Question

Eutrophication means

• A. Sudden increase in algal growth due to the entry of nitrates and phosphates into aquatic system
• B. High rate of photosynthesis
• C. High rate of decomposition of organic matter leading to oxygen depletion
• D. All of the above

Answer 1

The correct option is D All of the above

The streams draining the fertilisers into the lake introduce nutrients such as nitrogen and phosphorus, which encourage the growth of algae. As the lake's fertility increases, algal bloom occurs which is known as eutrophication. Algal bloom performs photosynthesis. The oxygen is used for the microbial degradation of the dead algae. This causes the deterioration of water quality and death of aquatic plants and animals like fishes due to a decrease in the oxygen content of the water.

Thus, the correct answer is option D.