This year, the first baula—Costa Rican for leatherback sea turtle—emerged on the night of February 2nd from the dark Caribbean waves, and onto the shores of Ecology Project International’s Pacuare Reserve. EPI Costa Rica Research Coordinator Claudio Quesada and volunteers welcomed her quietly, and under soft, red light did their best to unobtrusively collect her measurements as she entered her natural nesting “trance.”
The 2,000-acre Pacuare Reserve safeguards one of the most important nesting beaches in the world for the endangered leatherback sea turtle. The Reserve’s beach is the only one on Costa Rica’s Caribbean coast reporting a stable trend in nests from year to year.
Worldwide, illegal harvest, entanglement in fishing gear, climate change, beachfront development, and industrial lighting near beaches that disorient hatchlings have all contributed to this ancient reptile’s steep decline. (Read more about how climate change affects sea turtles in Costa Rica here.) Sea turtles already have a dismal survival rate—estimates suggest that only 1 in 1000 to 1 in 10,000 hatchlings survive until adulthood.
Pacuare Reserve staff and volunteers have done their utmost to protect these giants of the sea for more than thirty years. When the sea turtle conservation program began, more than 98% of eggs were being illegally harvested. By hiring staff to conduct educational outreach, patrol beaches, and work with local students and volunteers to conduct nightly censuses, the reserve reduced that rate to less than 2%.
Although Pacuare Reserve’s initial efforts successfully safeguarded nests, eggs, and mothers, and the beach continues to be visited by nesting females each year, Quesada reports that recent hatching rates of in situ—literally “in place”—nests have been poor. Only 23% of eggs from natural nests are actually hatching. In response, Quesada has developed a method to prepare sand, relocate, and safely sequester threatened sea turtle nests—the hatcheries of Pacuare Reserve.
Only 23% of eggs from natural nests at Pacuare Reserve are hatching.
You might envision a “hatchery” as a sterile building with lots of expensive, whirring technology bustling with lab coat-clad researchers. But in fact, Quesada is finding that the most effective hatchery for sea turtles may be the very same beach the females have chosen—just a bit farther up the beach, and with carefully prepared sand.
Quesada is quick to inform visitors about what a hatchery really is. “Turtle hatcheries are not zoos, sanctuaries, or rehabilitation centers. In Pacuare Reserve, we use this conservation tool only when natural sea turtle nesting conditions are threatened.” And sea turtle nests are threatened, even at Pacuare Reserve—from flooding with seawater, beach erosion, fly infection, and the warming of the beach itself.
“Turtle hatcheries are not zoos, sanctuaries, or rehabilitation centers."
Each year, before the first baulas arrive, staff and volunteers ready the research stations for their arrival by creating two hatcheries. Quesada walks up and down the beach, poking at the sand, looking for the ideal locations to build.
“The most important consideration,” he says, “is looking for an area that won’t be eroded or inundated with seawater.” After he’s chosen two sites—one at the north end of the Reserve (the North Station) and one at the south end of the Reserve (the South Station), the excavation begins. Each hatchery will be approximately 16m x 9m and dug 1m deep.
When you consider that a single shovelful of damp sand can weigh ten pounds or more, you start to realize what a daunting venture creating a hatchery like this could be. But with dozens of volunteers and staff, mostly wearing muddy, rainbow-hued Crocs instead of lab coats, Quesada leads the creation of the hatcheries each year.
Once all the sand has been excavated, EPI staff and volunteers sift it all back into place. Sifting accomplishes two things: It removes organic materials that can decompose and heat up the sand, and it adds oxygen necessary for embryo development back into compacted sand. Next, to prevent the transmission of any pathogens in the sand, a dilute solution of chlorine bleach is poured over the sand. Lastly, poles and netting are erected around each hatchery.
Every nest that is relocated to the hatchery will be surrounded by a tall cylinder driven carefully into the sand, with an insect-proof net attached over the top. This allows for study of individual nests, as well as providing a second layer of protection against predators for the eggs and hatchlings. Automated readings of temperature and humidity are sent back to the research station every two hours.
Quesada has discovered that hatchery-sequestered nests boast a 73% hatch rate—more than triple the success of nests left to their own devices on the beaches. Last year, between natural, relocated, and hatchery-raised nests, Pacuare Reserve released 36,000 sea turtle hatchlings. Quesada plans to continue his research to understand why hatching rates at natural nests are so low.
Mama baulas have continued to arrive through February and now March, and will do so through June. Just after the hatcheries were completed this year, the first leatherback sea turtle nest was relocated—at dawn on February 28th. In approximately 70 days, tiny, flapping, hatchlings will stretch and tear at their shells and tumble up and out of the sand at the hatchery—more formally known as “erupting.” From there, gentle gloved hands will release them to the ocean.
Once hatchlings reach the ocean, it will be sixteen years before any of them return to shore. Only the female leatherbacks will ever leave their cold ocean home again, and only to nest. EPI’s Pacuare Reserve will be there for them. In the meantime, Quesada will be sharing his methods with other researchers eager to learn more and protect sea turtles in their own communities.
Since Ecology Project International began operating at Pacuare Reserve in 2000, more than 13,000 students, teachers, and community members have contributed to our efforts in Costa Rica. Over the past 20 years, the number of nesting females at Pacuare has increased by 6%, while in other areas of Costa Rica, the number of nesting females has decreased by as much as 87%.
The continued success of our leatherback research and conservation program and collaboration with local students relies on continued support. Learn more here about EPI's work at Pacuare Reserve. You can symbolically adopt a hatchling at Pacuare Reserve for yourself or someone else, or visit our donation page to support all of our critical conservation programs. Thank you!
Heather McKee is a science communicator and educator working as the Content Creator at Ecology Project International. She has an M.S. in Environmental Studies from the University of Montana and is a Certified Interpretive Guide through the National Association of Interpreters. Most recently, she helped create the award-winning Wings Over Water NGSS-designed curriculum with the Montana Natural History Center.
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