422 



Fishery Bulletin 101(2) 



(1973) found menhaden and anadromous herrings to be 

 predominant (Homer and Boynton'') foods in brackish wa- 

 ters of Albemarle Sound and HoUis (1952) found menhaden 

 as well as anchovies and blue crabs to be predominant food 

 of striped bass in brackish waters of Chesapeake Bay. The 

 predatory impact of migratory striped bass depends upon 

 their residence time in these waters, as well as on striped 

 bass population size and feeding rates. Carmichael et al. 

 (1998) estimated that striped bass spend approximately 

 one week in their upstream and one week in their down- 

 stream transit of the Roanoke River There are no estimates 

 of residence time in the open waters of Chesapeake Bay or 

 Albemarle Sound; however, striped bass larger than 711 

 mm are captured in recreational fisheries in Chesapeake 

 Bay into June, suggesting that they are present in Chesa- 

 peake Bay from March through June. 



After leaving Chesapeake Bay and summering in New 

 England waters, large striped bass return to the bay in fall 

 (Dorazio et al., 1994) and fed primarily upon menhaden, 

 spot, and anchovies. At this time, most fish were taken from 

 open waters of Chesapeake Bay. In the lower bay during 

 fall, large numbers of transient young-of-the-year (YOY) 

 marine fishes (menhaden, spot, croaker, flounder, and 

 weakfish) congregate in open waters of Chesapeake Bay 

 prior to the fall out-migration, thus making them acces- 

 sible prey for returning striped bass. Striped bass exhibited 

 higher stomach fullness values and higher percentages of 

 nonempty stomachs in November and December than in 

 all other months, with the exception of June. This finding, 

 in conjunction with observations of striped bass aggres- 

 sively pursuing baitfishes in surface waters during the fall 

 (Mollis, 1952, this study), indicates high feeding intensity. 

 In bioenergetic simulations, striped bass growth potential 

 and prey density peaked in October (Brandt and Kirsch, 

 1993). Because much of the annual growth (Hartman and 

 Brandt, 1995a, 1995b) and gonadal development (Berlin- 

 sky and Specker, 1991) occur in the fall, this period is of 

 primary importance both for the accumulation of body 

 mass for overwintering and for the initial development of 

 gonadal products. 



Although pelagic fishes, notably anchovy and menhaden, 

 provided the bulk of the diet for large striped bass, this study 

 differs from the diet study of Hartman and Brandt (1995a) 

 and the network analysis of Baird and Ulanowicz (1989) in 

 that benthic fishes also contributed significantly to the diets. 

 Baird and Ulanowicz ( 1989) estimated that striped bass ob- 

 tained 91-100''^( of their diet from pelagic trophic pathways 

 and Hartman and Brandt (1995a) estimated that 68-75% 

 of the diet of age-2 to age-6 striped bass came from pelagic 

 sources. These estimates contrast with the high percentages 

 of benthic spot, croaker, summer flounder, and gizzard shad 

 observed in this study and indicate that larger striped bass 

 either prey to a greater extent upon benthic fishes or the 

 overall diet has shifted towards benthic prey Menhaden 

 and bay anchovy juvenile abundance indices have declined 



' Homer. M, and W R. Boynton. 1978. Stomach analysis offish 

 collected in the (lalvert (Miffs region, Chesapeake Bay — 1977. 

 Rep. UMCEES 78-154 CBL, ,!6,i p. Chesapeake Biological 

 Laboratory, Univ. Maryland, Solomons, MD. 



over the past 10 years (VIMS^) suggesting that a dietary 

 shift towards benthic prey may have occurred since the 

 collections of Hartman and Brandt (1995a) and the stud- 

 ies cited in the Baird and Ulanowicz ( 1989) model. Without 

 comprehensive and systematic annual diet sampling, it is 

 difficult to separate dietary shifts from differences in the 

 sizes of fish sampled or the sampling locations. Baird and 

 Ulanowicz (1989) incorporated diet composition data from 

 Hollis (1952), Gardinier and Hoff (1982), Manooch (1973), 

 and Homer and Boynton'* that included very few striped 

 bass larger than >600 mm and their model included no link- 

 ages between striped bass and gizzard shad, spot, croaker, 

 or summer flounder Furthermore, the absence of gizzard 

 shad in the Baird and Ulanowicz ( 1989) model represents a 

 missing pathway that might link benthic detritus directly 

 to piscivore production as occurs in freshwater impound- 

 ments where gizzard shad are the major prey of striped 

 bass (Mathews et al., 1988) and play a pivotal role in the 

 freshwater ecosystem (Stein et al., 1995). 



Acknowledgments 



This work represents part of a thesis presented to the Col- 

 lege of William and Mary (School of Marine Science) by 

 the first author. We would like to thank the first author's 

 committee members, David Evans, Robert Diaz, John 

 Hoenig, and Thomas Munroe, for reviewing the thesis and 

 this manuscript. We would like to acknowledge the many 

 seafood dealers and recreational and commercial fisher- 

 man who provided fish samples. This research was funded 

 by the Virginia Recreational Fishing Advisory Board and 

 the Virginia Commercial Advisory Board (grant numbers 

 RF-97-08 and CF-97-08). 



Literature cited 



Baird, D., and R. E. Ulanowicz. 



1989. The seasonal dynamics of the Chesapeake Bay eco- 

 system. Eeol. Mono. 59(4):329-364. 

 Berggren, T. J., and J. T. Lieberman. 



1978. Relative contribution of Hudson, Chesapeake and 

 Roanoke striped bass, Morone saxatilis, stocks to the Atlan- 

 tic Coast fishery Fish. Bull. 76:335-342. 

 Berlinsky, D. L. .and J. L. Specker. 



1991. Changes in gonadal hormones during oocyte develop- 

 ment in the striped bass, Morone saxatilis. Fish Phys. 

 Biochem. 9:51-62. 

 Boynton, W. R., T. T. Polgar, and H. H. Zion. 



1981. Importance of juvenile striped bass food habits in the 

 Potomac estuary Trans. Am. Fish. Soc. 110:56-63. 

 Brandt, S. B., and J. Kirsch. 



1993. Spatially explicit models of striped bass growth 

 potential in Chesapeake Bay. Trans. Am. Fish. Soc. 122: 

 845-869. 

 Carmichael, J. T, S. L. Haeseker, and J. E. Hightower, 



1998. Spawning migration of telemetered striped bass in 

 the Roanoke River, North Carolina. Trans. Am. Fish. Soc. 

 127:286-297 

 Chapman, R. W. 



1987. Changes in the population structure of male striped 



