Turtle Project Has ‘Another Exceptional Year’

The Bermuda Turtle Project, based at the Bermuda Aquarium Museum and Zoo, recently finished its 49th year of study of the sea turtles in Bermuda waters.

“The goals of the project are to better understand the biology of sea turtles of Bermuda and to share that understanding with other professionals and the public to ensure the long-term survival of these fascinating ocean voyagers,” the Bermuda Zoological Society said.

“Since 1968, project members, students and volunteers have captured, marked and released nearly 4,000 sea turtles at different sites around Bermuda. The Aquarium hosts the project which is supported by the Bermuda Zoological Society, the Sea Turtle Conservancy [U.S.], Florida Fish and Wildlife Conservation Commission, and Eckerd College [St. Petersburg, Florida].

“When the project [BTP] started, little was known about sea turtles in Bermuda. We have learned that five different species can occur here but by far the most abundant is the green turtle and this has become the focus of our studies.

“Green turtles once nested in Bermuda but the nesting colony is extinct [the single nest in 2015 was the first recorded in many decades]. The green turtles that live around Bermuda are not born here but are juveniles that have come from multiple nesting beaches elsewhere around the Atlantic, possibly from as far away as Guinea Bissau in West Africa!

“We know the origins of the green turtles in Bermuda waters from genetic analyses and from the tags that are put on during sampling by the BTP. Females with tags put on in Bermuda were later found nesting in Costa Rica and Mexico. These observations agree with genetic results that show that green turtles in Bermuda also come from Florida, Cuba, and either Surinam or Aves Island [Venezuela].

Members of this year’s Bermuda Turtle Project on Trunk Island

“Hatchlings from these different Atlantic Ocean nesting beaches do not come directly to Bermuda but instead spend an as yet undetermined number of years in the open ocean, mostly living in the sea weed known as sargassum.

“This year, the BTP started a special project that will use growth rings in bones of green turtles that wash up dead in Bermuda to determine the age of turtles when they first arrive in Bermuda. This is similar to looking at growth rings in a tree, but more complicated because in older turtles the center of the bone becomes hollow and the oldest growth rings are lost. A second new collaboration is the study of the green turtle’s diet.

“Both new studies will include chemical analyses of stable isotope values. Turtles that have been living and eating in the open ocean will have a different stable isotope signature than those living in the shallow coastal waters of Bermuda. The values in hard tissues like bone and scale should preserve a record of when the switch from open ocean to a near-shore habitat was made by an individual turtle.

“One of the major findings of the BTP is that Bermuda serves as a site where young turtles grow up for many years, but from which they leave just as they start to mature.

“We now have several satellite tracks and many distant captures of Bermuda-tagged turtles that all indicate that large immatures leave Bermuda and navigate across the open ocean to sea grass beds further south or southwest from Bermuda.

“It is at these sites that they will mature and then make their migrations to the nesting beaches, completing the long life cycle that may take 35 – 40 years to go from egg to reproductive adult.

Members of this year’s Bermuda Turtle Project on board the MV Endurance

“Since 1995, the main sampling session for the project has been associated with a course on the biology and conservation of sea turtles. Since 1998, this has been an international course with the specific goal of promoting the conservation of sea turtles in countries to which sea turtles are likely to travel after leaving Bermuda.

“Since the international course was started, 186 students from 40 overseas jurisdictions have come to Bermuda to learn about the biology and conservation of sea turtles during a hands-on course that produces valuable data for the scientific study of sea turtles. Funding to support travel and lodging for the 2016 course participants came from XL Catlin, Renaissance Re and the Bermuda Zoological Society.

“In 2016, course participants came from Anguilla [2], Bermuda, Brazil [2], Colombia, Italy [working in Guatemala] and the US [2]. Participants captured 226 green turtles during the two-week sampling session. They helped the project team set a special net 16 times and then they swam the net to catch turtles as they got caught.

“We estimate that altogether the group swam about 200 miles [with mask, snorkel and fins], they checked existing tags or put on new tags, and then measured and weighed about a ton-and-a- half of turtles.

“They also helped to collect biological samples that will allow us to determine the gender of individual turtles, the nesting beach that they came from, as well as details about what they have been eating.”

Dr. Peter Meylan, one of the projects scientific directors, says “The students this year were just excellent, both in terms of their desire to learn about and share their understanding of sea turtle biology, and their willingness to put in the long hours of hard, physical work that it takes to do the sampling.”

Turtles waiting to be tagged

The BZS added, “Three satellite transmitters were deployed during the 2016 netting season. The transmitters will relay information about the turtles’ movements for the next few months and possibly more than a year. Following local movements allows researchers to study habitat use in Bermuda. T

“he transmitters may also capture departures of the turtles from Bermuda waters. Last year, a turtle carrying a transmitter travelled to Grand Bahama Bank on a migration of 2698 kilometers. The tracks of this year’s turtles: Aquarius, Doppler and Hardy, can be followed by using the link here.”

Jennifer Gray, the Bermuda Director for the project, says “This has been yet another exceptional year for the project. We observed many more of the very small sea turtles recruiting inshore in Bermuda, quite dramatic changes in green turtle feeding habitats, with no turtles in areas that were once abundant with turtles and lots of turtles in areas where they were not before.

“It speaks to the need to continue to monitor these endangered animals and their habitats as understanding of any changes can be hugely beneficial to conservation management. Our visiting biologists have enjoyed their time in Bermuda, they are impressed by the project and take home with them a new knowledge and an inspiration to tackle conservation issues in their home countries.

“The Bermuda Turtle Project has become a network of communication and information sharing amongst friends and sea turtle devotees across the oceans that have joined us over the last twenty years.”

“The BZS’s Bermuda Turtle Project is one of the longest running sea turtle studies in the world,” said Dr. Ian Walker, Principle Curator at the Bermuda Aquarium, Museum and Zoo.

“During its almost half century, the project has amassed an extremely valuable dataset on the health and population dynamics of Bermuda’s sea turtles and their habitats.

“This could not have happened without extremely valuable partnerships with other experts who share our passion in protecting these amazing animals. I would like to thank all involved for all that they do to make this project’s research and conservation goals so successful.”

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