Table 1.— The distribution of mtDNA genotypes and G^ tests (Sokal and Rohlf 1969) 

 for random distributions in the Potomac River, the Choptank River and the Worton 

 Point area in 1984 and 1986. The expected values are in parentheses. 



take coastal migrations (c.f. Setzler et al. 1980). In 

 the Chesapeake Bay and Hudson River, tagging 

 studies suggest that individuals less than age 2 do 

 not migrate extensively from their natal tributaries 

 (c.f. Setzler et al. 1980). After this sedentary period, 

 females begin to leave the Chesapeake Bay for 

 coastal waters and virtually all females older than 

 age 4 return only to spawn (Kohlenstein 1980). 

 Females do not mature sexually until age 3 at the 

 earliest and most do not mature until age 4 or 5 

 (Jones et al. 1977). In contrast, few males leave the 

 Chesapeake Bay until age 4 or 5 and virtually all 

 age 2 are sexually mature. Tagging studies by 

 Manseuti (1961) suggest that larger males (ages 3-4) 

 moved greater distances within the Chesapeake 

 than small males (ages 0-2). Massman and Pacheco 

 (1961) supported this conclusion and also found that 

 James and York River fish tended to migrate north- 

 ward in the bay proper. These migration studies fit 

 nicely with the data presented here, if indeed the 

 changes in mtDNA frequencies were due to immi- 

 gration from the James and York Rivers. 



Further study of striped bass population dynamics 

 are needed to test the hypotheses outlined above. 

 Of particular importance will be an assessment of 

 populations from the James and York Rivers. 

 Whatever the outcome, the data presented here will 

 need to be considered in management plans for this 

 economically important species. 



Acknowledgments 

 I thank Harley Speir, Steve Early, John Foster 



and Louis Rugolo of Maryland DNR for their assis- 

 tance in this study. Comments by two anonymous 

 reviewers improved an earlier version of the manu- 

 script. The research was supported by Maryland Sea 

 Grants R/F-39 and R/F-57. 



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