316 
Fishery Bulletin 117(4) 
Figure 4 
Images of gonadal tissue from a specimen of snowy grouper (Hyporthodus niveatus) that was 
transitioning from female to male, showing (A) functional sperm sinuses and atretic oocytes 
(microscope magnification: 20x) and (B) atretic oocytes within spermatogenic tissue (microscope 
magnification: 40x). This specimen was captured on 27 August 2008 off South Carolina at a total 
length of 834 mm and age of 7 years. AO=a-stage atretic oocyte; SC=spermatocytes. 
0.20 - 
0.15 - 
C/D 
g 0.10 
0.05 
0.00 - 
Sex 
S| Female (n=1583) 
f.J Male (n=96) 
□ Transitional (n=16) 
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 
Age (years) 
Figure 5 
Density plots of age by sex for snowy grouper (Hyporthodus nivea¬ 
tus) captured off North and South Carolina during 1982-1985, 
1993-1994, and 2008-2012. Ages are counts of annual increments 
from otolith readings. The unit for density is the relative proportion 
of fish in each sex category. /r=number of fish examined. 
from snowy grouper captured during 2008-2012 revealed 
evidence of population recovery. Since the mid-1990s, SSB 
has increased gradually, but the biomass target has not been 
reached as of the terminal year of 2012 (SEDAR, 2013). 
However, overfishing, when the fishing mortal¬ 
ity rate is greater than the fishing morality rate 
at MSY, occurred only once in the last 6 years 
(2007-2012) of the assessment period, after sus¬ 
tained overfishing that had been happening 
since the mid-1970s. In the previous assessment 
conducted in 2004, the population was found to 
be both overfished and undergoing overfishing 
(SEDAR, 2004). 
Age and growth 
The results of this study indicate that there 
were noticeable differences in both size and age 
distributions over time. Results of our analy¬ 
ses indicate that the population has responded 
more quickly size-wise than age-wise. Density 
plots of size during each period show a substan¬ 
tial shift to smaller individuals (<500 mm TL) 
from the 1980s to the 1990s, with a lower num¬ 
ber of larger individuals (>800 mm TL) during 
the 1990s (Fig. 2A). However, data from the 
2000s reveal a symmetrical bell-shaped curve 
that encompasses both smaller and larger 
individuals. A population in which all size 
classes are represented would be better able to 
respond to factors that influence survivorship 
and recruitment, and the snowy grouper pop¬ 
ulation is trending in that direction. The age 
distributions are not as encouraging. The num¬ 
ber of older individuals (> 10 years) decreased 
dramatically in the population from the 1980s 
to the 1990s. In addition, although there was a slight 
increase in the proportion of older individuals from the 
1990s to the 2000s, the low number of older individu¬ 
als is of concern (Fig. 2B). A higher proportion of older 
