Depensatory Mortality, Density-Dependent Growth, and Delayed Compensation: Disentangling the Interplay of Mortality, Growth, and Density during Early Life Stages of Yellow Perch

Abstract We present long-term (>40-year) patterns in the density of age-0 yellow perch Perca flavescens in Oneida Lake at four early life stages (at egg deposition, at the attainment of a total length of 18 mm, on 1 August, and on 15 October), from which we calculated mortality and growth rates during the three intervals between these early life stages. At each of these stages, age-0 yellow perch densities have been lower in recent years than in the 1960s and 1970s. Mortality rates showed no time trend from egg to 18 mm (interval 1 [the larval stage]), increased from 18 mm to 1 August (interval 2 [the limnetic stage]), and decreased from 1 August to 15 October (interval 3 [the demersal stage]). We also tested previous hypotheses for density-dependent effects on mortality and growth using the entire long-term data set. Contrary to expectations from the 1960s, the mortality rates of age-0 yellow perch in Oneida Lake are no longer depensatory. Overall, the growth rate of age-0 yellow perch has increased over...