MICHAEL FISCHBACH AND PHILLIP W. BETTOLI, Tennessee Cooperative Fishery Research Unit, Tennessee Technological University, Box 5114, Cookeville, Tennessee 38505, USA

Sauger Stizostedion canadense of the Tennessee and Cumberland Rivers, Tennessee, have exhibited wide fluctuations in year-class strength; however, a decline in sauger populations in the mid- to late-80's prompted concern over their status. Experimental gill nets were used to sample sauger in four Tennessee River tailwaters and one Cumberland River tailwater from 1990 to 1996 and catch-per-unit-effort was calculated to index year-class strength. Age-1 sauger abundance was modeled as a function of the amount of water discharged and number of fingerlings stocked in previous years. The catches of age-1 sauger below two upper Tennessee River dams were positively related (r=0.71 and 0.85; P<0.05) to the amount of water released from each dam the previous spring. Below Cordell Hull Dam on the Cumberland River, sauger abundance each year was not related to spring discharges in previous years but the catch of age-2 sauger was positively correlated to the number of fingerlings stocked two years earlier (r=0.99; P<0.01). No significant relationship between spring discharge and sauger abundances were detected below two lower Tennessee River dams. Current models suggest that there may be an optimum discharge range to enhance natural reproduction by sauger in some reaches of the Tennessee River. Efforts are currently underway to assess the contribution of stocked fingerlings using oxytetracycline marking techniques.