KURT J. BOGENRIEDER AND MICHAEL J. VAN DEN AVYLE, Georgia Cooperative Fish and Wildlife Research Unit, University of Georgia, D.B. Warnell School of Forest Resources, Athens, Georgia 30602, USA

The importance of estuaries as nursery habitats for striped bass has been well documented. However, the classification and delineation of rearing microhabitats for larvae and juveniles has been a difficult task. The highly variable physicochemical nature of estuaries in conjunction with the euryhaline behavior of striped bass have allowed fishery managers to only speculate what portions of an estuary are vital for successful recruitment. The intent of my research was to test the hypothesis that juvenile striped bass prefer water of relatively low salinity when offered a range of salinities that may be proximal to the brackish/freshwater interface within estuaries. Specifically, four salinity concentrations were tested: 0, 5, 10, and 15 ppt. Gradients containing water of these concentrations were established within modified Stellionate salinity gradient devices. Individual fish were placed into a device and filmed over four hours to determine preference or avoidance of particular salinities. Fish acclimated at both 0 and 15 ppt were tested to determine if acclimation state affects preference. To test for ontogenetic shifts in preference, test fish ranged in size from approximately 35-125 mm. A total of 50 fish were tested for each acclimation state. Data analyses and thesis preparation are currently underway. Anticipated completion of final results is January 1997.