Globally, leatherback turtles are a critically endangered species; their numbers are only a quarter of what they were 20 years ago.
Leatherback sea turtles are the widest-ranging marine reptiles, with some migrating more than 11,000 kilometres every year. In the Pacific, they have been observed as far north as Alaska.
Dark skin colour, large body size, a thick layer of fat, and the ability to control blood flow to reduce heat loss all allow leatherbacks to maintain a body temperature as much as 18°C higher than the ambient temperature.
Leatherbacks found in colder waters are likely searching for or feeding on jellyfish. They appear to be attracted to areas of upwelling where jellies are abundant, as well as the boundaries between warm and cold waters.
Every few years, adult female leatherbacks return to nesting beaches in tropical waters to lay eggs. Once the eggs have been laid, the females return to the water, leaving their offspring to hatch and find their way to the open ocean. In the Pacific, leatherback nesting beaches can be found in Mexico, Costa Rica, Indonesia, and Malaysia.
Nesting habitat loss (due to development, tourism, poaching), fisheries bycatch, and ingestion of marine debris (plastics that resemble jellyfish) are all threats to this endangered species.