Environmental Biology of Fishes

, Volume 97, Issue 1, pp 79–90

Effects of turbidity and an invasive waterweed on predation by introduced largemouth bass

  • Maud C. O. Ferrari
  • Lynn Ranåker
  • Kelly L. Weinersmith
  • Matthew J. Young
  • Andrew Sih
  • J. Louise Conrad
Article

DOI: 10.1007/s10641-013-0125-7

Cite this article as:
Ferrari, M.C.O., Ranåker, L., Weinersmith, K.L. et al. Environ Biol Fish (2014) 97: 79. doi:10.1007/s10641-013-0125-7

Abstract

Anthropogenic activities lead to changes in characteristics of aquatic ecosystems, including alteration of turbidity and addition of invasive species. In this study, we tested how changes in turbidity and the recent invasion of an aquatic macrophyte, Egeria densa, may have changed the predation pressure by introduced largemouth bass on juvenile striped bass and delta smelt, two species that have seen a drastic decline in recent decades in the Sacramento-San Joaquin Delta. In a series of mesocosm experiments, we showed that increases in vegetation density decreased the predation success of largemouth bass. When placed in an environment with both open water and vegetated areas, and given a choice to forage on prey associated with either of these habitats, largemouth bass preyed mainly on open water species as opposed to vegetation-associated species, such as juvenile largemouth bass, bluegill or red swamp crayfish. Finally, we showed that turbidity served as cover to open water species and increased the survival of delta smelt, an endemic species at risk. We also found that such open water prey tend not to seek refuge in the vegetation cover, even in the presence of an imminent predation threat. These results provide the beginning of a mechanistic framework to explain how decreases in turbidity and increases in vegetation cover correlate with a decline of open water species in the Sacramento-San Joaquin Delta.

Keywords

Largemouth bass Micropterus salmoides Egeria densa Delta smelt Turbidity Predator–prey 

Copyright information

© Springer Science+Business Media Dordrecht 2013

Authors and Affiliations

  • Maud C. O. Ferrari
    • 1
    • 2
  • Lynn Ranåker
    • 3
  • Kelly L. Weinersmith
    • 1
  • Matthew J. Young
    • 4
  • Andrew Sih
    • 1
  • J. Louise Conrad
    • 1
    • 5
  1. 1.Department of Environmental Science and PolicyUniversity of California DavisDavisUSA
  2. 2.Department of Biomedical SciencesWCVM, University of SaskatchewanSaskatoonCanada
  3. 3.Department of BiologyLund UniversityLundSweden
  4. 4.Department of WildlifeFish and Conservation Biology, University of California DavisDavisUSA
  5. 5.Division of Environmental ServicesCalifornia Department of Water ResourcesWest SacramentoUSA

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