Kupchik and Shaw: Age, growth, and recruitment of larval and early juvenile Micropogonias undulatus 
31 
in the fall than in the spring. The observed differences 
in growth rates between the fall spawning and recruit- 
ment season and the spring recruitment season provide 
evidence of spawning subgroups for the first time in 
the northern GOM — a finding that is similar to growth 
rates of the subgroups that have been found in North 
Carolina waters and in the MAB. This result was con- 
firmed by the differences in otolith microstructure be- 
tween the fall and spring for both sampling years, and 
the microstructure analysis was able to show within- 
year variability in batch spawning — a variability that 
would produce different cohorts with variable distances 
from offshore spawning grounds to inshore recruitment 
corridors. The highly significant salinity component in 
the mixed model that revealed a relationship between 
growth rate and the hydrodynamics in Bayou Tartel- 
lan gave evidence of the importance of the low salinity 
and high productivity of estuarine waters for maximiz- 
ing growth for larval and, ultimately, juvenile Atlantic 
croaker. 
Acknowledgments 
We are grateful for funding under award 
NA06OAR4320264 06111039 to the Northern Gulf In- 
stitute by NOAA’s Office of Ocean and Atmospheric 
Research, NGI Project File No. 07-NOAA-07. We also 
thank R. Nero, C. Li, and B. Marx for their help with 
and suggestions for our research. Finally, we thank 
support from T. Farooqi, A. Armas, and W. Delaune. 
Literature cited 
Albuquerque, C. Q., J. H. Muelbert, and L. A. N. Sampaio. 
2009. Early developmental aspects and validation of daily 
growth increments in otoliths of Micropogonias furnieri 
(Pisces, Sciaenidae) larvae reared in laboratory. Pan.- 
Am. J. Aquat. Sci. 4:259-266. 
Able, K. W. 
2005. A re-examination of fish estuarine dependence: evi- 
dence for connectivity between estuarine and ocean habi- 
tats. Estuar. Coast. Shelf Sci. 64:5-17. 
Barbieri, L. R., M. E. Chittenden Jr., and S. K. Lowerre-Barbieri. 
1994a. Maturity, spawning, and ovarian cycle of Atlantic 
croaker, Micropogonias undulatus, in the Chesapeake 
Bay and adjacent coastal waters. Pish. Bull. 92:671-685. 
Barbieri, L. R., M. E. Chittenden Jr., and C. M. Jones. 
1994b. Age, growth, and mortality of Altantic croaker, Mi- 
cropogonias undulatus, in the Chesapeake Bay region, 
with a discussion of apparent geographic changes in 
population dynamics. Fish. Bull. 92:1-12. 
Brophy, D., and B. S. Danilowicz. 
2002. Tracing populations of Atlantic herring (Clupea 
harengus L.) in the Irish and Celtic Seas using otolith 
microstructure. ICES J. Mar. Sci. 59:1305-1313. 
Brothers, E. B. 
1984. Otolith studies. In Ontogeny and systematics of 
fishes. Based on an International Symposium dedicated 
to the memory of Elbert Halvor Ahlstrom Spec. Publ. 1; 
La Jolla, CA, 15-18 August 1983 (H. G. Moser, W. J. Rich- 
ards, D. M. Cohen, M. P. Fahay, A.W. Kendall Jr., and S. 
L. Richardson, eds.), p. 50—57. Am. Soc. Ichthyol. Her- 
petol., Lawrence, KS. 
Butler, J. L. 
1992. Collection and preservation of material for otolith 
analysis. In Otolith microstructure examination and 
analysis (D. K. Stevenson and S. E. Campana, eds.), p. 
13-17. Can. Spec. Publ. Fish. Aquat. Sci. 117. 
Campana, S. E. 
1984. Interactive effects of age and environmental modi- 
fiers on the production of daily growth increments in oto- 
liths of plainfin midshipman, Porichthys notatus. Fish. 
Bull. 82:165-177. 
1992. Measurement and interpretation of the microstruc- 
ture of fish otoliths. In Otolith microstructure examina- 
tion and analysis (D. K. Stevenson and S. E. Campana, 
eds.), p.59-71. Can. Spec. Publ. Fish. Aquat. Sci. 117. 
1999. Chemistry and composition of fish otoliths: path- 
ways, mechanisms and applications. Mar. Ecol. Prog. 
Ser. 199:263-297. 
Campana, S. E., and S. R. Thorrold. 
2001. Otoliths, increments, and elements: keys to a com- 
prehensive understanding of fish populations? Can. J. 
Fish. Aquat. Sci. 58:30-38. 
Chambers, J. M., W. S., Cleveland, B. Kleiner, and P. A. Tukey. 
1983. Graphical methods for data analysis, 395 p. Wad- 
sworth, Belmont, CA. 
Chen, Y., D. A. Jackson, and H. H. Harvey. 
1992. A comparison of von Bertalanffy and polynomial 
functions in modelling fish growth data. Can. J. Fish. 
Aquat. Sci. 49:1228-1235. 
Cowan, J. H., Jr. 
1988. Age and growth of Atlantic croaker, Micropogonias 
undulatus, larvae collected in the coastal waters of the 
northern Gulf of Mexico as determined by increments in 
saccular otoliths. Bull. Mar. Sci. 42:349-357. 
Diamond, S. L., L. G. Cowell, and L. B. Crowder. 
2000. Population effects of shrimp trawl bycatch on Atlan- 
tic croaker. Can. J. Fish. Aquat. Sci. 57:2010-2021. 
Ditty, J. G., G. G. Zieske, and R. F. Shaw. 
1988. Seasonality and depth distribution of larval 
fishes in the northern Gulf of Mexico above latitude 
26°00 N. Fish. Bull. 86:811-823. 
Eby, L. A., L. B. Crowder, C. M. McClellan, C. H. Peterson, and 
M. J. Powers. 
2005. Habitat degradation from intermittent hypox- 
ia: impacts on demersal fishes. Mar. Ecol. Prog. Ser. 
291:249-261. 
Fahay, M. P. 
1983. Guide to the early stages of marine fishes occurring 
in the western North Atlantic Ocean, Cape Hatteras to 
the southern Scotian Shelf. J. Northwest Atl. Fish. Sci. 
4:3-423. 
Gompertz, B. 
1825. On the nature of the function expressive of the law 
of human mortality, and on a new mode of determining 
the value of life contingencies. Philos. Trans. R. Soc. 
Lond. 115:513-585. 
Hare, J. A., and K. W. Able. 
2007. Mechanistic links between climate and fisheries 
along the east coast of the United States: explaining 
population outbursts of Atlantic croaker (Micropogonias 
undulatus). Fish. Oceanogr. 16:31—45. 
Hare, J. A., and J. J. Govoni. 
2005. Comparison of average larval fish vertical distri- 
