706 North American Journal of Fisheries Management 20:706–710, 2000  Copyright by the American Fisheries Society 2000 Size Selectivity of Crappie Angling L. E. MIRANDA* AND B. S. DORR Mississippi Cooperative Fish and Wildlife Research Unit, 1 Post Office Box 9691, Mississippi State, Mississippi 39762, USA Abstract.—Over 6,000 black crappies Pomoxis nigromaculatus and white crappies P. annularis were tagged in five lakes and reservoirs to quantify size selectivity of angling. Total length of fish tagged ranged from 20.0 to 39.8 cm; fish caught by anglers ranged from 20.0 to 38.8 cm. Return rates were low at lengths near 20 cm, increased gradually to a peak between 26 and 32 cm, and decreased for longer fish. This pattern was consistent among the five lakes and reservoirs and did not differ between species. Observed size-selective exploitation resulted in the lopsided removal of intermediate age-classes, thereby simulating a reversed slot length limit. Crappie population dynamics and fisheries can be severely affected if angling selectivity and exploitation are high. Management of crappies to favor desirable population characteristics may need to focus on en- hancing or weakening the effect of size selectivity. All fishing gears are size selective to varying degrees, thereby providing biased and unequal rep- resentation of the true size composition and spe- cies assemblage (Casselman et al. 1990; MacLen- nan 1992). These biases are often associated with changing gear efficiencies that are affected by characteristics peculiar to the gear, fish, and hab- itat. Hook-and-line gear used in recreational and commercial fisheries is also size selective (Leclerc and Power 1980; Lokkeborg and Bjordal 1992; Orsi et al. 1993). Tackle type, fishing method, and fishing locale are likely to influence size selection. A strong size selectivity under heavy exploitation can potentially shape population size structure, dy- namics, and even genetic characteristics (Brana et al. 1992; Orsi et al. 1993). Crappies Pomoxis spp. are some of the most heavily harvested and exploited freshwater fishes in the United States. Annual recreational harvest by angling averaged nearly 5 kg/ha in a sample of 279 reservoirs where crappies occurred (Miranda 1999). Annual exploitation rates of crappies in a sample of 18 lakes and reservoirs in the Southeast and Midwest averaged 0.48 (Allen et al. 1998). Exploitation of crappies varies with fish size, and large fish can be overexploited to depletion (Reed and Davies 1991; Webb and Ott 1991). Selective exploitation of a narrow range of age- groups may acutely affect crappie population dy- namics and fisheries. If selective exploitation is severe, appropriate management strategies may be * Corresponding author: smiranda@cfr.msstate.edu 1 The Unit is jointly sponsored by the Mississippi De- partment of Wildlife, Fisheries and Parks, Mississippi State University, and the U.S. Geological Survey. Received November 12, 1999; accepted February 21, 2000 needed to enhance or weaken the effect of size selectivity in favor of crappie populations and fish- eries. Nevertheless, accounts of size-selective ex- ploitation are usually anecdotal and poorly docu- mented. Our objective was to determine if angling exploitation of crappie populations was size se- lective. Study Areas Size selectivity was studied at Beulah, Chotard, and Eagle lakes and Columbus and Sardis reser- voirs. Lakes Beulah (Arkansas–Mississippi; 417 ha) and Chotard (Louisiana–Mississippi; 405 ha) are oxbows adjacent to the Mississippi River and are connected with the river for several months during high river stages. Eagle Lake (Louisiana– Mississippi; 1,902 ha) is also an oxbow adjacent to the Mississippi River, but it is isolated from the river by the river’s levee. At the time of this study, crappie fisheries in these oxbows were being reg- ulated with a daily creel limit of 50 fish/angler. Columbus Reservoir (Mississippi; 3,564 ha) is a navigation reservoir in the Tennessee–Tombigbee Waterway in east-central Mississippi. A 23-cm minimum length limit and a daily creel limit of 30 fish/angler were in effect. Sardis Reservoir (Mis- sissippi; 23,675 ha) is a flood control reservoir impounded on the Yazoo River in north-central Mississippi; a 25-cm minimum length limit and a daily creel limit 30 fish/angler were in effect. Methods Crappies were captured by trapnetting and elec- trofishing in late winter 1993 in Columbus Res- ervoir, fall 1993 and spring 1994 in Lake Beulah, late winter 1995 in Sardis Reservoir, fall 1995 in Chotard Lake, and late winter and spring 1996 in Eagle Lake. To minimize handling mortality, sam-