The Turtles That Turned

A small group of people, mainly tourists, stand in a row on the dark shore facing the sea. Each person is carefully holding a recently hatched turtle. The little animals fit snugly in the palm of one hand. Overhead the stars are shining brightly and a big moon provides enough illumination to throw gentle shadows. A strong onshore wind is blowing and the coconut palms are swinging wildly at the top of the shore

As one, the turtle-bearers kneel and place their tiny scraps of precious life on the sand. The little turtles seem to hesitate and then one by one start to make their precarious way – like so many clockwork toys – straight towards the lively sea.

This is a hatchling turtle release at Junquillal, a small town on the Pacific coast of Costa Rica. Here a WWF-led project involves the local community in caring for the turtles that come here to nest. Three species are involved,  the critically endangered leatherback, the Eastern Pacific greens and the olive ridleys, and each night a remarkable team of young people patrol the extensive soft sandy beaches until the morning to find any new turtle nest sites.

The mother turtles leave the sea under the cover of darkness and haul laboriously up the shore (this may be the first time that they have come onto land in decades) until, beyond the reach of the tidal sea, they select a site of deep soft, warm sand. Their huge flippers now become shovels and they scoop out a deep hole. They lay their eggs into this hole and then carfeully bury them by replacing the sand. Finally, the huge reptiles turn around and move back towards the sea, returning very laboriously (and seemingly exhaustedly) to the environment that they know best.

 Hatchling turtles awaiting release.

This is how it has been for millennia; ancient reptiles have left the sea to plant their eggs in the natural incubator provided by sandy shores and, in due course, the eggs hatch and tiny turtles make a famous scramble into the sea, often running a gauntlet of predators. But things have changed. The world is hotter and the turtle nests are no longer as productive as they should be. A higher temperature affects the sex-ratio of the hatchlings and more females are being born. Worse than this is that the temperature has now become so high that many of the eggs are cooked and killed in the increasingly hot sand.

So, the ground-breaking project in Junquillal is essentially a rescue. Once nests are located (and without frightening the mother turtles) the eggs are carefully dug up again and carried through the night to the shaded turtle hatchery where the temperature is controlled. Here, when they hatch and the hatchlings start to struggle to the surface, the team collects them up and, a little later, under the cover of darkness (and with the involvement of many locals and visitors), they are released onto the damp sand and allowed to make their own way into the sea. 

On one particular night in February the WDCS Science Director is fortunate enough to attend a release and he watches as the little turtles make their way into the frothy sea. They seem very vulnerable but our presence at least helps to keep predators away. After the last little turtle has disappeared into the waves the crowd slowly disperses.

On this evening, however, something unprecedented happens. There is a shout from the edge of the sea from the last observers still standing there that the little turtles are actually coming back out of the water. Small turtles are being cast up on the sand. They seem a little dazed and disorientated.

There is much consternation and concern coming from the turtle team. This is not meant to happen. In fact, this has never happened. Torches shielded with red-film to cause minimal disturbance to the turtles are deployed and many precious little animals are located and gently re-launched into the water.

The team stays on the shore anxiously watching for sometime, but this time the turtles stay in the sea. Will they make it and why were they so reluctant to do something that their whole survival is based on? The answer seems to be again to do with climate.

Costa Rica has been battered with strong winds and heavy rains these last few days. This is the dry season, but on the Caribbean Coast there is a state of emergency because of the flooding. We – and the turtles - are on the Pacific side of the country and here is usually windy and cold. The edge of the sea this evening is a chilly 14^oC when, more usually, it would be in the mid-twenties. Perhaps the strong winds have also contributed to this by causing deeper colder waters to mix with the surface layer.

Turtles are cold-blooded (unlike mammals they cannot control their own body temperature). So, what probably happened this one strange night was that the little turtles were too cold to swim efficiently and the waves pushed some of them back onto the shore. Hopefully, those that needed a second launch, once beyond the breakers on the shore’s edge, were able to gain the open sea and will join the hundreds of others that this remarkable project has released. (The next night when more little turtles were released, the temperature was much closer to the normal level.)

Unusual weather patterns are continuing to plague the planet, the bad weather is Costa Rica mirrors the severe winters still affecting Europe and North America, to say nothing of the drought and terrible fires in Australia.

The Science Director was in Costa Rica to help at a workshop looking at Climate Change in the region and particularly its impacts in the marine environment, including whales and is very grateful to his hosts. More about the turtle project in Junquillal can be found here.

 Turtle tracks