Original provider: Nathan J. Robinson, The Leatherback Trust Dataset credits: Nathan J. Robinson, The Leatherback Trust Abstract: Previous studies have shown that the world’s largest reptile – the leatherback turtle Dermochelys coriacea – conducts flexible foraging migrations that can cover thousands of kilometres between nesting sites and distant foraging areas. The vast distances that may be travelled by migrating leatherback turtles have greatly complicated conservation efforts for this species worldwide. However, we demonstrate, using a combination of satellite telemetry and stable isotope analysis, that approximately half of the nesting leatherbacks from an important rookery in South Africa do not migrate to distant foraging areas, but rather, forage in the coastal waters of the nearby Mozambique Channel. Moreover, this coastal cohort appears to remain resident year-round in shallow waters (<50 m depth) in a relatively fixed area. Stable isotope analyses further indicate that the Mozambique Channel also hosts large numbers of loggerhead turtles Caretta caretta. The rare presence of a resident coastal aggregation of leatherback turtles not only presents a unique opportunity for conservation, but alongside the presence of loggerhead turtles and other endangered marine megafauna in the Mozambique Channel, highlights the importance of this area as a marine biodiversity hotspot. Purpose: The data were collected from nesting leatherback turtles (Dermochelys coriacea) that tracked via satellite transmitters from the iSimangaliso Wetland Park, South Africa. Supplemental information: All the individuals were adult female leatherback turtles that were tagged while on their nesting beaches. As these data have already been processed in a State-Space Model there is only one location per day and time is not available.