Leatherback turtles (in Spanish, baulas) are giant creatures. Often described as a relic from the age of the dinosaurs, they’re also one of the oldest animals on earth, having existed largely unchanged for 120 million years. The leatherback’s most arresting characteristic is its sheer size, reaching a length of about 2.4m and a weight of 500kg. Its front flippers are similarly huge – as much as 2.7m long – and it’s these which propel the leatherback on its long-distance migrations (they’re known to breed off the West Indies, Florida, the northeastern coast of South America, Senegal, Madagascar, Sri Lanka and Malaysia). Leatherbacks are also unique among turtles in having a skeleton that is not firmly attached to a shell, but which consists of a carapace made up of hundreds of irregular bony plates, covered with a leathery skin. It’s also the only turtle that can regulate its own body temperature, maintaining a constant 18°C even in the freezing ocean depths, and withstanding immense pressures of over 1500 pounds per square inch as it dives to depths of up to 1200m.
Since the 1973 Convention on the International Trade of Endangered Species, it is illegal to harvest green, hawksbill, leatherback and loggerhead turtles. Unlike olive ridleys or hawksbills, leatherbacks are not hunted by humans for food – their flesh has an unpleasantly oily taste – though poachers still steal eggs for their alleged aphrodisiac powers. Even so, leatherbacks still face many human-created hazards. They can choke on discarded plastic bags left floating in the ocean (which they mistake for jellyfish, on which they feed), and often get caught in longline fishing nets or wounded by boat propellers – all added to a loss of nesting habitats caused by beachfront development and the fact that, even in normal conditions, only one in every 2500 leatherback hatchlings makes it to maturity.
The number of nesting females at Las Baulas alone dropped from 1646 in 1988 to 215 in 1997, although numbers have since increased to over 800. At Las Baulas, authorities have established a hatchling “farm” to allow hatchlings to be born and make their trip to the ocean under less perilous conditions than would normally prevail, though this will not affect adult mortality, which is believed to be the root cause of the drop in leatherback numbers. While the population is healthier than it was fifteen years ago, it continues to be plagued by longline fishing, large-scale rubbish dumping, ocean contamination and other factors contributing to fertility problems.
If you’re interested in volunteering, Earthwatch (wwww.earthwatch.org) have run conservation holidays on Playas Grande and Langosta for a number of years, documenting numbers of nesting turtles and their activity patterns.