30 
Fishery Bulletin 109(1 ) 
for Azores red bream, and this is probably due to a 
lack of specimens younger than 8 years in the present 
study, resulting in a less accurate estimation of the 
initial slope of the VBGF. We cannot say with certainty 
whether the observed differences of growth parameters 
are driven by differences in population dynamics or 
missing age groups in the analysis. 
We found that male red bream were more abundant 
than females at smaller sizes but females predominated 
in the higher size classes. In previous studies on splen- 
did alfonsino from the eastern North Atlantic, similar 
size distribution differences between the sexes were 
reported. This differential size and sex relationship was 
attributed to findings of slower growth in males and 
a distribution shift to greater depths with increasing 
size for this species which would result in skewed sex 
ratios when sampling over small depth ranges (Massey 
and Horn, 1990; Lehodey et ah, 1994; Lehodey et al., 
1997). We did not detect a difference in growth rates 
between male and female red bream, but the observed 
size frequency pattern and the lack of significance in 
growth rate differences from this study could be due to 
small sample sizes and low aging precision. 
Spawning seasonality 
All red bream specimens sampled from the Charleston 
Bump between 2003 and 2008 were sexually mature. 
These findings are in sharp contrast to maturity stages 
observed in the eastern North Atlantic, where the vast 
majority of specimens were immature, resting, or devel- 
oping (Isidro, 1996). This is not surprising, given the 
observed differences in red bream size ranges between 
the eastern and western North Atlantic. Isidro (1996) 
reported a length at 50% maturity of 276 mm FL for 
females, which is well below the size of the smallest 
female observed in this study (420 mm FL). Isidro 
did not detect population-level spawning aggregations 
around the Azores and observed only very few females 
in spawning condition. In addition, he reported that the 
ovaries of the few spawning females that he observed 
contained only small numbers of hydrated oocytes, 
whereas all other oocytes were in previtellogenic condi- 
tion, and therefore he concluded that only one batch of 
oocytes developed at a time. The ovaries of Charleston 
Bump females, however, contained oocytes in nearly all 
stages of development during the spawning season, indi- 
cating that several clutches of oocytes develop simulta- 
neously. Male red bream on the Charleston Bump seem 
to be spawning year-round, but sample sizes for males 
were very low for some months in our study, and no data 
were available for February, March, or October. More 
samples need to be collected before any conclusive state- 
ments about the seasonality of male spawning activity 
on the Charleston Bump can be made. 
Implications for fishery management 
Red bream landings in the southeastern United States 
are presently not monitored, and the species is not under 
federal management because it is currently caught only 
in very small numbers as bycatch in the wreckfish fish- 
ery. In 2007, the Charleston Bump was the only area 
with reported wreckfish landings in the southeastern 
United States, and only one vessel participated in the 
fishery (J. McGovern, personal commun. 2 ). U.S. red 
bream landings are so few that the population can prob- 
ably be considered to be at near-virgin biomass levels. 
This means that natural mortality (M) can be directly 
estimated from Hoenig’s total mortality equation and 
the algorithm in IGOR+, because Z approximates M 
in unfished populations. Natural mortality estimates 
are important input parameters for stock assessment 
models and are also commonly used in calculating refer- 
ence points for fishery management, such as minimum 
stock size threshold (the biomass level below which a 
stock would be considered overfished) and proxies for 
fishing mortality rates that would produce maximum 
sustainable yield. 
Underestimating the maximum age of a species, and 
thereby M, can bias stock assessment results and pro- 
ductivity estimates of a fish stock. Hoenig’s estimate 
of natural mortality for red bream is 0.06/yr when the 
highest estimated age from band counts of sectioned 
otoliths, 69 years, is used as t max . This value is in per- 
fect agreement with the IGOR+ catch-curve-based esti- 
mate of Z. If the bomb radiocarbon-validated minimum 
longevity estimate of 49 years is used for t max , M be- 
comes 0.094/yr, which is still less than half the value 
one would obtain by using the previous t max estimate 
of 15 years (M= 0.279). Estimates of natural mortality 
based on life history parameters according to the equa- 
tion of Pauly tended to be higher (0. 097-0. 124/yr) than 
longevity-based estimates of M but were very sensitive 
to the choice of mean annual temperature, which can 
be quite variable on bottom habitat of the Charleston 
Bump. It has been suggested that Pauly’s equation 
overestimates the natural mortality of long-lived fishes 
because relatively few representatives with high lon- 
gevity were included in the data set used by Pauly to 
derive the empirical equation (Newman et al., 2000). 
In contrast, Hoenig’s data set included a wide range 
of long-lived species, and estimates based on Hoenig’s 
equation have been shown to result in natural mortality 
rates similar to those derived from catch curves. This 
was indeed the case for red bream, where IGOR+ esti- 
mated the same M as Hoenig’s equation based on a t max 
of 69 years. We therefore suggest that 0.06/yr should be 
regarded as the current best estimate of natural mor- 
tality for the southeastern U.S. red bream population. 
This study has shown that red bream are slow grow- 
ing and exhibit an exceptional life-span, resulting in 
a very low natural mortality rate. Therefore, fisher- 
ies targeting this stock may be sustainable only at 
low exploitation rates. Other slow-growing, long-lived 
deep-water species that have been targeted by fisher- 
ies in the southeastern United States have already 
2 McGovern, Jack. 2008. NOAA Fisheries Southeast Regional 
Office, Saint Petersburg, FL 33701. 
