Diet and Feeding Success of Fast‐Growing Yellow Perch Larvae and Juveniles in Perturbed Boreal Lakes

Abstract

AbstractThe principal objective of this study was to test the hypothesis that enhanced early growth of yellow perch Perca flavescens in lakes affected by forest harvesting was related to favorable feeding conditions after the perturbation. Yellow perch larvae and juveniles and their zooplankton prey were sampled three times in three unperturbed lakes and in three perturbed lakes where forest harvesting had occurred in the catchment 2 years earlier. Univariate and multivariate analyses of the diets of age‐0 yellow perch from both treatments showed that fish in perturbed lakes primarily preyed upon Daphnia spp. and Polyphemus pediculus, whereas fish in unperturbed lakes preyed upon more diverse food items. Perturbed lakes showed higher dissolved organic carbon concentrations, algal biomass, and Daphnia spp. abundance. The feeding success index (number of prey items in the stomach per millimeter of fish length) and recent growth rates of age‐0 yellow perch showed a significant type II functional relationship with the abundance of Daphnia spp. We hypothesized that the increase in Daphnia spp. abundance and a darkening of water color in perturbed lakes may have favored prey detection and growth for larval and juvenile yellow perch, thereby affecting population recruitment.