The following schedule is from the 72nd Annual Conference of the Southeastern Association of Fish & Wildlife Agencies which was held October 21-24, 2018 in Mobile, Alabama.
AUTHORS: Garret J. Kratina, Dennis R. DeVries, Russell A. Wright – School of Fisheries; Aquaculture, and Aquatic Sciences, Auburn University; Steven J. Rider, Alabama Wildlife and Freshwater Fisheries Division
ABSTRACT: Fish hard-part microchemistry has become a powerful tool for examining natal habitat and movement patterns. To quantify fish habitat use and potential movement in a river system modified by the construction of dams, microelemental analyses were performed on paddlefish dentary bones collected during 2017. Paddlefish were sampled from four populations separated by lock-and-dam structures on the Alabama River. Water samples were obtained from 15 sites throughout the watershed seasonally during 2017-2018 to relate trace element conditions in water to those incorporated into paddlefish dentary bones. Dentary bone and water samples were analyzed for concentrations of Sr, Ba, Mn, Mg, and Ca. Water elemental signatures differed among major tributaries and some river sections, and were reflected in dentary bone age-0, edge, and whole-transect ablation element-to-calcium ratios. Analysis of variance identified significant differences in dentary bone Sr:Ca ratios among river sections. Additionally, linear discriminant function analysis of dentary bone elemental signatures classified paddlefish back to their river section of capture with 59-73% accuracy; errors nearly always assigned paddlefish to an adjacent section. Our results suggest that some population mixing occurs, but that this movement is limited and likely restricted to movement through the locks or over a spillway at the lowermost dam.
