Anidación de la tortuga <i>Dermochelys coriacea</i> (Testudines: Dermochelyidae) en playa Gandoca, Costa Rica (1990 a 1997)

Abstract

The nesting of the leatherback sea turtle was studied in Gandoca Beach, an important nesting beach on the southeastern Caribbean coast of Costa Rica, in the Gandoca/Manzanillo National Wildlife Refuge. Nesting was recorded from 1990 to 1997 (each February through July). Nesting peaked in April and May (depending on the year); 16 biological paramenters were recorded and part of the rookery was tagged with monel tags. During this period 1 045 females were studied and 3 484 nests were recorded; 534 nests was the yearly mean, (range 226-1 135), 20.8 % of the nests were relocated to hatcheries, as a conservation effort to prevent loss of nests. Mean curve carapace length was 154.65 cm and width 112.83 cm. Mean normal number of eggs/nest was 79.28 and 35 yolkless. Each turtle laid an average of 2.5 nests per season with an internesting interval of 9 days. In 1997, 39% of the nesting females had been previously tagged in Gandoca Beach and a few also in Colombia (Urabá Gulf), Pacuare and Tortuguero (Costa Rica). Poaching activity, beach debris and extensive erosion represent the main hazards that are leading to a decline of the sea turtles in Gandoca.