There is mass mortality of fishes in a pond. What may be the reasons?
One reason for the mass mortality of fish in a pond is eutrophication. Eutrophication is a process by which plant growth increases in a water body like a pond or lake. The increased growth and overcrowding of plants is due to either natural fertilizing agents that are washed off from the soil or the runoff of chemical fertilizers applied to agricultural lands. As the overcrowded plants die off, the dead and decaying vegetation depletes the pond’s oxygen supply. This in turn leads to the mass-scale death of fish in the pond. Any change in the water quality necessarily influences the whole of the surrounding environment. Hence to maintain a well-defined environment, the ecology of an ecosystem should not be disturbed. Some other reasons may be Poor water quality, Poor pond hygiene, Presence of Pests, etc.