The mysterious leatherback turtles are huge and difficult to get a glimpse of. The up to 500 kg heavy collosse cross several oceans. But for reproduction, under the cover of night, they always return to the beach where they themselves hatched from the egg. And they have been doing this since time immemorial, long before the first dinosaurs appeared.
Ten enterprising explorers work together at a remote research station, studying not only the behavior of the heaviest reptiles. Protection from poachers, who dig the eggs out of the black lava sand and sell them as an aphrodisiac miracle cure, is also a key aspect of the project run by the organization LAST (Latin America Sea Turtles).
Biosphere Expeditions is an ethical conservation organization that provides a unique vacation experience for its participants, who in this case have traveled from Canada, Australia, England, Germany and the United States. Once the participants arrive at a hotel in the capital San José at the agreed time, their onward journey to the remote research station is well organized. Previous experience in scientific work is not required. Thus, everyone participates in the research for a week and at the same time fulfills the wish for an active vacation in which one experiences a lot and still does good.
The Pacuare Research Station on Costa Rica’s Caribbean coast operates only during the breeding season, which begins in March each year. It can only be reached by small boats via canals that were constructed many years ago to open up the remote region. Simple accommodations fade into the background once the vacation experience takes off. Participants agree on this at the latest after they have made acquaintance with the elements on their first night on the beach.
This vacation gives the feeling of being able to get up close and personal with the systematic observation of nature. Alexander von Humboldt with his detail-obsessed passion or Charles Darwin, who studied evolution on a long voyage around the world, could be the role models for our group, which also happens to include a lot of basic scientific understanding. The microbiologist couple and the doctor from England, the film producer and the pharmacologist from Canada, the acupuncture therapist from New York or the chemist and the patent attorney from Germany. Everyone finds the exchange of experiences among themselves and the daily lecture by the biologist who leads the scientific project very invigorating. They talk in English and are on a first-name basis right from the start.
Ida Vincent, on behalf of Biosphere Expeditions, makes sure that the stay is safe, that a fair amount of science is taught, and that the expectations of the participants are met. Project leader Dr. Fabian Carrosco and his scientific staff familiarize us already on the day of arrival with the procedures that might have to be applied the next night. Using a turtle model, we learn which activities are necessary when a group encounters a turtle on the beach. Especially important: It must not be disturbed under any circumstances when it is choosing the place to lay its eggs. This is also the reason for the dark clothing and the absolute ban on using flashlights with white light.
The dimensions of the turtles are to be noted, as well as the numbers of the plaques used to mark each one. For example, it has been found out that leatherback turtles come ashore to lay their eggs an average of seven times in the course of a breeding season, which lasts from March to August. Incidentally, giant tortoises do not reach sexual maturity until they are 30 years old. When they are not in Costa Rican waters for mating, they prefer to stay in the Atlantic Ocean off South Africa, where they feed on algae and accumulate sufficient energy reserves under their leatherback (no shell) for their biennial trip to Costa Rica.
Fabian is a biologist and expert on sea turtles. Together with four scientific assistants, the Mexican has been recording all nesting activities on the more than seven kilometer long stretch of beach of the LAST project for two years. To protect them from egg thieves, the clutches must be transported immediately after egg laying to a guarded nesting area that the team made from cleaned sand at the beginning of the season.
Nightly encounter with a mythical creature
In the middle of the night, our patrol leaves the station. Silently, our group walks along the beach through the soft sand in single file behind the guide, who is difficult to see at first in her dark clothing. In time, however, I find it reassuring to be alerted by her stumbling to the driftwood, which is also hard to see. After only half an hour, we see a red light shimmering in the distance that, as we get closer, is recognizably part of another group that left hours before us. On the way back it has discovered a leatherback turtle that has just decided on a place to lay its eggs. We take the opportunity to follow the process in the light of the three red headlamps, before continuing our own patrol after a short time.
Concentrating, research assistant Sarah Palmer and her group watch as the turtle digs a 75 cm deep circular hole in the moist sand with its hind flippers. She dictates the depth and location of this nest to her colleague Grace Kibblewhite, as well as the dimensions of the shell. From the code on the marker tag, Fabian will discover the following day that this turtle has already filled a nest with eggs exactly 14 days ago at a location 500 meters away.
