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Presented at the NABS Annual meeting, Pittsburgh, Pennsylvania, 2002
in Urban Ecology I
QUANTIFYING RELATIONSHIPS BETWEEN URBAN LAND USE AND BIOMASS OF PERIPHYTON, BENTHIC INVERTEBRATES, AND FISH IN STREAMS.
J.M. Stephenson and A. Morin. Department of Biology, University of Ottawa, Ontario, Canada K1N 6N5
In order to quantify the biomass of periphyton, benthic invertebrates, and fish along an urban land use gradient, periphyton, benthic invertebrates, and fish were collected during summer 2001 from 21 streams containing a range of adjacent land use compositions in the Ottawa-Hull region of eastern Ontario and western Québec. Urban land use compositions were quantified within a 200-meter buffer surrounding each catchment at a one-kilometer distance upstream of each sampling site. Preliminary analyses reveal a positive relationship between periphyton biomass and urban land use and a negative, although not significant, relationship between fish biomass and urban land use. The constant or declining fish biomass along the urban land use gradient suggests that although autochthonous production increases, fish may be unable to tolerate reduced water quality. Stable isotope analyses that determine the relative proportions of algal carbon in consumers may verify how changes in autochthonous biomass along the urban land use gradient affect biomass at higher trophic levels.
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