Bjorndal et al.: Somatic growth function for immature Caretta caretta 
245 
Conclusion 
With length-frequency analyses, we estimated that growth 
from 46 to 87 cm CCL in Atlantic loggerhead sea turtles 
requires 20 years. This estimate falls within the range of 
estimates of 9 to 29 years that we calculated from other 
studies based on mark-recapture and skeletochronology. 
Because survivorship in this size class has been identified 
as a critical parameter for population recovery (Crouse 
et al., 1987; Crowder et al., 1994), accurate estimates for 
the duration of the stage are essential for developing suc- 
cessful management plans. Research must be continued to 
refine this estimate. 
Conservation of loggerhead sea turtles that spend an ex- 
tended period of time in nearshore habitats prior to reach- 
ing sexual maturity is compromised. Numerous and signif- 
icant threats — including incidental capture in commercial 
fishing operations, collisions with motorized vessels, dredg- 
ing operations, exposure to pollutants and biotoxins, and 
habitat degradation — are present in nearshore develop- 
mental habitats. There is a high probability that these tur- 
tles will encounter one or more of these threats during 
their maturation period (National Research Council, 1990; 
Eckert, 1995; Lutcavage et al., 1997). To be successful, re- 
covery activities must be sustained for long periods of time, 
and long-term monitoring programs to assess the status of 
populations of juvenile loggerhead sea turtles in U.S. wa- 
ters must be established. Because current loggerhead pop- 
ulation assessments depend upon the numbers of nesting 
females or nests, two or more decades must pass before re- 
sults of recovery activities aimed at the earliest age classes 
in nearshore waters can be evaluated. 
Acknowledgments 
This project could not have been conducted without the 
long hours invested by the many participants in the Sea 
Turtle Stranding and Salvage Network in Alabama, Flor- 
ida, Louisiana, Mississippi, and Texas. In particular, we 
thank Gary Hopkins and Robert Shipp, the coordinators 
for Mississippi and Alabama, respectively, and Carrie 
Crady, Allen Foley, and Ron Mezich. Support for this proj- 
ect was provided by the MARFIN program of the National 
Marine Fisheries Service (project NA57FF0063 to KAB 
and ABB). We thank Nancy Thompson for her assistance 
with this project. David Fournier generously provided 
advice and modification of the MULTIFAN software. Peter 
Eliazar assisted with data compilation, and Jennifer Pias- 
cik drafted Figure 4. 
