Skip to Main Content
U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Home > Search > Publication Information

  1. Share via EmailShare on FacebookShare on LinkedInShare on Twitter
    Dislike this pubLike this pub
    Author(s): Bret C. HarveyJason L. WhiteRodney J. Nakamoto
    Date: 2004
    Source: Ecology 85(1): 127-133
    Publication Series: Miscellaneous Publication
    PDF: Download Publication  (250 KB)


    While two cyprinid fishes introduced from nearby drainages have become widespread and abundant in the Eel River of northwestern California, a third nonindigenous cyprinid has remained largely confined to <25 km of one major tributary (the Van Duzen River) for at least 15 years. The downstream limit of this species, speckled dace, does not appear to correspond with any thresholds or steep gradients in abiotic conditions, but it lies near the upstream limits of three other fishes: coastrange sculpin, prickly sculpin, and nonindigenous Sacramento pikeminnow. We conducted a laboratory stream experiment to explore the potential for emergent multiple predator effects to influence biotic resistance in this situation. Sculpins in combination with Sacramento pikeminnow caused greater mortality of speckled dace than predicted based on their separate effects. In contrast to speckled dace, 99% of sculpin survived trials with Sacramento pikeminnow, in part because sculpin usually occupied benthic cover units while Sacramento pikeminnow occupied the water column. A 10-fold difference in benthic cover availability did not detectably influence biotic interactions in the experiment. The distribution of speckled dace in the Eel River drainage may be limited by two predator taxa with very different patterns of habitat use and a shortage of alternative habitats.

    Publication Notes

    • You may send email to to request a hard copy of this publication.
    • (Please specify exactly which publication you are requesting and your mailing address.)
    • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.


    Harvey, Bret C.; White, Jason L.; Nakamoto, Rodney J. 2004. An emergent multiple predator effect may enhance biotic resistance in a stream fish assemblage. Ecology 85(1): 127-133


    biotic resistance, Cottidae, cover, Cyprinidae, emergent multiple predator effects, introduced species, laboratory stream, predation risk, stream fish

    Related Search

    XML: View XML
Show More
Show Fewer
Jump to Top of Page