New study to help inform conservation efforts along East Coast and Caribbean
By Summit Voice
FRISCO — Threatened leatherback sea turtles like to hang out off the northeastern U.S. coast in late summer and fall, when mature jellyfish are abundant in the area, scientists said last week, sharing the results of a long-term study based on satellite data of tagged sea turtles.
“Our study provides new insights about how male and immature turtles behave, how they use their habitats and how that differs from adult females,” said University of Massachusetts researcher Kara Dodge. “Resource managers for protected marine species have lacked this key understanding, especially in coastal regions of the U.S. and Caribbean where leatherbacks and intense human activity coincide.”
The findings will help improve understanding of seasonal high-use habitats, diving activity and response to key ocean and environmental features in relation to their search behavior. The study followed leatherbacks in their northern US feeding grounds. It allowed for a rare glimpse into the migratory patterns and behavior of immature and adult male turtles.
Most satellite tagging studies of leatherbacks have focused on adult females on their tropical nesting beaches, so little is known worldwide about males and subadults, the researchers said. But now, tagging and satellite tracking in locations where leatherbacks forage has allowed the scientists to get a much richer picture of the leatherback’s behavior and dispersal patterns on the open ocean.
New knowledge about leatherbacks, particularly in coastal habitats, is important, because “coastal ecosystems are under intense pressure worldwide, with some of the highest predicted cumulative impact in the North American eastern seaboard and the eastern Caribbean. Parts of those regions constitute high-use habitat for leatherbacks in our study, putting turtles at heightened risk from both land- and ocean-based human activity.”
“We started the satellite tagging work in 1994, but had little understanding of their daily lives until recently because we first wanted to develop ways to directly attach the tag without encumbering the turtle,” said Molly Lutcavage of the University of Massachusetts Amherst’s Large Pelagics Research Center. “Once that was accomplished, we could collect accurate track locations via GPS along with dive data, and determine the leatherbacks’ residence time, high-use habitat and behavior on the Northeast US shelf and beyond,” she adds.
Leatherbacks are the largest turtles in the world, weighing up to 2000 pounds and up to seven feet long. They are warm-bodied, deep divers that can descend below 3000 feet. They have the widest global distribution of all reptiles and are the most migratory sea turtle species, traveling thousands of miles between feeding and breeding grounds. Unlike other sea turtles, leatherbacks exclusively eat soft-bodied gelatinous zooplankton such as jellyfish and salps. Their pursuit of patchily distributed “jellies” and unique thermoregulatory ability contributes to their expansive range.