Consumption and Growth Patterns of Flathead Catfish Derived From a Bioenergetics Model

Abstract

Bioenergetics models offer a useful framework for assessing the consumptive demand on ecosystems from nonnative fish. Consumption estimates from bioenergetics models can be combined with estimates of population abun- dance to quantify population-level consumption. This study applies a new bioenergetics modeling framework, developed by Walters and Essington (this volume), to estimate bioenergetics parameters using field data commonly collected from population monitoring programs. We used growth increment and size-at-age data to estimate the parameters of the bio- energetics model described by Walters and Essington (this volume) for an introduced population of Pylodictis olivaris from the Neuse River, North Carolina. The model fit the observed growth data well and predictions of consumption pat- terns were consistent with observed feeding patterns. The estimated consumption pattern from the general bioenergetics model represents the first characterization of adult flathead catfish consumption. Through use of capture-recapture data, the Walters and Essington bioenergetics model is able to integrate consumption estimates with growth and demographic data. Although further validation of the model is necessary, the modeling framework provides a straightforward approach to assessing the consumptive demand of fish populations.