Question

Eutrophication is caused by
A) Lack of algae in a lake
B) Abundant oxygen in ponds
C) Runoff fertilizers in lake
D) Excess nektons in lake

Answer 1

Eutrophication is the one type of water pollution. Water pollution is defined as the adding of extra and foreign substances into water which leads to changes in the property of the water and health hazard to the life of the water.

Complete Answer:
- Water pollution is three types: physical pollutants, chemical pollutants and biological pollutants.
- Physical pollutants include Heat and oils, Chemical pollutants include organic waste and pesticides, and Biological pollutants include pathogens.
- When phosphorus and nitrates dissolve in water and provide the nutrients and fast the growth of the algae is known as eutrophication.
- These alage then make the mat over the water surface.
- Phosphorus and nitrates are mostly present in the fertilizer.

So, the correct answer is Run off fertilizers in the lake.

Additional information:
- The excess of algae layer is formed due to eutrophication which uses the oxygen at night and leads to the decrease in the amount of oxygen to water animals causing the death of fish and other animals.
- There are various other factors which accelerate the eutrophication process like effluents from industries and residential premises.
- Nitrates and phosphorus not only caused the eutrophication, when these come in contact with blood leads to reduced the capacity of blood to carry oxygen.

Note: The mat of extra grown algae blocks the light for submerged plants.
- There is some other source of water pollution but nitrates and phosphorus is the major source.