Tropical fish owners must keep the water in
the tank form getting too warm or the fish will die. This is true because the
fish that as grown in an environment at mild temperature got used to that
environment. So if there is a constant increase or decrease of temperature,
even if at one degrees Celsius, overtime the fish will die. For them, their
environment has become polluted because of the change in temperature. It unbalances
the system of living they used to have.
