Contribution starting at $3,350
Exported from Streamline App (
9 days (avg. $372 a day) Includes accommodations, food, and all related research costs
Ocean Health

Costa Rican Sea Turtles

Parque Nacional Marino Las Baulas & Playa Cabuyal, Guanacaste Province, Costa Rica. Map it
Activity Level
Very Active
Wilderness Camp/Dorm
buffet-style meals
Dinner at local restaurants
Special diets accommodated
A leatherback sea turtle (Dermochelys coriacea) comes ashore to lay her eggs (C) Ellen Mcknight
Earthwatch volunteers collect data on a nesting female leatherback (C) Russ Schleipman
A leatherback sea turtle hatchling sprints to the ocean (C) Nathan Robinson
Earthwatch volunteers excavate a hatched leatherback sea turtle nest (C) Amy Rougier
Earthwatch volunteers record the location of a leatherback sea turtle nest (C) Brittney Rose
A female olive ridley sea turtle (Lepidochelys olivacea) returns to the ocean after laying her eggs (C) Nathan Robinson
Earthwatch volunteers take a day trip to assist with in-water boat surveys (C) Dr. Frank Paladino
A leatherback sea turtle (Dermochelys coriacea) comes ashore to lay her eggs
Earthwatch volunteers collect data on a nesting female leatherback
A leatherback sea turtle hatchling sprints to the ocean
Earthwatch volunteers excavate a hatched leatherback sea turtle nest
Earthwatch volunteers record the location of a leatherback sea turtle nest
A female olive ridley sea turtle (Lepidochelys olivacea) returns to the ocean after laying her eggs
Earthwatch volunteers take a day trip to assist with in-water boat surveys.

The leatherback sea turtle population in the Pacific, once the species' stronghold, has decreased by over 90% since 1980. Help scientists investigate this decline and find ways to save this and other sea turtle species.

Earthwatch research staff measures a leatherback sea turtle hatchlingCosta Rica’s Guanacaste Province is home to four of the seven species of sea turtles currently existing. Las Baulas National Marine Park and Playa Cabuyal are critical nesting grounds for endangered leatherback, green, and olive ridley sea turtles. The waters along North Pacific Guanacaste Province are critical foraging habitats for the juveniles of these species, along with the critically endangered hawksbill turtle. Together, this makes Guanacaste important for the multiple life stages of these turtles and especially important for their survival. 

In the beginning, on the sandy shorelines, the mama turtles haul themselves out of the ocean, dig holes with their rear flippers, and lay clutches of soft-shelled eggs. After a few months, fragile hatchlings will emerge and make their way to the ocean.

The world is a dangerous place for these tiny turtles and their parents. They’re threatened by climate change, boat traffic, fishing gear, coastal development, nest predation, and humans hunting them for their meat and eggs. To truly understand why these ancient species have declined so rapidly and what we can do to stop this decline, researchers need to know everything about them: their behavior, physiology, genetics, population biology, and migration patterns. Subsequently, it is essential to determine whether the current conservation and management efforts are working and how climate change impacts these populations.

To build this knowledge base, you’ll walk the beach at night when turtles are active, getting up close to these massive animals to identify individuals and take measurements that help determine how they have changed since they were last seen. In addition, you may help collect skin samples for genetic analysis or attach transmitters that will track their local and long-distance movements. You’ll also help relocate eggs to a hatchery from nests in dangerous spots, like where waves might wash them away. The researchers on this expedition have studied sea turtles for over three decades, and you'll help them expand the longest-running database on Pacific marine turtles. This work is critical: with sea turtle populations declining at an alarming rate, each turtle is precious.



