McBride et al.: Interspecific comparisons of searobin, Prionotus spp., movements, size structure and abundance 
305 
fish numbers and weight had similar 
trends (McBride, 1994); therefore only 
weight indices are reported here. Some 
descriptive statistics were also based on 
subsets of data (1982-91), as noted below. 
Statistical significance was evaluated at 
P<0.05. The above comments pertain to all 
data examined, and comments below out- 
line procedures specific to each sampling 
program. 
N.VfFS sampling 
Survey data from the National Marine 
Fisheries Service (NMFS), Northeast Fish- 
eries Science Center (NEFSC), were exam- 
ined. The survey area was divided into 76 
strata from Cape Fear, North Carolina, to 
Cape Sable, Canada, in waters 9-366 m 
deep. Spring and autumn cruises sampled 
a total of about 350 stations during a 6-8 
week period, whereas summer and winter 
cruises sampled about half as many sta- 
tions (Table 2). The primary gear used was 
a no. 36 Yankee trawl. In spring, summer, 
and autumn cruises a roller-rigged footrope 
was used; however, in winter cruises a 
cookie sweep and ground cable designed to 
target flatfish were used. Latitude, longi- 
tude, and depth were recorded at the start 
of each tow. Bottom temperature was usu- 
ally recorded by using an XBT cast or a 
CTD probe. See Grosslein (1969, 1976), 
Azarovitz (1981), and Bespres-Patanjo et 
al. (1988) for further sampling details. 
Exploratory data analyses considered all 
76 strata, but interannual comparisons of 
abundance considered only latitudinal 
strata within the Mid-Atlantic Bight be- 
cause both species were uncommon or ab- 
sent in the Gulf of Maine and on Georges 
Bank and because sampling south of Cape 
Hatteras was not broad in coverage or con- 
sistent between years. Because the distri- 
bution of both species varied seasonally, 
largely as an onshore-offshore pattern, dif- 
ferent depth strata sets were used for cal- 
culating spring and autumn abundances; 
the autumn strata selected were generally 
<27 m and the spring strata were >27 m 
deep. Because the purpose here was to com- 
pare interspecific abundances, the final 
selection of strata included the broadest 
possible latitudinal range within the Mid- 
Atlantic Bight where both species occurred. 
71 • 39 ' 62 ° 58 ' 
Figure 1 
Study area of the U.S. east coast, with some landmarks iden- 
tified in the text (additional landmarks are depicted in Fig. 3). 
The Mid-Atlantic Bight is defined as the coastal region be- 
tween Cape Cod and Cape Hatteras. Sampling strata for the 
Mid-Atlantic Bight survey (NEFSC, NMFS, Table 2) extended 
in total from Cape Fear to Cape Sable. Sampling regions for 
the Massachusetts and New Jersey surveys (Mass. Div. Mar. 
Fisheries and New Jersey Bureau of Mar. Fisheries; Table 2) 
are depicted in Figures 3 and 4. 
