updated 2/17/2011 10:48:56 AM ET 2011-02-17T15:48:56

The epic, danger-filled journeys of enormous leatherback turtles in the South Atlantic have just been revealed for the first time thanks to new satellite tracking research.

The findings, published in the latest Proceedings of the Royal Society B, demonstrate how remarkable these ancient animal mariners are. One turtle even traveled straight across the South Atlantic, from Africa to South America, during a 4,699-mile trip. She likely dodged fishing nets and other threats along the way.

"I suspect much of the route carries risk," lead author Matthew Witt told Discovery News. "It is difficult to elucidate whether this is risk of capture, or risk of capture and death. Both scenarios are, however, problematic."

Witt, a researcher at the University of Exeter's Center for Ecology and Conservation, and his team attached transmitters to 25 female leatherback turtles that were nesting in Gabon, Central Africa. The scientists monitored them via satellite and computer for four nesting seasons, noting the turtles' weight, how deeply they dove, where they went and other data.

The researchers determined the turtles used three migratory routes, with each turtle following one of the three defined paths. In addition to the clever female who went straight across the South Atlantic, some of the turtles moved from Gabon to jellyfish-rich habitats in the southwest or southeast Atlantic. Still others went to habitats off the coast of South Africa.

The turtles' time is spent almost entirely at sea.

"Between their first frantic run down the beach to the sea and when the females return to breed, they never go ashore," co-author Brendan Godley, an associate professor in conservation biology at the University of Exeter, told Discovery News. "Males never go ashore after their first day of life."

The turtles are on the go so much because "the basis for their evolution is that warm tropical beaches are a good place to lay your clutch, but the areas for maximal food production are elsewhere," he explained.

Once turtle babies hatch, they are widely dispersed by ocean currents, perhaps explaining the diversity in travel routes that they later follow as adults. There is also a strong chance that, like other turtle species, they return to their "home patch" once breeding has completed.

"In green turtles, this may be an area as small as a football field. For leatherbacks, it may be a region the size of a small -- or even large -- country," Godley said.

Although the new study looked at just females (since their brief beach time allows a moment for attaching transmitters), it is thought that males make similar lengthy, risk-filled trips.

"All of the routes we've identified take the leatherbacks through areas of high risk from fisheries, so there's a very real danger to the Atlantic population," Godley was quoted as saying in a press release. "Knowing the routes has also helped us to identify at least 11 nations who should be involved in conservation efforts, as well as those with long-distance fishing fleets."

In the Pacific Ocean, leatherback turtle populations have dramatically declined over the past three decades. For example, one nesting colony in Mexico went from 70,000 individuals in 1982 to only 250 by 1998. Turtle egg harvesting, coastal gillnet fishing, and long-line fishing have been identified as likely culprits.

It's thought that Atlantic leatherback turtles -- the focus of the latest research -- are doing better, but exact population figures have been difficult to obtain. This is due, in part, to variations in numbers at nesting sites each year.

Vincent Saba, a Princeton University research associate who also studies sea turtles, told Discovery News, "The tracking results from this work are invaluable to our leatherback knowledge base."

Saba agrees that difficult conservation challenges lie ahead, given that so many different nations would have to be involved in the regulation of fisheries, but all of the researchers remain hopeful that Atlantic leatherback turtles will have stable, or increasing, populations in future.

© 2012 Discovery Channel


Discussion comments


Most active discussions

  1. votes comments
  2. votes comments
  3. votes comments
  4. votes comments