging organic wastes rich in nutrients into a water body leads to several harmful effects:

1. Eutrophication: The excess nutrients, especially nitrogen and phosphorus, cause an overgrowth of algae and aquatic plants, particularly planktonic algae. This results in the formation of dense algal blooms and floating scums on the water surface.
2. Oxygen depletion: When these algae and plants die, their decomposition by microorganisms consumes a large amount of dissolved oxygen in the water. This leads to a sharp decline in dissolved oxygen levels.
3. Death of aquatic life: Reduced oxygen causes suffocation and death of fish and other aquatic animals, disrupting the aquatic ecosystem and food chain.
4. Growth of harmful aquatic weeds: Nutrient-rich conditions favor the growth of invasive aquatic weeds like Eichhornia crassipes (water hyacinth), which further imbalance the ecosystem.
5. Release of toxic substances: Some algal blooms release toxins harmful to aquatic animals.
6. Water quality deterioration: The water becomes foul, stinking, and unsuitable for drinking or other uses.