The Leatherback Turtle is the largest of all sea turtles in the world. Unlike other sea turtles, leatherbacks have a special layer of fat under their skin which protects them from cold temperatures. They also have a rubbery rather than hard shell. Leatherbacks may be the most widely found reptile in the world because of their habit of following drifting jellyfish, their primary food source. They are found in tropical and temperate waters of the Atlantic, Pacific and Indian Oceans and are currently on the endangered species list.
Leatherbacks may be the most widely distributed reptile in the world because of its habit of following drifting jellyfish. They are found in the tropical and temperate waters of the Atlantic, Pacific and Indian Oceans. Leatherbacks are pelagic creatures meaning that they prefer to live in the open sea rather than near the shore. They are sometimes found in shallow waters off bays and estuaries. Leatherbacks are carnivorous creatures that eat invertebrates (animals that do not have backbones). Their diet is comprised mainly of jellyfish (they can eat their body weight in jellyfish in one day!) but they may also eat sea urchins, octopi, squid, snails, crabs, small fish, other baby turtles, small bird feathers, algae and floating kelp. Leatherback turtles in captivity have been known to eat prawns, raw meat, chicken liver, cattle heart and bread.
Since they are very distinctive from other sea turtles, Leatherbacks belong to their very own separate family of reptiles called Dermochelys. Reptiles are normally characterized for being cold blooded. The Leatherback Turtle, however, has a unique ability that enables them to change their body temperature so that they can survive in very cold temperatures. There are layers of fat under the turtle’s skin which insulate them from the cold and a specialized circulatory system that minimizes heat loss. The Leatherback Turtle is also different from other sea turtles because it does not have a hard shell. Instead, it has a thick layer of cartilage strengthened by thousands of tiny bones that create a rubbery texture. Leatherbacks also have the amazing ability of traveling across oceans without relying on currents in the water for direction.
The Leatherback Turtle is often confused with other marine (sea) turtles that also grow to be six feet long and 1.6 meters wide. The front flippers of the Leatherback are also the same length among all sea turtles.
The mating process of the Leatherback Turtle occurs in three phases with the mating occurring between the second and third phases. The first phase involves nesting which may occur between April and July for Atlantic Leatherbacks and November to January for Pacific Leatherbacks. During the second phase of nesting, the turtles follow drifting schools of jellyfish, their primary source of food, from tropical to temperate waters. In the third phase of nesting, the turtles migrate back to the tropics as a result of cooling water temperatures and shortened amounts of daylight. The Western Atlantic Leatherback nesting areas occur in northern South America, Central America, Caribbean Islands and parts of the United States including Padre Island in Texas, Florida and Georgia. The Eastern Leatherback nesting areas include Ecuador, Panama, Costa Rica, Guatemala, and Mexico. Leatherbacks may also nest in temperate waters off Atlantic Canada and in the Pacific Ocean off Alaska and British Columbia. Leatherbacks favor easily accessible beaches for nesting so they can avoid damage to their soft plastron (underside of the shell) and flippers. Nesting on open beaches can be dangerous because seasonal changes in wind and wave direction result in many eggs laid on the beach being lost.
Leatherbacks dig nests in the sand like other sea turtles but often lay more eggs. In one nesting season, a female turtle may lay as many as twelve groups or clutches of eggs with 65 to 85 eggs in each group resulting in a total of between 780 and 1020 eggs. Unfertilized eggs are laid among fertilized eggs to allow air circulation in the nest. The eggs are equal to the size of a billiard ball and have soft shells. The total nesting process is believed to take approximately two hours after which the eggs undergo incubation for approximately 65 days. The nest is completely covered in sand in order to disguise it from predators. Leatherbacks nest an average of six times every two to three years. It is the only time that the turtle will return to land after hatching.
At birth, baby turtles (also called hatchlings) are mostly black with white stripes on the back and covered with tiny scales. They use a sharp tooth called a caruncle, or egg tooth, to break out of their egg. This egg tooth falls off shortly after the hatchling digs itself out of the nest, a process which may take several days. They are normally 61.3 millimeters long and weigh 45.8 grams. The underside of the hatchling is scattered with pinkish white and black blotches. Hatchling turtles emerge out of their nest as a group, usually during a rainstorm or at night and head immediately toward the sea, guided by the
reflected light off the water’s surface. This is the most dangerous part of in a young hatchlings life as it can easily be preyed upon by birds or crabs. It may also lose its way as a result of being distracted by the bright lights of civilization. Losing its way may result in the hatchling being exposed to dehydration and death. Little is known about the Leatherback’s growth rate after hatching or the age at which it reaches sexual maturity.
