Pollutants from man’s activities like effluents from the industries and homes can radically accelerate the aging process of the water bodies which, otherwise takes hundreds to to thousands of years. This phenomenon is called cultural or accelerated eutrophication.

Natural aging of lake is natural eutrophication.

Removal of fertile top-soil due to over-cultivation and poor irrigation practices leads to desertification.

Increase in concentration of toxic substances in the successive trophic levels is called biomagnification.