A large number of fish are suddenly found floating dead on a lake. There is no evidence of toixc dumping but you find an aboundance of phytoplanktons. Suggest a reason for the fish kill.

Explanation

As the abundance of phytoplanktons are present in water body the concentration of dissolved oxygen in water reduces. This process of depletion of concentration of oxygen in water is called eutrophication. Due to eutrophication, a large number of fishes are found floating dead on a lake.