Overton et al.: Interactions between Morone saxatilis and their prey during winter off the North Carolin coast 
175 
81 WW 80WW 79"0'0"W 78WW 77*0'0"W 76"0'0"W 75WW 
Figure t 
Map of U.S. east coast and the general sampling area (shaded oval 
shape) for striped bass (Morone saxatilis) collected in trawl and rec- 
reational catch samples from 1994 through 2007. 
their oceanic migrations in winter 
is limited. Walter et al. (2003) iden- 
tified the paucity of information on 
the foraging habits of striped bass 
along the Atlantic coast during their 
winter residency as one of the ma- 
jor gaps in the life history of this 
species. This paucity of information 
about feeding habits during winter 
is especially acute, given the impor- 
tance of predator-prey interactions 
and their relation to the population 
base in the area. The objective of this 
paper was to gather and synthesize 
detailed information on annual feed- 
ing habits of striped bass during 
winter off the coasts of Virginia and 
North Carolina from 1994 through 
2007. Therefore, we determined the 
important prey types and the prey- 
size spectrum of striped bass during 
winter. 
Materials and methods 
Striped bass were collected by two 
methods: trawls and dockside sam- 
pling of the catch of recreational fish- 
ermen. Beginning in 1988, a number 
of fisheries management agencies 
(National Marine Fisheries Service, 
United States Fish and Wildlife Ser- 
vice, North Carolina Department of 
Marine Fisheries, Maryland Depart- 
ment of Natural Resources, and Vir- 
ginia Marine Resource Commission) organized a trawl 
survey for striped bass from federal research vessels 
during winter off the coast of Virginia and North 
Carolina (Fig. 1). The primary objective of the survey 
was to tag and release striped bass to assess annual 
mortality of the coastal migratory stock. The trawl 
specification and trawl duration varied over the years. 
Generally, trawl sampling occurred around the clock 
during mid-January. Once the trawl was recovered, 
most striped bass were tagged and released; however, 
dead or moribund fish not selected for tagging were sac- 
rificed and processed for aging or food habit analyses. 
Few fish (n<19) were examined for stomach contents 
from 1997-99, 2001, and 2004-07; therefore data from 
these years were excluded from our analyses. 
From December to March 2004-07, striped bass were 
collected weekly at the Oregon Inlet Fishing Center 
(OIFC) in Manteo, North Carolina. Fish were sampled 
from recreational fishermen who brought their daily 
catches to the fish cleaning station at the OIFC. We 
randomly selected fish once they were cleaned (gener- 
ally filleted), measured the carcasses for total length 
(±1.0 mm), and identified the sex of each individual. 
Stomachs were removed and frozen for later analysis. 
Additional samples were obtained from Virginia Beach 
Fishing Center, Virginia Beach, Virginia and processed 
in the same manner as that used to process fish from 
the OIFC. All stomach samples presumably came from 
fish captured in the Atlantic Ocean 0-4.8 km from the 
shoreline because no fishing for striped bass is permit- 
ted in the U.S. Exclusive Economic Zone (EEZ), beyond 
4.8 km (3 miles) from shore. 
In the laboratory, stomach contents were thawed and 
all prey items removed, sorted, identified (to the lowest 
taxon possible, usually to species for fish and decapod 
crustaceans and family for other invertebrates), enu- 
merated, weighed to the nearest 0.1 g, and measured to 
the nearest mm (standard, carapace, or total length). 
The percentage of prey by number and percent composi- 
tion by weight (wet weight-biomass) were determined. 
A quantitative assessment of number and weight of 
each prey item was used, as well as the respective 
percentage values for each (Markle and Grant, 1970; 
Macdonald and Green, 1983). Percent weight is a mea- 
sure of the nutritional value of the prey (Macdonald 
and Green, 1983) and is calculated as the total weight 
of each prey category divided by the total weight of 
all prey categories. Frequency distributions of prey 
