Evaluation of an Index of Biotic Integrity: Temporal Variability and Regional Application in the Midwest

摘要

Assessment of biotic integrity in water resource systems has been hampered by lack of indices suitable for evaluating biological conditions. Biotic integrity is defined as presence of a balanced, integrated, adaptive community of organisms having a species composition, diversity, and functional organization comparable to that of a natural habitat for the region. Classical water quality assessments are usually based on chemical, bacterial, or thermal criteria. This approach neglects factors such as structural (habitat) characteristics, and patterns of temporal variation in environmental characteristics, both of which affect biological conditions and are subject to human alteration. An Index of Biotic Integrity (IBI) based on analysis of fish communities in streams was introduced by Karr.