66 



Fishery Bulletin 105(1) 



40 r 



10 



Males 



L 



_L 



J I I L 



_L 



^'i^ # ^'P ri? r,^ ^T? ^n^ 



ID 



30 



1 



10 



Females 



^(^filnffi 



B 



M I I T 1 I 1 I I 1 1 I I I 



1 I I I I I 1 I 1 1 I 1 I I 



,.i^,o,1^fc\6V\1VV\*\*\A*V^A"5VVV^''VV^^\^VVV^A•i^^^^^^ 



ID 



Figure 1 



Box and whisker plots of salinity records experienced over a lifetime 

 by individual male (A) and (B) female Chesapeake Bay striped bass 

 (Morone saxatilis) collected in 2000. Median values are given within each 

 box, which represents the first two quartiles of data about the median. 

 Asterisks and circles indicate near and far outliers in relation to the 

 first two quartiles, respectively. Salinity is given in practical salinity 

 units. ID indicates the identification number assigned to each fish. 



Discussion 



Oceanic incidence of striped bass 



Our analysis and that of Dorazio et al. (1994) does not 

 support Kohlenstein's (1981) model of mass egress of 

 female striped bass from Chesapeake Bay after ages 

 two or three. Rather, our life history transects indi- 

 cated a fairly gradual shift to use of ocean habitats — a 



shift associated with maturation at ages five to eight 

 (Table 1; Fig. 2). For mature age classes, evidence of 

 oceanic residence was observed for 50-75% of the female 

 sample. Also, in contrast to previous expectations, otolith 

 microanalysis indicated that a large fraction of males 

 leave Chesapeake Bay, albeit at rates <50'7f . 



Mirroring the results of Dorazio et al.'s (1994) tag- 

 ging experiment, our results showed a trend of in- 

 creasing oceanic residence with fish size, but found 