At the time of egg-laying it gets exciting again. Now a large plastic bag has to be placed in the nest (unnoticed by the turtle), which then has to be quickly pulled out of the hole filled with eggs, before the turtle pushes the hole closed again with sand with energetic flipper strokes.
Deeply impressed by the immense dimensions of the approx. 500 kg heavy reptile, which can move only with difficulty on land, puffing heavily, we move on through the darkness. Under the shining starry sky I get awe of the many wonders of nature.
Neighborly relationship with the population
The people on this stretch of coast near the mouth of the Pacuare River live simply. The nearest school is far away and there is much illiteracy. Fishing, coconut and banana harvesting are for their own consumption. For a long time, the sale of turtle eggs has been an important source of income. The sale of a single clutch of eggs is equivalent to half the monthly needs of a family of ten. Although sea turtles are also protected by law in Costa Rica and the trade in turtle products has been banned worldwide since the Washington Convention on International Trade in Endangered Species of 1973, this can practically only be achieved by offering people a substitute for their loss of income.
And this is where Biosphere Expeditions works on several levels. Two-thirds of the participant fees for each expedition go to the project, funding, among other things, the wages of local guides who now offer their knowledge as former poachers to researchers and an international audience, while coming into contact with foreign languages.
The research station has become a popular attraction, and the Sunday soccer matches between Costa Rica and the rest of the world also ensure the careful development of the region, although the rescue of endangered species was initially the main focus.
Species conservation and science
I find the nighttime encounters with poachers scary, but not really dangerous. A respectful “gentlemen’s agreement” has been established whereby confrontations are avoided. Whoever reaches an egg-laying turtle first gets to take the eggs. The poachers for sale, the project workers to the hatchery guarded around the clock at the research station. In order to be able to monitor the beach as closely as possible at night, Fabian and his research assistant Charline Fisseau draw up a different plan every evening. This keeps them unpredictable for the poachers and even allows them to adjust to the greater poaching pressure at the weekend. This is because egg collectors from other parts of Costa Rica also arrive then.
The so-called Hatchery has been filled up at the beginning of the season with sieved sand obtained from the surf and disinfected by the sun. A precise record is kept of all the staked fields. At the end of the breeding season, which lasts an average of 60 days, the hatched turtles are counted and measured. Then they are allowed to cover the 20 meters to the sea under their own steam. In the process, they memorize the “home scent” that can help them find their way back 30 years later.
The chances of each individual hatchling are not exactly favorable, because statistically only one in a thousand can reproduce again. Many enemies are especially hard on the young sea turtles. Man is one of the worst of them. Even if poaching has been effectively reduced on this part of the coast and therefore more mothers will return here in the future, there are other factors.
Environmental influences such as climate change, plastic in seawater and light pollution have reduced the average life expectancy of leatherback turtles from once 75 years to now 60 years.
Species protection leatherback turtles
Biosphere Expeditions’ citizen science project researches the endangered leatherback turtles in Costa Rica. The animals are huge and hard to get a good look at. The collosse weigh up to 500 kilos and cross several oceans on their journeys. But for reproduction, under the cover of night, they always return to the beach where they themselves hatched from the egg. This has been happening since time immemorial. Long before there were dinosaurs on earth.
The species conservation project of the organization LAST (Latin America Sea Turtles) researches the behavior of the heaviest reptiles. But protection from poachers, who dig the eggs out of the black lava sand and sell them as an aphrodisiac miracle cure, is also an essential aspect of the work.
Biosphere Expeditions is an ethical conservation organization that provides participants with a unique vacation experience in a remote research station. No previous experience in scientific work is required. In this way, everyone participates in research for a week and at the same time fulfills the desire for an active vacation in which one experiences a lot and still does good.
Other aspects: Systematic observation of nature à la Alexander von Humboldt / supervision and training by scientific staff / patrolling at night to protect against poachers / the egg-laying of the giant tortoises / work in the hatchery / the hatchlings / dealing with poachers / the population.
The stay in the research station was not charged