Development and Application of a Spatially Explicit Growth Model for Age-0 Scaphirhynchus Spp

Habitat requirements for early life stages of the federally endangered pallid sturgeon and the closely related shovelnose sturgeon are poorly understood. In this study, we developed a model that will allow researchers to evaluate habitat quality and estimate growth of age-0 Scaphirhynchus spp. under fluctuating conditions in the Missouri River. To do so, a series of experiments were performed to quantify temperature- (14-24°C) and size-dependent (19-70 mm total length) foraging dynamics (functional feeding response, satiation, gut evacuation rate) and energetics (respiration, activity, waste) of age-0 sturgeon that served as inputs to the model. The model was then evaluated by conducting foraging and growth trials in small scale mesocosms simulating natural conditions, and by comparing observations to model predictions. Lastly, an individual-based modeling platform (NetLogo) was used to estimate age-0 Scaphirhynchus spp. growth by using empirical data (water temperature and velocity, prey density) from various sites of the Missouri River. The application of this work should prove useful for managers to identify habitats that might act as bottlenecks to the recruitment of age-0 sturgeon in the Missouri River.