Developing a Predictive Model For the Probability of Capturing Pallid Sturgeon In the Mississippi River

Restoring the endangered pallid sturgeon Scaphirhynchus albus requires information about population demographics and habitat use.  Obtaining the needed information requires effective sampling of this less-than-common fish.  Given this obstacle, this project proceeded with the objective to attempt to identify important environmental parameters to help increase sampling efficiency.  Pallid sturgeon were captured with trotlines set in secondary channels and main channel borders.  Capture probability was modeled by stepwise logistic regression analysis of five abiotic variables:  river stage, change in state, temperature, surface current velocity, and depth.  Only temperature (P<0.001) and depth (P=0.028) significantly affected capture probability.  Temperature was inversely related to capture probabilities and depth was positively correlated with capture probabilities.  Our model indicates that capture probabilities are highest when trotlines are fished in water 7.5 meters deep when the water temperature is below 16°C.  This information can be used to increase the efficiency of capturing rare pallid sturgeon in the Lower Mississippi River and possibly other large rivers.