Author Institution: School of Natural Resources, The Ohio State UniversityMost of Ohio's remaining Lake Erie wetlands are diked to enhance habitat diversity. There is concern that fish communities in these wetlands may be isolated from adjacent waters. However, little data are available with which to evaluate possible isolation. We conducted a study that examined spring length frequencies, age structure, and growth of white crappie (Pomoxis annularis) populations in 3 diked wetlands and 2 undiked, adjacent areas. If populations are not isolated then differences in population parameters between the two types of systems should not be evident. White crappies were collected in April-May 1987 using trap nets. Length frequencies of white crappies were not similar between diked wetlands and adjacent areas, and mean lengths were significantly less in the diked wetlands. Populations were not comprised of similar age classes in the 5 systems. White crappies in diked wetlands grew significantly slower than their conspecifics in the undiked areas. These data indicate that white crappies hi diked wetlands are isolated from populations in undiked areas even though up to 75% of water in diked wetlands can be exchanged each year
