by Sara McClintock

The atmosphere is tense and exciting during the night-time vigil. Will they arrive? At what time? Where? How many? All unanswerable questions when waiting for our planet's last throwback to the dinosaur era to make an appearance.

On the beach at Playa Grande on the Pacific coast of Costa Rica, we wait for a mother leatherback turtle to nest. On the first night none appear. This is hugely disappointing and worrying as December is peak nesting season and this beach is one of the country's most important turtle nesting sites.

On the second night, however, luck is with us. There is a call to say that a female turtle has arrived and we rush to see her. We watch as she hulks her massive frame up the beach: it's easy to understand why myth and legend surround this great mariner. Spanning more than two metres in length, she is an impressive sight. Unlike other turtle species, leatherbacks can dive to depths of 1,000m in search of food. They are something from another era, another world.

She is an infrequent visitor to shore, only leaving the sea to lay her eggs. There is a quiet dignity - a sense of purpose - about her journey that leaves no doubt about her singular mission: to ensure the survival or her species. Today, despite her efforts, she can't do that alone.

In Costa Rica, the older generation talks with pride of the arrival of the leatherback to these beaches. Many still have pictures of them, taken when they were children, standing alongside the giant visitor. The brave, and some might say foolish, would follow the turtles, which feed on jellyfish, back down the beach and ride on their backs over the first waves.

These were their turtles and part of their community. They brought fun and fascination - a glimpse of an ocean world that was hidden to them for most of the year; and they brought food. Turtle eggs have been eaten by the people of Costa Rica for hundreds of years. They are considered a great delicacy, and women often talk of the virility the eggs give to their men. At a time when human populations were small and turtles were abundant, this practice was wholly sustainable. Today, with ever-growing human populations and dwindling turtle numbers, it is disastrous.

There are very few pictures of today's children alongside a leatherback. The closest that many of them come is a blow-up replica used in their classrooms as a teaching aid.

Over the last five years, Pacific leatherback numbers have gone into freefall. Current estimates show fewer than 2,300 nesting mothers are left in the world. Playa Grande beach in Costa Rica has seen numbers fall dramatically. This is critical - not only ecologically, but also economically. A recent report suggested that if Playa Grande lost the leatherback, it would lose approximately US$2.1 million generated by tourism, which goes directly to the local economy.

Today the turtle faces dangers at sea and on land. Commercial fishing brings with it the risk of turtles being caught on long fishing lines and in nets - an undesirable outcome for both fishermen and conservationists. But technological solutions are being sought: changes in the shape of nets to give turtles an escape route are proving valuable, as are different shaped hooks that turtles are less likely to swallow. But possibly the most important change is that of attitudes. WWF is working on a programme where fishermen teach colleagues about new techniques to deal with accidental turtle catch. Fishermen are being encouraged to develop their own technological solutions and tools to help them keep turtles off their lines.

It is hoped that next year this initiative will go a step further when fishermen meet with local communities and businesses that rely on turtle tourism. Tourism is Costa Rica's number one industry and the country prides itself on conservation.

Attitudes are starting to change. The small Junquillal community, which hosts the fourth most important turtle nesting beach in Costa Rica, has seen a huge shift in attitude towards the turtle. In 2004, almost all the eggs laid on the beach were taken to eat. Today, almost none are taken, thanks to a concerted community effort to protect the nests, as the Junquillal people see the turtle as an important ecological asset for the future. Every night, patrollers walk the beach to monitor nesting sites and discourage poachers. Children learn about turtles, and the leatherback in particular, in school. They also help the baby turtles find their way to the sea when they hatch.

These simple community gestures are guaranteeing the turtle its continued place in the culture of the Junquillal community. This experience needs to be recreated the entire length of Costa Rica and Central America to make future night-time vigils a less tense, but not any less exciting place to be.