Question

why should water bodies be conserved and what are the factors that lead to deterioration

Answer 1

Water conservation is important because all living organisms need water to survive.It involves caring for water and using it wisely.It also encompasses activities,strategies and policies of managing  the water environment.
-Dead plants as they harbor harmful bacteria within your aquarium which could dramatically increases the chances of water quality deterioration.
-Dead fish which provide a breeding ground for fungus which could transfer to the live fish which would need to be treated.