Impacts of urbanization on the bioenergetics of a common caddisfly: a supplementary approach to standard methods of stream bioassessment

Abstract

A combination of novel bioenergetics-based and standard rapid bioassessment techniques were applied to benthic macroinvertebrates from four streams with varying degrees of impervious surface cover within their watersheds. The energetic environment, characterized via dissolved organic carbon, silt lipid content, and silt carbon content, was more enriched with increasing urbanization. This increase in available resources translated to an increase in the energetic status of individual Trichoptera Hydropsychidae larvae, with a clear seasonal trend. At the community-level, taxa diversity and evenness indices decreased with increasing urbanization. Our results suggest that Trichoptera Hyrdopsychidae are able to capitalize on the enriched energetic environment found at urban-impaired streams. A predictive model utilizing environmental data to predict the energetic status of individual Trichoptera Hydropsychidae was demonstrated, supporting our hypothesis that a mechanistic-tie exists between the energetics of individual organisms and the energy present in the environment.