The Guardian knows where the world’s largest sea turtles go:
Matthew Witt, a researcher at the Centre for Ecology and Conservation at the University of Exeter, led the project. “Despite extensive research carried out on leatherbacks, no one has really been sure about the journeys they take in the south Atlantic until now,” he said.
“What we’ve shown is that there are three clear migration routes as they head back to feeding grounds after breeding in Gabon, although the numbers adopting each strategy varied each year. We don’t know what influences that choice yet, but we do know these are truly remarkable journeys – with one female tracked for thousands of miles travelling in a straight line right across the Atlantic.”
…As well as South America, Witt’s team identified two other migration routes. One saw turtles swim to the coast of South Africa, while the other led them around the middle of Atlantic Ocean. “Although sometimes they’re in the middle of nowhere, hundreds of kilometres from any coastal features, they have plonked themselves in the middle of a food hotspot,” said Witt.
In each case, the turtles swim thousands of miles to stay within food-rich areas of the oceans. Typically, a mature individual could stay swimming around the migration routes for up to five years, building up food reserves, before returning to their birthplace in Gabon to reproduce.
The data from the research project will be used to try to prevent the potential decline of leatherback turtles. “If you look at the Pacific Ocean, the population there has undergone a huge decline – greater than 98% [have gone] in 30 to 40 years,” said Witt. “The population is bordering on extinction; there are only hundreds of females left, rather than many tens of thousands.”
There are maps here.