It is almost like self- ...

It is almost like self- immunization or self-remediation of human body where the immune system of the body will gradually recover itself to its original healthy state to make the body disease free.  Similarly, in case of rivers, here Ganga, the immunity can be maintained by the ecosystem of the river. Hence, if a serious effort can be given to restore the damaged ecosystem of the river, the aim of self-purification of the river can be achieved automatically. A study with a holistic view of ecosystem goods and services of river Ganga will help in this regard.