Q. Consider the following statements regarding eutrophication:

1. It is primarily caused by the excess presence of nitrogen and phosphorus in water bodies.
2. It frequently leads to hypoxic (low-oxygen) conditions in aquatic ecosystems.
3. Eutrophication renders the affected water body alkaline by significantly raising its pH.

Which of the above statements is/are correct?
Answer: Only 1 and 2
Notes: Eutrophication is mainly caused by excess nitrogen and phosphorus, which stimulate algal blooms. The subsequent decomposition of these blooms leads to hypoxia (oxygen depletion) in the water body. However, eutrophication does not necessarily make the water body alkaline; in fact, algal blooms can sometimes lower pH during decomposition.