Question

How is the life of organisms living in the water get affected when water gets polluted?

Answer 1

Water gets polluted from domestic wastes, fertilizers, pesticides (from agricultural fields), and industrial waste. The effect of water pollution are as follows:
(a) Fertilizers and domestic wastes cause eutrophication (the environment becomes enriched with nutrients). This leads to the growth of algae causing algal bloom. They compete for the oxygen present in the water. This reduces oxygen available to aquatic animals.
(b) Domestic waste carries pathogens of a number of diseases. Some of them can cause diseases in aquatic animals as well.

(c) Pesticides and industrial wastes carry toxins that can directly harm aquatic organisms.