Leatherback Sea Turtle

Overview

The leatherback sea turtle (Dermochelys coriacea) is the world’s largest turtle and the only member of its family (Dermochelyidae). Rather than a hard, scute-covered shell, it has a smooth, flexible carapace of oily, rubbery skin supported by a mosaic of tiny bone fragments — the source of its common name. Adults reach up to 2.7 m in length and can weigh 500 kg or more, dwarfing every other sea turtle. A suite of physiological adaptations including countercurrent blood-flow systems allows leatherbacks to maintain elevated core temperatures, enabling deep dives (over 1,000 m recorded) and foraging in near-Arctic waters.

Leatherbacks feed almost exclusively on jellyfish and other gelatinous zooplankton. This dietary specialization makes them particularly vulnerable to plastic pollution — floating plastic bags are indistinguishable from jellyfish to a foraging turtle.

Why Tortuguero

The Tortuguero beach is a documented leatherback nesting site on the Costa Rican Caribbean coast, alongside other Caribbean beaches such as Parismina and Gandoca. The nesting season (roughly February–July, peaking March–May) precedes the main green turtle season, so a visitor in the shoulder period has the possibility of encountering both species. Numbers at Tortuguero are substantially smaller than the green turtle population; leatherbacks nest at lower density along the same stretch of beach.

The species connects directly to the park’s conservation mandate: Tortuguero was established in part to protect marine turtle nesting habitat, and leatherback nesting here is one more argument for the park’s existence.

How to see them (honestly)

• Season: February to July, with peak March–May. Outside this window, the chance of a nesting leatherback on the beach is essentially zero.
• Access: same night-tour rules as green turtles — authorized guide, SINAC permit, dark clothing, no lights, no scent.
• What to expect: a leatherback female is enormous — the sheer size distinguishes her immediately from any other turtle. She will be visibly slower and more deliberate on the beach than a green.
• What not to expect: a guaranteed encounter. Leatherbacks nest at lower density than greens at Tortuguero, so even during peak season a night on the beach may yield a green turtle encounter rather than a leatherback.

Status note

The IUCN classifies the leatherback globally as Vulnerable, but this headline conceals dramatic regional variation: the eastern Pacific subpopulation is Critically Endangered and has suffered collapse-level declines. The Atlantic and Caribbean populations are in better shape but not stable. Principal threats are plastic ingestion at sea, longline and trawl bycatch, egg harvesting, artificial lighting, and beach erosion. Costa Rica’s protected nesting beaches — Tortuguero among them — represent a meaningful contribution to Atlantic leatherback persistence.