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Fishery Bulletin 96(3), 1998 
growth at the Cedar Keys indicated an average in- 
crease of 4-5 cm/yr in carapace length. Growth rates 
of 6-9 cm/yr were obtained for Kemp’s ridley turtles 
at Cape Canaveral with the same data treatments 
(Schmid, 1995). The higher growth rates observed 
for east coast turtles are possibly due to measure- 
ment errors identified in the Cape Canaveral study. 
Error was minimized in the Cedar Key study because 
all measurements were determined by the author 
using the same equipment and techniques. Assum- 
ing a constant growth rate of 4-5 cm/yr, a Kemp’s 
ridley turtle would require 8-10 years to grow from 
a 20-cm postpelagic subadult (Ogren, 1989) to a 60- 
cm adult. An estimate of 10-12 years to maturity is 
calculated by combining the duration of the subadult 
stage with the estimated 2-year pelagic juvenile stage 
(Schmid and Ogren, 1990). This calculated age to 
sexual maturity is in agreement with Kemp’s ridley 
growth models computed from skeletochronological 
age estimates (Zug and Kalb, 1989; Zug, 1990) and 
the combination of recapture data for Cape Canaveral 
and Cedar Keys (Schmid and Witzell, 1997). 
The Kemp’s ridley turtle aggregation at the Cedar 
Keys was considered an open “population” with re- 
cruitment in terms of postpelagic turtles and sub- 
adult immigrants from other locations and with 
losses in terms of death and permanent emigration 
to other subadult or adult aggregations. Annual es- 
timates from the Jolly-Seber analysis were indica- 
tive of the catchable turtle population at Corrigan 
Reef within the months fished, which may or may 
not be representative of the entire aggregation in this 
area (Krebs, 1989). The relatively low number of re- 
captures, and corresponding low estimated capture 
probability, reduced the precision of the population 
estimates as evidenced by their high standard er- 
rors (Pollock et al., 1990). Nonetheless, general com- 
ments can be made concerning the estimates of re- 
cruitment and survival of Kemp’s ridley turtles in 
the Cedar Keys area. The majority of turtles cap- 
tured in this locality were mid- to late subadults; 
there were very few captures of postpelagic turtles. 
Therefore, provided that sampling bias due to the 
large-mesh nets was minimal, the high level of re- 
cruitment estimated from the Jolly-Seber analysis 
was presumably a result of immigration by larger 
subadult turtles. The low estimated survival rate was 
probably a function of emigration rather than high 
turtle mortality. However, there were no recaptures 
of turtles tagged at Cedar Key to indicate emigra- 
tion to other localities and there was no systematic 
sampling of turtle strandings to demonstrate the 
extent of mortality in this region. 
In conclusion, tagging studies conducted at the 
Cedar Keys are models for characterizing foraging 
populations of marine turtles and these efforts must 
be expanded to include regions not yet sampled in 
order to accurately manage these threatened and 
endangered species (Magnuson et al., 1990; Thomp- 
son et al., 1990; U.S. Fish and Wildlife Service and 
National Marine Fisheries Service, 1992). Areas 
where marine turtle congregate need to be identi- 
fied through anecdotal information, historical 
records, incidental captures, and stranding data. In- 
water sampling programs should be conducted over 
an extended period of time to establish the distribu- 
tion and abundance of turtles in areas of aggrega- 
tion. After implementing a mark-recapture study, 
supplementary research activities may include the 
following: holding turtles for fecal sample collection; 
sampling blood for stress response, sex determina- 
tion, and genetic analyses; monitoring local move- 
ments via radio and sonic telemetry; discerning mi- 
grations via satellite telemetry; and developing GIS 
models for marine turtle habitat associations. 
Acknowledgments 
This project was initiated and managed in part by 
Larry Ogren, who was assisted by the late Junior 
McCain on earlier netting surveys. I am indebted to 
Edgar and Rosa Campbell for their expert advice on 
netting marine turtles and for the unrestrained use 
of their facilities. Thanks are also due to Kenny 
Collins, Lloyd Collins, and Tracey Collins for the use 
of their fishing vessels and for their assistance in 
capturing turtles; Richard Byles and Charles 
Caillouet for supplying PIT tags; Jamie Barichivich, 
Mike Cherkiss, Kris Fair, Lisa Gregory, Debbie 
Weston, and numerous student volunteers for their 
assistance in the field during the later stages of this 
project; and Frank Maturo for confirming the iden- 
tification of mollusc shells. Alan Bolten, Larry Ogren, 
Wayne Witzell and two anonymous reviewers pro- 
vided constructive comments during manuscript prepa- 
ration. This study was supported by the NMFS Panama 
City and Miami laboratories and through NMFS grants 
to the Archie Carr Center for Sea Turtle Research. 
Literature cited 
Abbott, R. T., and P. A. Morris. 
1995. A field guide to shells of the Atlantic and Gulf coasts 
and the West Indies, fourth ed. Houghton Mifflin Co., New 
York, NY, 350 p. 
Bender, E. S. 
1971. Studies of the life history of the stone crab, Menippe 
mercenaria (Say), in the Cedar Key area. M.S. thesis, 
Univ. Florida, Gainesville, FL, 110 p. 
