Scientists track leatherback turtle travels for the first time

By David Hewitt - 06 Jan 2011 13:32:40 GMT
Scientists track leatherback turtle travels for the first time

The marked decline seen in global populations of leatherback turtles can be partly attributed to the fact that their annual migratory routes force the animals to run the gauntlet of long-line fishing boats in the middle of the Atlantic Ocean.

Making use of new satellite tracking technology, a team of scientists in England have been able to map out the route the critically-endangered turtles take from the nesting sites of West Africa to feeding grounds off the coast of Central and South America. In particular, the research looked into the movements of 25 female turtles over the course of five years, enabling the experts at the University of Exeter's Centre for Ecology and Conservation to identify three principal migratory routes for the first time. Specifically, it is now known that many leatherback females will make the 4,700-mile journey from the world's largest breeding colony in Gabon to the food-rich waters off South America in one go and will then stay there for a period of up to five years as they build up the reserves they need to go back to Africa and reproduce once again.

While the work will serve to satisfy the curiosity of wildlife-lovers, the findings are also cause for some alarm, not least as they illustrate the extent to which these turtles are being exposed to the risk of being caught accidentally by fishing boats in the Atlantic. Indeed, those tagged females that did take the more-ambitious route were seen to travel right through the middle of what is one of the world's long-line fishing hotspots, with by-catch having long been established as a serious threat to a range of animals, including turtles, dolphins and tuna.

However, according to lead researcher Dr Brendan Godley from the University of Exeter, now that the migratory patterns of Atlantic leatherbacks have finally been identified, it should be possible to take action and ensure that the animals don't suffer the same misfortune as their Pacific counterparts, whose numbers have been decimated by coastal gillnet fishing, long-line fishing and egg poaching over recent years.

"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," he explained, writing up the team's findings in the Royal Society journal Proceedings B. "Knowing the routes has also helped us identify at least 11 nations who should be involved in conservation efforts, as well as those with long-distance fishing fleets."

Certainly, Atlantic leatherback turtles are at an advantage given that the majority of the nesting sites in Gabon - which are estimated to welcome up to 40,000 females each year - are located within protected national parks, thereby significantly minimising the risk of their eggs being poached.

However, though this new data will help conservationists work alongside both governments and fishing industry professionals to halt the decline and even oversee an upturn in turtle numbers, as always there could be a marked discrepancy between rhetoric and action. Given that the real danger to the animals lies hundreds of miles out to sea, away from the watching eyes of their protectors, means it still remains to be seen how effectively any new conservation efforts will be implemented in the years ahead.