Leatherback Turtle & Costa Rica

Leatherback sea turtles stand out as the largest of all sea turtle species and the only living species of the Dermochelidae family. Unlike their counterparts in the Cheloniidae family, which include all the other six sea turtle species, leatherbacks exhibit distinct features that set them apart.

Their physical appearance immediately distinguishes them. After hatching from the egg using a modified scale known as the “egg tooth”, leatherbacks shed their scales. As they mature, leatherbacks develop a smooth, hydrodynamic body with seven distinctive dorsal ridges, perfectly suited for navigating the vast expanses of the open ocean, which is the leatherback preferred habitat.

What truly sets leatherbacks apart from other sea turtle species is their shell composition. While other sea turtle species possess hard shells comprised of solid bones, leatherbacks’ shells are formed from a keratinous material with a texture that resembles leather. In addition to giving leatherbacks their name, this unique adaptation affords them flexibility, enabling them to undertake deep dives with ease as their shells can compress under high pressure, allowing leatherbacks to explore depths beyond the reach of other sea turtle species. Leatherbacks can dive more than 1km (3,000ft.) in depth in search of prey, which consists mostly of jellyfish and other gelatinous invertebrates. Did you know that leatherbacks can eat over 300kg (660lbs) of jellyfish per day?

In essence, leatherback sea turtles exemplify nature’s ingenuity, perfectly adapted to thrive in the challenging environments of the open ocean.

Scientific name

Dermochelys coriacea

Common names

English: Trunkback

Spanish: Baula, Canal, Cana, Laúd, Espalda de cuero, Siete quillas, Tridente del diablo

Portuguese: Tartaruga de couro, Tartaruga gigante, Sete quilhas

Size and weight

The largest leatherback turtle ever found washed up off the coast of Wales. It was a male that measured 222cm (7.2ft) in curved carapace length and weighed around 900kg (1980lbs). However, nesting females usually measure between 130 and 180cm (50 and 70in) and weigh about 400kg (880lbs).

Distribution

Leatherbacks are present in all ocean basins, except the Arctic. Whereas they nest in tropical areas, leatherbacks wander into subpolar waters, which makes them the reptile species with broadest distribution. The leatherback nesting population in the Caribbean of Central America is one of the largest in the world. Check out this SWOT map for more information on the location of nesting beaches and foraging areas for this species.

Reproduction

Female leatherback sea turtles reproduce approximately every two to three years, whereas males may reproduce annually. Every nesting season, female leatherbacks will lay an average of 7 nests, which will typically contain around 80 viable eggs as well as between 15 and 50 yolkless eggs. Although we do not know the exact function of the yolkless eggs, they may be useful to stabilize the temperature and moisture inside the nest and provide space for oxygen to penetrate the nest. A typical interval of 10 to 14 days between nesting events is observed among leatherback sea turtles.

Following nesting, leatherback sea turtles often embark on long-distance migrations to various foraging grounds. Most leatherbacks that were satellite tracked after nesting on the Caribbean coast of Central America moved into the gulf of Mexico and the eastern coast of the United States and Canada. Close to Turtle Love project site, we saw a turtle that had been tagged at their foraging grounds off Nova Scotia, Canada. That is a 5,000km (3,000mi) journey as the crow flies.

In Costa Rica, on the Pacific coast, the Leatherback turtle nesting season runs from early October to March, peaking in November and December. On the Caribbean coast, most nesting occurs between March and May.

Diet

Gelatinous invertebrates, including moon jellies, jellyfish, and tunicates.

Identifying features

Color

Dark blue with pale splotches

Pink spot

At the crown of a leatherback turtle’s head is a larger pale splotch called the pink spot. Supposedly, this spot sits right on top of the turtle’s pineal gland, which is responsible for sensing changes in photoperiod and dosing the production of the hormone melatonin (yes, the same one takes before sleeping). This hormone may be involved in telling the turtles when the time is to reproduce.

Conservation status

Leatherback turtles are listed as globally vulnerable by the IUCN Red List of Threatened Species. However, the Northwest Atlantic Subpopulation, which includes leatherbacks nesting at Turtle Love’s project site, is considered endangered.