chapter  1
6 Pages

Introduction

References ..................................................................................................................5

body.

A broadly applicable indicator for use in biological assessment is the Index of Biotic Integrity (IBI) (Karr 1981). The IBI approach was developed to identify levels of stream impairment using the fish assemblage as a biological indicator. Using the IBI as a model, many biomonitoring programs have expanded to incorporate several types of multimetric indices using fish, macroinvertebrates, and periphyton assemblage-level data. It has been shown that using multiple assemblages from various trophic levels can provide assessments of a broader array of stressors causing stream impairment (Karr 1991).