Bioenergetic Approach to Describing Gulf Sturgeon (Acipenser oxyrinchus) Growth in Two Florida Rivers

Abstract

Bioenergetics models are commonly used by scientist and managers to describe energy uptake and metabolism of fish species. Much data is needed to inform these models and often species specific data is unavailable or difficult to acquire, such as in the case with Gulf of Mexico sturgeon. This study applied a new method, developed by Walters and Essington (this issue), to estimate bioenergetics parameters using field observations for Gulf sturgeon populations in the Apalachicola and Suwannee Rivers, Florida, U.S.A. Bioenergetics derived growth curves were compared to growth curves developed using traditional direct aging methods. We obtained bioenergetic parameter estimates for both popula- tions and the bioenergetic method was able to accurately simulate annual variability in Gulf sturgeon growth rates. Fur- ther, the bioenergetics growth estimates, which incorporate length-at-age and length-increment data estimated very differ- ent growth trajectories than traditional von Bertalanffy curves that used only length-at-age. This indicates that length-at- age data alone can lead to errors in growth estimates, resulting in erroneous management advice. Using field data to in- form bioenergetic models should be a useful approach for fisheries researchers and managers to describe the growth and energetic characteristics of fish populations.