326 
Fishery Bulletin 116(3-4) 
100 -1 
2006 
80 - 
□ All, 58 ±11, n=447 
■ Aged, 55 ±10, n=200 
Total length (mm) 
Figure 2 
Length-frequency distributions for all (white bars) 
and aged (overlayed black hatched bars) black sea bass 
(Centropristis striata) collected in 2006 (upper panel) 
and 2007 (lower panel) in southeastern Massachusetts. 
Mean values, with standard deviations, (SDs) for sizes 
and number of fish in) are indicated. 
of limited biological significance; there was no differ¬ 
ence in aged and all fish collected in 2007 (Student’s 
*=-0.27, df=863, P=0.78) (Fig. 2). 
Hatching dates were calculated by subtracting the 
total count of microincrements for each fish from the 
date of capture, assuming that the first ring observed 
corresponded to the hatching date and that there 
was negligible time difference between spawning and 
hatching (unknown but considered in the discussion). 
Capture dates were similar between years (mean: Au¬ 
gust 28 or 29 [standard deviation (SD) 18-19 d], in 
2006 and 2007) and areas (August 28-31 [SD 18-20 
d], Buzzards Bay and Nantucket Sound); however, cap¬ 
ture dates were 1 month earlier for estuarine than for 
inshore collections (August 18 [SD 13 d] vs. September 
19 [SD 3 d]). Therefore, capture date was a confound¬ 
ing variable, which precluded a comparison of a full 
3-way analysis of variance (ANOVA) of hatching dates 
between years, and between estuarine and inner shelf 
sites in both Buzzards Bay and Nantucket Sound. Also, 
because different sampling gears (traps, trawls), were 
used in estuarine and inshore habitats, there may also 
have been a gear effect, although this effect would not 
arise from mesh selectivity, which was the same for 
both gears (7-mm mesh). Because of these potential 
confounding variables, hatching dates are described 
and plotted separately by year and location. 
Daily increments and TL at capture were also used 
to calculate mean growth (in millimeters per day). As 
reported above for hatching dates, capture date had a 
significant effect when included in a full multifactorial 
ANOVA comparison of growth rates between years, and 
between estuarine and inner shelf sites in both Buz¬ 
zards Bay and Nantucket Sound. Consequently, size at 
age and growth rates are also described separately by 
year and sampling location. 
A time series of fish distributions 
Annual time series, from 2 otter trawl surveys conduct¬ 
ed since the late 1970s and early 1980s, were examined 
to map the distribution of adult female and age-0 black 
sea bass collected in coastal waters and on the conti¬ 
nental shelf. Plots of different maturity classes depict 
distributions of adult females and spawning grounds. 
Maturity classification, completed at sea, followed 
Burnett et al. (1989). For graphical clarity, 3 classes 
were plotted: 1) developing fish (prespawning females 
but also likely to include spawning fish between batch 
spawning events [Klibansky and Scharf, 2015]); 2) 
spawning fish (females with hydrated oocytes), and 3) 
postspawning fish (spent females). Immature and rest¬ 
ing fish were not plotted because these were reproduc- 
tively inactive at time of capture. Distributions of age- 
0 fish depict nursery grounds. Identification of age-0 
fish followed the methods of Penttila and Dery (1988) 
for examinations of prepared otoliths. Subsequently, it 
was determined that age-0 fish were readily identified 
by size (Suppl. Material), and a proxy size (< 12 cm TL) 
was used to select age-0 fish in order to include indi¬ 
viduals that were age-0 but that had not been specifi¬ 
cally examined for age. 
Site selection for these 2 otter trawl surveys fol¬ 
lowed a stratified-random sampling design. The first 
survey (MA-DMF), in coastal waters off Massachusetts, 
was the inshore bottom trawl survey described in the 
previous section; sampling occurred during spring 
(May) and autumn (September). The second survey was 
performed by the National Marine Fisheries Service’s 
Northeast Fisheries Science Center (NMFS-NEFSC) in 
the spring (March-May) and autumn (September-No- 
vember). It was conducted in federal waters primarily, 
covering offshore waters across the continental shelf 
to the shelf break, from North Carolina to the north¬ 
ern Gulf of Maine, including adjacent territorial seas 
of Canada. For both surveys, the time series of age-0 
fish started in 1978, the time series of mature adults 
started in 1983, and the terminal year of all data was 
2016. Further details are summarized in Reid et al. 
(1999). 
