Turtle power: members of this year’s Bermuda Turtle Project on Trunk Island in Harrington Sound

The Bermuda Turtle Project ­— a study of seas turtles in Bermuda waters — has completed its 49th year of research.

Based at the Bermuda Aquarium Museum and Zoo, the study has been running since 1968 during which time project members, students and volunteers have captured, marked and released nearly 4,000 sea turtles at different sites around the island.

The goals of the project have been to better understand the biology of 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,” said a project statement.

Bermuda Zoological Society, the US Sea Turtle Conservancy), Florida Fish and Wildlife Conservation Commission, and Eckerd College in St Petersburg, Florida have all been involved in the research.

Jennifer Gray, Bermuda Director for the project, said: “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 among friends and sea turtle devotees across the oceans that have joined us over the last 20 years.”

Dr Ian Walker, Principle Curator at BAMZ, said: “The Bermuda Turtle Project is one of the longest running sea turtle studies in the world.

“During its almost half century, the project has amassed an extremely valuable data set 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.”

When the project started, little was known about sea turtles in Bermuda but much has changed.

“We have learnt 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”, continued the statement.

“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).

“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 centre 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 was 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.”

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

Over 186 students from 40 overseas jurisdictions have come to Bermuda to learn about turtles during hands-on courses that produce data for the scientific study.

Funding to support travel and lodging for the 2016 course participants came from XL Catlin, Renaissance Re and the Bermuda Zoological Society.

This year, course participants came from Anguilla (2), Brazil (2), Colombia, Italy (working in Guatemala) and the US (2). They 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 with 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, said: “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.”

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. The 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 kilometres. The tracks of this year’s turtles: Aquarius, Doppler and Hardy, can be followed by using the following link:

http://www.conserveturtles.org/seaturtletracking.php?page=currentsatelliteturtles