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): Darren M. Ward; Keith H. Nislow; Carol L. Folt; James Grant
    Date: 2011
    Source: Canadian Journal of Fisheries and Aquatic Sciences
    Publication Series: Scientific Journal (JRNL)
    Station: Northern Research Station
    PDF: Download Publication  (130.0 KB)


    Predator effects on prey populations are determined by the number of prey consumed and effects on the traits of surviving prey. Yet the effects of predators on prey traits are rarely evaluated in field studies. We measured the effects of predators on energetic traits (consumption and growth rates) of juvenile Atlantic salmon (Salmo salar) in a large-scale field study. Salmon fry were released at 18 sites that encompassed a wide range of predatory slimy sculpin (Cottus cognatus) abundance. We sampled salmon after 21 and 140 days to measure salmon growth and estimate consumption using a massbalance model of methylmercury accumulation. Salmon population density was reduced fivefold at sites with abundant sculpin. Over the early season, salmon consumed less where sculpin were abundant, suggesting that reduced foraging under predation risk contributed to predator-caused mortality. In contrast, over the late season, salmon grew more where sculpin were abundant, suggesting that compensatory growth at reduced salmon population density moderated predator-caused mortality. Predator effects on prey energetics can drive variation in survival and growth, with important consequences for population dynamics.

    Publication Notes

    • Check the Northern Research Station web site to request a printed copy of this publication.
    • Our on-line publications are scanned and captured using Adobe Acrobat.
    • During the capture process some typographical errors may occur.
    • Please contact Sharon Hobrla, if you notice any errors which make this publication unusable.
    • 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.


    Ward, Darren M.; Nislow, Keith H.; Folt, Carol L.; Grant, James. 2011. Seasonal shift in the effects of predators on juvenile Atlantic salmon (Salmo salar) energetics. Canadian Journal of Fisheries and Aquatic Sciences. 68(12): 2080-2089.


    Google Scholar

    Related Search

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