How does a green sea turtle’s choice of where she lays her eggs affect her babies’ survival? The answer to that question will help conservationists who work with the endangered turtles.
Marielle Livesey, a master’s candidate at Antioch University New England (AUNE), went looking for an answer and spent two months last year in Akumal, Quintana Roo, Mexico, studying the endangered green sea turtle. Her work – a thesis for her master’s degree in Environmental Studies with a concentration in Conservation Biology, at AUNE – will eventually project how the population of the turtle, affected by global warming, will look in the year 2100.
Marielle, working with Central Ecologico Akumal (CEA) through an internship with Science Exchange at San Diego State University, gathered extensive data on sixty-two green sea turtles. As a result of her work collecting data on how a female chooses her nest site, and the conditions in the nest during the incubation period, Marielle hopes to make a recommendation to CEA conservationists about whether they should build a hatchery for sea turtles in order to mitigate the effects of global warming. With the data collected, CEA conservation managers now know how to closely replicate the natural habitat and artificially incubate the eggs under the same conditions.
Choosing a Nesting Site
A female green sea turtle climbs onto the beach to lay her eggs, searches for just the right place to lay her eggs, digs a bed and then a chamber and drops her eggs. Finally, after much effort covering her nest, she returns to the ocean about two hours later. After two months, the baby turtles hatch and make their own way to the water from the nest. Where the nests are located may have a lot to do with if the hatchlings survive. Nests sites built closer to the water are more likely to be flooded and lost to erosion, while nests built farther inland are more likely to be dehydrated, or the females, eggs, and hatchlings destroyed by predators.
Marielle collected data along the track of each of the females until the turtle stopped at the place she perceived as the most conducive to producing a high success rate for her hatchlings, thereby increasing her reproductive fitness. Once the female laid her eggs, Marielle collected additional data at the nest site and, when the eggs hatched, she collected data on the clutch size and both the hatchling success and survival rates. (All hatchlings that live through the incubation and hatch do not make it to the top of the nest to crawl out, so two different numbers are significant).
Protecting the Sea Turtles of Akumal
CEA promotes conservation initiatives in the resort town, encouraging hotels, resorts, businesses, and tourists to act responsibly and to respect the surrounding marine habitat. Akumal, located on the Yucatan Peninsula’s Caribbean coast, means “Place of the Turtles” in Mayan. Its beaches are a nesting ground for the green sea turtle, a big attraction for tourists who come to Akumal’s beach-front hotel and tourist community. It’s one of the only locations in the world where people can snorkel and swim with the sea turtles and other marine species for free in their natural ocean habitat. At night, when the sea turtles come to nest, some resorts move their sun-tanning chairs from the beach to accommodate the arriving females, replacing them in the morning.
Marielle, a Boston native, always had a love for endangered species. While she was attending the University of Massachusetts-Amherst, during a study-abroad semester at Macquarie University in Australia she researched the science of sex as the underlying principle of reproduction, with an eye to applying the knowledge to conservation of endangered species. Her capstone project was on sea turtle populations in Costa Rica, which led to her interest in sea turtles.
As a student in AUNE’s conservation biology program, Marielle also learned how to use ArcGIS software through an internship with the Nature Conservancy. And now, a new graduate, she plans to use her skills and education to find a job in North Carolina integrating sea turtles, marine science, and ecology with GIS technology.