Using stable isotopes to assess the trophic ecology of a native and invasive fish species in the western basin of Lake Erie.

摘要

Using stable isotopes of carbon (delta13C) and nitrogen (delta15N), I investigate the trophic ecology and niche overlap of Yellow Perch (Perca flavescens) and White Perch (Morone americana) across the western basin of Lake Erie. Stable isotopes varied spatially and temporally in lower trophic level organisms, which are used to estimate carbon sources and trophic position of consumers. These variations inhibit our ability to assess trophic relationships, particularly in large lakes. Yellow Perch relied on benthic food sources, while White Perch occupied higher trophic positions and had larger niche widths. Trophic positions of yellow and white perch were related to size however a lack of delta13C- length relationship suggests these species exhibit no changes in carbon source. Significant differences in delta 13C/ delta15N and high niche overlap among Yellow and White Perch indicated that the species are utilizing different forage bases, however, have the potential to compete if resources become limited.