Model Development to Support Pallid Sturgeon Recovery

The pallid sturgeon population model was developed to provide an objective and transparent tool to formalize understanding of factors affecting population dynamics as part of the ongoing Effects Analysis. The model was collaboratively developed as a life-history stage-based population model to evaluate management actions.  Hypothesized effects of management actions in the initial model were evaluated through their influence on demographic rates.  The stage-based model was effective at evaluating simple management actions like stocking.  However, management actions hypothesized to affect pallid sturgeon at specific times and locations required increased spatial and temporal resolution.  Therefore, we recast the model as individual-based, operating at a finer spatial and temporal resolution needed to address management-relevant hypotheses.  For example, the population model allows fish to move among river bends, which will allow for evaluation of scenarios where flow modification is hypothesized to affect the migration and aggregation of reproductive adults.  Similarly, the model can track where larvae recruit within the river allowing evaluation of management actions hypothesized to affect larval drift distance and interception into rearing complexes.  We present the current state of the model, discuss how the results of ongoing monitoring can be integrated into the model, and highlight its capabilities to evaluate management.