Effects of Stocking Adult Largemouth Bass in Renovated Iowa Impoundments On Bass Abundance and Bluegill Size Structure

Largemouth bass Micropterus salmoides abundance and bluegill Lepomis macrochirus size structure have varied in impoundments following complete fish renovations. We evaluated three post-renovation stocking strategies that utilized juvenile (10 in) or adult (11-15 in) largemouth bass. These were: 1) juvenile largemouth bass stocked one month after renovation in Lake Icaria at 0.5/ac, 2) adult largemouth bass stocked post-spawn in Twelve Mile at 0.5/ac, and 3) adult largemouth bass stocked pre-spawn in Little River at 1.0/ac. First year largemouth bass electrofishing catch-per-unit-effort (CPUE) for the three impoundments were 303/hour, 230/hour, and 1084/hour, respectively. Furthermore, largemouth bass electrofishing CPUE the second year were 280/hour for Icaria and 528/hour for Twelve Mile. Fyke net bluegill PSD the first year for the three impoundments were 0 (N=9), 7 (N=60), and 46 (N=123) with maximum lengths of 5.8 in, 7.1 in, and 7.6 in, respectively. Furthermore, fyke net bluegill PSD-7.5 the second year were 0 (N=46) for Icaria and 7 (N=41) for Twelve Mile with maximum lengths of 7.4 in and 7.6 in, respectively. This evaluation has shown adult largemouth bass stocking in two renovated impoundments has increased largemouth bass abundance and increased bluegill size structure.