Abstract. — Atlantic croaker, 

 Micropogonias undulatus, col- 

 lected from commercial catches in 

 Chesapeake Bay and in Virginia 

 and North Carolina coastal waters 

 during 1988-1991 (n = l,967) were 

 aged from transverse otolith sec- 

 tions. Ages 1-8 were recorded, but 

 eight-year-old fish were rare. Mar- 

 ginal increment analysis showed 

 that for ages 1-7, annuli are 

 formed once a year during the pe- 

 riod April-May. Otolith age read- 

 ings were precise: >99% agree- 

 ment within and between readers. 

 Observed lengths-at-age were 

 highly variable and growth rate 

 decreased after the first year. De- 

 spite the high variability in sizes- 

 at-age, observed lengths for ages 

 1-7 fit the von Bertalanffy growth 

 model (r 2 =0.99; n=753) well. No 

 differences in growth were found 

 between sexes. Total annual in- 

 stantaneous mortality (Z) esti- 

 mated from maximum age and 

 from a catch curve of Chesapeake 

 Bay commercial catches ranged 

 from 0.55 to 0.63. Our results do 

 not indicate the existence of a 

 group of larger, older Atlantic 

 croaker in Chesapeake Bay com- 

 pared with more southern waters 

 and suggest that the hypothesis of 

 a basically different population 

 dynamics pattern for this species 

 north and south of Cape Hatteras, 

 North Carolina, should be reevalu- 

 ated. 



Age, growth, and mortality of 

 Atlantic croaker, Micropogonias 

 undulatus, in the Chesapeake Bay 

 region, with a discussion of 

 apparent geographic changes \n 

 population dynamics* 



Luiz R. Barbieri 



College of William and Mary, Virginia Institute of Marine Science 

 Gloucester Point. Virginia 23062 



Present address: University of Georgia Marine Institute 



Sapelo Island. Georgia 31327 



Mark E. Chittenden Jr. 



College of William and Mary, Virginia Institute of Marine Science 

 Gloucester Point, Virginia 23062 



Cynthia M. Jones 



Old Dominion University. Applied Marine Research LaPoratory 

 Norfolk, Virginia 23529 



Manuscript accepted 12 August 1993 

 Fishery Bulletin 92:1-12 (1994) 



The Atlantic croaker, Micropo- 

 gonias undulatus (Linnaeus), is 

 one of the most abundant inshore 

 demersal fishes along the Atlantic 

 and Gulf of Mexico coasts of the 

 United States (Joseph, 1972). Al- 

 though recent commercial and rec- 

 reational catches have come prima- 

 rily from the South Atlantic Bight 

 and the Gulf of Mexico, Atlantic 

 croaker still support important 

 fisheries along the Mid-Atlantic 

 coast, especially from Maryland to 

 North Carolina (Wilk, 1981). In 

 Chesapeake Bay, they are caught 

 by commercial and recreational 

 fishermen during late spring and 

 early fall migrations and, to a 

 lesser extent, during the summer. 

 In winter, Atlantic croaker leave 

 the Bay to overwinter off the coast 

 of Virginia and North Carolina, 

 where they are caught by otter 

 trawl and gillnet fisheries (Haven, 

 1959). 



Little is known about age, 

 growth, and mortality of Atlantic 



croaker in the Middle Atlantic and 

 Chesapeake Bay regions. Studies 

 based on length frequencies (Ha- 

 ven, 1957; Chao and Musick, 1977) 

 require considerable subjective in- 

 terpretation given the extended 

 spawning period of Atlantic croaker 

 (Morse, 1980; Warlen, 1982; Bar- 

 bieri et al., unpubl. ms.) and the 

 difficulty in distinguishing modal 

 groups at older ages (White and 

 Chittenden, 1977; Jearld, 1983). Al- 

 though scale-ageing has also been 

 used (Welsh and Breder, 1923; 

 Wallace, 1940; Ross 1988), prob- 

 lems in applying this method to 

 Atlantic croaker have been widely 

 reported (Roithmayr, 1965; Joseph, 

 1972; Barger and Johnson, 1980; 

 Barbieri, 1993). 



In this study we provide informa- 

 tion on age, growth, and mortality 

 of Atlantic croaker in the Chesa- 



* Contribution No. 1806 from the College of 

 William and Mary, School of Marine Sci- 

 ence/Virginia Institute of Marine Science, 

 Gloucester Point, Virginia 23062 



