Definition of Oligotrophic
Oligotrophic are those environments in which there is a low supply of nutrients which makes it difficult for life to sustain. It is commonly used to describe those land and water bodies that have a very low concentration of nutrients like nitrates, iron, phosphates, and carbon compounds. The organisms that can inhabit such an environment are termed oligotrophs.
They have acquired some mechanisms that have made them capable of living in that environment. For Example, they express genes despite periods of low nutrient conditions. They become so habitual to low nutrient supply that if they are moved to nutrient-rich environments, they are not able to survive. Examples of such environments include polar ice caps, ocean waters, leached soils, caves, etc.