The majestic leatherback turtle is the largest sea turtle in the world, growing to more than 6 feet in length. It is also one of the most threatened. A major new study of migration patterns has identified high-use areas—potential danger zones—in the Pacific Ocean for this critically endangered species. Dr. Helen Bailey of the University of Maryland Center for Environmental Science’s Chesapeake Biological Laboratory in Solomons, Maryland, led a group of prominent turtle researchers from around the world to assemble leatherback satellite tracking data in a major new analysis of migration patterns. This new understanding could help inform decisions about fishing practices to help reduce further deaths of this fragile species. “The study shows that leatherbacks can be found throughout the Pacific Ocean and identifies high-use areas that are of particular importance to their survival,” said lead author Dr. Helen Bailey of the University of Maryland Center for Environmental Science. “This information on their movements is essential for identifying hot spots and assessing where limiting fishing at particular times of year may be effective for protecting leatherbacks.”
Leatherbacks are the widest-ranging marine turtle species and are known to migrate across entire ocean basins. Female leatherbacks lay their eggs on tropical nesting beaches, but then migrate to foraging areas to feed on jellyfish. These long-distance migrations are likely to increase the risk that these animals may be caught in fishing gear, undermining conservation efforts to protect turtles on their nesting beaches. Interaction with fisheries is believed to be a major cause of death, which is of particular concern in the eastern Pacific Ocean, where the number of leatherback turtles has dropped by more than 90% since 1980.
“Leatherback turtles are long-lived animals that take a long time to reach maturity, so when they are killed in fishing gear it has a huge impact on the population,” said study coordinator Dr. James Spotila of Drexel University. “Their numbers are declining so rapidly it is critical that measures are taken quickly to ensure these animals don’t go extinct.”
Leatherback turtles can travel enormous distances between their nesting and feeding sites. In the Pacific Ocean there are two populations of leatherback turtles that nest in the eastern and western Pacific. The study used state-of-the art satellite tracking, the largest satellite telemetry data set ever assembled for leatherbacks, to track 135 turtles. Leatherbacks in the eastern Pacific were tagged at the nesting sites in Costa Rica and Mexico. The western Pacific population was tagged at two nesting sites in Indonesia and at foraging grounds off the coast of California. The tracks were combined with oceanographic satellite data provided by NOAA, NASA, and a num
