ABSTRACT
This chapter demonstrates the application of Index of Biotic Integrity (IBI) to three very different situations in California: evaluation of watersheds in the entire Sierra Nevada range for setting conservation priorities; long-term evaluation of a regulated stream and evaluation of a fairly pristine stream that has been extensively invaded by exotic species. The low diversity and shifting nature of the fish faunas make it difficult to develop metrics based on species diversity, trophic specialization, and reproductive strategy that are typical of IBIs for eastern streams. Three solutions to this problem have been suggested: use standard IBI metrics anyway, reduce the number of metrics, or develop metrics based on aquatic organisms other than fish. Introduced fishes present a particular problem in the West because they frequently dominate local faunas. The Sierra Nevada is a range of mountains that makes up much of the eastern third of California and is the source of much of the state’s water developed for human use.
