Leatherbacks are the largest sea turtle species living today. Adults can be more than 6 feet long and weigh up to 2,000 pounds! Leatherbacks are the only sea turtle species without a bony carapace. Instead, they have a leathery carapace (upper shell), as their name implies! Leatherbacks prefer deep oceanic waters where they forage primarily on jellyfish. In Texas, they occur in deeper Gulf of Mexico waters and are often reported with blooms of large jellyfish. Only one leatherback nest has been documented in Texas recently (in 2008) and it was at Padre Island National Seashore. All historic leatherback nesting in Texas was also documented at the National Seashore (before it became a unit of the National Park System) during the 1920s and 1930s.
Although they are large, leatherback sea turtles are the gentle giants of the ocean. Find out more interesting facts about the leatherback below!
Size: Adult carapace (upper shell) length is 48-96 inches (121-244 cm) (U.S. Fish and Wildlife Service 2020)
Adult weight: 500-2,000 pounds (227-907 kg) (U.S. Fish and Wildlife Service 2020)
Coloration: Hatchlings and adults are primarily black with some pinkish-white spotting; the carapace (upper shell) has a leathery appearance with 7 longitudinal (lengthwise) ridges; hatchlings have white striping on these ridges and on the edges of their flippers (National Marine Fisheries Service 2020).
Nesting Range: In the Pacific, the largest remaining nesting assemblages are in northern South America, New Guinea, Papua New Guinea, West Africa’s Solomon Islands, Mexico, and Costa Rica; in the Atlantic, the largest nesting colonies are Gabon in Africa and French Guiana; in the U.S., nesting occurs in the Caribbean, Puerto Rico, the Virgin Islands, and southeastern Florida (National Marine Fisheries Service 2020).
Non-nesting Range: The leatherback has the widest global distribution of all reptile species; it occurs worldwide in tropical and temperate open ocean and coastal waters of the Atlantic, Pacific, and Indian Oceans; small numbers are found as far north as British Columbia, Newfoundland, and the British Isles, and as far south as Australia, Cape of Good Hope, and Argentina (National Marine Fisheries Service 2020).
Diet: Sea jellies and other similar, soft-bodied animals (National Marine Fisheries Service 2020, U.S. Fish and Wildlife Service 2020)
Lifespan: Unknown; age at sexual maturity unknown
Nesting season: Nesting can occur from February to July; females nest every 2-3 years and lay 5-7 clutches (nests) in one nesting season; each nest contains an average of 100 eggs that take about 2 months to hatch (National Marine Fisheries Service and U.S. Fish and Wildlife Service 1992).
Historic population: Early historic population levels are unknown; in 1982, an estimated 115,000 females existed in the global population, with about half of all females nesting in Pacific Mexico (National Marine Fisheries Service and U.S. Fish and Wildlife Service 1992).
Lowest population: Unknown
Current population: Current population sizes are not well known in most areas; however in the North Atlantic the population is estimated to be between 34,000 and 94,000 adults (U.S. Fish and Wildlife Service 2020).
Population trends: The global population of leatherbacks is estimated to have declined 40% over the past 3 generations; Pacific populations have declined 80-97% over that time; the Eastern Pacific population that nests in Mexico – once considered the world’s largest leatherback nesting population – is now less than 1% of the size it was in 1980; Atlantic populations are smaller but are generally increasing (National Marine Fisheries Service 2020, U.S. Fish and Wildlife Service 2020).
Reasons for decline: Historic and ongoing direct harvest of eggs, juveniles, and adults; historic and ongoing incidental capture in fishing gear (National Marine Fisheries Service 2020, U.S. Fish and Wildlife Service 2020)
Current threats: Direct harvest of eggs, juveniles, and adults; incidental capture in fishing gear; degradation of nesting and marine habitats (National Marine Fisheries Service 2020, U.S. Fish and Wildlife Service 2020)
Fun Facts about the Leatherback Sea Turtle!
Throw your weight around! The leatherback is the largest turtle and one of the largest living reptiles in the world. One male leatherback, found on the coast of Wales in 1998, weighed over a ton!
Deep diving flexibility! The leatherback is very different from other sea turtles. It is the only sea turtle without a hard, bony shell. Its carapace (upper shell) is composed of a mosaic of small, loosely interlocking bones covered by a 1 ½ inch (4 cm) thick layer of rubbery, oil-saturated tissue. Their slightly flexible shell enables the leatherback’s shell to withstand the extreme pressure of the deep ocean waters. (National Marine Fisheries Service 2020, U.S. Fish and Wildlife Service 2020).
Hold your breath! Leatherbacks are deep sea divers and can reach depths of over 4,000 feet and hold their breath for more than an hour (National Marine Fisheries Service 2020)!
Cold-blooded? Leatherbacks, like all reptiles, are cold-blooded (ectothermic) and can be dramatically affected by surrounding temperatures. The leatherback has several adaptations allowing it to withstand cold temperatures. It has a counter-current heat exchange system that helps prevent heat loss. Its body has a high oil content providing insulation. And its large body size helps keep its core warm. In combination, these mechanisms keep the leatherback’s core body temperature higher than the surrounding water.
It’s a slippery slope! Leatherbacks specialize in eating jellies, or sea jellies (once called jellyfish), and other soft-bodied creatures of the open ocean. They have sharp-edged jaws and pointed tooth-like cusps for grabbing and slicing sea jellies. To help hold onto slippery sea jellies, the leatherback has backward-pointing spines lining its mouth and throat (National Marine Fisheries Service 2020). It is amazing such a large animal can survive just by eating jellies!
National Marine Fisheries Service and U.S. Fish and Wildlife Service. 1992. Recovery Plan for Leatherback Turtles in the U.S. Caribbean, Atlantic and Gulf of Mexico. National Marine Fisheries Service, Washington, D.C.