Lowerre-Barbieri et al.: A comparison of otolith and scale ageing methods for Cynoscion regalis 567 



can result in underestimates of longevity, overesti- 

 mates of mortality, inaccurate growth calculations, 

 and improper modelling and management decisions 

 (Beamish and McFarlane, 1983). Similarly, current 

 estimates of weakfish growth, longevity, and mor- 

 tality may need to be reevaluated, as suggested by 

 our findings that scales underage older fish and have 

 crowded annuli past age 6. The need for this reevalu- 

 ation is underscored by the recording of a 17-year- 

 old, as aged by otoliths, which was previously aged 

 as a 7-year-old by scales (Lowerre-Barbieri 3 ). 



Acknowledgments 



We would like to thank the Chesapeake Bay com- 

 mercial fishermen, James Owens, and the people at 

 the Delaware Weakfish Sport Fishing Tournament 

 for helping us obtain samples. Richard Seagraves 

 provided us with information on the Delaware fish- 

 ery as well as otolith samples. Steve Bobko and 

 Donna Kline helped with the processing and origi- 

 nal analysis of the four hardparts. We would like to 

 thank J. M. Casselman, Luiz R. R. Barbieri, and an 

 anonymous reviewer for their helpful suggestions to 

 improve the manuscript. Financial support was pro- 

 vided by the College of William and Mary, Virginia 

 Institute of Marine Science, by Old Dominion Uni- 

 versity, Applied Marine Research Laboratory, and by 

 a Wallop/Breaux Program Grant from the U.S. Fish 

 and Wildlife Service through the Virginia Marine 

 Resources Commission for Sport Fish Restoration, 

 Project No. F-88-R3. 



Literature cited 



Bagenal, T. B., and F. W. Tesch. 



1978. Age and growth. In T, B. Bagenal (ed.). 

 Methods for assessment offish production in fresh 

 waters, 3rd ed.. p. 101-136. Blackwell Scientific 

 Pubis., Oxford. 

 Barbieri, L. R., M. E. Chittenden Jr., and 

 C. M. Jones. 



1994. Age, growth, and mortality of Atlantic croaker, 



Micropogonias undulatus, in the Chesapeake Bay 



region, with a discussion of apparent geographic 



changes in population dynamics. Fish. Bull. 92:1-12. 



Barnes, M. A., and G. Power. 



1984. A comparison of otolith and scale ages for 

 western Labrador lake whitefish (Coregonus clu- 

 peaformis). Env. Biol. Fish. 10:297-299. 



1 Lowerre-Barbieri, S. K. 1993. Age and growth of weakfish, 

 Cynoscion regalis, in the Chesapeake Bay region. School of Ma- 

 rine Science, VIMS, College of William and Mary, unpubl. manuscr. 



Beamish, R. J. 



1979. Differences in the age of Pacific hake (Mer- 

 luccius product us ) using whole otoliths and sections 

 of otoliths. J. Fish. Res. Board Can. 36:141-151. 

 Beamish, R. J., and D. E. Chilton. 



1981. Preliminary evaluation of a method to deter- 

 mine the age of sablefish iAnoplopoma fimbria). 

 Can. J. Fish. Aquat. Sci. 39:277-287. 

 Beamish, R. J., and G. A. McFarlane. 



1983. The forgotten requirement for age validation in 

 fisheries biology. Trans. Am. Fish. Soc. 112:735-743. 

 1987. Current trends in age determination metho- 

 dology. In R. C. Summerfelt and G. E. Hall (eds.), 

 Age and growth offish, p. 15-42. Iowa State Univ. 

 Press, Ames. 

 Beckman, D. W., A. L. Stanley, J. H. Render, and 

 C. A. Wilson. 



1990. Age and growth of black drum in Louisiana 

 waters of the Gulf of Mexico. Trans. Am. Fish. Soc. 

 119:537-544. 

 Bigelow, H. B., and W. C. Schroeder. 



1953. Fishes of the Gulf of Maine. U.S. Fish Wildl. 

 Serv. Fish Bull. 53:1-577. 

 Brothers, E. B. 



1983. Summary of round table discussions on age 

 validation. U.S. Dep. Commer., NOAA Tech. 

 Rep. NMFS 8:35-44. 

 Campana, S. E. 



1990. How reliable are growth back-calculations based 

 on otoliths? Can. J. Fish. Aquat. Sci. 47:2219-2227. 

 Casselman, J. M. 



1983. Age and growth assessment offish from their 

 calcified structures — techniques and tools. U.S. 

 Dep. Commer, NOAA Tech. Rep. NMFS 8:1-17. 

 1987. Determination of age and growth. In A. H. 

 Weatherley and H. S. Gill (eds.), The biology of fish 

 growth, p. 209-242. Academic Press, London. 

 1990. Growth and relative size of calcified structures 

 offish. Trans. Am. Fish. Soc. 119:673-688. 

 Criehton, M. I. 



1935. Scale resorption in salmon and sea 

 trout. Salm. Fish., Edinb. 4:1-8. 

 Draper, N. R., and H. Smith. 



1981. Applied regression analysis, 2nd ed. John 

 Wiley & Sons, New York, 709 p. 

 Francis, R. I. C. C. 



1990. Back-calculation of fish length: a critical 

 review. J. Fish Biol. 36:883-902. 

 Gallucci, V. F., and T. J. Quinn II. 



1979. Reparameterizing, fitting, and testing a 

 simple growth model. Trans. Am. Fish. Soc. 

 108:14-25. 

 Hyndes, G. A., N. R. Loneragan, and I. C. Potter. 



1992. Influence of sectioning otoliths on marginal 

 increment trends and age and growth estimates 

 for the flathead, Platycephalus speculator. Fish. 

 Bull. 90:276-284. 

 Joseph, E. B. 



1972. The status of the sciaenid stocks of the middle- 

 Atlantic coast. Chesapeake Sci. 13:87-100. 



