Evidence of Inter- and IntraSpecific Competition as Factors Regulating Walleye (Stizostedion vitreum vitreum) Biomass in Oneida Lake, New York

Abstract

The sequence of events that led to a decline in numbers of American eel (Anguilla rostrata) and esocids and an increase in numbers of walleye (Stizostedion vitreum vitreum) in Oneida Lake from 1900–74 are reviewed. Demise of eel and esocids was followed by a rise in numbers of walleye, but little change in mean size of individual walleye. Reduced interspecific competition apparently enhanced walleye recruitment, but the anticipated increase in growth of walleye was probably inhibited by intensified intraspecific competition. This interpretation was supported by evidence that recruitment and growth of walleye in 1957–74 were regulated by prey abundance. Transition from a diverse predator population to one dominated by walleye was orderly and yellow perch (Perca flavescens) remained the most abundant prey. Key words: Percidae, competition, walleye biomass, Stizostedion, population dynamics, community ecology