Danielle R. Painter and Thomas J. Kwak, Arkansas Cooperative Fish and Wildlife Research Unit, Department of Biological Sciences, University of Arkansas, Fayetteville, AR 72701

Brown trout, Salmo trutta, reproductive success in White River tailwater is highly variable, resulting in the need for supplemental stocking. A better understanding of physical and biotic factors contributing to reduced survival and variation among tailwaters will facilitate fisheries composed of greater proportions of wild populations to increase the quality of the fish and fishery. Fecundity was estimated from 12 female brown trout collected prior to spawning from four tailwater sites. Brown trout from one tailwater known for reproductive failure had significantly lower fecundity measures and condition factors than those of three other sites, while there was no difference among other sites with higher reproductive success. Brown trout spawning occurred from October 11 to November 23, and fry emergence began February 23. Significant among-site differences were found for spawning and fry microhabitat variables; however, variables fell within optimal ranges reported in the literature. There were no significant differences in spawning gravel quality to percent fines obtained by freeze-core sampling. Significant differences were found among sites for fry and juvenile density, but not for their size. Ongoing investigations into trout early life history may reveal additional influential factors to improve trout reproductive success and increase the proportion of wild fish in these systems.