Leatherback Turtle Migration Patterns and Behavior Habits Revealed by Satellite Data

Migrating leatherback turtles tagged off the coast of New England are giving biologists an opportunity to better understand the endangered species' use of seasonal habitats and diving activity. The satellite data generated by the turtles also gives scientists an idea of how the reptiles respond to environmental features in relation to their migration patterns.

The research, conducted by Kara Dodge, her advisor Molly Lutcavage of the University of Massachusetts Amherst's Large Pelagics Research Center, and their colleagues, offers biologists a rare glimpse into the migratory patterns and other behavior of the turtles in more comprehensive detail than ever before. Prior tagging studies have primarily focused on adult females on tropical nesting beaches.

However, the new study follows adult and adolescent turtles of both sexes, providing a more complete picture of the species' behavior. The leatherback turtle is the world's most migratory sea turtle species, as well as the world's largest turtle, capable of growing up to 7 feet long and weighting 2,000 pounds. The reptiles are capable of diving more than 3,000 feet below the surface.

The new data reveal a more complete explanation of the leatherback's search patterns for prey that encompasses sea temperature, topography and ecoregion.

The satellite data reveal the leatherback turtles cluster in the Northeast US during the summer and fall months when the waters are filled with large jellyfish for them to eat.

Conservation opportunities are highlighted by the new data, the researchers said in a statement.

"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," the researchers said.

The data was collected between 2007 and 2009 from 20 leatherback turtles tagged in New England waters.

"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," Lutcavage said. "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."

Leatherback's preferences on water depth and temperature were also revealed by the satellite data.

"Our study provides new insights about how male and immature turtles behave, how they use their habitats and how that differs from adult females," Dodge said. "Resource managers for protected marine species have lacked this key understanding, especially in coastal regions of the US and Caribbean where leatherbacks and intense human activity coincide."

Dodge and her collaborators published their research in the journal PLOS One.