Relationship between Walleye Fingerling Stocking Density and Recruitment in Lower Lake Oahe, South Dakota

Abstract

This study evaluated four methods ofexpressing fingerling stocking density for walleye Stizostedion vitreum: number per surface area, number per littoral-zone area, number per shoreline development value, and number per shoreline distance, Walleye fingerlings were stocked in embayments of lower Lake Oahe in 1988 and 1989 at varying densities. Stocking success was assessed by means of fall gillnetting for young-of-year walleyes. Mean gill-net catch rates varied significantly within each method of expressing stocking density. Effects of stocking density on gill-net catch rate for walleye young of the year were analyzed with linear regression. Fingerling densities expressed as number per shoreline development value had the highest coefficient of determination. Shoreline development value may provide a better measure of walleye fingerling habitat than traditional expressions of stocking density such as number per surface area. Based on this assessment, a minimum stocking density of 17,006 fingerlings/shoreline development value is needed to establish significant recruitment in lower Lake Oahe embayments greater than 150 hectares in surface area. For smaller embayments, a minimum density of 2.78 fingerlings/shoreline meter or 17,006 fingerlings/shoreline development value (whichever is less) should be used. For shoreline nursery areas in lower Lake Oahe, a minimum stocking density of 471.2 fingerlings/hectare of littoral zone is recommended.