Leatherback sea turtle shallower water at night (when the jellyfish rise up the water column). This hunting strategy often places turtles in very frigid waters. One individual was found actively hunting in waters that had a surface temperature of 0.4 °C. (32.72 °F). Leatherback turtles are known to pursue prey deeper than 1000 m—beyond the physiological limits of all other diving tetrapods except for beaked whales and sperm whales. Their favored breeding beaches are mainland sites facing the deep water, and they seem to avoid those sites protected by coral reefs. Adult "D. coriacea" turtles subsist almost entirely on jellyfish. Due to their
Loggerhead Key done to provide the monkeys a place to breed, to supply the animals for medical research laboratory experiments. Around 1,322 of the monkeys existed on the island between 1987–1990. The Dry Tortugas Light is a lighthouse located on Loggerhead Key. It began operations in 1858 and was decommissioned in 2014. The Carnegie Marine Biological Laboratory, also referred to as the Tortugas Laboratory, was a marine biology laboratory and research facility constructed on the northern end of Loggerhead Key that operated from 1904 to 1939. It was constructed and operated by the Carnegie Institution of Washington. The Carnegie Marine Biological Laboratory