AGE, GROWTH, AND MORTALITY OF SPOTTED SEA-TROUT IN FLORIDA WATERS

Estimates of age, growth, and mortality of spotted seatrout Cynoscion nebulosus were made by analyzing fish from commercial and recreational catches in 1986-1988 in three estuarine areas of Florida: Apalachicol a Bay, Charlotte Harbor, and Indian RiVeT Lagoon. Thin sections of sag ittae were used to determine age; annulus formation occurred in Novemb er-May. The maximum observed age differed among areas, ranging from 5 to 9 years for males and from 6 to 8 years for females. Spotted seatro ut reached 301-337 mm total length at the end of their first year. Fem ales were generally larger at age than males, although growth was high ly variable. After age 1, male growth slowed to an average of 34-51 mm /year and was modeled best by area-specific linear growth equations. F emales showed asymptotic growth that slowed from 87-107 mm at ages 1-2 to 46-60 mm at ages 4-5 and that was modeled best by area-specific Go mpertz growth equations. Males and females from Indian River Lagoon an d Apalachicola Bay were generally larger than those from Charlotte Har bor. Males were heavier than females of the same length. Estimates of total annual mortality were 48-76% in 1986-1988 and seemed highest in Apalachicola Bay. Patterns of growth did not reflect those previously used to support hypothesized divisions of spotted seatrout into separa te subpopulations in Florida estuaries. Differences in growth and age composition observed among estuaries may reflect differences in enviro nmental and fishing effects rather than genetic differentiation among estuaries.