414 



Abstract— Large (>458 mm) striped 

 bass {Morone saxatilis) are dominant 

 predators in Chesapeake Bay. In recent 

 years, the Chesapeake Bay stock of 

 striped bass has increased dramatically, 

 raising concerns about their predatory 

 impact and their forage requirements. 

 In response to these concerns and the 

 need for more recent ecological stud- 

 ies, this investigation was conducted 

 to characterize feeding habits of large 

 striped bass in Chesapeake Bay. Stom- 

 ach contents from 1225 striped bass 

 from 458 to 1151 mm TL were exam- 

 ined in the spring and fall of 1997 and 

 1998. Striped bass consumed 52 differ- 

 ent species of vertebrates and inverte- 

 brates; however, only a few species of 

 clupeoid and sciaenid fishes dominated 

 diets across both the seasons and size 

 ranges of striped bass examined. Of 

 finfish species, menhaden \Brevoortia 

 tyrannus) was the dominant prey in 

 most areas and gizzard shad (Doro- 

 soma cepedianum) replaced menhaden 

 in importance in lower salinity waters. 

 Spot [Leiostomus xanthurus) and 

 other sciaenid fishes and anadromous 

 herrings t.Alosa spp.) also contibuted 

 large percentages of striped bass diet. 

 Although pelagic schooling fishes 

 formed the majority of the diet, benthic 

 fishes contributed a higher percentage 

 to the diet than in previous studies of 

 striped bass diet composition. 



Diet composition of large striped bass 

 iMorone saxatilis) in Chesapeake Bay* 



John F. Walter III 



Herbert M. Austin 



Virginia Institute of Marine Science 



School of Marine Science 



The College of William and Mary 



PO Box 1346, Gloucester Point, Virginia 23062 



E mail address (for J, F Walter): ifwalterfiivims edu 



Manuscript accepted 22 October 2002. 



Manuscript received 9 January 2003 

 at NMFS .Scientific Publications Office. 



Fish. Bull. 101:414-423 (2003). 



Along the Atlantic coast of North Am- 

 erica, the striped bass is one of the most 

 important commercial and recreational 

 fishes (Richards and Rago, 1999). In 

 the face of intense overfishing, the 

 Atlantic Coast population of striped 

 bass experienced drastic declines in the 

 1970s (Field, 1997; Richards and Rago, 

 1999). During these periods of intense 

 harvesting, smaller fish dominated the 

 stock composition and the fishery (Koo, 

 1970). With the relaxation of fishing 

 pressure and the implementation of 

 regulations designed to protect older 

 age classes, populations rebounded 

 to the point where, currently, large, 

 older fish comprise a high percentage 

 of the population (Richards and Rago, 

 1999). The increased abundance of 

 large striped bass has raised concerns 

 over both the predatory impact and 

 prey needs of this large population of 

 seasonally abundant species in Chesa- 

 peake Bay. 



Within Chesapeake Bay, historically 

 a center of striped bass abundance and 

 one of the largest sources of juvenile 

 production for the Atlantic coast (Mer- 

 riman, 1941; Berggren and Lieberman, 

 1978; Kohlenstein, 1981), striped 

 bass are seasonally abundant upper 

 trophic level predators. Chesapeake 

 Bay striped bass are partitioned into 

 a resident, primarily male or juvenile, 

 group of fish found year-round and a 

 migratory group consisting of older, 

 larger (>711 mm total length) and of- 

 ten primarily female fish found in the 

 spring and fall (Chapman, 1987). The 

 Atlantic States Marine Fisheries Com- 

 mission manages fish greater than 711 

 mm (28 inches) total length as migra- 

 tory (ASMFC) because the majority of 

 these fish leave Chesapeake Bay and 



migrate throughout the Atlantic coast. 

 Striped bass within Chesapeake Bay 

 migrate during the spring when mature 

 fish ascend tidal freshwater tributaries 

 to spawn (Chapoton and Sykes, 1961; 

 Dorazio et al., 1994). After spawning, 

 these fish leave Chesapeake Bay and 

 migrate northward along the Atlantic 

 coast, returning to Chesapeake Bay in 

 large numbers during the fall. With a 

 major peak in March-April and a minor 

 peak in October-November, the histori- 

 cal landings data reflect the migratory 

 behavior and seasonal abundance of 

 larger fish (Koo, 1970). 



Diet studies represent the first step 

 in determining the magnitude and di- 

 rection of trophic interactions and are 

 essential data for the management of 

 both predators and prey (Livingston, 

 1985). For the management of multi- 

 species fisheries, detailed information 

 on fish food habits is required in order 

 to account for the temporal, spatial, 

 and ontogenetical nature of trophic 

 interactions (Walters et al., 1999; Hol- 

 lowed et al., 2000; Wliipple et al, 2000). 

 Although the feeding habits of resident 

 juvenile and early adult striped bass 

 have received considerable study in 

 Chesapeake Bay (Hollis, 1952; Markle 



* Contribution 2507 of the Virginia Insti- 

 tute of Marine Science, School of Marine 

 Science, The College of William and Mary, 

 Gloucester Point, VA 23062. 



• ASMFC (Atlantic States Marine Fisheries 

 Commission I. 2000. Public informa- 

 tion document for Amendment 6 to the 

 Interstate Fishery Management Plan for 

 striped bass, 17'p. ASMFC, 1444 Eye 

 Street NW. Washington, DC 20005. http: 

 //www.jcaa.org/I^ID.htm (March 2001). 



