Age, growth, and mortality of gray snapper, Lutjanus griseus, from the east coast of Florida

Gray snapper, Lutjanus griseus, were sampled from recreational headboat and commercial landings along the east coast of Florida, 1994-97. Fish were we ighed (g) and measured (total Length, Ttl in nlm): and sagittal otoliths we re removed for aging. Marginal increment analysis on sectioned otoliths (n= 1243) confirmed annulus formation in June and July: The oldest fish examine d was 24 years old and measured 760 mm TL. Weight-length relations were not significantly different by sex. Weight-length relations were significantly different (F=39.198. P < 0.001, df=10,705) for fish measured from the head boat survey from 1982-97 between north Florida (W=8.4 x 10(-9) x TL3.08, n= 4034) and south Florida (W=5.45 x 10(-9) x TL3 15, n=6670), where W = total weight (kg). The TL-otolith radius (OR) relationships were described by th e following equations: TL = (10.02 x OR) - 52.98 (r(2) = 0.90, n=519, north Florida), and TL = (9.90 x OR)- 91.68 (r(2) = 0.78, n=724, south Florida). Mean lengths at age from back-calculations to the last annulus ranged from 121 mm at the end of age 1 to 740 mm at age 24 for north Florida, and 227 mm at age 2 to 495 mm at age 15 For south Florida. The von Bertalanffy grow th equations were L-t = 717 x (1-e ' (-0.17 mu + 0.025 eta)) for north Flor ida and L-t = 625 x (1 - e ' (-0.13 mu + 1.33 eta)) for south Florida. Esti mates of M ranged from 0.14 to 0.43 for north Florida and from 0.29 to 0.38 for south Florida. Estimates of Z averaged 0.34 for north Florida and 0.95 for south Florida. Recruitment to the fisheries occurred between ages 5 an d 8 for north Florida and ages 4 and 5 for south Florida. Estimates off for gray snapper by area were 0.16 for north Florida and 0.66 for south Florid a.