An individual-based model framework was used to assess growth potential of the federally endangered pallid sturgeon (Scaphirhynchus albus) in the Missouri River. The model,developed for age-0 sturgeon, combines information on functional feeding response, and bioenergetics and swimming ability to regulate consumption and growth within a virtual foraging arena. Empirical data on water temperature,water velocity and prey density were obtained from three sites in the Missouri River and used as inputs in the model to assess hypotheses concerning factors affecting pallid sturgeon growth. The model was also used to assess the impacts of environmental heterogeneity and water velocity on individual growth variability, foraging success and dispersal ability. Growth was simulated for a period of 100 days using 100 individuals (first feeding; 19 mm and 0.035 g) per scenario. Higher growth was shown to occur at sites where tall densities of Ephemeroptera and Chironomidae larvae occurred throughout the growing season. Highly heterogeneous habitats (i.e., or wide range of environmental conditions) and moderate water velocities (0.3 m/s) were also found to positively affect growth rates. The model developed here provides an important management and conservation tool for evaluating growth hypotheses and(or) identifying habitats in the Missouri River that are favourable to age-0 pallid sturgeon growth.
Source: usgs.gov