ON THE TURTLE TRAIL IN BARBUDA WITH KATE LAVASSEUR Friday 20th December 2013
On the turtle trail in Barbuda: Tagging the first hawksbills on Antigua’s sister island
By Kate Levasseur
Photo of Coco Point, Barbuda by Kate Lavasseur.
Marine turtle populations have endured dramatic declines over the last century, leaving remnant nesting populations scattered throughout the Caribbean. Three types of marine turtle visit the beaches of Antigua and Barbuda to lay their eggs: the giant leatherback, the green turtle and the hawksbill. In fact, Antigua hosts one of the densest nesting aggregations of hawksbill turtles in the Caribbean. Currently, about 70 nesting females lay over 300 nests every year on a 650-meter long stretch of beach at Jumby Bay, in Antigua’s North Sound.
Located about 30 miles north, the vast and remote west coast of Barbuda likely hosts an even larger population of nesting hawksbills. Every summer, around July and August, the west coast is littered with turtle tracks. I was able to witness this remarkable site twice this summer due to the generosity of Marguerite and Paul Jackson, two genuine people who love the ocean and could easily write a best-selling novel about their world adventures. After hearing of the need to survey nesting turtles in Barbuda, they offered transport on their catamaran, the lovely AFTICA. Nesting activity has long been documented on Barbuda (see Fuller et al. 1992); however, compiling details of the exact number of nests and their distribution over several nesting seasons at this relatively unknown nesting hotspot is critical for current population estimates and recovery strategies for the hawksbill.
Photo of Hawksbill Turtle by Kate Lavasseur.
Surveying Barbudan beaches, particularly at night with the hope of intercepting nesting turtles, has been a goal of mine for several years. I have been returning to Antigua to trek along nesting beaches for six years, first as a field biologist for the Jumby Bay Hawksbill Project (JBHP) and now as a PhD student at the University of South Carolina. With the help of the JBHP and the Antigua Sea Turtle Conservation Project (ASTP), I have been building a collection of tissue samples from nesting hawksbills for my graduate research. While we know sea turtles return to the area where they were born once they reach reproductive maturity, we do not know how precise this natal-homing behavior can be. For my dissertation research, I am using DNA analyses in combination with long-term nesting data from the JBHP to determine if the veteran females on Jumby Bay are now nesting concurrently with their own daughters. The Jumby Bay population is ideal for this type of fine-scale study, but has a narrow geographic scope. To get a better idea of the genetic diversity and population structure of hawksbills on a broader scale, I plan to also analyze samples from hawksbills nesting across other beaches of Antigua and Barbuda. Studying hawksbills at a wider geographic range will be especially useful for determining conservation priorities for this dwindling species.
I recruited Jepson Prince, a member of the ASTP who has patrolled Antiguan beaches for over a decade. The four of us sailed to Barbuda one early morning in late July. Marguerite and Paul took us the length of Low Bay, from Palmetto Point to the mouth of Codrington Lagoon, even anchoring and moving to the dingy when AFTICA could go no further. With binoculars and a handheld Garmin, we noted every crawl. Seeing the densest set of crawls on either side of what we called the “barrens”, a mile-long stretch of beach void of vegetation at the south end of Low Bay, we anchored to target this area on our first night. We trekked 4 miles that night before deciding to turn back. Just 15 minutes after turning back, we spotted a fresh crawl in the distance and sprinted up the beach.
Although the nesting process takes about an hour and 20 minutes, there is only a very small window during which we can tag and collect data. To minimize disturbance, we wait until a female has started laying eggs to move close. Once a female starts depositing eggs, we have about 10 to 15 minutes to tag her, take a tissue sample, and collect biometric and nest data.
Photo of Hawksbill Turtle nest by Kate Lavasseur
We followed the fresh track up the beach almost to the berm where it disappeared under an old, gnarly patch of seagrape branches. Deep in the branches, we could see a hawksbill digging her nest chamber and breathed a sigh of relief. We hadn’t missed the window. Crouched and silent, we waited only a few minutes for her to start laying. Jepson applied the first tag and Marguerite applied the second, one on each front flipper, while I took a small piece of skin from her back flipper. We took her shell measurements, took note of her nesting location, and then sat back to watch her finish under the moonlight, referring to her as “Marguerite” instead of WS1078 (her tag ID). Night one was a success – we had tagged the first nesting turtle in Barbuda.
In the end, we were able to survey over 20 miles of coastline on that trip, from the mouth of the Codrington Lagoon to Spanish Point. We counted over 60 crawls, most of which were hawksbill crawls. We also logged 15 miles of nightly foot patrols over three nights, finding two nesting females (the second nester was named “Paulette”). Returning for another survey in August, we again counted over 60 crawls and found one nesting female during night patrols.
These surveys would not have been possible without the incredible generosity of Marguerite and Paul Jackson. My field season this past summer was made possible through support from the JBHP, the ASTP, the Women Divers Hall of Fame Graduate Scholarship in Marine Conservation, the South Carolina Slocum-Lunz Foundation, my advisor, Dr. Joseph M. Quattro, and the University of South Carolina’s Presidential Fellowship Program. A very special thank you goes to John and Sarah Fuller for providing constant support and opening their home to me for the past six years.
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