More than a place for monitoring, research, and protection, our hatchery is an essential incubation space for the sea turtles of the Osa Peninsula.
Photos and text by Giancarlo Velmarch
Before Osa became a peninsula, these shores were already an essential part of the sea turtles’ life cycle. For millions of years, mountains covered in primary forest have descended to meet the Pacific Ocean, sinking into a coastline of canyons and reefs. Between these two worlds lies an ecosystem gradually built by sediments carried by rivers, shells, and reef remains, and constantly transformed by the great, thundering waves of the Pacific: Playa Piro.
This beach is one of the few places in Costa Rica where all four species of sea turtles that inhabit the country’s coasts have been recorded: the green turtle, the hawksbill turtle, the olive ridley turtle, and the leatherback turtle. For some of them, Piro is a regular nesting site; for others, their presence is much more occasional. But they all share something: when a female emerges from the ocean and begins moving across the sand, she is following a cycle that began millions of years ago, long before the Osa Peninsula we know today existed. And it is precisely on this beach that millions of years of evolution and species adaptation encounter the threats of the present.
More than a specie
By traveling enormous distances throughout their lives, sea turtles connect different environments through their migrations, meaning that risks and threats occurring on one beach can be related to what is happening hundreds or thousands of kilometers away. They also function as bioindicators, as their presence allows us to understand the condition of ecosystems, the changes they are undergoing, and the threats affecting the species that inhabit them. That is why caring for sea turtles is not only about ensuring that a species survives, but also about conserving the ecosystems on which we depend.
Our work
Each season, all four species of sea turtles arrive on the shores of Osa. Females return to the same area of the beach where they were born to lay their eggs, in some cases traveling hundreds or thousands of kilometers to complete this cycle. This behavior is known as natal philopatry.
Their reproductive success is very low: it is estimated that only 1 in every 1,000 hatchlings reaches adulthood. From the moment they emerge from the nest, hatchlings face predators such as mammals, crabs, and other animals that may prey on them. Once in the water, the dangers continue: large fish, seabirds, and threats caused by human activity, such as bycatch and plastic pollution, mean that few manage to survive to adulthood.
At Piro, this problem occurs even before they leave the nest. Human presence and habitat fragmentation have altered the balance of the ecosystem, causing a decline in populations of large predators, such as pumas and jaguars, and favoring secondary predators such as raccoons and coatis, which are experts at detecting nests and feeding on the eggs.
The importance of the hatchery
We estimate that 9 out of every 10 natural nests are depredated at Piro, which is why we developed one of the tools we now use to mitigate predation and give turtles a greater chance of survival: the hatchery.
Patrols are carried out at least twice a day, covering 6.5 kilometers of beach. The first shift begins in the morning, when part of the team leaves the biological station at 4:30 a.m., and the second takes place at night, leaving at 8:30 p.m. During these patrols, they walk along the beach looking for the tracks left by turtles as they move from the sea toward the forest, indicating that they have come ashore to nest. When they find a track, the team carefully uses red light to locate the individual and identify what stage of the process it is in: whether it has just arrived, is already digging, or is even laying its eggs.
During egg-laying, the turtle uses so much energy that it enters a trance-like state. This is when the team gets to work. They begin by taking measurements of the turtle, checking whether she has a tag on her flipper, and, if not, tagging her so that they can keep a record of that individual. Before the turtle begins covering her nest, they measure its depth. Once she returns to the sea, the team carefully excavates the eggs and places them in a bucket to transport them to the hatchery.
To create this essential space, we used reusable materials, and two months of construction were required with the help of 60 people, including volunteers, interns, and staff from different countries around the world. But its importance goes far beyond keeping the eggs safe from predators. Every egg that reaches the hatchery also represents an opportunity to learn, conduct research, and better understand what these species need to survive.
such as covering part of the enclosure to analyze the different nest temperatures in the
shade and without it.
From nest to knowledge
In this way, the hatchery becomes a space where people can get closer to conservation work and understand firsthand what it means to protect some of the country’s most emblematic species. Volunteers, interns, students, and groups from schools and local communities can see up close the process that takes place behind every nest, from the moment a turtle arrives at the beach until her hatchlings finally break through their shells and begin their journey toward the sea. Each visit is an opportunity to turn the experience into knowledge that lasts and, above all, to create a real connection with a species that we rarely have the opportunity to truly observe and appreciate.
But to conserve a species, we need to keep learning about it and how it responds to its environment. That is why the hatchery also functions as a space for research. Monitoring the nests allows us to collect information about their development, incubation conditions, and hatching success, while implementing new monitoring methods can help us better understand what happens during this particularly vulnerable stage of their life cycle. The information we obtain here does not stay within the hatchery: it becomes knowledge that can help us improve our conservation strategies and make better decisions for future seasons, which is vital for a species that increasingly depends on human intervention.
the new generation of this species.
A safer future
When the last nest of the season hatches and all the hatchlings reach the sea, the work is only beginning. Each season leaves us with new questions, new data, and new opportunities to better understand sea turtles and the threats they face. In addition to allowing us to protect a percentage of nests today, the hatchery also helps us learn more about what happens during the early stages of their lives and identify how we can improve our conservation strategies for these species in the future.
Our marine conservation work is not solely focused on protecting sea turtles during a nesting season. All the work behind it—the constant monitoring of the beach, nest tracking, research, and incorporation of new techniques—allows us to build, year after year, a more complete picture of these species and what they need from us to survive. Every piece of data collected, every nest monitored, and every turtle that safely reaches the sea becomes another piece of an ongoing effort toward a future in which these beaches remain a place where turtles can return.
Would you like to visit the hatchery and take part in the recovery of our turtles?
Come experience it at our campus: https://osaconservation.org/visit-us/
