By analyzing the genetic fingerprints of giant loggerhead sea turtles, a team of international researchers has determined that 57 percent of the juvenile loggerheads living in the rich waters of the Mediterranean hatched on U.S. beaches.
The researchers, led by Dr. Brian W. Bowen of the University of Florida in Gainesville and Dr. Luc Laurent of Lyon University in France, identified genetic markers that are unique to turtles that lay eggs along the Florida coast. Then they looked for the markers in turtles killed in Spanish swordfish fisheries.About 30,000 adult female loggerheads nest on Atlantic beaches in Florida, Georgia and South Carolina. Each year, some 10,000 females drag themselves ashore and lay about 100 eggs that they bury in the sand. The 2-inch hatchlings that emerge several weeks later immediately head for the ocean.
If they reach maturity, they feed about 20 years in the Mediterranean before genetic programming compels them to return to the beaches where they hatched.