Mensurative approach to examine potential interactions between age-0 yellow perch (Perca flavescens) and bluegill (Lepomis macrochirus)

Bluegill (Lepomis macrochirus) and yellow perch (Perca flavescens) populations are often sympatric in the Great Plains region of the U.S.A. and portions of Canada; however, very little attention has been given to potential interactions between these species for available resources, especially during the early life stages. Relationships between age-0 bluegill and yellow perch growth and relative abundance were explored across multiple lakes and years within the Nebraska Sandhill region, USA. In addition, four habitat patch types (open water, Phragmites spp., Typha spp., Scirpus spp.) were sampled for age-0 bluegill and yellow perch, and food habits were examined for each species during August, September, and October of 2009 in one of these lakes. Age-0 yellow perch growth was negatively related to age-0 bluegill relative abundance across a spatiotemporal scale. Age-0 bluegill and yellow perch exhibited similar habitat use (moderate–high overlap), but generally consumed different important and dominant prey taxa (bluegill consumed both macroinvertebrates—56?% and zooplankton—44?%, while yellow perch consumed more zooplankton—66?%), which resulted in low overall diet overlap between species. Previous research indicates that age-0 yellow perch diet ontogeny often results in feeding predominately on macroinvertebrates and positively selecting them (and avoiding zooplankton prey) at sizes observed in our study. Therefore, yellow perch growth rates may be compromised by the presence of bluegill because of the need to consume less energetically profitable prey items such as zooplankton.