Christopher J. O'Bara, Christopher L. Centraccio, Charles Drumright, Center for the Management, Utilization and Protection of Water Resources, Tennessee Technological University, PO Box 5033, Cookeville, Tennessee 38505, and Douglas Peterson, Tennessee Wildlife Resources Agency, 6032 Andrew Johnson Highway, Talbott, TN 37877

Abstract. Walleye Stizostedion vitreum are an important sportfish in many southeastern reservoirs and large rivers. Norris Reservoir, a large tributary reservoir of the Tennessee River, was historically noted for both riverine and reservoir spawning populations of walleye. Horizontal experimental gill nets have been employed since 1993 to evaluate the reservoir-residing walleye population in Norris Reservoir and to evaluate possible effects of recently introduced alewife Alosa pseudoharengus on pelagic fish populations. Sampling was conducted monthly from May through November in the lenthic section of the reservoir. Larval fish collections were taken in late-winter and early spring in 1996 and 1997 throughout the system. No larval walleye were collected in either 1996 and 1997, although several other species were noted. Age-0 walleye CPUE (no./net-night) were not significantly different in the Fall 1993 and 1994. No Age-0 walleye have been collected since the Fall 1994. Age-1 CPUE were not significantly different from 1993 through 1995, but no Age-1 walleye have been collected in 1995, 1996 and 1997. Angler creel surveys also indicate that reduced recruitment to the fishery has occurred and the harvest is currently dominated by larger and older individuals. Consequently, it appears walleye have not successfully reproduced in Norris Reservoir since 1994. Concurrent with the reproductive failure of walleye has been a significant increase in the abundance of alewife. Alewife CPUE has increased significantly since 1994 and are now the most abundant clupeid inhabiting the reservoir. An extensive stocking program is recommended to mitigate the loss in natural reproduction.