Abstract. Weakfish, Cynoscion 



regalis, were collected in 1989-93 from 

 commercial catches in the Chesapeake 

 Bay region, and special collections of 

 large fish were made in Delaware Bay. 

 Ages were based on sectioned otoliths. 

 Most weakfish were 200-600 mm TL 

 and ages 1-4 years. Maximum age was 

 17 years from a 1985 Delaware Bay 

 fish. Maximum current observed ages 

 were 12 years in Chesapeake Bay and 

 11 years in Delaware Bay. However, fish 

 older than age 6 were rare in both ar- 

 eas. There was no evidence that Dela- 

 ware Bay fish reached a larger maxi- 

 mum size or maximum age than Chesa- 

 peake Bay fish. Although weakfish size 

 was a poor predictor of age, weakfish 

 growth was well described by the von 

 Bertalanffy growth model (r 2 =0.98, 

 rc=854). Maximum size and age has 

 fluctuated in both Chesapeake and 

 Delaware Bays over the past thirty 

 years. In both areas the maximum size 

 of fish, based on citation records, 

 greatly increased from the late 1960s 

 until the mid-1980s, as did the num- 

 bers of these large fish. These fluctua- 

 tions appear to be due to a series of 

 strong year classes, beginning in the 

 late 1960s. 



Age and growth of weakfish, 

 Cynoscion regalis, in the 

 Chesapeake Bay region with 

 a discussion of historical 

 changes in maximum size* 



Susan K. Lowerre-Barbieri** 

 Mark E. Chittenden Jr. 

 Luiz R. Barbierf * 



Virginia Institute of Marine Science 

 College of William and Mary 

 Gloucester Point, Virginia 23062 



Manuscript accepted 10 May 1995. 

 Fishery Bulletin 93:643-656 ( 1995). 



The weakfish, Cynoscion regalis, is 

 a recreationally and commercially 

 important sciaenid which ranges 

 from eastern Florida to Massachu- 

 setts but is most abundant from 

 North Carolina to New York (Mer- 

 cer, 1985). Although believed to be 

 resident year-round in the Caroli- 

 nas, weakfish occur farther north 

 only seasonally ( Bigelow and Schroe- 

 der, 1953). In the spring, weakfish mi- 

 grate northward and inshore to es- 

 tuarine feeding and spawning 

 grounds; this pattern is reversed in 

 the fall (Wilk, 1979), and most fish 

 are believed to overwinter off North 

 Carolina (Pearson, 1932). Weakfish 

 occur in Chesapeake Bay, roughly 

 from April through November (Pear- 

 son, 1941; Massmann et al., 1958), 

 where they support one of the 

 region's most important fisheries 

 (Rothschild et al., 1981). 



Although weakfish have been 

 important in Atlantic coast fisher- 

 ies since the 1800's (Mercer, 1985), 

 weakfish landings have fluctuated 

 widely. Changes in maximum size 

 and age have occurred concurrently 

 with fluctuations in presumed 

 abundance (Massmann, 1963; Jo- 

 seph, 1972; Feldheim, 1975; Villoso, 

 1989). For example, in Chesapeake 

 Bay, the largest reported weakfish 



was 16 lb (7.3 kg) in 1921 (Hilde- 

 brand and Schroeder, 1928). How- 

 ever, by the mid-1950's, when land- 

 ings were low, mean size decreased 

 and few fish weighed more than 2 

 lb (0.91 kg) (Massmann, 1963). 

 Large fish again became common in 

 Chesapeake Bay as the fishery re- 

 covered in the 1970's and early 

 1980s; a 19-lb (8.6 kg) weakfish was 

 caught in Chesapeake Bay in 1983 

 (Mercer, 1985). 



It is necessary to understand age 

 structure and growth, and how they 

 vary regionally and temporally, in 

 order to gain insight into the causes 

 of historical fluctuations in weak- 

 fish landings and abundance. Al- 

 though there have been many stud- 

 ies on weakfish age and growth 'e.g. 

 Taylor, 1916; Nesbit, 1954; Perl- 

 mutter et al., 1956; Massmann, 

 1963; Merriner, 1973; Feldheim, 

 1975; Seagraves, 1981; Shepherd 

 and Grimes, 1983; Hawkins, 1988), 

 all have been based on scales which 

 underage older fish of many species 

 (Beamish and McFarlane, 1987), 



'Contribution 1952 from the School of Ma- 

 rine Science, Virginia Institute of Marine 

 Science, The College of William and Mary, 

 Gloucester Point, VA 23062. 

 "Present address: University of Georgia 

 Marine Institute, Sapelo Island, GA 31327. 



643 



