Black Sea Turtle (Chelonia mydas agassizii) Life History in the Sanctuary of Colola Beach, Michoacan, Mexico

SIMPLE SUMMARY: This paper presents important aspects of the life history of the black sea turtle (Chelonia mydas agassizii) population nesting on the beaches of Michoacan, Mexico. Information on morphometric and reproductive traits related to the life history of black sea turtles (body size, clutch size, egg size, fecundity, remigration interval, age at sexual maturity, and growth rate) was studied. An analysis of interannual variations in the life history traits of the species is also carried out, and the results obtained indicate that C. m. agassizii differs from the information reported for other populations of Chelonia mydas mydas distributed pantropically. ABSTRACT: Sea turtles present strategies that have allowed them to survive and reproduce. They spend most of their lives in the sea, except when they emerge as hatchlings from the nest and when the adult females return to nest. Those moments of their life cycle are vital for their reproductive success, conservation, and knowledge of their biology. This study reports the life history traits exhibited by female black sea turtles from Colola Beach, Mexico using morphometric and reproductive data obtained during 15 sampling seasons (1985–2000, n = 1500). The results indicate that nesting females have a mean body size of 85.7 cm and reach sexual maturity at 24 years old at a minimum size of 68 cm. Females deposit a mean of 69.3 eggs per clutch, and the mean fecundity was 196.4 eggs per female per season. The remigration intervals of 3 and 5 years were the most frequent registered. The life history traits found in the black sea turtle population present the lowest values reported with respect to studies conducted in the Atlantic and Indo-Pacific green turtle populations, which supports the hypothesis that this population is recovering, since morphometric and reproductive data represent young nesting turtles.