Abundance and Growth Patterns of Chelonia mydas in Culebra, Puerto Rico

Abstract

Baseline information on abundance and growth patterns of green turtles was collected at Culebra, Puerto Rico from 1987 to 1989. A total of 167 individuals was captured, measured, tagged, and released. Twenty-five were recaptured 32 times for a recapture rate of 19%. Of 7 sampling areas, Mosquito Bay and Culebrita harbored the highest abundance of turtles with 2.16 and 2.04 caught per net set, re- spectively. Carapace length (CL) ranged from 24.6 to 75.3 cm, averaging 46.34 cm. The observed size-class composition was indicative of a juvenile population. A U.S. Virgin Islands age-size model suggested that turtles ranged in age from 2 to 14 yr old. Turtles grew at an annual rate of 5.08 cm (CL) with the highest growth rates recorded in the 40-50 cm CL interval. At the observed rates, turtles may spend 10 yr growing through the recorded CL range. Principal components analysis indicated that 99% of the variance was explained by the first or size component, with CL exhibiting the fastest relative growth rates of 4 mor- phometric variables. Shape components explained the remaining variance, with carapace width influencing most the general appearance of turtles. Our findings established that Culebra supports a juvenile green turtle population, and along with those of the U.S. Virgin Islands, confirmed the presence of developmental habitats and maturing populations through the eastern portion of the Puerto Rican Bank.