With reference to a fresh water lake, consider the following characteristics: 1. Richness in nutrients 2. Rapid turnover of phytoplankton 3. Depletion of dissolved oxygen Which of the above is/are observed in a lake after its eutrophication?

Answer: Option D

Depletion of dissolved oxygen is observed in a lake after its eutrophication. Eutrophication is the process by which a body of water becomes enriched in dissolved nutrients (as phosphates), stimulating the growth of aquatic plant life usually resulting in the depletion of dissolved oxygen.