SCA’s Dana DeSousa on Working with Leatherback Sea Turtles
Dana DeSousa (second from left) with other members of the 2016 turtle survey team at Sandy Point National Wildlife Refuge. Also… a sea turtle. Photo Credit: Dana DeSousa
Ever wonder what it’s like to work with dinosaurs? Well I can’t tell you what it’s like to work with a Tyrannosaurus rex, but I can tell you about working with a reptile whose ancestors were around during the Cretaceous period.
Her body emerges from the surf indifferent to the waves crashing over her head and carapace. She moves slowly but methodically up the beach dragging her 700-pound-body a few feet with each stroke of her front flippers. All of a sudden she starts to swivel her body and rear flippers, throwing sand from side to side with her front limbs. Once this movement has created a body pit, she begins to dig. With her front flippers anchored in the beach, she alternates the use of her rear flippers to scoop sand to form an egg chamber. She is almost ready to lay her eggs. Unfortunately, this leatherback sea turtle has chosen to deposit her eggs in a known erosion zone, so tonight we will have to relocate them to a more stable stretch of beach.
Leatherback hatchlings at Sandy Point National Wildlife Refuge. Photo credit: Shannon Borowy.
I crawl up right behind the astonishingly large creature and lie in the sand behind her to catch her eggs in a special double bag that will keep them in their natural state and enable me to remove the clutch in one swift movement. I lie motionless as she digs her chamber carefully. Finally, after she feels the space is the perfect depth and shape, I find the two- or three-second window in which I can put my bag under her cloaca and begin to catch the eggs. I see her entire body contract, and a wave of movement shudders across her, resulting in the release of four or five eggs. Each time she contracts, a few eggs fall into my bag as I keep a steady hold on the sides. After about 10 minutes, she starts to lay spacers, or yolkless eggs. I know they are spacers because fertilized leatherback eggs are the size of billiard balls; spacers come in all different sizes – marble, ping pong ball, sausage, etc. Leatherback turtles are the only turtles that lay spacers. They are thought to aid in gas exchange within the nest.
The spacers are my signal to prepare to move the bag because she will be done after a few more pushes. After the final egg is laid and her rear flippers start to make the slightest movement, I remove the bag in one fell swoop. She starts to cover her chamber as if the eggs are still there because she has no idea that her eggs have been removed. While I work to catch the eggs, other members of our team work up the turtle by taking measurements, checking for flipper and Passive Integrated Transponder (PIT) tags and examining her for injuries. These research activities all take place in the short period of time that the turtle is laying her eggs, ensuring minimal disturbance.
Members of the summer 2016 turtle survey team at Sandy Point National Wildlife Refuge. Photo Credit: Dana DeSousa
Now it’s time to become a surrogate leatherback and dig a new chamber in a suitable beach. I try to be as methodical and precise as the nesting female was a few minutes prior. When I have reached the maximum depth of 60 centimeters, I release the eggs from the bottom of the bag to imitate the laying process as accurately as possible. Next I tamp the sand to cover the eggs in the same way that our nesting females do. This will hopefully ensure a high hatching success.
This is what happens sometimes on patrol at Sandy Point National Wildlife Refuge. A team of six Student Conservation Association interns, NOAA marine biologist Kelly Stewart and refuge biologist Claudia Lombard monitor nesting and hatching success for leatherbacks. Each night we patrol for nesting females every 45 minutes until the sun begins to rise. When we come across a turtle who is nesting in the area of beach that slowly disappears due to wave erosion by the end of summer — the “erosion zone” — it’s time for team members to spring into action.
Fast forward 60 days, and it’s time to scan the beach for small black noses poking up through the sand. We patiently watch and wait as the tiny heads pop up and out. Next shoulders and front flippers appear. Soon enough the hatchlings push off their brothers and sisters and climb all the way out, starting their journey to the ocean.
A leatherback hatching attempting to find its way to the surf at Sandy Point National Wildlife Refuge. Photo credit: Shannon Borowy.
Witnessing the full process from eggs being laid to hatchlings emerging really puts into perspective the work my team and I are doing each night. I have learned an extensive amount about sea turtles during my SCA internship, but what has affected me most is the knowledge that my work has made a real difference for an endangered species. For every nest that is relocated, 80 or so eggs, instead of being washed out or eroded away, will have a chance to develop into hatchlings, grow into adults and eventually return to the beach where they were born. It’s a time- and labor-intensive effort, but it has really paid off. The year that sea turtle conservation began here, 1982, only 19 leatherbacks nested at Sandy Point. For the past five years, the refuge has recorded an average of 95 individual nesting females. 95! With this knowledge, the long nights, the biting bugs and the soaking rain don’t seem as daunting, and every bead of sweat is a small reminder of the hard work paying off. Every day of this internship provides further encouragement to continue on a career path in conservation.
Equipped with a Wildlife Management degree from the University of Delaware, Dana DeSousa gained hands on experience working with leatherback sea turtles as a SCA intern for the U.S. Fish and Wildlife Service at Sandy Point National Wildlife Refuge in the U.S. Virgin Islands during the spring and summer of 2016. This piece was originally published on USFWS’s blog, Open Spaces.