ABSTRACT

This chapter summarizes present index of biological integrity (IBI) applications outside the US and Canada, with particular emphasis on the way metrics have been modified while retaining the IBI’s theoretical foundations. The goal in doing so is to encourage further applications in other countries. The IBI is based on the hypothesis that there are predictable relationships between fish assemblage structure and the physical, chemical, and biological condition of stream systems. Classes of attributes (metrics) in the IBI include species richness, species composition, trophic structure, fish abundance, and fish condition. Furthermore, there is no loss of information as the structure and calculation of IBI preserves both the original data and also provides a metric-by-metric evaluation of stream condition. Perhaps the most fundamental requirements for further application of the IBI model are increased knowledge of regional fish faunas (biology, ecology and systematics), together with improved sampling methodologies and monitoring programs.