324 
Fishery Bulletin 116(3-4) 
Figure 1 
Map of estuarine and inshore sites where black sea bass 
(Centropristis striata) were collected off southeastern Mas¬ 
sachusetts during 2006-2007. Collections were used for 
otolith microincrement analyses. The rhombus indicates 
the spawning area identified by Kolek (1990), from Suc- 
connesset Shoal to Point Gammon in Nantucket Sound. 
migrations, because individuals move offshore and 
south in autumn and back inshore and north in spring 
and show a substantial degree of site-fidelity evident 
from tag-recapture data (Moser and Shepherd, 2009; 
Fabrizio et al,. 2013). One or more contingents may be 
leading the way in expanding northward. 
Climate change may also be affecting reproduction 
by shifting spawning seasons or grounds in a manner 
that could affect productivity rates (Pankhurst and 
Munday, 2011), which is our focus here. Testing this 
hypothesis is challenging given that the first year of 
life of black sea bass at the northern extent of its his¬ 
torical range is poorly understood. Kendall (1972; p. 
1254) advanced the idea: “Seasonally, there seems to 
be some northerly progression of spawning” but add¬ 
ed “Details of the suggested northward progression 
of spawning need clarification” (p. 1257). Differences 
in modal peaks in spawning seasonality north versus 
south of Cape Hatteras are not in dispute here (Table 
1). To the south, black sea bass spawn in a protracted 
manner, beginning as early as January, peaking in 
March, and ending with a smaller peak in September 
(Mercer, 1978; Wenner et al., 1986). Juveniles, 3-17 
cm standard length, are reported year-round off South 
Carolina, within a coastal, subtropical range of prac¬ 
tical salinities (11-35) and temperatures (10-32°C) 
(Lehnert and Allen, 2002). Farther north, in Maryland 
and Virginia, Musick and Mercer (1977) concluded that 
spawning peaked in June. Klein-MacPhee (2002) stated 
that spawning between Chesapeake Bay and Long 
Island peaked in August. Age-0 black sea bass, 3-11 
cm total length (TL), have occurred in New Jersey 
coastal habitats during summer-autumn, but they 
cannot survive winter temperatures, and instead 
migrate offshore (Able and Hales, 1997; Hales and 
Able, 2001; Fabrizio et al., 2013). 
Although sparse, such data fit Kendall’s (1972) 
initial proposal that spawning progresses season¬ 
ally from south to north. However, Caruso’s (1995) 
and Wuenschel et al.’s 2 sampling of black sea bass 
off Massachusetts, at the northernmost range limit 
of this species, provide evidence of peak spawning 
activity early, in late May or mid-June, not later in 
the season. They examined gonads macroscopically 
for evidence of spawning, whereas much of the other 
research was based on ichthyoplankon collections 
(Table 1). Ichthyoplankton surveys in waters off 
Massachusetts are not representative of black sea 
bass spawning, because such surveys did not sample 
in Nantucket or neighboring sounds (Table 1), where 
black sea bass have been observed in spawning con¬ 
dition during May-June and juveniles are present in 
autumn (Fig. 1; Wilson, 1889; Lux and Nichy, 1971; 
Kolek, 1990; Able et al., 1995; Caruso, 1995; Drohan 
et al., 2007). We conclude that spawning seasonality 
and the first year of life have not been adequately 
described for this species at the northern extent of 
its range. 
To resolve the issue of spawning seasonality, 
age-0 black sea bass were collected with multiple 
gears in Buzzards Bay and Nantucket Sound during 
summer and autumn of 2006 and 2007 to determine 
age, by day, within that annual age class. Herein and 
elsewhere (Hales and Able, 1995), this otolith microin¬ 
crement method has been validated as both accurate 
and precise with respect to daily increment formation. 
In addition to defining spawning seasonality based on 
backcalculated hatch dates, we examined growth rates 
and resulting size of age-0 fish entering their first over¬ 
wintering period. 
To check for shifting spawning and nursery grounds, 
we examined geographic distributions of spawning 
adults and age-0 black sea bass from 2 time series of 
fishery-independent groundfish (otter trawl) surveys 
since at least the 1980s. We plot the distributions of 
these fish roughly by decade and correlate the annual 
distributions of settled, age-0 fish by both latitude and 
temperature. 
2 Wuenschel, M. J., G. R. Shepherd, R. S. McBride, R. Jor¬ 
gensen, K. Oliveira, E. Robillard, and J. Dayton. 2011. Sex 
and maturity of black sea bass collected in Massachusetts 
and Rhode Island waters; preliminary results based on mac¬ 
roscopic staging of gonads with a comparison to survey data. 
A working paper for SARC 53- Black Sea Bass Data Meet¬ 
ing. In 53rd Northeast Regional Stock Assessment Work¬ 
shop (53rd SAW) assessment report. Northeast Fish. Sci. 
Cent. Ref. Doc. 12-05, p. 529-559. [Available from website.] 
