In October 1997, apparent spatial heterogeneity in the black crappie (Pomoxis nigromaculatus) age distribution was observed in B.E. Jordan Reservoir. The number of age groups for black crappie increased from downlake to uplake. The objective of this study was to verify this spatial heterogeneity. Trap nets were used to collect black crappie in 4 sections of the reservoir. Black crappie ages ranged from 1 to 17 years, and fish ≥10 years were found only in the upper 2 sections of the reservoir. Significant (P<0.05) differences in the black crappie age distribution were found between most reservoir sections in April 1998. However, only the lower most section and upper most section were significantly different in November 1998. There were no differences between sections in April 1999. The reason this spatial heterogeneity existed in the black crappie age distribution remains unclear; however, it is likely that the otolith sample sizes were too low to detect spatial differences in age distribution prior to 1997. Age distribution data is an important component in the development of management recommendations for crappie fisheries. Failure to assume that spatial heterogeneity may exist in crappie age distributions when designing age sampling schemes may result in poor management decisions.
