Leatherbacks. They are the Olympians of the turtle world swimming farther, diving deeper and venturing into colder waters than any other marine turtle species. But for all their toughness, they have still suffered a 90 percent drop in their population in the eastern Pacific Ocean over the last 20-plus years, largely at the hands of humanity.
Now, new data from a 5-year-long project tagging and tracking the turtles are providing insights into their behavior, explaining why they congregate for months in what appeared to be one of the most nutrient-poor regions in the oceans, the South Pacific Gyre, and also helping researchers predict their movements on the high seas.
This new view of the lives of leatherbacks could offer a way to keep the turtles out of harm's way and give their numbers a chance to rebound.
"By taking the data we've gathered on their movements and integrating it with data on the surrounding oceanographic conditions, we've been able to identify what kind of habitats the leatherbacks prefer. This information is helping us develop models to predict where they might go and when they might show up there," said Stanford biologist George Shillinger, lead author of a paper to be published in Marine Ecology Progress Series and available online.
Until now, researchers didn't know why the leatherbacks that nest at Playa Grande in Costa Rica headed for the gyre and lingered for months. Satellite surface data suggested that this area spanning the Pacific Ocean between South America and New Zealand, from the low to mid-latitudes, appeared to be a virtual desert in the ocean, largely devoid of nutrients.
However, the presence of substantial tuna and swordfish fisheries within the region suggested there must be ample forage of some sort available.
Because only limited data exist concerning the diversity, abundance and distribution of the leatherback's favorite prey gelatinous zooplankton, su
|Contact: Louis Bergeron|