Leatherback Sea Turtle

Dermochelys coriacea

Maximum Size: 8 ft (2.44 m)
Maximum Weight: 4000 lbs (1,814 kg)
Lifespan: 30 - 50 yrs or more

Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Reptilia
Order: Chelonia
Family: Cheloniidae
Genus: Dermochelys
Species: coriacea

Description

Leatherback sea turtles are the largest of all sea turtles, weighing between 500 and 1500 pounds (250-700 kg). They can reach lengths that range from four to six feet (121-183 cm). The leatherback is the only sea turtle that lacks a hard shell. Instead, their unique shell is composed of a layer of thin, tough, rubbery skin, strengthened by thousands of tiny bone plates that make it look "leathery." Their head has a deeply notched upper jaw with 2 cusps. Their carapace is large, elongated and flexible with seven distinct ridges running the length of the animal. The carapace is dark grey or black, with white or pale spots. The plastron is whitish to black and marked by five ridges. Only hatchlings possess scales on their carapace, which have white blotches. Unlike other sea turtles, all of their flippers are without claws.

While they once lived in all oceans of the world, they are currently in grave danger of becoming extinct.

Top

Range and Habitat

Leatherback sea turtles are the most widely distributed of all sea turtles. They are primarily found in the open ocean, as far north as Alaska and as far south as the southern tip of Africa. Recent satellite tracking research indicates that Leatherbacks feed in areas just offshore.

Top

Behavior

The Leatherbacks are the only known reptile to remain active in water below 40 degrees Fahrenheit (four degrees Celsius). With their streamlined body shape and powerful front flippers, leatherbacks can swim thousands of miles over the open ocean and against fast currents.

Top

Reproduction

Although adult females will usually return to the same nesting beaches, Leatherbacks do sometimes change nesting beaches. The female will lay an average of 80 fertilized eggs, each the size of a billiard ball, and 30 smaller, unfertilized eggs. Adult females nest about six to nine times per season, with an average of ten days between nestings. Hatchlings will begin to emerge after about 65 days. On average, females nest every two to three years, but are capable of nesting every year.

Top

Food and Foraging

Leatherbacks have delicate, scissor-like jaws. Their jaws would be damaged by anything other than a diet of soft-bodied animals, so they feed almost exclusively on jellyfish. It is remarkable that this large, active animal survives on a diet of jellyfish, which are composed mostly of water and appear to be a poor source of nutrients.

Top

Status and Conservation

Leatherback sea turtles are listed as endangered under the U.S. Federal Endangered Species Act. Internationally, they are listed as critically endangered (extremely high risk of becoming extinct in the immediate future) by the International Union for Conservation of Nature and Natural Resources.

The population estimate of Pacific Leatherbacks is believed to be about 34,000 nesting females, based on beach monitoring reports from the early and mid 1990s. Adult females nest in four major locations. Critical Pacific nesting areas include Malaysia, Irian Jaya, New Guinea, Mexico to Costa Rica, and Central America to Peru. Populations nesting in Malaysia are basically gone with only 11 nesting females as of 2002, and those in Mexico (200 females) and Costa Rica (68 females) are declining dramatically. About 5,000 nesting females are thought to nest in the Pacific basin.

Prior to 1991, the largest enemy was the driftnet fishery, which laid out thousands of miles of monofilament line in attempts to catch swordfish and tuna. These driftnets trapped and killed everything in its path, including thousands of dolphins, whales, and hundreds of thousands of sea birds. These non-target species are called “by-catch” and are simply thrown back into the water, dead. In 1991, following a UN band on open ocean driftnets, most commercial fishermen converted to longlining.

Longlining

Monofilament lines often 60 miles long are dressed with thousands of baited hooks and left overnight. The following morning, the line is retrieved and non-target species such as sharks, marine mammals, sea birds, and sea turtles are thrown back into the water, usually dead. This longline industry is growing exponentially killing an average of 3.7 million sharks, over 400,000 marlin, 40,000 sea turtles, 14,000 albatross, 2,000 dolphins, and 1,500 whales. This devastation is so alarming that the UN is being pressed for a moratorium to ban longline fishing, until better regulation or protection can occur. Additionally, most of the fish caught by these longlines contain such high levels of mercury that they are nearly unfit for human consumption. (click here to support the moratorium)

The greatest threat to Leatherback sea turtles is human consumption of their eggs. Other threats include entanglement in coastal gillnets, and loss of proper nesting beaches due to development. Marine pollution, such as balloons and plastic bags floating in the water, are often mistakenly ingested by the Leatherbacks (they believe these items are jellyfish). Plastic bags and balloons eventually obstruct the digestive system, causing the sea turtle to starve to death. It is estimated that only one in a thousand Leatherback eggs will survive to adulthood.

Efforts are being made to prevent the development of nesting beaches by purchasing these lands, and by pressuring the UN for international treaties that reduce longline fishery interactions.

What you can do to help the leatherbacks:

• 1. Don’t eat swordfish or any top of the food chain fish
   

• 2. Write or email the United Nations and ask for a moratorium on longlining in the Pacific.  Add your name to a list urging the UN to protect endangered leatherbacks at its June meeting. Click here
  
  United Nations Environment Program
  Two United Nations Plaza, DC2-803 New York, NY 10017
  Info@nyo.unep.org
   

• 3. Urge Safeway to label mercury-laden fish nationwide. Click here

*Order your free video

Top