Loggerhead research shows turtles congregate in same Gulf spots
By Kate Spinner Herald Tribune
Monday, February 6, 2012 at 5:26 p.m.
SARASOTA - New research shows that loggerhead sea turtles from different nesting beaches gather to eat in some of the same places, a finding that could lead to better protections for turtle habitat at sea.
Researchers with Mote Marine Laboratory, the U.S. Geological Survey and the University of Florida tracked loggerhead turtles with satellite tags from nesting areas on Casey Key, the Dry Tortugas and Cape San Blas. Even though the turtles left from different beaches, they swam to many of the same areas off the coast of Southwest Florida and Mexico's Yucatan Peninsula.
"Animals are in pretty distinct, almost predictable, foraging locations for long periods of time," said Kristen Hart, lead author of the study and a research ecologist with USGS in Davie. "It's a really nice starting point for where in the Gulf of Mexico you might consider a hot spot for protecting turtles."
The study could help regulators decide where to restrict activities such as fishing or oil drilling to protect sea turtles that nest here and elsewhere along the Gulf coast.
Though rare globally, loggerheads are the most common sea turtles on Florida's beaches, where 90 percent of the U.S. population nests. The turtles are protected as threatened under the federal Endangered Species Act.
Most protection for sea turtles is focused on beaches, but few measures protect the turtles at sea.
When loggerhead females reach maturity, at about 35 years, they begin a long journey back to the beach where they hatched. They build nests there every three years on average. Now scientists know that between nesting, the turtles spend most of their time feeding in the same area and with other turtles born on different beaches.
"It confirms what we would have been able to have done if we went to a feeding population and sampled it genetically," said Tony Tucker, a Mote sea turtle scientist.
The information is important because new national policies call for setting aside more marine preserves to keep fishing gear, oil rigs and other harmful human activities out of areas that provide important habitat for rare animals. Before those protected areas are created, regulators need to pinpoint habitats.
Loggerheads face multiple threats at sea, including becoming ensnared by fishing hooks, shrimp nets or fishing line and starvation after mistaking plastic bags or balloons for jellyfish.
Two years ago the BP Deepwater Horizon oil spill created additional strain for the animals.
In the months following the spill, more than 1,000 sea turtles of all species were found dead or injured, including 88 loggerheads, according to stranding data from the National Oceanic and Atmospheric Administration.
Federal grants for the research were linked to the oil spill and restricted the study to the Gulf of Mexico. Scientists put satellite tags on dozens of turtles, but only focused on the 10 that stayed in the Gulf.
Though limited, the study lays the groundwork for more research on where turtles congregate.
"There are likely other shared foraging areas," Hart said.
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