SS3.18 Habitat Coupling in Lakes
Date: Thursday, June 13, 2002
Time: 10:00:00 AM
Location: Esquimalt
 
ScheuerellMD, University of Washington, Seattle, USA, scheuerl@u.washington.edu
Schindler, D, E, University of Washington, Seattle, USA, deschind@u.washington.edu
 
IMPACTS OF LAKESHORE RESIDENTIAL DEVELOPMENT ON THE SPATIAL DISTRIBUTION AND ENERGY SOURCES OF FISHES
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Lakeshore residential development has been shown to alter riparian and littoral habitats, and negatively affect fish growth rates. We surveyed 25 lakes in western Washington and southern British Columbia across a residential development gradient to assess differences in the spatial distribution of fishes and the relative contribution of benthic versus pelagic prey to their diets. As the density of lakeshore houses increased, so did the spatial scale at which fishes were aggregated. We found no significant main effect of predator density on this spatial scaling, but we did find a significant interaction between predator density and the density of houses. All trophic levels demonstrated enriched 13C and 15N with increased housing density. The proportion of benthic carbon in the fishes was inversely correlated with housing density, suggesting a shift to more pelagic prey with increasing human disturbance.