Evaluating the biotic integrity of watersheds in the Sierra Nevada, California

  • Moyle P
  • Randall P
  • 112

    Readers

    Mendeley users who have this article in their library.
  • 89

    Citations

    Citations of this article.

Abstract

We developed a watershed index of biotic integrity that used whole watershed variables for metrics rather than site-specific variables. We used the index to evaluate the biological health of 100 watersheds in the Sierra Nevada of California. The index scores, which were based on various measures of distribution and abundance of native fish and frogs, indicated that 7 of the watersheds were in excellent condition (high biotic health), 36 were in good to very good condition, 48 were in fair condition, and 9 were in poor condition. The biggest factors contributing to low index scores were large dams and introduced fishes, although measures of road density and indicators of intensity of use of terrestrial habitats were also important. Large areas of the Sierra Nevada that were once fishless now contain trout in most waters, anadromous fishes are excluded from many streams from which they were once abundant, assemblages of native fishes have been disrupted, and ranid frogs have been extirpated from many areas. All watersheds in the Sierra Nevada have thus experienced loss of biotic integrity, but some have suffered much less than others. Evaluations of the biotic integrity of watersheds over wide regions can help managers set priorities for watershed-oriented systems of aquatic conservation and provide starting places for more-intensive studies.

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Get full text

Authors

  • Peter B. Moyle

  • Paul J. Randall

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free