An international team of scientists has discovered the world’s largest nesting population of leatherback sea turtles in the west-central African nation of Gabon. The researchers combed the country’s beaches by foot and by plane, estimating a population of between 15,730 and 41,373 female turtles using the nesting beaches. The study highlights the importance of conservation work to manage key sites and protected areas in Gabon.

Leatherbacks are the most widespread marine turtle, found in the Pacific, Indian, and Atlantic Oceans, particularly in tropical regions. They are also the largest sea turtle, reaching up to 6.5 feet and 1190 pounds. Unlike other sea turtles, the leatherback’s shell is not hard, but made up of a mosaic of small bones covered by firm, rubbery skin. Leatherbacks are strong swimmers, able to travel thousands of miles to cross ocean basins and dive up to three-quarters of a mile in search of their jellyfish prey.

Populations of leatherbacks in the Indo-Pacific crashed by more than 90 percent in the 1980s and ’90s. The IUCN lists the species as Critically Endangered across the globe, but detailed population assessments in much of the Atlantic, especially Africa, are lacking. Leatherbacks were first described nesting in Gabon in 1984.

Wildlife Conservation Society (WCS) researchers carried out the research in collaboration with the University of Exeter (UK) and other groups. WCS spearheads the Gabon Sea Turtle Partnership, a network of organizations concerned with the protection of marine turtles in Gabon.

Over three nesting seasons between 2002­ and 2007, the team carried out the most comprehensive survey of marine turtles ever conducted in Gabon. During aerial surveys along the 372-mile coast, they recorded videos of nests and nesting females. They were also able to identify key sites for leatherback nesting, information that is crucial to developing conservation management plans. The team found that 79 percent of the nesting occurs within national parks and other protected areas.

Dr. Matthew Witt of the University of Exeter was the lead author on the research paper, published in the May issue of Biological Conservation. He said the discovery has helped direct new conservation efforts for sea turtles in Gabon.

“We are now focusing our efforts on working with local agencies to ensure this population is protected against the threats from illegal fisheries, nest poaching, pollution and habitat disturbance, and climate change,” Witt said.

The study was made possible through funding by the Natural Environment Research Council (UK), the United States Fish and Wildlife Service (USFWS), and the Marine Turtle Conservation Fund (U.S. Department of the Interior). Additional funding was provided by the United States Agency for International Development (USAID). The team has now also received $450,000 in Darwin funding for a three-year project to work with local agencies to improve marine biodiversity management in Gabon.