Effectiveness of Walleye Fry and Fingerling Stocking in Rathbun Lake, Iowa, 1990–1999

Abstract

I evaluated the performance of walleyes Stizostedion vitreum in Rathbun Lake, Iowa, by comparing stockings of fry, intensively reared fingerlings, and extensively reared fingerlings (fall and spring) during 1984–1999. The management goal was to triple the biomass of walleye adults (>17.5 in). Fry were stocked at 2,000/acre (1984–1995) and 3,000/acre (1996–1999), extensively reared fingerlings were stocked at 10/acre (1984–1990), and intensively reared fingerlings were stocked at 5/acre (1985–1999). Spring- and fall-stocked fingerlings were also compared during 1992–1999. Fry stockings were highly variable, but produced large year-classes in 1985, 1986, 1993, 1995, 1997, and 1998. October samplings of fingerlings, which originated from fry stockings, yielded 9–27 fish/acre. Intensively reared fingerling survival was about four times greater than that of the smaller, extensively reared fingerlings. Survival of spring-stocked fingerlings was higher than that of fall-stocked fingerlings in 3 of 5 years. Findings from this investigation were used to develop walleye management strategies for Rathbun Lake. Walleye culture and stocking protocols for fingerlings and fry should be guided by water-body-specific angler demand, production economics, and survival characteristics.