Leatherback Day

**Leatherback Day** is celebrated annually on June 15 as part of Sea Turtle Week.

## Distribution

Leatherbacks have the widest distribution of all sea turtle species. They are found throughout the Pacific, Atlantic, and Indian Oceans. In the Pacific, their range extends as far north as Alaska and south beyond the southernmost tip of New Zealand. In the Atlantic, they can be found as far north as Norway and the Arctic Circle and south to the tip of Africa. They are mainly pelagic (open ocean) wanderers but migrate to tropical and subtropical coastal regions to mate and nest.

## Fun Fact

The leatherback is the oldest of all sea turtle species. They have ben around for more than 150 million years! They even survived the extinction of the dinosaurs and thrived until the last several decades when human threats began impacting their numbers.

## Behavior

   Leatherbacks are highly migratory, some swimming over 10,000 miles a year between nesting and foraging grounds. They spend most of their lives in the ocean, but nest on the beach as females. They are strong swimmers and can dive to depths of approximately 4000 feet - deeper than any other turtle and most marine mammals - and can stay down for up to 85 minutes.

Leatherbacks lack the hard crushing jaws characteristic of other sea turtles. Instead, they have pointed tooth-like cusps and sharp-edged jaws that are perfect for a diet of soft-bodied open ocean prey such as jellyfish and scalps. A leatherback's mouth and throat also have backward pointing spines that help retain gelatinous prey (jellyfish).

## Major Threats

The Pacific population has declined by over 90% in the last two decades due primarily to entanglement in commercial fishing gear, particularly longlines and gill nets. Their eggs are also consumed in many parts of the world. These ancient creatures are also vulnerable to ingestion of floating marine debris like discarded plastics. Plastic bags and balloons resemble their favorite prey, jellyfish, and when ingested may block their digestive tract, preventing them from eating.

STATUS: IUCN - listed as Vulnerable, Population Trend: Decreasing - with subpopulations that are listed as Endangered and Critically Endangered / ESA - listed as Endangered

## Leatherback Facts & Tidbits

* Leatherbacks can consume nearly their own body weight in prey per day (about 73% of their weight), feeding exclusively on soft-bodied invertebrates like jellyfish and tunicates. Learn more about their diet.
* They have downward curving spines (also known as papillae) in their mouth and throat which help them to capture and swallow their prey.
* Unlike all other sea turtles, these giants do not possess a carapace (shell) covered with hard scales, also known as scutes. Their smooth, leathery skin covers a flexible matrix of bone. This specialized, flexible carapace allows them to dive to great depths unlike other species.
* Their widespread distribution and ability to tolerate cold water are due to thermoregulatory adaptations (called gigantothermy) which allow them to maintain their core body temperature.
* They are considered Vulnerable around the world by the IUCN Red List and listed as Endangered in the US.
* Their scientific name is *Dermochelys coriacea*.

## Movement

Like all turtles a leatherback turtle moves slowly on land. In the sea, however, they are very fast swimmers. Their paddle-like flippers and the shape of their shell helps a lot in moving through water.

Leatherback turtles cannot rely on its shell for complete protection. So it swims fast to escape from its enemies. One among several interesting leatherback turtle facts is that some leatherbacks can make a quick escape by swimming 20 mph (miles per hour).

## Clutch

The nest of eggs that a turtle lays is called a clutch. In a season, a mother leatherback turtle can lay four or more clutches. Each clutch has about 100 eggs.

A bird’s egg is fragile. A leatherback turtle’s egg, however, is tough as leather. It is almost the size of a Ping-Pong ball. The sand warms the eggs and incubates it. In about two months the baby turtles hatch and find their way to the sea.

## Why are leatherback sea turtles endangered?

In recent decades the species of leatherback turtles have experienced a worldwide decline due to several factors. The breeding grounds of these turtles have suffered greatly from industrial development, especially in South America and Central America.

Beach erosion through severe storms has broken their nesting sites. Poachers have been known to raid the turtle’s nests for the meat and eggs. Artificial light from beach front hotels and restaurants attracts the newly born turtles away from the ocean, making these turtles exceptionally vulnerable.

At sea, many leatherbacks have drowned after they were knotted in fishing gear. These turtles also eat ocean debris, to their misfortune: plastic totes are often fatally mistaken for jellyfish, which is the favorite food of leatherback turtles.

Leatherbacks are currently on the international list of species that are endangered, making it unlawful to harm or kill a leatherback turtle.

Conservation initiatives throughout the world include 24-hour seaside patrols by trained personnel to protect the breeding grounds of these turtles. These initiatives are assisting these magnificent turtles to regain their footing.

## Conservation

Leatherback sea turtles are federally listed as endangered. Their biggest threats are the result of human activity. Clutches of eggs are often illegally poached, and the offspring that do hatch sometimes become attracted to beach resort lighting, so they crawl away from the sea instead of toward it. Adults are also victims of poaching, as well as entanglement in fishing gear. They are also susceptible to marine pollution and debris, sometimes ingesting plastic marine litter.

Climate change is major threat as well. Beach erosion caused by increased storm frequency and intensity is a major threat to nest success. Warming temperatures are a concern for the long-term reproductive success of the leatherback population. Temperature increases could lead to a greater prevalence in feminizing beaches, The identification of existing male-producing beaches will be of critical importance to population viability. Another threat related to climate change is the thermal expansion of oceans. Sea level rise could impact nesting beaches even sooner than changes in ambient temperatures.

## Leatherback sea turtles have existed in their current form since the age of the dinosaurs!

Leatherbacks are highly migratory, some swimming more than 10,000 miles a year between nesting and foraging grounds. They are also accomplished divers with the deepest recorded dive reaching nearly 4,000 feet—deeper than most marine mammals. They have spiny “papillae” lining their mouth and esophagus—these spines help them trap and consume their main prey species, jellyfish.

## What do leatherback sea turtles eat?

A leatherback turtle does not have teeth. Instead it has pointy and sharp ridges along its upper and lower jaws. It uses these to cut its food before swallowing it.

Leatherback turtles are omnivorous and can eat sea plants and grasses. Their ridges look like the edge of a saw. It uses these to easily tear off tough plants.

A leatherback sea turtle diet may also include small fish and jellyfish. They have ridges that are as sharp as knives. Their jaws are also very strong. Once it grabs a passing fish with its jaws, it cannot slip away.

## Senses

Leatherback turtle’s ears are covered by thick skin. Although their ears are invisible they can hear verywell. They can hear low-pitched sounds as well as a human.

A leatherback turtle has a very sharp sense of smell. This is its strongest sense. It can smell better than a dog. It also has very good eye sight. This helps it to see well in the dark. It uses these senses to find food and know if an enemy is near.

## External links

* June 15th is leatherback day! Learn about these giant turtles and the threat of plastic pollution: www.seaturtleweek.com/leatherback-day
* Leatherback turtles (Dermochelys coriacea) are not only the biggest sea turtles in the ocean... They are also the California State Marine Reptile! These iconic giants can be found chowing down on jellyfish in San Francisco Bay every autumn, stocking up on food reserves before making their long trek to breeding grounds in the South Pacific. To learn more about these gentle giants and how you can help them, visit www.SoCalSeaTurtles.org
* Leatherback turtles can dive 2/3rds of a mile deep, deeper than all but a couple of the larger species of whales. Their softer shell allows them to withstand the pressure of more depth. Learn more about this fascinating species: www.seaturtleweek.com/leatherback-day