328 
Fishery Bulletin 116(3-4) 
2006 
NS 1 - 
•-[iiH 
NS E - 
e-dl-H 
BB 1 - 
o i—-rn —h 
BB E ~ 
° e- m— ■ 
120 140 160 180 200 
2007 
NS 1 - 
h-CO-H 
NS E - 
o h—□}—■H 
BB 1 - 
>.an~-H 
BB E ~ 
h — ~| | |- 
Apr 30 May 20 Jun 9 Jun 29 Jul 19 
Figure 4 
Hatching dates of black sea bass ( Centro- 
pristis striata ) in 2006 (upper panel, with 
numerical days of the year along the bot¬ 
tom axis) and 2007 (lower panel, with cor¬ 
responding calendar dates). Box-whisker 
plots represent aged individuals collected 
from estuarine (E) and inshore (I) sites 
within Nantucket Sound (NS) and Buz¬ 
zards Bay (BB) in southeastern Massachu¬ 
setts, each with the median (thick line), 
the 25-75 percentile (boxes), the approxi¬ 
mate 95% confidence limits (whiskers), and 
outliers (dots). 
that would provide the most direct evidence of spawn¬ 
ing. Few spent females were found. 
Black sea bass nursery grounds have also been mov¬ 
ing northward over the last 40 years (Fig. 7). Over¬ 
all, age-0 black sea bass were found distributed from 
the southern Gulf of Maine, specifically Cape Cod and 
Massachusetts Bay, to North Carolina (Suppl. Mate¬ 
rial). In the Gulf of Maine, they have been most fre¬ 
quently collected during the last decade, but they have 
been present in the southern Gulf of Maine since both 
surveys operated together in the late 1970s. Although 
the NMFS-NEFSC trawled well into Canadian waters 
(> 45°N), the maximum latitude of age-0 black sea bass 
occurrence during 1978-2016 ranged from 41°35'N in 
1993 to 42°56'N in 2014. 
The maximum latitude of age-0 black sea bass has 
steadily increased 0.021 degrees annually, on average, 
since 1978, for a total of about 1°N during the last 40 
years (Fig. 8). Most relevant for future monitoring is 
the association between autumn sea temperature and 
the maximum latitude of age-0 fish. This association 
100 
80 
60 - 
40 
cn 
c 
0) 
ro 
,o 
2006 
□ NS I 
■ NS E 
o BB I 
• BB E . * 
50 
nr 
70 
ir 
90 
110 
130 
100 - 
80 - 
60 - 
40 
2007 
□ NS I 
■ NS E 
o BB I 
• BB E 
50 
70 
- r 
90 
Age (days) 
I 
110 
130 
Figure 5 
Size at age of black sea bass (Centropristis stria¬ 
ta) in 2006 (upper panel) and 2007 (lower panel). 
Individuals are represented according to the loca¬ 
tion of collections from estuarine (E) and inshore 
(I) sites within Nantucket Sound (NS) and Buz¬ 
zards Bay (BB) off southeastern Massachusetts. 
is modeled in Figure 8 as a linear relationship, but 
also suggests a break point pattern, with a break val¬ 
ue around 16-17°C, below which this species is found 
much farther south and above which it is found much 
farther north. 
Discussion 
Black sea bass is already a winner under conditions 
of warming temperatures. Earlier spring warming has 
led to earlier and more extensive spring migrations, 
