Influence of habitat heterogeneity on the foraging ecology of first feeding yellow perch larvae, Perca flavescens, in western Lake Erie

The diet of first-feeding fish larvae can influence their future growth and survival. The foraging ecology of yellow perch (YP) larvae was studied in western Lake Erie, a region characterized by habitat heterogeneity associated with the Maumee River Plume (MRP) and a high prevalence of invasive species. To determine the influence of the MRP on YP diet, water physical characteristics, zooplankton prey community, and larval YP diet and foraging selectivity were compared between MRP and non-MRP waters, 2006-2008. Water temperature was higher, while water clarity was lower in the MRP when compared to non-MRP waters. The zooplankton prey community (groups constituting >. 1% of YP prey items) did not differ between MRP and non-MRP waters, being composed of small cladocerans, cyclopoid and calanoid copepods and non-native dreissenid mussel veligers. Ration increased with YP total length (TL), with no differences found between MRP and non-MRP waters. Diet composition also varied with larval YP length, with the smallest larvae preying more heavily on dreissenid veligers than larger fish, and no differences between MRP and non-MRP waters. Most sizes of larvae positively selected for cyclopoid copepods in MRP and non-MRP waters, while selection for other prey was neutral or negative. Our study reveals a similar zooplankton community and larval foraging ecology between MRP and non-MRP waters during spring season, despite habitat physical differences, and points to mechanisms unassociated with larval foraging (i.e., predation) as a reason for higher recruitment of YP residing inside versus outside of the MRP as larvae.