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Fishery Bulletin 96(3), 1998 
validated ages from 44 to 59 years, we have found 
(see above) that black drum otoliths satisfy the cri- 
teria of Van Oosten (1929) for annuli: the number of 
rings increased with mean size, rings were consis- 
tently located on otoliths of different putative ages, 
and otolith radii correlated highly with putative age. 
Although we did not evaluate scales because of 
their problematic use in ageing, we believe there is 
direct evidence that they underestimate black drum 
age in the Chesapeake Bay region. Beamish and 
McFarlane ( 1983) documented the tendency of scales 
to underestimate age, especially at older ages. 
Richards (1973) and Desfosse (1987) estimated maxi- 
mum ages for Chesapeake Bay region black drum of 
only 35 and 10 yr, respectively, using scales. Consid- 
ering that size composition has not changed over the 
intervening years (Desfosse, 1987; Hutchinson and 
Rogers 2 * ), these ages are much younger than we ob- 
served. Richards should have seen maximum ages 
of at least 41, Desfosse at least 57. We therefore ar- 
gue against using scales for ageing black drum. 
Implications of age structure 
Although we had only three years of data, the long 
lives of black drum allowed our collections to repre- 
sent a history of recruitment of over 50 years — as 
was the case with Pereira et al. (1995) for freshwa- 
ter drum ,Aplodinotus grunniens. Our data show that 
recruitment of black drum from the Chesapeake Bay 
region generally appears to be low, with only occa- 
sional strong year classes that persist for many years, 
for example the 1934 and 1942 cohorts. Moreover, 
low average recruitment is anticipated for a species 
with a long reproductive lifespan (20 years at the 
age of capture), high batch fecundity (1-14 million 
eggs), and several batches in a spawning season 
(Wells, 1994), especially when the population remains 
at low abundance throughout the years. 
Our recruitment history of black drum also showed 
an absence of fish ages 1 to 5, which is consistent 
since at least the 1960s. There are several possible 
causes: 1) low abundance of black drum young that 
is hard to measure, 2) recent complete recruitment 
failure, 3) gear specificity, and 4) migration south- 
ward during this life stage and later northward mi- 
gration. We review the evidence in support of these 
alternatives briefly. 
Given its demography, this stock should have a low 
survival rate during the early life stages that is dif- 
ficult to distinguish from zero. Black drum’s poten- 
tial lifetime production of 60-840 million eggs requires 
2 Hutchinson R., and C. Rogers. 1969. Salt water fishing in 
Virginia. Dep. Conserv. and Econ. Devel., Richmond, VA, 41 p. 
mortalities of at least 10 6 or 10 7 during larval and ju- 
venile stages to maintain stable populations. Hence, 
the high mortality seen in the field (Cowan et al., 1992) 
is predictable and is difficult, if not impossible, to dif- 
ferentiate from 100% in the field during early life. 
The absence of several year classes in the catch of 
a fishery could also signify complete recruitment fail- 
ure. Yet indirect evidence does not support this 
throughout the east coast range. Frisbie ( 1961 ) noted 
the virtual absence of young black drum in the bay 
and Richards ( 1973) stated that “black drum of more 
than 220 to less than 800 mm in length were not readily 
available . . .”. These observations correspond to cohorts 
from the late 1950s and 1960s which, seen retrospec- 
tively in modern catches, showed normal recruitment 
levels. Even though fish of the expected size of 1-5 
year-olds are not typically seen in the bay, these young 
fish are not missing from the entire geographic range. 
Fish ages of l—k years are found in bycatch from north- 
east Florida (Murphy and Taylor, 1989). Hence, exami- 
nation of the catch argues against complete recruit- 
ment failure throughout the stock’s range. 
Fishing gear and practices used for black drum in 
Chesapeake Bay target large fish and may exclude 
small fish. The commercial fishery uses anchored and 
drifted gill nets with 33-cm stretch mesh, which al- 
low smaller fish to escape. Likewise, recreational 
anglers use hooks that target large fish. Hence, we 
can explain some of the absence of smaller fish by 
gear selectivity in the directed fishery. However, if 
these fish were present in the bay, we would expect 
to see them in other fisheries, but fishermen have 
told us that they have never seen these fish in their 
gear — gear such as pound nets and gill nets of 7.6- 
15.2 cm (3-6 inch) stretch mesh that would retain 
these smaller sizes. 
Perhaps the strongest alternative explanation for 
missing 1-5 year-olds lies in the migratory patterns 
seen in many sciaenids. Specifically, black drum un- 
dergo long-range migration along the coasts of the 
southeast states. Although black drum have been 
noted as far north as Canada (Welsh and Breder, 
1923; Silverman, 1979), they occur more commonly 
from Delaware south to Florida. Even in the Chesa- 
peake Bay, however, black drum are not resident year 
round. Frisbie (1961) suggested a southward migra- 
tion of young fish from Chesapeake Bay in the fall, 
and the same pattern of fall emigration of juveniles 
has been shown for Delaware Bay (Thomas and 
Smith, 1973). Thereafter, only larger and older fish 
migrate into the bay in the spring — with few younger 
than six years. In contrast with the Chesapeake Bay 
pattern, Murphy and Taylor (1989) found that only 
20% of their sample from Florida included fish older 
than age four. Our adult catch data could be ex- 
