Stocking Contribution and Growth of Largemouth Bass in Pools of the Arkansas River

Abstract

In response to concerns about a declining population of largemouth bass Micropterus salmoides in the Arkansas River, the Arkansas Game and Fish Commission stocked pools 5 and 9 with largemouth bass fingerlings (∼50 mm total length (TL)) marked with oxytetracycline in June 2002 at rates of 18 and 25 fish/ha, respectively. We evaluated the contribution of stocked largemouth bass to the 2002 year-class at age 0 in September 2002 and at age 1 in May 2003. Stocked largemouth bass comprised 15% in pool 5 and 20% in pool 9 of the 2002 year-class at age 0 and 10% in pool 5 and 13% in pool 9 at age 1. Contributions of stocked largemouth bass to the year-class did not differ significantly between pools (P = 0.2850 in pool 5 and 0.1824 in pool 9) or years (P = 0.3521 in fall and 0.5061 in spring). Mean lengths of stocked and wild largemouth bass did not differ significantly in either pool during fall 2002 (P = 0.2863 in pool 5 and 0.9281 in pool 9) or spring 2003 (P = 0.4809 in pool 5 and 0.1233 in pool 9). However, largemouth bass were significantly longer in pool 9 than in pool 5 at age 0 (181 mm TL versus 172 mm TL, respectively; P = 0.0113) and age 1 (204 mm TL versus 182 mm TL, respectively; P < 0.0001). Largemouth bass stocked into the Arkansas River, an open system, contributed to year-class strength to a similar degree as fish stocked into closed reservoirs and lakes.