Leatherback Sea Turtle

(Tortuga Laud or Baula)

Dermochelys coriacea
Family: Dermochelyidae

Status: Critically Endangered

Adult Leatherback in Ostinal, Costa Rica
Hatchling Leatherback in Rancho Nuevo, Mexico

 

Description

This turtle can reach enormous proportions. It is the largest living turtle, ranging from 550 to 1,200 pounds (295-545 kilograms) and growing to lengths of 6 to 8 feet (1.8-2.4 meters). There are records of at least one specimen weighing 2,000 pounds (907 kilogram).

It is the only living species of family Dermochelyidae. "Derma" is Greek for skin or leather, and "khelus" is Greek, meaning tortoise. These turtles lack the typical bony shell covered with horn-like scutes. Instead, they have a cartilaginous shell with a matrix of hexagonal bones imbedded in it. The leatherback is distinctly triangular in shape, having a prominent keel down to the center of the upper shell (carapace), flanked by three more keels on each side, or seven in all. The skin is black or dark brown, spotted with white. Hatchlings of this species have white coloration on the edges of their flippers.

Habitat and Distribution

The leatherback's habitat is typically tropical or subtropical seas, but it has been found as far north as Nova Scotia. Major nesting beaches in the western hemisphere are on the Pacific Coast of Mexico at Barra de la Cruz, Chacahua, Oaxaca, Mexiquillo, Michoacan, and at Tierra Colorado, Guerrero, Playa Grande and Playa Langosta, Costa Rica. U.S. nesting is restricted to Florida with some nesting along the Mexican Gulf of Mexico.

 

General Information

This species is a highly migratory, pelagic (deep water) species.It has a streamlined body and is capable of dives of up to an estimated 4,265 feet. Its high fat content provides insulation and gives it the ability to maintain deep body temperatures at a level above that of the surrounding cold water. Like most sea turtles, it is a nocturnal nester. It is also the most marine of all the sea turtles and has great difficulty hauling ashore to nest. Like other species of sea turtles, the leatherback is unable to back up. If it cannot push through beach debris, it will overheat and die in the heat of the sun the following day. New World nesting occurs primarily during the month of December. Most females nest each year and produce 6 to 7 clutches at 10 day intervals. In Pacific Mexico, the average is 3 nests per female with a clutch size of 50. However, in other areas, from 100 to 180 eggs per clutch are recorded. The incubation period will vary from 50 to 55 days.

Somewhat surprisingly, the diet of this giant turtle is almost exclusively jellyfish. Many die each year when they become impacted from swallowing discarded plastic bags.

Current Threats and Historic Reasons for Decline

Longline fishing is the biggest threat to Leatherback populations. The type of hooks currently used, called "J Hooks" are accidentily catching and subsequently drowning thousands of leatherbacks. A new hook called a "Circle Hook" is currently being tested and implemented within many of the longline fisheries. This new style of hook catches tuna and swordfish (the desired catch) but not sea turtles.

Other major threats to leatherback populations are the accidental consumption or entanglement with plastics and discarded nets and line. Historically, the seasonal harvest of millions of eggs and the slaughter of thousands of nesting turtles has brought this species to its endangered status.