Leatherbacks turn up by the tens of thousands

The largest population of leatherback sea turtles in the world has been identified off the coast of Gabon, Africa, and is estimated at somewhere between 15,700 and 41,400 female turtles. This seems to be a big bounceback for the endangered turtles, which are the largest living members of the sea turtle superfamily.

This rough estimate was compiled during three nesting seasons between 2002 and 2007, using video to capture footage along Gabon’s 372-mile coastline, in addition to terrestrial monitoring. The study, which appears in Biological Conservation, also identifies the key sites for leatherback nesting, which can be used in assessing and developing management strategies.

Beginning about 25 years ago, leatherback populations in the Indo-Pacific oceans were reduced to less than 10 percent of their former size. Although the International Union for Conservation of Nature (IUCN) lists leatherback turtles as critically endangered on a global scale, adequate population assessments across much of the Atlantic, especially along the African coast, are in short supply.

In a press release, lead author Matthew Witt of the University of Exeter said:

“We knew that Gabon was an important nesting site for leatherback turtles but until now had little idea of the size of the population or its global ranking. We are now focusing our efforts on working with local agencies to coordinate conservation efforts to ensure this population is protected against the threats from illegal fisheries, nest poaching, pollution and habitat disturbance, and climate change.”

The study also showed that about 79 percent of nesting in Gabon occurs within national parks and other protected areas. Good news for the turtles, as these areas will be much easier to manage than privately owned lands.

Photo courtesy Matthew Witt.

Witt, M., Baert, B., Broderick, A., Formia, A., Fretey, J., Gibudi, A., Moussounda, C., Mounguengui Mounguengui, G., Ngouessono, S., & Parnell, R. (2009). Aerial surveying of the world’s largest leatherback turtle rookery: A more effective methodology for large-scale monitoring Biological Conservation DOI: 10.1016/j.biocon.2009.03.009