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Communication at the NABS Annual meeting, Keystone, 2000
(9) EFFECTS OF FISHES ON BENTHIC PHENOMENA IN MIDWESTERN STREAMS.
W. Matthews1, F.P. Gelwick2, and K. Gido1. 1Sam Noble Museum of Natural History, University of Oklahoma, Norman, Oklahoma 73072, 2Wildlife and Fisheries Sciences Department, Texas A&M University, 2258 TAMUS, College Station, TX 77843-2258
Of the several hundred fish species that occur in streams of the midwestern United States, many are bottom-dwellers with potential for direct effects on benthic processes or food webs (e.g., by substrate disturbance, or eating periphyton and/or invertebrates on the stream bottom), whereas others (water-column inhabitants) should only indirectly affect benthic processes. Vertical position of a fish species in the water column is reflected in its potential to directly influence benthic food webs, as indicated by stomach analyses of > 20 species in a midwestern stream fish assemblage. Previous experimental studies of the benthic, algivorous stoneroller minnow (Campostoma anomalum) showed this species had strong direct as well as indirect effects on many benthic phenomena, but some fish that feed directly on periphyton, such as southern redbelly dace (Phoxinus erythrogaster), may lack such strong effects. In contrast, the water column red shiner minnow (Cyprinella lutrensis) had significant effect on benthic primary productivity, presumably by enhancement of nutrient transfer to benthic compartments. We review and speculate upon a variety of direct and indirect mechanisms by which various functional groups of fishes could impact benthic food webs in streams of the midwestern United States.
Presented at 1:00 PM on Monday, May 29, 2000 in Wanted Dead or Alive: Role of fish in benthic food webs I
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