Apart from their nesting pattern, very little is known about the behavior of Leatherback Turtles. The exact hours of feeding are not known but Leatherbacks spend most of their time near the surface of the water in the morning between nine and twelve. They sleep while floating on the surface. Leatherbacks are very powerful swimmers as a result of a synchronized beating of the turtle’s forelimbs. Leatherbacks can swim at a maximum speed of 5 km/hour but they have been recorded swimming at speeds of up to 9.3 km/hour, allowing the turtle to travel great distances whether for migration or random trips. Leatherbacks usually travel on their own but have been recorded traveling in groups. Leatherbacks can be very aggressive when captured. They flail their flippers and may even bite. When threatened in the wild, Leatherbacks will dive to escape their predators. They may also make sounds when distressed and swim away from harm very quickly.
Leatherback Turtles are listed as endangered on the Species at Risk List in Canada and the Endangered Species List in the United States. Today, there are only an estimated 30,000 Leatherbacks left in the world, compared to 115,000 in 1998. The numbers of nesting females continue to rapidly decline. The Eastern Pacific Leatherback is facing immediate extinction while the Western Atlantic Leatherback is being destroyed at a very rapid rate from being caught unintentionally in shrimp fishing nets. Leatherbacks are facing extinction mainly as a result of human interaction with their environment. Nesting sites are often disturbed by tourism or commercial development and by poachers who steal the eggs for food. Development of beachfronts may prevent or discourage nesting females from getting to nesting sites as well as washing out nests. The artificial lights of construction sites also pose a threat to leatherbacks by causing disorientation to both adults and hatchlings. Turtles are attracted to light so they may come out of the ocean towards it which may result in death or injury. The use of off-road vehicles on beaches also poses a serious problem because it can result in decreased hatchling success due to sand compaction or in worse cases, the killing of hatchlings. Ruts in the beach caused by the vehicles may also make it difficult for the turtles to nest. Adult turtles are sometimes captured for food and their body parts are used FOR various products such as traditional medicines. Leatherbacks may also be injured or killed in collisions with boats or by mistakenly swallowing garbage as food. Leatherbacks are also affected by oil spills with affect their respiration, skin, blood chemistry and salt gland functions. The survival of leatherbacks is also threatened by predators such as crabs, lizards, gulls, turnstones, plovers (types of wading birds), sandpipers, vultures, opossums, raccoons, coatis (related to the raccoon), feral dogs, mongooses and pigs who eat their eggs. Once born, hatchling are preyed upon by crabs, gulls, crows, vultures, birds, hawks, owls, cuttlefish, octopi, sharks and other large fish. Predators of adult turtles include humans, jaguars who attack nesting females, large sharks and killer whales.
What Can We Do to Help?
Efforts on the part of governments and non-government agencies and private individuals such as the Center for Marine Conservation, Greenpeace and National Audubon Society have helped to increase public awareness of sea turtle conservation efforts. They have distributed audio-visual aids and printed materials about sea turtles including booklets, bumpers stickers and decals, coloring books, video tapes and full color identification posters for turtles. Fishing companies have included Turtle Exclusion Devices (TEDs) in their nets which allow turtles to escape the nets when they are caught. In Canada, the Nova Scotia Leatherback Turtle Working Group (NSLTWG) has been instrumental in helping fishermen to recover the Leatherback population. Conservation efforts in Canada have also been assisted by research conducted at the Bedford Institute of Oceanography and Dalhousie University. Nest protection efforts have been increased in Mexico, Costa Rica and the United States. National parks have been created to help prevent further commercial construction and the theft of eggs by poachers. Leatherbacks have also been fitted with satellite tracking devices which help conservation efforts by determining where the turtles go and how many are left in the ocean.
There are many helpful websites available that provide information on leatherbacks and other sea turtles and what each individual can do to help.