261 
National Marine 
Fisheries Service 
NOAA 
Fishery Bulletin 
é established in 1881 << 
Spencer F. Baird 
First U.S. Commissioner 
of Fisheries and founder 
of Fishery Bulletin 
Abstract—Inaccurate age determi- 
nations can have serious effects on 
age-structured stock assessments that 
are used to manage fish populations. A 
recent push toward using an age-based 
model for the northern stock of black 
sea bass (Centropristis striata) led to 
an increase in direct aging effort in 
the northeastern United States. Yet, no 
large-scale otolith age validation study 
for this stock exists. We examined the 
annual periodicity of otolith growth in 
this species through marginal incre- 
ment analysis with otoliths of fish 
from 3 age groups (fish of ages 1-2, ages 
3-4, and ages 5+) and from 2 regions, 
north and south of the Hudson Canyon. 
Additionally, we validated the assign- 
ment of the first annulus through 
modal length—frequency analysis of 
young-of-the-year fish. The marginal 
increment ratio differed between age 
groups throughout the year, support- 
ing the separation of these samples for 
age validation purposes. Higher ratios 
were observed in black sea bass from 
the region south of the Hudson Canyon 
throughout most of the year; however, 
fish from north of the canyon appear 
to accrete more otolith material during 
winter. Annual growth increments 
were deposited once per year, in spring 
or early summer, for all fish. In addi- 
tion, absolute age was validated for the 
first time for this stock. 
Manuscript submitted 9 April 2021. 
Manuscript accepted 13 October 2021. 
Fish. Bull. 119:261—273 (2021). 
Online publication date: 17 November 2021. 
doi: 10.7755/FB.119.4.6 
The views and opinions expressed or 
implied in this article are those of the 
author (or authors) and do not necessarily 
reflect the position of the National 
Marine Fisheries Service, NOAA. 
Age validation of the northern stock of black sea 
bass (Centropristis striata) in the Atlantic Ocean 
Elise R. Koob (contact author)' 
Scott P. Elzey' 
John W. Mandelman? 
Michael P. Armstrong‘ 
Email address for contact author: elise.koob@mass.gov 
" Annisquam River Marine Fisheries Station 
Massachusetts Division of Marine Fisheries 
30 Emerson Avenue 
Gloucester, Massachusetts 01930 
* Anderson Cabot Center for Ocean Life 
New England Aquarium 
1 Central Wharf 
Boston, Massachusetts 02110. 
The range of the northern stock of 
black sea bass (Centropristis striata) 
off the coast of the northeastern United 
States extends from Cape Hatteras, 
North Carolina, to the Gulf of Maine 
(Mercer, 1978). This species can live 
to 15 years of age and reach approx- 
imately 60 cm in total length (TL) 
(Shepherd and Lambert, 1996). Black 
sea bass support an important commer- 
cial fishery and a valued recreational 
fishery that is worth over half the total 
annual landings (Musick and Mercer, 
1977; NEFSC, 2017). This stock experi- 
enced a recent range expansion, linked 
to warming ocean trends (Bell et al., 
2015; McBride et al., 2018), into coastal 
Maine waters—an area where this 
species had been rarely seen histori- 
cally (Bigelow and Schroeder, 1953). 
The importance of this fishery, and the 
gaps in data on growth, age, migration 
patterns, and stock structure of black 
sea bass, led to a push for additional 
research on this species. 
The accuracy of age data is crucial to 
stock assessments; errors in these esti- 
mates can undermine fisheries man- 
agement and lead to overexploitation 
(Campana, 2001). A catch-at-age stock 
assessment model for the northern 
Atlantic stock of black sea bass was 
rejected in 2012, because of insufficient 
age data (NEFSC, 2012; ASMFC’). In 
response, agencies along the Atlantic 
coast of the United States began to col- 
lect and age samples of black sea bass, 
and a statistical catch-at-age model 
was accepted in 2016 (NEFSC, 2017). 
However, despite the increase in direct 
aging, there has been little effort to 
complete a large-scale age validation 
study for this stock. 
Age estimates for black sea bass are 
primarily done by using otoliths, which 
are often the most accurate aging struc- 
ture (Casselman, 1983). Calcium car- 
bonate layers are accreted onto otoliths 
daily, and a seasonal banding pattern 
is formed, with bands differentiated 
as opaque or translucent (Campana 
and Thorrold, 2001). Age is determined 
"ASMFC (Atlantic States Marine Fish- 
eries Commission). 2013. Proceedings of 
the 2013 black sea bass ageing workshop, 
17 p. ASMFC, Arlington, VA. [Available 
from website.] 
