Leatherback turtles are found in every major ocean basin, from tropical nesting beaches near the equator to cold sub-polar waters approaching 0°C. They have the widest geographic range of any living reptile, spanning the Atlantic, Pacific, and Indian Oceans. Their ability to regulate body temperature lets them thrive in waters that would be lethal to other sea turtles, and satellite tracking has recorded individual turtles passing through the waters of more than 26 countries on a single migration.
Nesting Beaches: Where Leatherbacks Reproduce
Leatherbacks nest exclusively on tropical and subtropical sandy beaches. The largest remaining nesting colonies in the Atlantic are in Trinidad and Tobago and in Gabon, on the west coast of Africa. In the Eastern Pacific, the primary nesting beaches are in Mexico and Costa Rica, with smaller numbers nesting in Panama and Nicaragua.
The Western Pacific population nests mainly in Papua Barat, Indonesia, which supports an estimated 50 to 75 percent of that entire subpopulation. That colony has declined by over 80 percent, making it one of the most threatened nesting groups in the world. Other nesting sites are scattered across the Indian Ocean coast of Africa, though data on those populations remains limited.
Atlantic Ocean Range
The Atlantic holds the most robust leatherback populations. After nesting in the Caribbean and West Africa, turtles fan out across the entire ocean basin to feed. Satellite-tagged females from a rookery in Bocas del Toro, Panama, split into two main routes: about 55 percent headed north toward Canada and even the waters around the United Kingdom, while the remaining 45 percent stayed within the Gulf of Mexico and around Florida.
Canadian Atlantic waters are a major seasonal destination. Every summer, leatherbacks congregate in three key areas off eastern Canada: the Scotian Shelf, the Gulf of St. Lawrence, and the Bay of Fundy. Research found that leatherback density in the Gulf of St. Lawrence closely matched jellyfish concentrations there, particularly around the Magdalen Islands and through the Cabot Strait. The Scotian Shelf appears to function more as a travel corridor, with turtles passing through on the way to richer feeding grounds farther north.
Along the U.S. East Coast, leatherbacks are regularly spotted from Florida up through the mid-Atlantic states and into New England waters, especially during warmer months when jellyfish blooms peak.
Pacific Ocean Range
Pacific leatherbacks face steeper population declines, but they still cover enormous distances. The Eastern Pacific population nests in Mexico and Central America, then disperses into open ocean waters along the western coast of the Americas. Leatherbacks arrive along the U.S. West Coast in spring and summer to feed on sea jellies, particularly brown sea nettles, that bloom during seasonal coastal upwelling off California, Oregon, and Washington. This foraging area was important enough that the U.S. designated it as critical habitat for leatherbacks in 2012, and a seasonal drift-gillnet fishing closure runs from August 15 to November 15 each year to protect them.
Western Pacific leatherbacks nesting in Indonesia migrate across the Pacific to reach these same West Coast feeding grounds, a journey of thousands of miles. This means that a single foraging area off California can host turtles originating from opposite sides of the ocean.
Indian Ocean Range
Leatherbacks in the Indian Ocean are the least studied of any population. Nesting occurs along the coasts of eastern and southern Africa, including Mozambique and South Africa, and possibly in parts of Southeast Asia. The Northeast Indian Ocean subpopulation is listed as Data Deficient by the IUCN, meaning scientists don’t have enough information to assess its size or trend. The Southwest Indian Ocean subpopulation is classified as Critically Endangered.
How They Survive in Cold Water
What makes leatherbacks’ range so remarkable is that they’re reptiles living in water cold enough to kill most other turtle species. Researchers have recorded a 500-kilogram leatherback repeatedly diving into water at just 0.4°C. They manage this through a combination of body size, insulation from a thick layer of oily tissue beneath their skin, and active control of blood flow.
In cold water below about 25°C, leatherbacks increase their flipper stroke rate to generate metabolic heat, while simultaneously restricting blood flow to their skin and flippers. This minimizes heat loss and allows them to maintain a body temperature up to 2.3°C warmer than the surrounding water. In warm tropical waters, they do the opposite: blood flow to the skin increases, tripling heat loss to prevent overheating. This thermal flexibility is what allows the same animal to nest on an equatorial beach and then feed in near-freezing sub-polar seas weeks later.
How Deep They Go
Leatherbacks don’t just range widely across the surface. They exploit the ocean vertically in ways no other turtle can. The maximum recorded dive depth is 1,250 meters, roughly three-quarters of a mile down. In a tagging study off Massachusetts, 15 out of 20 tracked turtles dove deeper than 500 meters, and three males exceeded 1,200 meters. Single dives can last nearly 90 minutes.
What’s unusual is how they use those dives. Rather than spending time at a particular depth, leatherbacks appear to spend almost the entire dive descending to maximum depth and then returning, essentially scanning as much of the water column as possible. This likely helps them locate dense patches of deep-water jellyfish and other gelatinous prey scattered at various depths.
Population Status by Region
The IUCN classifies leatherbacks as Vulnerable globally, but that label masks dramatic differences between subpopulations. Four of the seven recognized subpopulations are Critically Endangered: the East Pacific, Southwest Atlantic, Southwest Indian Ocean, and West Pacific groups. The Northwest Atlantic subpopulation, centered on Caribbean nesting beaches and Canadian feeding grounds, is listed as Endangered but is considered the healthiest remaining group. Two subpopulations, the Northeast Indian Ocean and Southeast Atlantic, lack enough data for a formal assessment.
These regional differences matter for anyone looking at where leatherbacks are found today versus where they once were. The Eastern Pacific population has collapsed to such a degree that sightings off Central American beaches are a fraction of what they were a few decades ago. Meanwhile, Atlantic populations, though declining, still support large-scale annual migrations between the tropics and temperate feeding grounds.