INFLUENCE OF SIZE AT STOCKING ON SURVIVAL OF SAUGEYE IN A NORTHERN-LATITUDE IMPOUNDMENT

The saugeye [walleye (Stizostedion vitreum) X sauger (S. canadense)] h as been used effectively as a predator to reduce recruitment and impro ve growth and size structure for overabundant crappie (Pomoxis spp.) p opulations. Saugeye were stocked into 336-ha Richmond Lake, South Dako ta, an impoundment that contained an overabundant black crappie (Pomox is nigromaculatus) population. Small fingerling (circa 3-4 cm) stockin gs in 1992 and 1993 had relatively low survival; fall electrofishing c atch per unit effort (CPUE) values for age-0 saugeye were 5/hr and 3/h r. In 1994 and 1995, larger (circa 14-19 cm) fingerlings were stocked, and fall CPUE values were 185/hr and 33/hr. In addition, the fingerli ngs stocked in 1994 were collected during fall 1995 electrofishing as age-1 fish at a rate of 41/hr. At northern latitudes, small fingerling saugeye grow slowly and likely remain vulnerable to predation by and competition with overabundant black crappie populations. Stocking larg er saugeye fingerlings may overcome this problem.