Water pollution is very harmful to animals. It dissolves oxygen,decreasing the concentration available to fish. Mercury bioaccumulates in food chains and makes it dangerous for us to eat ocean fish like the tuna and swordfish.
The same way that polluted water effects human beings. It can cause death, sickness, abnormalities in offspring, etc. It could also effect their mating cycles so it might cause the extinction of that species.
Many minerals and proteins are include in water. The animals are consume the water with the food like lead and other elements. These are affected by the polluted water. The man who eats these type of animals it also affects the man. It causes to many diseases. Pure water is control to coming diseases.