Index of biological integrity

An index of biological integrity (IBI), also called an index of biotic integrity, is a scientific tool typically used to identify and classify water pollution problems, although there have been some efforts to apply the idea to terrestrial environments. An IBI associates anthropogenic influences on a water body with biological activity in the water body, and is formulated using data developed from biosurveys.

Source: Wikipedia — Index of biological integrity (CC BY-SA 4.0)