Researchers in the US have used advanced tracking technology to identify new migration corridors and foraging areas for leatherback sea turtles along the US East Coast, specifically in the South Atlantic Bight, Mid-Atlantic Bight and southern New England. These findings, published in the journal Frontiers in Marine Science, highlight important foraging areas and have conservation implications for these endangered species, especially in light of threats from fishing and offshore wind development.

Leatherback sea turtles, the largest extant turtles, embark on long migration journeys that can last several years. These turtles move from warm subtropical and tropical nesting areas to cooler temperate regions where they forage for food. Even after years of tracking, knowledge gaps remain regarding migration routes and feeding grounds in specific regions, particularly the northwest Atlantic.

Using new, more advanced tracking technology, a team of US researchers set out to identify migration corridors and potential foraging areas used by leatherbacks along the US East Coast. The findings were published at: Frontiers in Marine Sciences.

“Using models of locomotor behavior, we show that leatherbacks migrating along the US East Coast exhibit foraging behavior in specific regions of the South Atlantic Bight (SAB), a coastal region extending from North Carolina to upper Florida-Braids; Massachusetts “The Mid-Atlantic Bight (MAB), a coastal region stretching from North Carolina to North Carolina; and southern New England (SNE),” said Dr. Mitchell Ryder. “It appears that MAB may be an important food source for leatherbacks.”

New places discovered to search for food

To track the turtles, the researchers attached satellite transmitters to two groups of leatherback turtles. The first group was observed off the coast of Massachusetts in the summer, and the second was observed off the coast of North Carolina in the spring.

There is a foraging area near Massachusetts where leatherbacks are known to migrate north after foraging. Tracking them from there allowed the researchers to identify secondary foraging and wintering grounds along the continental shelf. Tracking turtles captured off North Carolina allowed them to assess diving and movement behavior along their migratory routes and identify foraging areas downstream. Between 2017 and 2022, 52 leatherbacks were successfully tracked for 15-302 days.

The researchers’ findings indicate that leatherbacks use the SNE, MAB and SAB regions as migration and foraging corridors, in addition to known foraging areas in SNE and Nova Scotia. “The rapid use of MAB by both leatherback groups is the most important finding of our study. Ryder said heavy use is characterized by largely predictable foraging behavior. “To date, few studies have followed echinoderms in this region, but we are the first to take this a step further and characterize the behaviors associated with their movement patterns.”

Information to be saved

New information about the foraging ranges and movement ecology of leatherbacks along the northwest Atlantic shelf will create new opportunities for future studies of leatherbacks in the MAB and SAB, the researchers say. “Now that we understand the key points where foraging occurs, we need to focus our attention on these specific areas by applying methods that allow us to make direct observations,” Ryder explained. “To do this, we need to introduce more in situ research methods, such as video surveillance of animals.”

Although they now have a better understanding of leatherback movement and foraging, researchers say there is still work to be done. This includes studies of leatherbacks in the SAB, as this area serves turtles for wintering, spring nesting, and summer foraging.

According to the researchers, their findings are also important for the protection of endangered species. Leatherfish are prone to being accidentally caught and attacked by fishing vessels. New discoveries can be used to identify key areas for protection and prevention of these accidents. In addition, numerous offshore wind farms will be seen in the MAB and Southern New England, and conservationists can use this information to mitigate impacts on endangered sea turtles.