All seven of the planet's species of marine turtles are threatened or endangered. The human threats to their survival are legion, from habitat destruction or alteration of their nursery, feeding, or nesting areas, to poaching of their meat, shells, and eggs, to accidental drowning at sea on longlines or in gillnets.
Because sea turtles are long-lived, slow to mature, frequently migratory, and rarely glimpsed (only females ever come ashore-to nest), it has proven an exceptional challenge for biologists to gather the most basic data about their life cycles, population trends, and survival needs to inform conservation decisions.
It is precisely these kinds of challenges, however, that the Earthwatch model of participant funding was designed to meet. Starting in 1977 with a project investigating the in-water behavior of hawksbill turtles off Grenada, Earthwatch has sent more than 4,000 volunteers and $3.4 million into the field with turtle researchers on 18 projects. Together with dedicated biologists, they have investigated myriad aspects of the lives of five marine turtle species and catalyzed the creation of two nationally protected areas for nesting leatherback turtles: the Sandy Point National Wildlife Refuge on St. Croix, U.S.V.I. in the Caribbean, and Parque Nacional Las Baulas on Costa Rica's Pacific coast.
In 1987, the US Department of the Interior presented Earthwatch a Conservation Award for its work on St.Croix. Earthwatch data from Parque Nacional Las Baulas played into the uplisting of the leatherback turtle as Critically Endangered and is a vital component in the CITES Hawksbill Range States Dialogue that guides development of a regional management plan for hawksbill sea turtles (See "Changing the Future for Sea Turtles").
The Earthwatch model of supplying volunteer workers and funds gave sea turtle researchers the labor force to thoroughly monitor the nesting activities and productivity of sea turtles while discouraging egg-poachers along stretches of prime nesting habitat. The success of these multi-year projects is measured in hundreds of miles of beach walked at all hours of the night by Earthwatch team members awed and inspired by the sight of sea turtles performing their ancient nesting ritual.
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"It's been more than 20 years [in fact, it's been 25 years] since we led the first Earthwatch teams at what is now Sandy Point National Wildlife Refuge. It was clear from the start that it would be a match! I'm pleased to see Earthwatch sponsoring more and more sea turtle programs, including a new offering in Trinidad, which give the public an opportunity to participate directly in the survival of these gentle, ancient creatures. With Earthwatch's unflinching dedication to excellence and the passion shown by their volunteers, we certainly are changing the future for endangered populations that otherwise would continue to decline."
-Dr. Karen L. Eckert, Executive Director, WIDECAST and former Field Director, Saving the Leatherback Turtle, St. Croix
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For young biologists, an Earthwatch grant to study sea turtles often launched a distinguished career (see "Rising Stars"). For volunteers, the stirring and slightly surreal experience of patrolling beaches into the wee hours of the morning, witnessing a turtle's laborious nesting procedure, and playing midwife and chaperone to hatchlings made an indelible impression. So did working with local people, including former poachers turned park guards and children with a new investment in wildlife. As a result, some volunteers have returned home to actively pursue new conservation concerns (See "Going Above and Beyond").
On many nesting beaches, Earthwatch teams have substantially reduced or eliminated poaching, educated hundreds of tourists and local people about sea turtle conservation, inspired community involvement (See "The Local Connection"), and moved hundreds of erosion-prone nests to safe hatcheries. On St. Croix alone since 1982, the hatchery has produced well over 100,000 leatherback hatchlings that otherwise would have been lost to erosion and has boosted hatchling output by 40 percent.
Earthwatch volunteers' all-night beach patrols have enabled biologists to conduct saturation monitoring and tagging programs of nesting female turtles over consecutive years. These long-term projects have been crucial in determining average number of viable eggs laid per nest, average number of nests per turtle per season, inter-nesting interval, and beach fidelity.
All this information is critical to tracking populations, reproduction, and migrations. From the voluminous data teams have collected on leatherback turtles, for instance, biologists have established that leatherbacks tend to nest every second or third year and may lay as many as 10 or 11 nests a season (800 eggs or more). This discovery corrected previous estimates of population and productivity (based on numbers of tracks), which both overestimated the population and underestimated its fecundity.
Recent dramatic increases in the number of small, "clean" (without tags) nesting leatherbacks on Parque Nacional Las Baulas and Sandy Point beaches may indicate that female hatchlings Earthwatch volunteers shepherded to the sea a decade or more ago have returned to nest-a phenomenal success story, if true. It would also establish a critical date in the leatherback's life cycle: age at reproductive maturity, but this hypothesis awaits the results of current DNA research on nesting leatherbacks (see "The Lost Years")
Volunteers have helped test and refine identification, egg/hatchling-counting, and nest-moving and nest-monitoring methods (see "Maximizing Turtle Survival"). Earthwatch-supported sea-turtle research has also been on the forefront of investigating the 99 percent of turtles' lives they spend at sea,: what they eat, where they go when they leave the nesting beach, and what guides their travel (see "Investigating Turtles' Lives at Sea").
Over the years, Earthwatch teams have helped write the book on how to conduct a turtle-nesting study and run a hatchery, the starting point for beach-based sea turtle conservation programs. The flagship project on St. Croix has been cloned the world over, and was a model for Caribbean-wide sea-turtle conservation efforts initiated by the United Nations Environmental Program's WIDECAST program. The program is currently headed by one of the St. Croix leatherback project's earliest field investigators, Dr. Karen Eckert, whose doctoral research was based largely on the leatherback turtle-nesting data that Earthwatch teams collected.
Earthwatch will continue to support projects exploring the population biology of sea turtles around the world, projects that in many cases spell the difference between survival and extinction for some turtle populations