Ancient leatherback turtles face extinction 'within decade'

The giant leatherback turtle, which has outlived the dinosaurs to survive unchanged for at least 50 million years, is heading for extinction.

The giant leatherback turtle, which has outlived the dinosaurs to survive unchanged for at least 50 million years, is heading for extinction.

Marine biologists have recorded a drastic decline in the turtle's Pacific breeding population and have for the first time documented the complete collapse in the number of females visiting one of the world's main nesting sites.

In 1988, the number of nesting females visiting Playa Grande, a beach on the Pacific west coast of Costa Rica, was 1,367. The latest survey, published in the journal Nature, shows that last year was the worst nesting season on record, with 117 female leatherbacks laying eggs in the warm sand of Playa Grande.

Scientists estimated that in 1982 there were about 115,000 breeding females in the world. By 1996, the number had fallen to just 34,500 individuals, with no signs of a recovery over the past five years. A mathematical model predicting the decline of Pacific leatherback numbers suggests that by 2004 there will be just 50 nesting females supporting a population of fewer than 300 individuals - which falls below the minimum number needed to sustain a viable population.

Biologists from Drexel University in Philadelphia believe that adult turtles dying in the open ocean, rather than hatchlings dying in the first few weeks of life, is the chief reason for the decline. Commercial fishing was also to blame.