Long‐term patterns in growth of Oneida Lake walleye: a multivariate and stage‐explicit approach for applying the von Bertalanffy growth function

Abstract

Total length (LT) and its inter annual variation of walleye Sander vitreus from Oneida Lake, New York, based on 51 years (1950–2000) of data for ages 1 to 7 years were analysed. Growth increased over time at young ages, did not change at intermediate ages and decreased at old ages. Total length at age increased over time to age 4 or 5 years, but was stable at older ages. Principle component analysis was used to study the pattern of variations in annual LT increments among years. More than 92 and 91% of inter annual variability in growth was described by the first three principal components for males and females, respectively. The first principal component was a general indicator of annual growth at all ages, but was dominated by annual growth at intermediate ages. The second and third principal components represented contrasts among yearling LT, yearling growth and growth at older ages. Therefore, changes in the three stage‐specific parameters, yearling LT, yearling growth and asymptotic LT, explained most of the variance in observed growth. Using these three stage‐specific parameters for the von Bertalanffy growth function facilitated interpretations of growth comparisons.