637 
Abstract.-The effect of different 
fishing mortality (F) and natural mor- 
tality (M), and age at first capture (t c ) 
on yield-per- recruit of Atlantic croaker, 
Micropogonias undulatus, in the lower 
Chesapeake Bay and North Carolina 
were evaluated with the Beverton-Holt 
model. Independent of the level of M 
(0.20-0.35) or F (0.01-2.0) used in 
simulations, yield-per-recruit values for 
Chesapeake Bay were consistently 
higher at t c = 1 and decreased continu- 
ously with increases in t c (2-5). Al- 
though maximum yield-per-recruit al- 
ways occurred at the maximum level 
ofF(F=2.0), marginal increases in yield 
beyond F = 0.50-0.75 were negligible. 
Current F ( F CUR ) is estimated to be be- 
low the level that produces maximum 
potential yield-per-recruit ( F MAX ) and 
at or below the level of F 0 x if M > 0.25. 
Although modeling results indicated 
yield-per-recruit could be maximized by 
reducing the current level of t c (t c = 2), 
the resultant gains were small and did 
not appear to justify such management 
measures. Instead, it is suggested that 
regulatory measures be directed at 
maintaining the current level of t c in 
the lower Chesapeake Bay. Simulation 
results for North Carolina showed a 
pattern opposite to that shown for 
Chesapeake Bay, with yield-per-recruit 
curves increasing consistently with in- 
creases in t c . Estimates of F CUR for t c = 1 
were consistently higher than F 0 l as 
well as F max , indicating that during the 
period 1979-81 Atlantic croaker were 
being growth-overfished in North Caro- 
lina. However, differences between 
Chesapeake Bay and North Carolina 
seem to reflect temporal rather than 
spatial differences in Atlantic croaker 
population dynamics, because data for 
North Carolina came from a period co- 
inciding with the occurrence of unusu- 
ally large Atlantic croaker along the 
east coast of the United States. 
Manuscript accepted 11 March 1997. 
Fishery Bulletin 95:637-645 (1997). 
Yield-per-recruit analysis and 
management strategies for Atlantic 
croaker, Micropogonias undulatus, 
in the Middle Atlantic Bight* 
Luiz R. Barbieri** 
Mark E. Chittenden Jr. 
Virginia Institute of Marine Science 
School of Marine Science 
The College of William and Mary 
Gloucester Point, Virginia 23062 
**Present address: University of Georgia Marine Institute 
Sapelo Island, Georgia 31327 
E-mail address: Barbieris@msn.com 
Cynthia M. Jones 
Applied Marine Research Laboratory 
Old Dominion University 
Norfolk, Virginia 23529 
The Atlantic croaker, Micropogonias 
undulatus (Linnaeus), is one of the 
most important commercial and rec- 
reational fishery resources of the 
southeastern coast of the United 
States (Wilk, 1981; Schmied and 
Burgess, 1987; Mercer * 1 ). Along the 
Atlantic coast, commercial fisheries 
for Atlantic croaker are centered in 
Chesapeake Bay and in North Caro- 
lina waters (Joseph, 1972; Roths- 
child et al., 1981; Ross, 1988; Mer- 
cer 1 ); both inshore and offshore 
catches are distributed according to 
the seasonal migratory patterns of 
Atlantic croaker. From late spring 
to early fall Atlantic croaker are 
caught in estuarine areas, primarily 
by haul-seine, pound-net, and gill- 
net fisheries (Ross, 1988; Chitten- 
den, 1991; Barbieri et al., 1994a). 
From late fall through winter, after 
adults have moved out of estuaries, 
they are caught in continental shelf 
waters by otter-trawl and gill-net 
fisheries (Wilk, 1981; Ross, 1988; 
Mercer 1 ). 
Commercial landings of Atlantic 
croaker have fluctuated widely over 
the past 50-60 years (Joseph, 1972; 
Rothschild et al., 1981; Wilk, 1981). 
Landings exceeded 20,000 metric 
tons (t) between 1937 and 1940, 
peaked at ca. 29,000 t in 1945 and 
dropped to less than 1,000 1 between 
1967 and 1971 (Wilk, 1981; McHugh 
and Conover, 1986). The most re- 
cent peak in landings occurred in 
1977 and 1978 at just over 13,000 t 
annually (Mercer 1 ). Recreational 
catches in the mid-Atlantic and 
South Atlantic regions during 1979- 
93 have also fluctuated, although 
they do not reflect fluctuations in 
commercial landings for the same 
period. Commercial landings from 
Virginia and North Carolina— the 
* Contribution 2057 from Virginia Institute 
of Marine Science, School of Marine Sci- 
ence, College of William and Mary, Glouce- 
ster Point, Virginia 23062. 
1 Mercer, L. P. 1987. Fishery manage- 
ment plan for Atlantic croaker ( Micro- 
pogonias undulatus). North Carolina 
Dep. Nat. Res. Comm. Dev., Div. Mar. 
Fish., Spec. Sci. Rep. 48, 90 p. [Available 
from North Carolina Department of Envi- 
ronment, Health, and Natural Resources, 
Div. Marine Fisheries, PO Box 769, 
Morehead City, NC 28557-0769.] 
