Question

Excessive nutrients in a fresh water body cause fish mortality. Give two reasons.

Answer 1

Excessive nutrient availability in a water body results in the formation of algal blooms, this phenomenon is called as eutrophication. This nutrient enrichment, however, increases fish mortality due to following reasons:-

1. Algal blooms deprive the water body of oxygen making it unavailable for fishes. This leads to their death.
2. The dead remains of these fishes further deplete water of oxygen this leads to further increase in fish mortality.