420 



Fishery Bulletin 101(2) 



Discussion 



Our study addresses the diet of striped bass 

 above 458 mm total length in Chesapeake Bay. 

 In previous studies of striped bass diet (Hollis, 

 1952; Hartman and Brandt, 1995a) in Chesa- 

 peake Bay and adjacent waters (Manooch, 

 1973), few fish above 458 mm were sampled. 

 The comprehensive work by Hartman and 

 Brandt ( 1995a) did not include fish above age 

 6. The current study focuses specifically on 

 the diet of larger striped bass that previously 

 were undersampled or were rare during peri- 

 ods of severe overfishing (Koo, 1970). 



Throughout the two size ranges of striped 

 bass sampled and in both seasons and loca- 

 tions, schooling fishes dominated the diets in 

 Chesapeake Bay. In particular, clupeid fishes 

 (menhaden, gizzard shad) and the closely 

 related anchovies exceeded all other prey spe- 

 cies in frequency of occurrence, number, and 

 biomass. Among other fishes, only spot rivaled 

 the clupeids and anchovies in overall impor- 

 tance; however, white perch, croaker, weakfish, 

 and summer flounder contributed important 

 percentages of the diet in certain seasons. Hol- 

 lis (1952), Manooch (1973) and Hartman and 

 Brandt ( 1995a ) and Overton ( 2002 ) also found 

 that schooling clupeoid fishes formed the ma- 

 jority of the diets of striped bass from Chesa- 

 peake Bay and nearby Albemarle Sound. 



There was a shift in the relative importance 

 of smaller schooling fishes (anchovies) in 

 striped bass 458-710 mm to larger schooling 

 fishes (menhaden, gizzard shad) in striped 

 bass 711-1151 mm. Although there was a 

 tendency for larger striped bass to consume 

 larger prey, this relationship should more 

 accurately be described as one where larger 

 striped bass have a greater size range of prey 

 to consume (Fig. 4). The largest striped bass 

 consumed prey ranging from several millime- 

 ters up to 400 mm in total length, correspond- 

 ing to 40'^( of their total length and equaling 

 the ratio of mean maximum forage length to 

 striped bass length found by Manooch ( 1973). 

 Similarly, smaller striped bass consumed prey 

 that approached 40'~f of their total length; 

 however, most prey consumed by all sizes of 

 striped bass were smaller, young-of-the-year 

 fishes — a finding corroborated by Overton 

 (2002), who predicted an optimal prey size to 

 be 21% of the striped bass length. 



The predominance of fish in adult striped 

 bass diets attests to the piscivorous nature of 

 larger striped bass and corroborates the find- 

 ings of other studies (Hollis, 1952; Manooch, 

 1973; Overton, 2002). Hartman and Brandt 

 (1995a) and Gardinier and Hoff (1982) ob- 

 served an ontogenetic shift at 200 mm TL 



