Green Turtle

Sea turtles are often sighted around Dry Tortugas National Park. Originally named Las Tortugas (Spanish for The Turtles) by Ponce de Leon in 1513, this collection of small sand and coral islands is famous for the abundance of sea turtles that annually nest on them. Loggerhead, hawksbill, and green turtles can sometimes be spotted lounging on the surface of the sea on the trip between Key West and Dry Tortugas National Park.

Dry Tortugas National Park is the most active turtle nesting site in the Florida Keys. Park biologists have been monitoring sea turtle nesting activity within park boundaries since 1980. The park's seven islands are surveyed throughout the nesting season to document the presence of turtles in the park. Researchers find turtle nests by looking for a characteristically shaped mound of sand on the beach. Each nest is marked and recorded and then checked for signs of hatchlings about forty-five days later. After hatching, researchers evacuate the nest, release any trapped hatchlings, and record the number of eggs.

The five species of sea turtles found in the Dry Tortugas region are green, loggerhead, Kemp's ridley, hawksbill, and leatherback. All five species were once more abundant; now all five species are listed as either threatened or endangered under the Endangered Species Act.

A turtle capture, tagging, and tracking project of Dry Tortugas sea turtles is currently being conducted by the U.S. Geological Survey. Turtles are captured by intercepting reproductive females on nesting beaches and catching turtles in the water using rodeo, hand-capture, and dip-netting methods. Each turtle that is caught is tagged, measured, and sampled for genetics, isotopes, and diet. Satellite and acoustic telemetry techniques are used to determine daily location and movement patterns for tagged turtles, to calculate home ranges and core use areas, and to statistically summarize the extent of overlap of these areas with the Dry Tortugas Research Natural Area. The data sets are combined to determine survival, growth rates, and diet of juvenile green turtles; residence times in the park and core use areas for all three species; and definitive links to other nesting grounds.