A Typical Itinerary

  • Day 1: Arrival and orientation at Goldring-Gund Marine Biology Field Station (Playa Grande, Las Baulas National Marine Park)
  • Days 2–4: Surveying the beach at Playa Grande, monitoring nesting turtles, relocating nests, & releasing hatchlings (team-dependent)
  • Days 5–7: Transfer to the rustic Los Horizontes Station at Playa Cabuyal. Surveying the beach at Playa Cabuyal, monitoring nesting turtles, relocating nests, and using camera traps to assess biodiversity in the nearby mangrove estuary (team-dependent) 
  • Day 8: Day trip to conduct boat-based research on marine turtles at Bahía Matapalito, Santa Rosa National Park. Return to Goldring-Gund Marine Biology Field Station for concluding activities. 
  • Day 9: Departure




You’ll do much of your work at night when the turtles haul themselves onto the beach to lay their eggs. A rotating group of team members will work six hours each night and have time to sleep during the day when the other group of volunteers goes out. You and your teammates will help:


Observe and monitor nesting leatherbacks © Nathan Robinson

Those working on the beach at night will visit each nesting female turtle to take measurements, count eggs, and record any unusual markings or injuries. In other words, you’ll get as close as a person can to these majestic animals.

Relocate sea turtle nests © Ed Talbot

Early in the breeding season, you'll check for nests in danger of getting washed away, then relocate the eggs in those nests to a hatchery where they can incubate safely. From mid-December to February, when the hatchlings emerge from the eggs in the hatchery, teams will take the tiny turtles to the beach and release them into the wild.

Earthwatch participants survey the beach © Amy Rougier

During the day, teams will count sea turtle nests on the beach, take nest temperatures, and look for signs of erosion that could threaten nests.


Teams will also take a day trip to Bahía Matapalito to assist with boat-based surveys. Participants will help local researchers monitor juvenile and adult green, olive ridley, and hawksbill turtles. You’ll assist with weighing, measuring, and tagging turtles as a part of this work.

Field conditions and research needs can lead to changes in the itinerary and activities. We appreciate your cooperation and understanding.





5 Reviews on this Expedition

If you have been on this expedition, others considering attending would love to hear about your experience.
2023 Earthwatch Participant |
I didn't know anything about sea turtles before I started and I learned a ton, mostly on-the-job. I was in the center of some thrilling and important work with a cast of characters from around the world. It was a great way to get to know the Guanacaste region of Costa Rica, I feel way more connected to the country now than if I'd just been a tourist passing through.
Nerys Nicholls |
I thought I might be lucky to see one or two turtles in my time with the team at the Playa Grande Research Station, but I never expected to see over a dozen (not including the hundreds I was lucky to see at the Ostional arribada!). Working with a nesting leatherback is a memory that will stay with me for a lifetime. Pictures do not do these animals justice, they truly feel like living dinosaurs. Adam and Abby, along with the rest of the biologists, were super welcoming and made us feel right at home and confident during our nighttime beach patrols. The accommodation is lovely within a beautiful setting, and nothing is more rewarding after a night patrol than brunch at Kiki's Place! I've been craving the bean pizza since I left.
Ann Coles |
Supporting the project's biologists in their efforts to save leatherback turtles from extinction was one of the most challenging, yet learning-filled and rewarding experiences I have had. I knew nothing about sea turtles when I arrived at the research station and did not appreciate how hard it would be to patrol the beach where the leatherbacks nest from 11 pm to 5 am almost every night with only a new moon and stars as light. After the first night, I wanted to return home as quickly as possible. But I am so glad I stayed! Leatherbacks are incredible, other-worldly creatures returning to the beach where they first hatched every three years to lay hundreds of eggs, and then going back to the sea without ever knowing their hatchlings. Releasing babies that fit into the palm of a hand into the sea, wondering how they will survive with a nurturing parent and yet they do. The commitment of the biologists - mostly recent college graduates - to the turtles and the research protocol also impressed me deeply. The project also had great amenities - a location on a beautiful, three-mile beach populated mostly by surfers, a gorgeous sunset every evening, good meals at a nearby cafe, internet connection, and air-conditioning in the living area. I would highly recommend the project for someone in excellent physical condition with a passion for learning and a love of the seaside.

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