Leatherback sea turtles
UD alumna studies leatherback sea turtles in Costa Rica
9:27 a.m., Feb. 17, 2014--It’s not every day that you get to see a creature that has been around for 110 million years emerge from the ocean and lay its eggs on the beach. Unless, of course, you’re like University of Delaware graduate Lauren Cruz, who spends her days in Costa Rica with the Leatherback Trust studying leatherback sea turtle nesting ecology.
Cruz, a 2013 graduate who studied wildlife conservation in UD’s College of Agriculture and Natural Resources, is tracking the demographics of the turtles that nest at Playa Grande and Parque Nacional de las baulas -- which translates to the park of leatherback sea turtles -- and spends her nights with a team patrolling the beach looking for nesting turtles.
When they find a turtle, they will scan it to see if it is a returning turtle. If not, they will outfit the turtle with a tag in order to track it.
“We also count the eggs, and sometimes we have to relocate the eggs, depending on whether they’re close to the water, close to the vegetation, and then after they lay the eggs, we monitor their nests and see them through until the hatchlings grow out of the nest,” said Cruz.
Cruz has worked with the organization since October and said her favorite part of the work is the turtles, but that she also enjoys learning about the Costa Rican culture.
“What’s great is that out here they have a good ecotourism program where the locals -- a lot of them who used to be poachers -- found that it’s more sustainable to take tourists out to see the turtles rather than take their eggs,” said Cruz, who explained that the organization will work with groups of locals to help locate nests.
“When we find a turtle, we tell them so they can grab their tourist and it’s just a great experience working with the local Costa Ricans,” Cruz said. “And my Spanish has gotten much better since I’ve been here. So it’s a cultural experience and I really like working with the community and the education aspect of it.”
Cruz said that so far this winter, they have had 24 individual leatherback sea turtles nest on the beach. She said that this figure is in line with the amount they had last year, but they are hoping to see an increase any time soon. The nesting season lasts until March so there is still some time and Cruz is optimistic that they will have more turtles nest on the beach.
Still, when compared to numbers from the past, it becomes obvious why leatherback sea turtle conservation is of the upmost importance. “When they first started doing this project, 20 years ago, they’d have 1,000 individuals or so on the beach so it’s sad that it went from 1,000 to 20,” said Cruz.
Cruz said that while the leatherback turtles who nest on the Caribbean coast have seen a population rebound in recent years, ones that nest on the Pacific coast are still critically endangered. “A major facet to their endangerment is the development because so many people want this beach,” said Cruz. “They want to develop on it and they want to build hotels, and when they build hotels they emit a lot of light and also change the topography of the beach so it makes it unusable for turtles to nest on it anymore.”
Cruz also said that climate change is a threat to leatherback sea turtles, as the species is temperature dependent on determining if a turtle will be male or female. “The pivotal point for the sex ratio of leatherback sea turtles is 29.4 degrees Celsius, so any nests that incubate above that temperature will be mostly female and any nests that incubate below that temperature will yield mostly males,” said Cruz.
Because the sand heats up sooner and there is a shorter wet season, the turtle clutches are hypothesized to yield more females than males, which will ultimately lead to a population decline. Cruz also said she has observed the eggs in the nest have been heating above their critical temperature which has cut down on nest success.
The other big threat is long line fisheries that catch leatherback sea turtles in their hooks.
As for how she got interested in turtles, Cruz said that it happened during her time at UD. “It’s definitely something that came about at UD. While at UD, I was able to participate in a lot of different research projects to figure out what I was really interested in because I knew I loved wildlife but I wasn’t sure what kind of animal or what kind of area I wanted to work with,” said Cruz.
Cruz said that it was while at UD on a study abroad trip with Doug Tallamy, professor of entomology and wildlife ecology at UD, that she fell in love with sea turtles and with Costa Rica. “I think that’s a big factor as to why I’m here and was selected for the position, because I had known of Costa Rica and had traveled here before. And also, the first time I came to Costa Rica with study abroad, I wasn’t really into birds until the end of the trip and then I really got into birding and really just fell in love with the place.”
Cruz said that it was on that trip that she gained hands on experience with sea turtles, as the group spent couple of nights on a research station and released olive ridley sea turtle hatchlings.
She added that while she loves working with sea turtles, she is “trying to keep my options open and get experience working with other species. I know that I’m interested in coastal environments and studying sea turtles is just kind of what happens naturally,” said Cruz. “But I’m also interested in shore birds and I think a lot of that interest was sparked at UD with ornithology classes.”
Cruz recently accepted a position for the summer as a "Teen Team Facilitator" with the Earthwatch Institute, where she will supervise high school students as they travel on environmental research based expeditions abroad in the Bahamas and Puerto Rico.
“I'm excited for this opportunity because it is similar to the UD study abroad program that sparked my interest in this type of research,” said Cruz. “Additionally, I believe education is a major driver of conservation and am pleased to be able to pass on this similar experience with other students.”
Article by Adam Thomas
Photos by Lauren Cruz