Researchers studying leatherback turtles over a period of 5 years have tracked the epic journeys of a group of leatherback sea turtles in the South Atlantic, with astounding results. Satellite tracking has revealed three clear migratory routes—including one 4,699-mile journey straight across the South Atlantic from Africa to South America.
The research has been carried out by the Centre for Ecology and Conservation at the University of Exeter with the help of the Wildlife Conservation Society, Parcs Gabon, Marine Turtle Partnership for Gabon, the Trans-Atlantic Leatherback Conservation Initiative, and SEATURTLE.org.
Many of the 25 females studied traveled great distances as they moved from their breeding colony in Gabon to feeding grounds in the southwest and southeast Atlantic and off the coast of Central Africa. The turtles stay in these areas for 2–5 years to build up the reserves to reproduce, then return to Gabon.
The research, published in the Proceedings of the Royal Society B on January 5, has shed new light on the little-known migration behavior of these animals.
Dr Matthew Witt of the University of Exeter said, “Despite extensive research carried out on leatherbacks, no-one has really been sure about the journeys they take in the South Atlantic until now.”
In the Pacific Ocean, leatherback turtles have sharply declined over the past three decades, with one nesting colony in Mexico dropping from 70,000 in 1982 to just 250 by 1999. The exact cause of the dramatic fall-off is not clear, but turtle egg harvesting, coastal gillnet fishing, and longline fishing are potential factors.
In the Atlantic, population levels have been more robust, but due to variations in numbers at nesting sites each year, it’s not clear whether they are declining. Conservationists are urging action to avoid a repeat of the Pacific story.
The new research will be vital for informing a conservation strategy for leatherbacks. All three routes take the turtles through areas where they risk being caught up in the nets of commercial trawler fishing boats.
“Knowing the routes has helped us identify at least 11 nations who should be involved in conservation efforts, as well as those with long-distance fishing fleets,” said Dr Brendan Godley, also of the University of Exeter.
Dr. Howard Rosenbaum, Director of WCS’s Ocean Giants Program, said, “This important work shows that protecting leatherback turtles—the ancient mariners of our oceans—requires research and conservation on important nesting beaches, foraging areas and important areas of the high seas. Armed with a better understanding of migration patterns and preferences for particular areas of the ocean, the conservation community can now work toward protecting leatherbacks at sea, which has been previously difficult.”