Cs. Manooch et Jc. Potts, AGE, GROWTH, AND MORTALITY OF GREATER AMBERJACK, SERIOLA-DUMERILI, FROM THE US GULF-OF-MEXICO HEADBOAT FISHERY, Bulletin of marine science, 61(3), 1997, pp. 671-683
Sectioned otoliths (saggitae) from 340 greater amberjack, Seriola dume
rili, 305-1512 mm total length (270-1355 mm fork length) were examined
. The fish were sampled from recreational headboats operating in the G
ulf of Mexico from Naples, Florida, to Port Aransas, Texas, from 1988
to 1993, and therefore, best represent age and growth of the species a
s harvested by this fishery. Most (53%) of the fish were landed in Tex
as, but others came from northwest Florida and Alabama (46%) and Louis
iana (1%). The oldest fish was estimated to be age 15 and measured 151
2 mm total length (1355 mm fork length). Rings formed on most otoliths
between March and May, and are thus considered to be true annual mark
s. Back-calculated mean total lengths for 225 fish were 415, 614, 742,
839, 915, 976, 1044, 1100, 1156, 1209, 1256, 1283, 1299, 1332, and 13
65 mm for ages 1 through 15, respectively. Equations were derived to c
onvert lengths: FL = -17.7319 + 0.8847(TL), and TL = 24.2327 + 1.1247(
FL). Back-calculated lengths at age were used to derive the following
von Bertalanffy growth equations: TLt = 1272 (1-e(-0.2272(t+0.7931))),
and FLt = 1109 (1-e(-0.2270(t+0.7198))). Greater amberjack are fully
recruited to the headboat fishery in the Gulf of Mexico at age 4. Tota
l instantaneous mortality estimates (Z) generated from catch curves of
the Gulf of Mexico headboat fishery were 0.68 for 1988 and 0.70 for 1
993.