Fabrizio et al.: Home range and seasonal movements of Centropristis striata 
93 
Table 2 
Estimated parameters from the general linear mixed model of activity level for Black Sea 
Bass ( Centropristis striata ) at a reef in the mid-Atlantic Bight during the period May-No- 
vember 2003, with the activity index log e transformed to meet homogeneity of variance 
assumptions. The model was fitted to 11,843 observations from 121 Black Sea Bass. The 
additional variance associated with individual fish was 0.1578; the correlations among 
activity levels during dawn, day, dusk, and night were modeled with an autoregressive 
moving average model with parameters a 2 , p, and T, where o 2 is the estimate of the re- 
sidual variance for each time period, I' is the estimated correlation between 2 successive 
repeated measures, Fp is the estimated correlation between observations 2 (time) units 
apart, Tp 2 is the estimated correlation between observations 3 (time) units apart, and so 
forth. Temp is temperature in degrees Celsius (°C) at the bottom of the seafloor; B1 refers 
to the acoustic station depicted in Figure 1; time period refers to dawn, day, dusk, and 
night; df is degrees of freedom. 
Covariance parameter 
Dawn 
Day 
Dusk 
Night 
o 2 
0.4840 
0.5548 
0.4637 
0.4530 
P 
0.8351 
0.8619 
0.8636 
0.7622 
r 
0.2332 
0.2533 
0.2603 
0.3297 
Type-III tests of fixed effects 
Effect 
Numerator df 
Denominator df 
F 
P 
Sex 
1 
116 
0.90 
0.345 
Season 
1 
7062 
0.38 
0.536 
Release group 
2 
118 
1.06 
0.350 
Time period 
3 
431 
1.96 
0.120 
Time 
1 
2829 
96.88 
<0.001 
Time 2 
1 
5366 
8.45 
0.004 
Time 3 
1 
4244 
47.76 
<0.001 
Temp difference 
1 
8431 
7.23 
0.007 
Temp at B1 
1 
5713 
19.06 
<0.001 
Salinity difference 
1 
6163 
1.54 
0.215 
Temp at Bl*time 
1 
5144 
9.53 
0.002 
Temp at Bl*time 2 
1 
6003 
22.83 
<0.001 
Temp at Bl*sex 
1 
4797 
34.06 
<0.001 
Season*time 3 
1 
5825 
28.52 
<0.001 
Release group*time 3 
2 
3809 
19.67 
<0.001 
successfully establish territories for reproduction and 
recruitment. 
The observed variations in home-range size among 
Black Sea Bass have implications for management of 
these fisheries. In the mid-Atlantic, commercial and 
recreational fisheries target fish at specific reefs; al- 
though the distribution of fishing activity at the reefs 
is not strictly random, vulnerability to capture is likely 
to increase with increasing home-range size. The larg- 
est home ranges were observed for fish of unknown sex 
that occupied the site for shorter (<50 d) periods of 
time; occupancy duration may have been short because 
these fish dispersed from the site or because they were 
harvested or died of natural causes. Males released 
in early June had home-range areas that were larger 
than those areas of other males, indicating that groups 
of males may be differentially vulnerable to capture. 
Because reefs may support populations characterized 
by groups of fish that exhibit differences in space use 
and activity levels, differential vulnerability of groups 
may further exacerbate variation in exploitation rates 
among reefs. In addition, fishery removal of mature 
males may initiate sex transformation in females (Ben- 
ton and Berlinsky, 2006), a process that is ensured by 
social interactions among individuals with overlapping 
home ranges. 
Seasonal movements of Black Sea Bass 
During their inshore residency in the mid-Atlantic 
Bight, Black Sea Bass were more likely to undertake 
large-scale movements (>400 m) during summer, when 
mean cross-shelf differences in water temperature at 
the bottom of the seafloor were more pronounced than 
