Predation by fish on walleye eggs on a spawning reef in western Lake Erie, 1969-71

Abstract

Nearly 2,000 fish representing 21 species were captured with experimental gillnets on Kelleys Island Shoal during the spawning and incubation periods of walleyes (Stizostedion v. vitreum) in 1969-71. A total of 794 stomachs were examined. Four species contained walleye eggs: yellow perch (Perca flavescens), spottail shiner (Notropis hudsonius), stonecat (Noturus flavus) and white sucker (Catostomus commersoni). Yellow perch were by far the most consistent predators of walleye eggs, and spent female perch consumed more eggs than did males. The average number of walleye eggs in perch stomachs collected on any one day ranged from 36 to 734 for females and from 4 to 237 for males. The loss of walleye eggs due to fish predation appeared to be significant only when the rate of water warming slowed or stopped, thereby creating an extended overlap in the walleye-yellow perch reproductive period. Only under the uncommon condition of an extended time interval between walleye hatching and perch spawning, coupled with the presence of a large quantity of actively feeding perch, could egg predation reduce walleye reproductive success.